Animal migration Research Papers - Academia.edu (original) (raw)

The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for... more

The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was found to stimulate the onset of sexual maturation. In this study, we have investigated the interplay between migration and maturation in the field during the downstream migration of female silver eels. Temporal changes in migratory status and sexual maturation among silver eels of the upstream Rhine River system over 3 months of the migration season (August, September and October) were determined in biometrical parameters, plasma 17b-estradiol and calcium levels, oocyte histology and gonadal fat levels. Furthermore, the ecological relevant parameters age as determined by otolithometry and health aspects indicated by haematocrit, haemoglobin and swim-bladder parasite load were measured. Silver eels were estimated to be 14 years old. A strong temporal progression in migratory stage was shown over the months of downstream migration. Catches probably represented a mix of reproductive migrants and feeding migrants of which the ratio increased over time. Furthermore, this study confirmed our hypothesis linking the migratory stage to early maturation as indicated by enlargement of the eyes, oocyte growth and fat deposition in the oocytes, exactly the same changes as found induced by exercise but not ruling out environmental influences. Migrants show extensive fat uptake by the oocytes, probably stimulated by the swimming exercise. In addition, at least 83% of the silver eels in this spawning run may have suffered from negative effects of swim-bladder parasites on their swimming performance.

Genetic data are commonly used to estimate connectivity between putative populations, but translating them to demographic dispersal rates is complicated. Theoretical equations that infer a migration rate based on the genetic estimator ,... more

Genetic data are commonly used to estimate connectivity between putative populations, but translating them to demographic dispersal rates is complicated. Theoretical equations that infer a migration rate based on the genetic estimator , such as Wright's equation, ≈ 1/(4 + 1), make assumptions that do not apply to most real populations. How complexities inherent to real populations affect migration was exemplified by Atlantic cod in the North Sea and Skagerrak and was examined within an age-structured model that incorporated genetic markers. Migration was determined under various scenarios by varying the number of simulated migrants until the mean simulated level of genetic differentiation matched a fixed level of genetic differentiation equal to empirical estimates. Parameters that decreased the / ratio (where is the effective and is the total population size), such as high fishing mortality and high fishing gear selectivity, increased the number of migrants required to achieve ...

Environments undergo short-term and long-term changes due to natural or human-induced events. Animals differ in their ability to cope with such changes which can be related to their ecology. Changes in the environment often elicit... more

Environments undergo short-term and long-term changes due to natural or human-induced events. Animals differ in their ability to cope with such changes which can be related to their ecology. Changes in the environment often elicit avoidance reactions (neophobia) which protect animals from dangerous situations but can also inhibit exploration and familiarization with novel situations and thus, learning about new resources. Studies investigating the relationship between a species' ecology and its neophobia have so far been restricted to comparing only a few species and mainly in captivity. The current study investigated neophobia reactions to experimentally-induced changes in the natural environment of six closely-related blackbird species (Icteridae), including two species represented by two distinct populations. For analyses, neophobic reactions (difference in number of birds feeding and time spent feeding with and without novel objects) were related to several measures of ecological plasticity and the migratory strategy (resident or migratory) of the population. Phylogenetic relationships were incorporated into the analysis. The degree of neophobia was related to migratory strategy with migrants expressing much higher neophobia (fewer birds feeding and for a shorter time with objects present) than residents. Furthermore, neophobia showed a relationship to diet breadth with fewer individuals of diet generalists than specialists returning when objects were present supporting the dangerous niche hypothesis. Residents may have evolved lower neophobia as costs of missing out on opportunities may be higher for residents than migrants as the former are restricted to a smaller area. Lower neophobia allows them approaching changes in the environment (e.g. novel objects) quickly, thereby securing access to resources. Additionally, residents have a greater familiarity with similar situations in the area than migrants and the latter may, therefore, initially stay behind resident species.

Abstract: Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a... more

Abstract: Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a population or species meets criteria for conservation action (false negative) or may incorrectly show that such criteria have been met (false positive). To quantify the rate of both types of error for 20 commonly used indicators of declining abundance (threat indicators), we used receiver operating characteristic curves derived from historical (1938–2007) data for 18 sockeye salmon (Oncorhynchus nerka) populations in the Fraser River, British Columbia, Canada. We retrospectively determined each population's yearly status (reflected by change in abundance over time) on the basis of each indicator. We then compared that population's status in a given year with the status in subsequent years (determined by the magnitude of decline in abundance across those years). For each sockeye population, we calculated how often each indicator of past status matched subsequent status. No single threat indicator provided error-free estimates of status, but indicators that reflected the extent (i.e., magnitude) of past decline in abundance (through comparison of current abundance with some historical baseline abundance) tended to better reflect status in subsequent years than the rate of decline over the previous 3 generations (a widely used indicator). We recommend that when possible, the reliability of various threat indicators be evaluated with empirical analyses before such indicators are used to determine the need for conservation action. These indicators should include estimates from the entire data set to take into account a historical baseline.Resumen: Aunque existen muchos indicadores de riesgo (i.e., sí las poblaciones o especies cumplen con criterios para justificar acciones de conservación), su confiabilidad ha sido probada pocas veces. Dichos indicadores pueden fallar al identificar que una población o especie cumple con criterios para acciones de conservación (negativo falso) o pueden mostrar incorrectamente que tales criterios se han cumplido (positivo falso). Para cuantificar la tasa de ambos tipos de error para 20 indicadores de declinación de abundancia (indicadores de amenaza) utilizados comúnmente, utilizamos curvas de características de operación de receptores derivadas de datos históricos (1937–2008) de 18 poblaciones de salmón (Oncorhynchus nerka) en el Río Fraser, Columbia Británica, Canadá. Retrospectivamente determinamos el estatus anual de cada población (reflejado en cambios en la abundancia en el tiempo) con base en cada indicador. Posteriormente comparamos el estatus de la población en un año determinado con el estatus de años subsecuentes (determinado por la magnitud de la declinación en abundancia en esos años). Para cada población de salmón, calculamos la frecuencia en que cada indicador de estatus pasado era igual al estatus subsecuente. Ningún indicador de amenaza proporcionó estimaciones de estatus libres de error, pero los indicadores que reflejaron la extensión (i.e., magnitud) de la declinación en abundancia pasada (mediante comparación de la abundancia actual con la abundancia histórica de referencia) tendieron a reflejar de mejor manera el estatus en años anteriores que la tasa de declinación en las 3 generaciones previas (un indicador ampliamente utilizado). Recomendamos que, cuando sea posible, se evalúe la confiabilidad de varios indicadores de amenaza con análisis empíricos antes de que esos indicadores sean utilizados para determinar la necesidad de acciones de conservación. Estos indicadores deben incluir estimaciones a partir del total de datos para considerar una referencia histórica.Resumen: Aunque existen muchos indicadores de riesgo (i.e., sí las poblaciones o especies cumplen con criterios para justificar acciones de conservación), su confiabilidad ha sido probada pocas veces. Dichos indicadores pueden fallar al identificar que una población o especie cumple con criterios para acciones de conservación (negativo falso) o pueden mostrar incorrectamente que tales criterios se han cumplido (positivo falso). Para cuantificar la tasa de ambos tipos de error para 20 indicadores de declinación de abundancia (indicadores de amenaza) utilizados comúnmente, utilizamos curvas de características de operación de receptores derivadas de datos históricos (1937–2008) de 18 poblaciones de salmón (Oncorhynchus nerka) en el Río Fraser, Columbia Británica, Canadá. Retrospectivamente determinamos el estatus anual de cada población (reflejado en cambios en la abundancia en el tiempo) con base en cada indicador. Posteriormente comparamos el estatus de la población en un año determinado con el estatus de años subsecuentes (determinado por la magnitud de la declinación en abundancia en esos años). Para cada población de salmón, calculamos la frecuencia en que cada indicador de estatus pasado era igual al estatus subsecuente. Ningún indicador de amenaza proporcionó estimaciones de estatus libres de error, pero los indicadores que reflejaron la extensión (i.e., magnitud) de la declinación en abundancia pasada (mediante comparación de la abundancia actual con la abundancia histórica de referencia) tendieron a reflejar de mejor manera el estatus en años anteriores que la tasa de declinación en las 3 generaciones previas (un indicador ampliamente utilizado). Recomendamos que, cuando sea posible, se evalúe la confiabilidad de varios indicadores de amenaza con análisis empíricos antes de que esos indicadores sean utilizados para determinar la necesidad de acciones de conservación. Estos indicadores deben incluir estimaciones a partir del total de datos para considerar una referencia histórica.

