Concerningly high breeding success rates for the European Starling after a recent invasion in the Neotropics (original) (raw)
Related papers
2021
The European Starling (Sturnus vulgaris)-hereafter 'starling'-has been introduced in many countries, and its South American population recently started expanding exponentially. This invasive species has a worldwide negative impact on the breeding performance of woodpeckers, competing for cavity use. Nevertheless, information is still lacking regarding southern temperate neotropical woodpeckers nest defence strategies and starling effects on woodpeckers' breeding performance. We monitored Campo Flicker (Colaptes campestris) and Green-barred Woodpecker (Colaptes melanochloros) nests in a native southern temperate forest of central-eastern Argentina, to detect interactions with starlings and to assess the effect of starlings presence on woodpeckers' breeding performance. We assessed whether woodpeckers perform defensive behaviours against the starlings by exposing taxidermied starling models to woodpecker breeding pairs. We detected interactions with starlings at 11% of the nests. These nests had a significantly higher probability of being abandoned during the early stages (until the third incubation day), compared to nests without interactions. Moreover, woodpeckers attacked and made distress calls more frequently in response to the presentation of the starling, compared to predator and non-competing species models. We also documented evidence of joint nesting, as four breeding pairs of woodpeckers shared their nest chamber with starlings. Our results indicate that neotropical woodpeckers are more likely to abandon their cavity when they interact with starlings. As the starling is expanding quickly in Argentina, this information points at the need to develop management programmes to control the impacts of this invasive species on the native fauna, especially on species with conservation concerns.
Nest-site selection and breeding success of passerines in the world’s southernmost forests
PeerJ, 2020
Background Birds can maximize their reproductive success through careful selection of nest-sites. The ‘total-foliage’ hypothesis predicts that nests concealed in vegetation should have higher survival. We propose an additional hypothesis, the ‘predator proximity’ hypothesis, which states that nests placed farther from predators would have higher survival. We examined these hypotheses in the world’s southernmost forests of Navarino Island, in the Cape Horn Biosphere reserve, Chile (55°S). This island has been free of mammalian ground predators until recently, and forest passerines have been subject to depredation only by diurnal and nocturnal raptors. Methods During three breeding seasons (2014–2017), we monitored 104 nests for the five most abundant open-cup forest-dwelling passerines (Elaenia albiceps, Zonotrichia capensis, Phrygilus patagonicus, Turdus falcklandii, and Anairetes parulus). We identified nest predators using camera traps and assessed whether habitat characteristics ...
Journal of Arid Environments, 2020
Understanding the mechanisms underpinning nest-site selection offers novel insights about selective forces shaping the breeding ecology of birds, and provides vital information for conservation planning. We evaluated and compared nest-site selection and breeding success of Vermilion Flycatchers (VEFL) and Fork-tailed Flycatchers (FTFL) in areas with and without livestock in the Espinal biome of La Pampa Province, Argentina. VEFL selected nest sites with greater tree cover, whereas FTFL nested in taller trees with narrower trunks. We found a weak positive effect of nest height, diameter of nest-support branches and the absence of livestock on VEFL nest survival, and a weak positive effect of nest orientation on FTFL nest survival. However, although some habitat characteristics varied between the two areas, nest site characteristics of both species in areas with and without livestock did not differ significantly. The nest survival was 12.7% for VEFL and 28.7% for FTFL, and did not differ significantly between these two flycatchers. The breeding ecology of these birds has likely been molded by a broad suite of selective pressures, such as severe weather, brood parasites and predators that characterize habitats in central Argentina.
The main cause of nest mortality for most bird species is predation and nest survival rates often vary in relation to time-specific variables. Few investigators have examined time-specific patterns of nest survival in Neotropical birds, and most such studies have focused on tropical and subtropical species. To better understand age-related patterns of nest survival, we studied nest survival of Red-crested Cardinals (Paroaria coronata, Thraupidae) in a south-temperate forest in Argentina. We modeled daily nest survival rates (DSR) using program MARK. We examined the relationship between nest age and nest survival rate, controlling for the effects of physical characteristics of nest sites and progression of the breeding season. We monitored 367 nests for a total of 4018 exposure days. We found that DSR increased with nest age and was higher in small isolated patches than in large continuous patches of forests. The increase of DSR with nest age could be a consequence of more vulnerable nests being predated early in the nesting cycle or a result of parents defending nests more vigorously as nestlings age because of their increasing reproductive value. Open areas of grassland that surrounded the small isolated patches of forests in our study may have been a barrier to predator movements, possibly explaining the lower predation rates. Nest survival rates in our study were lower than those reported for tropical or Nearctic temperate birds, but similar to those reported in other studies of Neotropical temperate birds. Reasons for the low nest survival rates of Neotropical temperate birds remain unclear, and additional studies of predator communities are needed to help elucidate this topic.