communities, values of b i,j were selected from uniform distributions between 0 and 20.1 (plant-plant competition), 20.3 (herbivores ! plants; that is, the effect of herbivores on plants), 0.1 (plants ! herbivores), 20.1 (predators !... more

communities, values of b i,j were selected from uniform distributions between 0 and 20.1 (plant-plant competition), 20.3 (herbivores ! plants; that is, the effect of herbivores on plants), 0.1 (plants ! herbivores), 20.1 (predators ! herbivores), and 0.05 (herbivores ! predators). Intraspecific interactions were selected at random between 20.1 and 20.2 for plants, and set to 20.2 for herbivores and predators. For competitive communities, interspecific values of b i,j were selected uniformly between 0 and 20.1, and intraspecific values between 20.06 and 20.16. For the arbitrary topology, the probability of any pair of species interacting was 0.5, and of the interacting pairs of species 45% were competitors, 45% were prey and predators, and 10% were mutualists. The magnitudes of interspecific values of b i,j were selected uniformly between 0 and 0.1, with sign dictated by type of interaction, and intraspecific values were selected between 20.06 and 20.16.

Climate change is taking place more rapidly and severely in the Arctic than anywhere on the globe, exposing Arctic vertebrates to a host of impacts. Changes in the cryosphere dominate the physical changes that already affect these... more

Climate change is taking place more rapidly and severely in the Arctic than anywhere on the globe, exposing Arctic vertebrates to a host of impacts. Changes in the cryosphere dominate the physical changes that already affect these animals, but increasing air temperatures, changes in precipitation, and ocean acidification will also affect Arctic ecosystems in the future. Adaptation via natural selection is problematic in such a rapidly changing environment. Adjustment via phenotypic plasticity is therefore likely to dominate Arctic vertebrate responses in the short term, and many such adjustments have already been documented. Changes in phenology and range will occur for most species but will only partly mitigate climate change impacts, which are particularly difficult to forecast due to the many interactions within and between trophic levels. Even though Arctic species richness is increasing via immigration from the South, many Arctic vertebrates are expected to become increasingly ...

It has been hypothesized that salmonids use olfactory cues to return to their natal rivers and streams. However, the key components of the molecular pathway involved in imprinting and homing are still unknown. If odorants are involved in... more

It has been hypothesized that salmonids use olfactory cues to return to their natal rivers and streams. However, the key components of the molecular pathway involved in imprinting and homing are still unknown. If odorants are involved in salmon homing migration, then olfactory receptors should play a critical role in the dissipation of information from the environment to the fish. Therefore, we examined the expression profiles of a suite of genes encoding olfactory receptors and other olfactory-related genes in the olfactory rosettes of different life stages in two anadromous and one nonanadromous wild Atlantic salmon populations from Newfoundland, Canada. We identified seven differentially expressed OlfC genes in juvenile anadromous salmon compared to returning adults in both populations of anadromous Atlantic salmon. The salmon from the Campbellton River had an additional 10 genes that were differentially expressed in juveniles compared to returning adults. There was no statistically significant difference in gene expression of any of the genes in the non-anadromous population (P < 0.01). The function of the OlfC gene products is not clear, but they are predicted to be amino acid receptors. Other studies have suggested that salmon use amino acids for imprinting and homing. This study, the first to examine the expression of olfactory-related genes in wild North American Atlantic salmon, has identified seven OlfC genes that may be involved in the imprinting and homeward migration of anadromous Atlantic salmon.

The ontogeny of orientation mechanisms in migratory birds involves a complex of programmed learning rules and calibrations between the several compasses used during migration. Visual information at sunset, especially the pattern of... more

The ontogeny of orientation mechanisms in migratory birds involves a complex of programmed learning rules and calibrations between the several compasses used during migration. Visual information at sunset, especially the pattern of polarized skylight, provides a primary source of orientation information for night-migrating species. To examine the development of visual orientation mechanisms at sunset, hand-raised Savannah sparrows, Passerculus sandwichensis, were given controlled experience with the clear daytime sky during the first 3 months of life. One group of birds saw the daytime sky only within an earth-strength magnetic field with magnetic north shifted 90 clockwise to true east; a control group had similar exposure to the sky within a normal, unshifted magnetic field. Orientation tests were performed on clear evenings between the time of sunset and the first appearance of stars within a vertical magnetic field of normal earth intensity (no directional magnetic information). There was no difference in the orientation of the two groups: both showed southwestward orientation. Contrary to indications from earlier experiments, the visual orientation mechanism at sunset develops independently of magnetic directions and, in this context, is similar to the ontogeny of stellar orientation.

Linear infrastructure such as roads, highways, power lines and gas lines are omnipresent features of human activity and are rapidly expanding in the tropics. Tropical species are especially vulnerable to such infrastructure because they... more

Linear infrastructure such as roads, highways, power lines and gas lines are omnipresent features of human activity and are rapidly expanding in the tropics. Tropical species are especially vulnerable to such infrastructure because they include many ecological specialists that avoid even narrow (<30-m wide) clearings and forest edges, as well as other species that are susceptible to road kill, predation or hunting by humans near roads. In addition, roads have a major role in opening up forested tropical regions to destructive colonization and exploitation. Here, we synthesize existing research on the impacts of roads and other linear clearings on tropical rainforests, and assert that such impacts are often qualitatively and quantitatively different in tropical forests than in other ecosystems. We also highlight practical measures to reduce the negative impacts of roads and other linear infrastructure on tropical species.

Invasive rats (Rattus rattus, R. norvegicus, R. exulans) have large impacts on island habitats through both direct and indirect effects on plants. Rats affect vegetation by extirpating burrowing seabirds through consumption of eggs,... more

Invasive rats (Rattus rattus, R. norvegicus, R. exulans) have large impacts on island habitats through both direct and indirect effects on plants. Rats affect vegetation by extirpating burrowing seabirds through consumption of eggs, chicks, and adults. These seabirds serve as ecosystem engineers, affecting plant communities by burying and trampling seeds and seedlings, and by altering microclimate. Rats also directly affect plant communities by consuming seeds and seedlings. We studied the direct and indirect impacts of rats on the seedlings of woody plants on 21 islands in northern New Zealand. We compared seedling densities and richness on islands which differed in status with respect to rats: nine islands where rats never invaded, seven islands where rats were present at the time of our study, and five islands where rats were either eradicated or where populations were likely to be small as a result of repeated eradications and re-invasions. In addition, we compared plots from a subset of the 21 islands with different burrow densities to examine the effects of burrowing seabirds on plants while controlling for other factors that differ between islands. We categorized plant communities by species composition and seedling density in a cluster analysis. We found that burrow densities explained more variation in seedling communities than rat status. In areas with high seabird burrow density seedling densities were low, especially for the smallest seedlings. Species richness and diversity of seedlings, but not seedling density, were most influenced by changes in microclimate induced by seabirds. Islands where rats had been eradicated or that had low rat populations had the lowest diversity and richness of seedlings (and adults), but the highest seedling density. Seedling communities on these islands were dominated by Pseudopanax lessonii and Coprosma macrocarpa. This indicates lasting effects of rats that may prevent islands from returning to pre-invasion states.

European eels live most of their lives in freshwater until spawning migration to the Sargasso Sea. During seawater adaptation, eels modify their physiology, and their digestive system adapts to the new environment, drinking salt water to... more

European eels live most of their lives in freshwater until spawning migration to the Sargasso Sea. During seawater adaptation, eels modify their physiology, and their digestive system adapts to the new environment, drinking salt water to compensate for the continuous water loss. In that period, eels stop feeding until spawning. Thus, the eel represents a unique model to understand the adaptive changes of the enteric nervous system (ENS) to modified salinity and starvation. To this purpose, we assessed and compared the enteric neuronal density in the cranial portion of the intestine of freshwater eels (control), lagoon eels captured in brackish water before their migration to the Sargasso Sea (T0), and starved seawater eels hormonally induced to sexual maturity (T18; 18 weeks of starvation and treatment with standardized carp pituitary extract). Furthermore, we analyzed the modification of intestinal neuronal density of hormonally untreated eels during prolonged starvation (10 weeks) in seawater and freshwater. The density of myenteric (MP) and submucosal plexus (SMP) HuC/D-immunoreactive (Hu-IR) neurons was assessed in wholemount preparations and cryosections. The number of MP and SMP HuC/D-IR neurons progressively increased from the freshwater to the salty water habitat (control > T0 > T18; P < 0.05). Compared with freshwater eels, the number of MP and SMP HuC/D-IR neurons significantly increased (P < 0.05) in the intestine of starved untreated salt water eels. In conclusion, high salinity evokes enteric neuroplasticity as indicated by the increasing number of HuC/D-IR MP and SMP neurons, a mechanism likely contributing to maintaining the body homeostasis of this fish in extreme conditions.

Elephant seals migrate over vast areas of the eastern Nonh Pacific Ocean between rookeries in southern California and distant northern foraging areas. Several models of particle movement were evaluated and a model for great-circle motion... more

Elephant seals migrate over vast areas of the eastern Nonh Pacific Ocean between rookeries in southern California and distant northern foraging areas. Several models of particle movement were evaluated and a model for great-circle motion found to give reasonable results for the movement of an adult female. This model takes specific account of the fact that the movement is on the surface of a sphere and that the animal is apparently heading toward a particular destination. The parameters of the motion were estimated. Such a great-circle path of migration may imply that these seals have the ability to assess their position with respect to some global or celestial cues, allowing them to continually adjust their course and achieve the most direct geodesic route between origin and destination of migration. But the navigational mechanism actually used by these seals to accomplish such feats is as yet unknown. Deux fois par annee. les elephants de mer entreprennent de longues migrations au nord de I'ocCan Pacifique. Plusieurs sont poneurs d'instruments qui enregistrent la profondeur et I'intensitt lumineuse h intervalles rtguliers. Ces instruments sont ensuite recupirts et permettent de faire plusieurs estimations. par exemple les positions i mi-journte. Dans cet expose on s'interessera h la modelisation des itineraires de surface des animaux i I'aide d'equations differentielles stochastiqeus. Les distances sont suffisament importantes pour ftre incluses dans le modele la nature sphtrique de la surface terrestre. Une question intiressante est de determiner si les itineraires sont des grands cercles de la sphere terrestre.

Synopsis Evidence for climate-driven phenological changes is rapidly increasing at all trophic levels. Our current poor knowledge of the detailed control of bird migration from the level of genes and hormonal control to direct... more

Synopsis Evidence for climate-driven phenological changes is rapidly increasing at all trophic levels. Our current poor knowledge of the detailed control of bird migration from the level of genes and hormonal control to direct physiological and behavioral responses hampers our ability to understand and predict consequences of climatic change for migratory birds. In order to better understand migration phenology and adaptation in environmental changes, we here assess the scale at which weather affects timing of spring migration in passerine birds. We use three commonly used proxies of spring-time climatic conditions: (1) vegetation ''greenness'' (NDVI) in Europe, (2) local spring temperatures in northern Europe, and (3) the North Atlantic Oscillation Index (NAO) as predictors of the phenology of avian migration as well as the strength of their effect on different subsets of populations and the dependence of correlations on species-specific migratory strategy. We a...

Cladoceran composition and did horizontal migration were studied in 2,10 and 25 m diameter macrophyte exclosures established in the littoral zone of shallow Lake Stigsholm, Denmark. The exclosures were protected from waterfowl grazing,... more

Cladoceran composition and did horizontal migration were studied in 2,10 and 25 m diameter macrophyte exclosures established in the littoral zone of shallow Lake Stigsholm, Denmark. The exclosures were protected from waterfowl grazing, but open to fish. The macrophyte community comprised Polamogeton pectinatus, Potamogeton pusillus and Callitriche hermaphroditica. Cladocerans were sampled randomly every third hour inside and outside the macrophyte exclosures during a 24 h period. In the 2 m exclosure, the pelagic species Ceriodaphnia spp. and Bosmina spp. dominated during the day, mean density being as high as 3430 indiv. h 1. During the night, density decreased to 10-20% of the daytime density, thus indicating diel horizontal migration. In the 10 and 25 m exclosures, the daytime mean density of Ceriodaphnia spp. was 865 and 202 indiv. h 1 , respectively, and did not decrease at night. In contrast to the pelagic species, the density of macrophyte-associated species tended to be higher in the 10 and 25 m exclosure than in the 2 m exclosure. In the daytime, Eurycercus lamellatus density in the 2,10 and 25 m macrophyte exclosures was 7,28 and 16 indiv. H, respectively, while that of Simocephalus vetulus was 11, 171 and 92 indiv. I" 1 , respectively. There was no day-night difference in the density of macrophyte-associated species. We conclude that cladoceran community composition varies with macrophyte bed size, and that the edge zone between the bed and open water is an important daytime refuge for potentially migrating pelagic cladocerans.