The effect of egg size and habitat on starling nestling growth and survival
Oecologia, 1998
In spite of the fact that hatchling size and energy reserves in birds are aected by egg size, many studies have failed to ®nd an eect of egg size on ospring ®tness. One possibility is that this is because they have been performed in areas with high food availability and that eects of egg size on ospring ®tness are most apparent in areas of low food availability. To investigate this, egg size, ospring mass and survival of European starlings (Sturnus vulgaris) were measured in an agricultural landscape with a low but variable amount of pasture, the preferred foraging habitat of parent starlings. Ospring mass was related to egg size, but egg size explained a declining proportion of the variation in nestling mean mass as nestlings grew older. Ospring survival during the early, but not during the late nestling period was related to egg size. Throughout the nestling period, survival was related to the mass of the nestlings. It is suggested that the eect of egg size on ospring survival is through the eect of egg size on ospring mass, this eect declining as ospring grow older. Ospring survival during the early part of the nestling period was related to egg size when availability of pasture was low, but not when it was high. However, the interaction was not signi®cant. Selection for larger egg size is discussed in relation to the structuring of starling populations into sources and sinks. Key words Egg size á Chick survival á Chick mass á Food availability á European starling
Breeding Biology of Passerines in a Subtropical Montane Forest in Northwestern Argentina
The Condor, 2007
The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with opencup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species.
Nest survival in the Neotropical Black Catbird (Melanoptila glabrirostris)
We estimated nest survival and evaluated factors affecting this demographic parameter for the Black Catbird (Melanoptila glabrirostris), a poorly known mimid endemic to the Yucatán Peninsula. During the 2008 and 2009 breeding seasons, we monitored 136 nests spread across four sites in Mexico, including three mainland coastal sites in the Sian Ka'an Biosphere Reserve and one site on Cozumel Island. We documented higher nest loss in the mainland sites (74 % failed) in contrast to the island site (21 % failed). Based on our observations, we suspect that predation was the main cause of nest failure. Using logistic exposure models and Akaike's Information Criterion, we found date, nest age, and nest type to be the main factors influencing nest survival. Nest survival was lower for open cup-nests in comparison with semi-cavity nests. Interval nest survival (proportion of nests expected to survive the entire nesting season) was 0.102 (CI = 0-0.660) for open-cup nests and 0.618 (CI = 0-0.981) for semi-cavity nests. Additional research on adult and juvenile survival and dispersal patterns, especially for the mainland population, is needed to determine if these rates of nest survival are sufficient to maintain stable populations.
Alternative nesting behaviours following colonisation of a novel environment by a passerine bird
Oikos, 2007
When birds settle in new environments, they may encounter different suites of nest-predators, resulting in strong selection to nest in novel locations. An important axis of variation is in height of nest placement, because offground nests are likely to be subject to different predation pressures than on-ground nests. In their native habitats, i.e. temperate montane forest, dark-eyed juncos Junco hyemalis predominantly nest on the ground. A population of juncos became established on the urban campus of the Univ. of California at San Diego in the early 1980s, and now has a relatively high frequency (Â20%) of off-ground nests. Off-ground nesting is associated with strong fitness benefits: based on returns from 579 nests, an egg laid off the ground has Â80% higher chance of producing a recruit to the next generation than one laid on the ground. In addition, some nests were occasionally re-used by Â10% of females and off-ground nests were more likely to be re-used. Many females that bred off-ground also built an on-ground nests and we did not detect an association in nest site positions of mothers and daughters, implying low heritability of this novel nest placement trait. By contrast, certain territories consistently had on-ground nests irrespective of the identity of the breeding female. We suggest that a limitation of suitable off-ground nest sites for a species predominantly adapted to on-ground nesting greatly slows the rate of evolution of this trait.
Journal of Ornithology, 2017
A large part of the variation in bird reproductive success is often explained by nest predation. Many studies report negative relationships between breeding density and reproductive success due to the predation effect. In this study, we tested the hypothesis that the total nest density should affect nest predation stronger than the nest density of a single species. We used a large sample (n = 320) of Booted Warbler Iduna caligata and Whinchat Saxicola rubetra nests obtained during a period of 6 years in abandoned fields. We used model selection to evaluate effects of density, nest age, season and year on daily nest survival rate. We used a single-species (the distance to the nearest conspecific nest and the number of conspecific nests around the focal nest) and total (the distance to the nearest nest of any passerine species and the total number of passerine nests around the focal nest) nest-density variables. Our results suggest that nest density affects nest survival negatively. Both Booted Warbler and Whinchat nests were more likely to be depredated when neighboring nests of any passerine species were closer. Daily nest survival rates were better predicted by the total nest density than single-species nest density. We suggest that generalist predators performing an area-restricted search may play an important role in nest predation in abandoned fields. The total nest density should be estimated when studying density-dependent nest predation as conclusions about nest predation based on single-species nest densities may be incorrect. The potential impact of density-dependent predation on real nests should be considered when designing artificial nest experiments.