Most of the world's large rivers are fragmented by dams. Fragmentation of the river ecosystem alters migration patterns among fish populations and converts free-flowing river to reservoir habitat. In this study, we used an... more

Most of the world's large rivers are fragmented by dams. Fragmentation of the river ecosystem alters migration patterns among fish populations and converts free-flowing river to reservoir habitat. In this study, we used an individual-based genetic metapopulation model to study the effects of fragmentation on the population viability and genetic diversity of a large-river fish, the white sturgeon, Acipenser transmontanus. In the first of two simulation experiments, we fragmented a 200 km river reach by building 1 to 20 virtual dams. Increased fragmentation produced an exponential decline in the likelihood of persistence, but no extinction threshold to suggest a minimum viable length of river. Compounding isolation with the loss of free-flowing habitat did not further reduce viability until free-flowing habitat was nearly eliminated, at which point extinction was certain. Genetic diversity within (among) populations decreased (increased) as we 'built' the first several dams. Adding more dams caused the number of persisting populations to decline and eroded genetic diversity within and among populations. Our second simulation experiment evaluated the effects of different levels of upstream and downstream migration between river segments. The results of these migration experiments highlighted the importance of balanced migration rates. We found that extinction risk was high for populations linked by high downstream, and low upstream, migration rates, as is often the case in impounded rivers. Our results support the view that migration patterns will play a significant role in determining the viability of riverine fishes, such as the white sturgeon, in river ecosystems fragmented by dams.

One of the most difficult problems in developing spatially explicit models of population dynamics is the validation and parameterization of the movement process. We show how movement models derived from capture-recapture analysis can be... more

One of the most difficult problems in developing spatially explicit models of population dynamics is the validation and parameterization of the movement process. We show how movement models derived from capture-recapture analysis can be improved by incorporating them into a spatially explicit metapopulation model that is fitted to a time series of abundance data. 2. We applied multisite capture-recapture analysis techniques to photo-identification data collected from female grey seals at the four main breeding colonies in the North Sea between 1999 and 2001. The best-fitting movement models were then incorporated into state-space metapopulation models that explicitly accounted for demographic and observational stochasticity. 3. These metapopulation models were fitted to a 20-year time series of pup production data for each colony using a Bayesian approach. The best-fitting model, based on the Akaike Information Criterion (AIC), had only a single movement parameter, whose confidence interval was 82% less than that obtained from the capture-recapture study, but there was some support for a model that included an effect of distance between colonies. 4. The state-space modelling provided improved estimates of other demographic parameters. 5. The incorporation of movement, and the way in which it was modelled, affected both local and regional dynamics. These differences were most evident as colonies approached their carrying capacities, suggesting that our ability to discriminate between models should improve as the length of the grey seal time series increases. Fig. 2. Pup production data (circles) and smoothed estimates (solid line) for the best-fitting state-space model of the North Sea grey seal population. Dashed lines show the posterior 95% Bayesian credibility intervals.

subtracting each judge's rating of the typical American from his or her rating of the typical compatriot for each NCS item. Assuming that cultures agree on the typical American, this procedure in effect subtracts the bias plus a constant... more

subtracting each judge's rating of the typical American from his or her rating of the typical compatriot for each NCS item. Assuming that cultures agree on the typical American, this procedure in effect subtracts the bias plus a constant and leaves a potentially better estimate of national character. We standardized the differences as T scores, using difference score normative values from the worldwide sample, excluding the United States. The difference scores were highly correlated with NCS scores (rs 0 0.65 to 0.91, P G 0.001) and provided essentially the same results. ICCs between difference scores and NEO-PI-R observer ratings ranged from -0.44 for England to 0.48 for Lebanon (median, 0.03). ICCs between differences scores and NEO-PI-R self-reports ranged from -0.47 for Russia to 0.53 for Poland (median, 0.01). For the five factors, correlations with observer ratings across cultures ranged from 0.08 to 0.23, and those with self-reports ranged from -0.37 to 0.23. These results suggest that the lack of correspondence between NEO-PI-R and NCS profiles is not simply due to different standards of evaluation in different cultures. A different issue concerns the referencegroup effect (28), according to which self-reports and observer ratings of individuals are implicitly made by reference to the distribution of scores in the rater's culture. Such an effect would tend to make aggregate personality scores uniform for all cultures, and the failure to find correlations with NCS factors would be due to a lack of variation in aggregate NEO-PI-R means. However, NEO-PI-R means in fact vary systematically across cultures and show strong correlations across methods and with other culturelevel variables . Thus, the reference-group effect cannot explain the failure to find correlations with NCS scales. 28.

The literature on fisheries co-management is almost silent on the issue of the movement of fisherfolk within fisheries, although such movement must have implications for the effectiveness of co-management. The introduction of... more

The literature on fisheries co-management is almost silent on the issue of the movement of fisherfolk within fisheries, although such movement must have implications for the effectiveness of co-management. The introduction of co-management often involves the formation of new structures that should enable the participation of key stakeholder groups in decision-making and management, but such participation is challenging for migrating fishers. The article reports on a study on Lake Victoria, East Africa, which investigated the extent of movement around the lake and the implications of movement for how fishers participate and are represented in co-management, and the implications of the extent and nature of movement for co-management structures and processes. The analysis draws on the concept of space from the literature on participation in development and on a framework of representation in fisheries co-management in addressing these questions. The created space is on an 'invited&...

Large numbers of bats are killed by collisions with wind turbines, and there is at present no direct method of reducing or preventing this mortality. We therefore determine whether the electromagnetic radiation associated with radar... more

Large numbers of bats are killed by collisions with wind turbines, and there is at present no direct method of reducing or preventing this mortality. We therefore determine whether the electromagnetic radiation associated with radar installations can elicit an aversive behavioural response in foraging bats. Four civil air traffic control (ATC) radar stations, three military ATC radars and three weather radars were selected, each surrounded by heterogeneous habitat. Three sampling points matched for habitat type and structure, dominant vegetation species, altitude and surrounding land class were located at increasing distances from each station. A portable electromagnetic field meter measured the field strength of the radar at three distances from the source: in close proximity (<200 m) with a high electromagnetic field (EMF) strength >2 volts/metre, an intermediate point within line of sight of the radar (200-400 m) and with an EMF strength <2 v/m, and a control site out of...

Strictly Protected Areas and riparian forests in Brazil are rarely large enough or connected enough to maintain viable populations of carnivores and animal movement over time, but these characteristics are fundamental for species... more

Strictly Protected Areas and riparian forests in Brazil are rarely large enough or connected enough to maintain viable populations of carnivores and animal movement over time, but these characteristics are fundamental for species conservation as they prevent the extinction of isolated animal populations. Therefore, the need to maintain connectivity for these species in human-dominated Atlantic landscapes is critical. In this study, we evaluated the landscape connectivity for large carnivores (cougar and jaguar) among the Strictly Protected Areas in the Atlantic Forest, evaluated the efficiency of the Mosaics of Protected Areas linked to land uses in promoting landscape connectivity, identified the critical habitat connections, and predicted the landscape connectivity status under the implementation of legislation for protecting riparian forests. The method was based on expert opinion translated into land use and land cover maps. The results show that the Protected Areas are still co...

There are several remote-sensing tools readily available for the study of nocturnally flying animals (e.g., migrating birds), each possessing unique measurement biases. We used three tools (weather surveillance radar, thermal infrared... more

There are several remote-sensing tools readily available for the study of nocturnally flying animals (e.g., migrating birds), each possessing unique measurement biases. We used three tools (weather surveillance radar, thermal infrared camera, and acoustic recorder) to measure temporal and spatial patterns of nocturnal traffic estimates of flying animals during the spring and fall of 2011 and 2012 in Lewes, Delaware, USA. Our objective was to compare measures among different technologies to better understand their animal detection biases. For radar and thermal imaging, the greatest observed traffic rate tended to occur at, or shortly after, evening twilight, whereas for the acoustic recorder, peak bird flight-calling activity was observed just prior to morning twilight. Comparing traffic rates during the night for all seasons, we found that mean nightly correlations between acoustics and the other two tools were weakly correlated (thermal infrared camera and acoustics, r ¼ 0.004 6 0.04 SE, n ¼ 100 nights; radar and acoustics, r ¼ 0.14 6 0.04 SE, n ¼ 101 nights), but highly variable on an individual nightly basis (range ¼ À0.84 to 0.92, range ¼ À0.73 to 0.94). The mean nightly correlations between traffic rates estimated by radar and by thermal infrared camera during the night were more strongly positively correlated (r ¼ 0.39 6 0.04 SE, n ¼ 125 nights), but also were highly variable for individual nights (range ¼ À0.76 to 0.98). Through comparison with radar data among numerous height intervals, we determined that flying animal height above the ground influenced thermal imaging positively and flight call detections negatively. Moreover, thermal imaging detections decreased with the presence of cloud cover and increased with mean ground flight speed of animals, whereas acoustic detections showed no relationship with cloud cover presence but did decrease with increased flight speed. We found sampling methods to be positively correlated when comparing mean nightly traffic rates across nights. The strength of these correlations generally increased throughout the night, peaking 2-3 hours before morning twilight. Given the convergence of measures by different tools at this time, we suggest that researchers consider sampling flight activity in the hours before morning twilight when differences due to detection biases among sampling tools appear to be minimized.

The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date... more

The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River.

The goal of this article is to discuss considerations regarding implementation of the parametric tolerance interval two one-sided test (PTI-TOST) for delivered dose uniformity (DDU) of orally inhaled products (OIPs). That test was... more

The goal of this article is to discuss considerations regarding implementation of the parametric tolerance interval two one-sided test (PTI-TOST) for delivered dose uniformity (DDU) of orally inhaled products (OIPs). That test was proposed by FDA in 2005 as an alternative to the counting test described in the 1998 draft FDA guidance for metered dose inhalers and dry powder inhalers. The 2005 PTI-TOST, however, still has not found much use in practice despite the general desirability of parametric approaches in modern pharmaceutical quality control. A key reason for its slow uptake is that it rejects, with high probability, batches whose quality is considered acceptable by all other published regulatory and pharmacopeial standards as well as by the DDU specifications for many approved OIPs. Manufacturers therefore continue using nonparametric counting tests for control of DDU. A simulated case study presented here compares the consequences of the PTI-TOST compared to the counting test. The article discusses three possibilities that would help increase the uptake of the PTI-TOST approach, namely: product-specific quality standards, a different default standard suitable for the majority of OIPs, and integration of the PTI-TOST with a continuous verification control strategy rather than using it as an isolated-batch (transactional) end-product testing. In any of these efforts, if a parametric test is used, it is critical not to set the target quality close to, or at the boundary of the process/product capabilities, because PTI tests are designed to reject with high probability the identified target quality.

Animals use the geomagnetic field in many ways: the magnetic vector provides a compass; magnetic intensity and/or inclination play a role as a component of the navigational 'map', and magnetic conditions of certain regions act as 'sign... more

Animals use the geomagnetic field in many ways: the magnetic vector provides a compass; magnetic intensity and/or inclination play a role as a component of the navigational 'map', and magnetic conditions of certain regions act as 'sign posts' or triggers, eliciting specific responses. A magnetic compass is widespread among animals, magnetic navigation is indicated e.g. in birds, marine turtles and spiny lobsters and the use of magnetic 'sign posts' has been described for birds and marine turtles. For magnetoreception, two hypotheses are currently discussed, one proposing a chemical compass based on a radical pair mechanism, the other postulating processes involving magnetite particles. The available evidence suggests that birds use both mechanisms, with the radical pair mechanism in the right eye providing directional information and a magnetitebased mechanism in the upper beak providing information on position as component of the 'map'. Behavioral data from other animals indicate a lightdependent compass probably based on a radical pair mechanism in amphibians and a possibly magnetitebased mechanism in mammals. Histological and electrophysiological data suggest a magnetite-based mechanism in the nasal cavities of salmonid fish. Little is known about the parts of the brain where the respective information is processed.

worldwide: a comparative study of plants and birds. Am. Nat. 160, 766-783 6 Vila, M. et al. (2009) How well do we understand the impacts of alien species on ecosystem services? A pan-European, cross-taxa assessment. Front. Ecol. Environ.,... more

worldwide: a comparative study of plants and birds. Am. Nat. 160, 766-783 6 Vila, M. et al. (2009) How well do we understand the impacts of alien species on ecosystem services? A pan-European, cross-taxa assessment. Front. Ecol. Environ., A framework for debate of assisted migration in an era of climate change.

Passive acoustic towed linear arrays are increasingly used to detect marine mammal sounds during mobile anthropogenic activities. However, these arrays cannot resolve between signals arriving from the port or starboard without vessel... more

Passive acoustic towed linear arrays are increasingly used to detect marine mammal sounds during mobile anthropogenic activities. However, these arrays cannot resolve between signals arriving from the port or starboard without vessel course changes or multiple cable deployments, and their performance is degraded by vessel self-noise and non-acoustic mechanical vibration. In principle acoustic vector sensors can resolve these directional ambiguities, as well as flag the presence of non-acoustic contamination, provided that the vibration-sensitive sensors can be successfully integrated into compact tow modules. Here a vector sensor module attached to the end of a 800 m towed array is used to detect and localize 1813 sperm whale "clicks" off the coast of Sitka, AK. Three methods were used to identify frequency regimes relatively free of non-acoustic noise contamination, and then the active intensity ͑propagating energy͒ of the signal was computed between 4-10 kHz along three orthogonal directions, providing unambiguous bearing estimates of two sperm whales over time. These bearing estimates are consistent with those obtained via conventional methods, but the standard deviations of the vector sensor bearing estimates are twice those of the conventionally-derived bearings. The resolved ambiguities of the bearings deduced from vessel course changes match the vector sensor predictions.

One model for marine migration of Atlantic salmon Salmo salar proposes that North American and southern European stocks (<62 • N) move directly to feeding grounds off west Greenland, then overwinter in the Labrador Sea, whereas northern... more

One model for marine migration of Atlantic salmon Salmo salar proposes that North American and southern European stocks (<62 • N) move directly to feeding grounds off west Greenland, then overwinter in the Labrador Sea, whereas northern European stocks (>62 • N) utilize the Norwegian Sea. An alternate model proposes that both North American and European stocks migrate in the North Atlantic Subpolar Gyre (NASpG) where S. salar enter the NASpG on their respective sides of the Atlantic, and travel counterclockwise within the NASpG until returning to natal rivers. A review of data accumulated during the last 50 years suggests a gyre model is most probable. Freshwater parr metamorphose into smolts which have morphological, physiological and behavioural adaptations of epipelagic, marine fishes. Former high-seas fisheries were seasonally sequential and moved in the direction of NASpG currents, and catches were highest along the main axis of the NASpG. Marking and discrimination studies indicate mixed continental origin feeding aggregations on both sides of the Atlantic. Marked North American smolts were captured off Norway, the Faroe Islands, east and west Greenland, and adults tagged at the Faroes were recovered in Canadian rivers. Marked European smolts were recovered off Newfoundland and Labrador, west and east Greenland, and adults tagged in the Labrador Sea were captured in European rivers. High Caesium-137 ( 137 Cs) levels in S. salar returning to a Quebec river suggested 62·3% had fed at or east of Iceland, whereas levels in 1 sea-winter (SW) Atlantic Canada returnees indicated 24·7% had fed east of the Faroes. Lower levels of 137 Cs in returning 1SW Irish fish suggest much of their growth occurred in the western Atlantic. These data suggest marine migration of S. salar follows a gyre model and is similar to other open-ocean migrations of epipelagic fishes.

Phylogeographic patterns and sex-biased dispersal were studied in riverine populations of West Indian (Trichechus manatus) and Amazonian manatees (T. inunguis) in South America, using 410bp D-loop (Control Region, Mitochondrial DNA)... more

Phylogeographic patterns and sex-biased dispersal were studied in riverine populations of West Indian (Trichechus manatus) and Amazonian manatees (T. inunguis) in South America, using 410bp D-loop (Control Region, Mitochondrial DNA) sequences and 15 nuclear microsatellite loci. This multi-locus approach was key to disentangle complex patterns of gene flow among populations. D-loop analyses revealed population structuring among all Colombian rivers for T. manatus, while microsatellite data suggested no structure. Two main populations of T. inunguis separating the Colombian and Peruvian Amazon were supported by analysis of the D-loop and microsatellite data. Overall, we provide molecular evidence for differences in dispersal patterns between sexes, demonstrating male-biased gene flow dispersal in riverine manatees. These results are in contrast with previously reported levels of population structure shown by microsatellite data in marine manatee populations, revealing low habitat restrictions to gene flow in riverine habitats, and more significant dispersal limitations for males in marine environments.

Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but... more

Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory-movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress.

A passive sonar array designed for tracking diving sperm whales in three dimensions from a single small vessel is presented, and the advantages and limitations of operating this array from a 6 m boat are described. The system consists of... more

A passive sonar array designed for tracking diving sperm whales in three dimensions from a single small vessel is presented, and the advantages and limitations of operating this array from a 6 m boat are described. The system consists of four free floating buoys, each with a hydrophone, built-in recorder, and global positioning system receiver ͑GPS͒, and one vertical stereo hydrophone array deployed from the boat. Array recordings are post-processed onshore to obtain diving profiles of vocalizing sperm whales. Recordings are synchronized using a GPS timing pulse recorded onto each track. Sensitivity analysis based on hyperbolic localization methods is used to obtain probability distributions for the whale's three-dimensional location for vocalizations received by at least four hydrophones. These localizations are compared to those obtained via isodiachronic sequential bound estimation. Results from deployment of the system around a sperm whale in the Kaikoura Canyon in New Zealand are shown.

How have humans colonised the entire planet and reshaped its ecosystems in the process? This unique and groundbreaking collection of essays explores human movement through time, the impacts of these movements on landscapes and other... more

How have humans colonised the entire planet and reshaped its ecosystems in the process? This unique and groundbreaking collection of essays explores human movement through time, the impacts of these movements on landscapes and other species, and the ways in which species have co-evolved and transformed each other as a result. Exploring the spread of people, plants, animals, and diseases through processes of migration, colonisation, trade, and travel, it assembles a broad array of case studies from the Pliocene to the present. The contributors from disciplines across the humanities and natural sciences are senior or established scholars in the fields of human evolution, archaeology, history, and geography.

349 NOUVELLES MAGAZINE during open heart surgery in infants on the immune function later in life. Clin Exp Immunol 2004 ; 136 : 349-55. 5. Ogle BM, West LJ, Driscoll DJ, et al. Effacing of the T cell compartment by cardiac transplantation... more

349 NOUVELLES MAGAZINE during open heart surgery in infants on the immune function later in life. Clin Exp Immunol 2004 ; 136 : 349-55. 5. Ogle BM, West LJ, Driscoll DJ, et al. Effacing of the T cell compartment by cardiac transplantation in infancy. J Immunol 2006 ; 176 : 1962-7. 6. Prelog M, Keller M, Geiger R, et al. Thymectomy in early childhood: Significant alterations of the CD4(+)CD45RA(+)CD62L(+) T cell compartment in later life. Clin Immunol 2009 ; 130 : 123-32. 7. Sauce D, Larsen M, Fastenackels S, et al. Evidence of premature immune aging in patients thymectomized during early childhood. J Clin Invest 2009 ; 119 : 3070-8. 8. Sylwester AW, Mitchell BL, Edgar JB, et al. Broadly targeted human cytomegalovirus-specific CD4+ and CD8+ T cells dominate the memory compartments of exposed subjects. J Exp Med 2005 ; 202 : 673-85. 9. Snyder CM, Cho KS, Bonnett EL, et al. Memory inflation during chronic viral infection is maintained by continuous production of shortlived, functional T cells. Immunity 2008 ; 29 : 650-9. 10. Wikby A, Maxson P, Olsson J, et al. Changes in CD8 and CD4 lymphocyte subsets, T cell proliferation responses and non-survival in the very old: the Swedish longitudinal OCTO-immune study. Mech Ageing Dev 1998 ; 102 : 187-98.

We investigated the risk associated with crossing the Sahara Desert for migrating birds by evaluating more than 90 journeys across this desert by four species of raptors (osprey Pandion haliaetus, honey buzzard Pernis apivorus, marsh... more

We investigated the risk associated with crossing the Sahara Desert for migrating birds by evaluating more than 90 journeys across this desert by four species of raptors (osprey Pandion haliaetus, honey buzzard Pernis apivorus, marsh harrier Circus aeruginosus and Eurasian hobby Falco subbuteo) recorded by satellite telemetry. Forty per cent of the crossings included events of aberrant behaviours, such as abrupt course changes, slow travel speeds, interruptions, aborted crossings followed by retreats from the desert and failed crossings due to death, indicating difficulties for the migrants. The mortality during the Sahara crossing was 31 per cent per crossing attempt for juveniles (first autumn migration), compared with only 2 per cent for adults (autumn and spring combined). Mortality associated with the Sahara passage made up a substantial fraction (up to about half for juveniles) of the total annual mortality, demonstrating that this passage has a profound influence on survival and fitness of migrants. Aberrant behaviours resulted in late arrival at the breeding grounds and an increased probability of breeding failure (carry-over effects). This study also demonstrates that satellite tracking can be a powerful method to reveal when and where birds are exposed to enhanced risk and mortality during their annual cycles.

If there were geese anywhere in the universe besides earth, we should probably expect to find them in the constellation Vulpecula. Vulpecula the Fox was contrived by Johannes Hevelius, the famous Polish astronomer who was based in Gdansk... more

If there were geese anywhere in the universe besides earth, we should probably expect to find them in the constellation Vulpecula. Vulpecula the Fox was contrived by Johannes Hevelius, the famous Polish astronomer who was based in Gdansk in the seventeenth century. Hevelius originally named this constellation Vulpecula & Anser, or the Fox & Goose. It’s no longer possible, however, to take a gander at the Goose. The Goose is long gone, ingested by the Fox in whose jaws Hevelius mapped its neck. Vulpecula is located right next to Cygnus the Swan, and for this 2005 Boeing Science Writing Contest article, Bernie Taylor has allowed those extraterrestrial geese to migrate to an imagined planet in the Swan, Cygnus 3. Bernie Taylor is a quantitatively-minded naturalist living in Oregon’s Willamette Valley. His 2004 book, Biological Time, examines the rhythms that regulate the lives of animals and plants and documents as well as ancient and indigenous knowledge of these natural cycles.
Some of these biological rhythms are modulated by celestial phenomena, and so Mr. Taylor asks whether different astronomical circumstances would alter the behavior of geese on another world or even eliminate the possibility of their existence. His imaginary planet in some ways parallels the earth. It is the third planet from its sun, a solar-like star in Cygnus. Notwithstanding the similarity of Cygnus 3 to earth, looking for geese on that planet could be a wild-goose chase.
The ancients imagined the constellation Cygnus as a swan in flight, headed south. They linked its seasonal departure from the night sky to the autumn migration of water fowl. Our failure to find any geese on Cygnus 3 wouldn't necessarily mean they don’t exist. They could, after all, have just gone south on us. What’s good for the Goose is sauce for the Swan. —E.C. Krupp, Director of the Griffith Observatory

Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used... more

Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

The waters of the Cres-Lošinj archipelago are subject to intense boat traffic related to the high number of leisure boats frequenting this area during the summer tourist season. Boat noise dominates the acoustic environment of the local... more

The waters of the Cres-Lošinj archipelago are subject to intense boat traffic related to the high number of leisure boats frequenting this area during the summer tourist season. Boat noise dominates the acoustic environment of the local bottlenose dolphin (Tursiops truncatus) population. This study investigates the spatial and temporal change in the underwater noise levels due to intense boating, and its effect on the distribution of the bottlenose dolphins. In the period 2007-2009 sea ambient noise (SAN) was sampled across ten acoustic stations. During data collection the presence of leisure boats was recorded if they were within 2 km of the sampling station. Bottlenose dolphin spatial distribution was monitored in the same period. Results showed a strong positive correlation between high SAN levels and boat presence, particularly in the tourist season. Dolphin distribution indicated significant seasonal displacements from noisy areas characterized by the intense leisure boating.

We approach the problem of the evolution of bird migration by asking whether migration evolves towards new breeding areas or towards survival areas in the nonbreeding season. Thus, we avoid the ambiguity of the usually discussed... more

We approach the problem of the evolution of bird migration by asking whether migration evolves towards new breeding areas or towards survival areas in the nonbreeding season. Thus, we avoid the ambiguity of the usually discussed "southern-home-theory" or "northernhome-theory". We argue that migration evolved in birds that spread to seasonal habitats through gradual dispersal to enhance survival during the non-breeding season; this in contrast to the alternative idea suggesting that migration evolved towards new breeding areas to increase reproductive success. Our synthesis is based on the threshold model explaining how migratory traits can change rapidly through microevolutionary processes. Our model brings former theories together and explains how bird migration, with the appropriate direction and time program, evolves through selection after genetically non-directed events such as dispersal and colonization. The model does not need the former untested assumptions such as competition as a reason for migration and for the disappearance of sedentary populations or higher reproductive success in temperate breeding areas. Our theory offers answers to questions such as how birds with a southern origin may gradually reach northern latitudes, why migration routes may follow historical expansion routes and why birds leave an area for the non-breeding season and move back instead of breeding on their wintering grounds. The theory proposes gradual change through selection and not sudden changes such as long distance dispersal or mutations and can be applied to migration at all latitudes and in all directions. The scenario provides a reasonable concept to understand most of the existing migratory phenomena on the basis of the ecology and genetics of migratory behaviour.

We studied the phylogeny of avian haemosporidian parasites, Haemoproteus and Plasmodium , in a number of African resident and European migratory songbird species sampled during spring and autumn in northern Nigeria. The phylogeny of the... more

We studied the phylogeny of avian haemosporidian parasites, Haemoproteus and Plasmodium , in a number of African resident and European migratory songbird species sampled during spring and autumn in northern Nigeria. The phylogeny of the parasites was constructed through sequencing part of their mitochondrial cytochrome b gene. We found eight parasite lineages, five Haemoproteus and three Plasmodium , infecting multiple host species. Thus, 44% of the 18 haemospiridian lineages found in this study were detected in more than one host species, indicating that host sharing is a more common feature than previously thought. Furthermore, one of the Plasmodium lineages infected species from different host families, Sylviidae and Ploceidae, expressing exceptionally large host range. We mapped transmission events, e.g. the occurrence of the parasite lineages in resident bird species in Europe or Africa, onto a phylogenetic tree. This yielded three clades, two Plasmodium and one Haemoproteus , in which transmission seems to occur solely in Africa. One Plasmodium clade showed European transmission, whereas the remaining two Haemoproteus clades contained mixes of lineages of African, European or unknown transmission. The mix of areas of transmission in several branches of the phylogenetic tree suggests that transmission of haemosporidian parasites to songbirds has arisen repeatedly in Africa and Europe. Blood parasites could be viewed as a cost of migration, as migratory species in several cases were infected with parasite lineages from African resident species. This cost of migration could have considerable impact on the evolution of migration and patterns of winter distribution in migrating birds.

We compared the effects of water resource development on migratory fish in two North American rivers using a descriptive approach based on four highlevel indicators: (1) trends in abundance of Pacific salmon, (2) reliance on artificial... more

We compared the effects of water resource development on migratory fish in two North American rivers using a descriptive approach based on four highlevel indicators: (1) trends in abundance of Pacific salmon, (2) reliance on artificial production to maintain fisheries, (3) proportion of adult salmon that are wild-versus hatchery-origin, and (4) number of salmon populations needing federal protection to avoid extinction. The two rivers had similar biological and physical features but radically different levels of water resource development: the Fraser River has few dams and all are located in tributaries, whereas the Columbia River has more than 130 large mainstem and tributary dams. Not surprisingly, we found substantial effects of development on salmon in the Columbia River. We related the results to potential effects on migratory fish in the Mekong River where nearly 200 mainstem and tributary dams are installed, under construction, or planned and could have profound effects on its 135 migratory fish species. Impacts will vary with dam location due to differential fish production within the basin, with overall effects likely being greatest from 11 proposed mainstem dams. Minimizing impacts will require decades to design specialized fish passage facilities, dam operations, and artificial production, and is complicated by the Mekong's high diversity and productivity. Prompt action is needed by governments and fisheries managers to plan Mekong water resource development wisely to prevent impacts to the world's most productive inland fisheries, and food security and employment opportunities for millions of people in the region.

The timing and propensity for migration between fresh-and seawater is a key theme in the diversity of life histories within the salmonid fishes. Across salmonid species, life-history strategies range from wholly freshwater-resident... more

The timing and propensity for migration between fresh-and seawater is a key theme in the diversity of life histories within the salmonid fishes. Across salmonid species, life-history strategies range from wholly freshwater-resident populations, to migratory and nonmigratory variation within populations, to populations and species that are primarily migratory. Despite the central theme of migration to the evolution of these fishes, the genetic architecture of migration-related processes is poorly understood. Using a genetic cross of clonal lines derived from migratory and nonmigratory life-history types of Onchorhynchus mykiss (steelhead and rainbow trout, respectively), we have dissected the genetic architecture of the complex physiological and morphological transformation that occurs immediately prior to seaward migration (termed smoltification). Quantitative trait loci (QTL) analyses were used to identify the number, effects, and genomic location of loci associated with smoltification-related traits, including growth and condition factor, body coloration, morphology, and osmoregulatory enzymes during the smoltification period. Genetic analyses revealed numerous QTL, but one locus in particular is associated with multiple traits in single and joint analyses. Dissecting the genetic architecture of this highly complex trait has profound implications for understanding the genetic and evolutionary basis of life-history diversity within and among migratory fishes.

Tracking small migrant organisms worldwide has been hampered by technological and recovery limitations and sampling bias inherent in exogenous markers. Naturally occurring stable isotopes of H (δ(2)H) in feathers provide an alternative... more

Tracking small migrant organisms worldwide has been hampered by technological and recovery limitations and sampling bias inherent in exogenous markers. Naturally occurring stable isotopes of H (δ(2)H) in feathers provide an alternative intrinsic marker of animal origin due to the predictable spatial linkage to underlying hydrologically driven flow of H isotopes into foodwebs. This approach can assess the likelihood that a migrant animal originated from a given location(s) within a continent but requires a robust algorithm linking H isotopes in tissues of interest to an appropriate hydrological isotopic spatio-temporal pattern, such as weighted-annual rainfall. However, a number of factors contribute to or alter expected isotopic patterns in animals. We present results of an extensive investigation into taxonomic and environmental factors influencing feather δ(2)H patterns across North America.

Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of... more

Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of declines (pre- versus post-1980) in local bee diversity in both countries; however, divergent trends were observed in hoverflies. Depending on the assemblage and location, pollinator declines were most frequent in habitat and flower specialists, in univoltine species, and/or in nonmigrants. In conjunction with this evidence, outcrossing plant species that are reliant on the declining pollinators have themselves declined relative to other plant species. Taken together, these findings strongly suggest a causal connection between local extinctions of functionally linked plant and pollinator species.

Biological invasions are caused by human-mediated extra-range dispersal and, unlike natural extra-range dispersal, are often the result of multiple introductions from multiple sources to multiple locations. The processes and opportunities... more

Biological invasions are caused by human-mediated extra-range dispersal and, unlike natural extra-range dispersal, are often the result of multiple introductions from multiple sources to multiple locations. The processes and opportunities that result in propagules moving from one area to another can be used more broadly to differentiate all types of extra-range dispersal. By examining key properties of dispersal pathways (notably propagule pressure, genetic diversity and the potential for simultaneous movement of coevolved species), the establishment and evolutionary trajectories of extrarange dispersal can be better understood. Moreover, elucidation of the mechanistic properties of dispersal pathways is crucial for scientists and managers who wish to assist, minimise or prevent future movements of organisms.

Otolith microchemistry can provide valuable information about stock structure and mixing patterns when the magnitude of environmental differences among areas is greater than the cumulative influence of any vital effects. Here, the current... more

Otolith microchemistry can provide valuable information about stock structure and mixing patterns when the magnitude of environmental differences among areas is greater than the cumulative influence of any vital effects. Here, the current understanding of the underlying mechanisms governing element incorporation into the otolith is reviewed. Hard and soft acid and base (HSAB) theory is employed to explore the differences in chemical behaviours, distributions and affinities between elements. Hard acid cations (e.g. Mg 2+ , Li + and Ba 2+ ) tend to be less physiologically influenced and accepted more readily into the otolith crystal lattice but are relatively homogeneous in seawater. Soft acid cations (e.g. Zn 2+ and Cu 2+ ) on the other hand, exhibit more varied distributions in seawater, but are more likely to be bound to blood proteins and less available for uptake into the otolith. The factors influencing the geographical distribution of elements in the sea, and their incorporation into the otoliths of marine fishes are reviewed. Particular emphasis is placed on examining physiological processes, including gonad development, on the uptake of elements commonly used in population studies, notably Sr. Finally, case studies are presented that either directly or indirectly compare population structuring or movements inferred by otolith elemental fingerprints with the patterns indicated by additional, alternative proxies. The main obstacle currently limiting the application of otolith elemental microchemistry to infer movements of marine fishes appears to lie in the largely homogeneous distribution of those elements most reliably measured in the otolith. Evolving technologies will improve the discriminatory power of otolith chemistry by allowing measurement of spatially explicit, low level elements; however, for the time being, the combination of otolith minor and trace element fingerprints with alternative proxies and stable isotopic ratios can greatly extend the scope of migration studies. Among the otolith elements that routinely occur above instrument detection limits, Ba, Mn and Li were deemed the most likely to prove reliable geographic markers in marine species.