Beavers Research Papers - Academia.edu (original) (raw)

The European beaver Castor fiber is well-known as an ecosystem engineer that greatly affects landscape structure, biodiversity as well as physical and chemical properties of surface water bodies. Beaver ponds alter surface water bodies by raising water elevation, decreasing flow velocity and altering the morphology of streams or drainage ditches, which can reduce the concentrations of organic carbon (OC) and nutrients (N, P). Recent studies indicated that mercury transforms into hazardous and neurotoxic methylmercury (MeHg) in beaver impoundments by biological processes in anaerobic conditions. However, the knowledge about nutrients and MeHg levels in impounded forest waterbodies is scarce in Lithuania. We aimed to ascertain the alteration in concentrations and stocks of OC, nutrients and MeHg in water and sediments from upstream and downstream, as well as within beaver dams and ponds during the growing seasons of 2016–2018. Results showed higher concentrations of dissolved organic carbon (DOC) and nutrients (P and N) in upstream water samples compared to those of downstream from beaver dams. Meanwhile, in sediments mean stocks of OC, P and N were the highest in the middle part of the ponds and in beaver dams. Moreover, the concentrations and stocks of MeHg in sediments were higher in beaver dams than in any other parts of beaver impoundments (upstream, mid-pond, pond periphery and downstream). We conclude that dam bottom sediments were rich in OC, N and P, and at the same time, contained toxic MeHg. Therefore, beaver dams could act as a trickle filter by improving water quality, in our case, DOC, N and P leaching, from riparian forests and soils, but may also act as hotspots of mercury methylation.

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- Environmental Science, Wildlife Biology, Beavers, Methylation

Understanding the amount of impact and distribution of invasive species is important for both basic ecological research and making management decisions. Because of their extensive impacts in southern Patagonia, invasive North American beavers (Castor canadensis) are considered both a scientific and conservation priority. However, little is known about the landscape-scale effects of these exotic ecosystem engineers. Using satellite imagery, we estimated the impact of beavers in the Argentine portion of Tierra del Fuego Island and determined the habitat factors (vegetation cover, forest type, stream presence and topography) related to their presence using both non-parametric statistical and information-theoretic approaches. Results indicated that more than 31,000 ha (1.6 % of the study area) were impacted by beavers and that the presence, but not the amount, of beaver impacts were spatially clustered. Impacts were greater in the Mountain ecoregion (2.8 % of the ecoregion) and lower in the Steppe (0.1 %). The best model for predicting beaver presence included variables related to water availability (presence of peat-lands and streams), forage availability (forest type cover), and topography (slope and elevation). These findings support previous assertions that this invasion is the largest alteration to the sub-Antarctic forests in the Holocene. They also serve as a foundation for the development of maps based on habitat-and landscape-scale conditions to assist with the orientation of control, eradication, and restoration efforts currently being planned.

What transgressions and transformations does cross-species imagination demand, amid the violence of extinctions? In a thoroughly surveilled and disciplined “environment” that disowns ecological processes, where can fugitives (including antiassimilationist queers and endangered beavers) find a foothold to invoke these imaginaries? The newly named Anthropocene gathers a swarm of diversely cohering recognitions: as an era of extinction, grief, and shocking change; as a platform for unprecedented ecological interventions figured as necessary for various strands of human survival; as occasion for a totalized human self-recognition positing (global) humankind scientifically exiled from a (fantasy) nature that high technology renders unlocatable. The authors here coax and aggravate anxieties we see underlying the figure of the Anthropocene engineer, an upright Euro-American hero. Inviting conversation that turns away from flattening and globalizing aspects of dominant Anthropocene discourse, we add our voices to recent feminist science and technology studies queries and work to learn from the ongoing decolonizing praxis of Native American and indigenous thinkers.

- by Cleo A Woelfle-Erskine and +1
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- Transgender Studies, Critical Animal Studies, Gay And Lesbian Studies, Performance

At first sight, brown bears and beavers do not have much in common: the brown bear (Ursus arctos), the largest terrestrial predator in Europe, dreaded by humans but also respected, on the one hand, and on the other hand the beaver (Castor fiber), a primarily aquatic rodent, at all times exploited for fur and meat. Some aspects, however, link these two very different species. T here is, first, their pelt, which was appreciated and utilized because of its high quality at all times. A second similarity is that both species were originally distributed all over Europe but widely extirpated by human hunting and by habitat loss in modern times. However, both bear and beaver have undergone a comeback in many European regions during the last decades as a result of the changing perception of wild animals in present-day societies, which results in legal protection, hunting restrictions, reintroductions, habitat protection and restoration. A final aspect linking the two species is much more abstract, but at the same time extraordinary and meaningful: bear and beaver are ‘ The Browns ’. Their names both have, in all Indo-European languages, the same shared root, meaning ‘brown’ and ‘brown animal’ respectively.
This observation brings us in the first part of the present essay to considerations about the role of ‘The Browns’ in spiritual worlds of former humans and about archaeological findings connected to rituals. Subsequently, hunting procedures and hunting motivations as well as different kinds of utilizations will be debated. In the end we will take a look at ‘cultural refuges’ of traditional human-bear/beaver interactions which survived until today.

- by Ulrich Schmölcke and +2
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- Archaeology, Mythology, History of Religion, History of Medicine
- by Alexandra Liarsou
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- Beavers

El castor es un animal salvaje que destaca por su historia asociada a la de ser humano, siendo considerado un animal totémico en muchas culturas por su presencia en leyendas, historias, mitos y cuentos infantiles. No obstante, estas creencias no impidieron que la codicia humana ocasionara una de las persecuciones más masivas de un animal salvaje en todo el planeta, lo cual estuvo a punto de acarrear su extinción total. En los últimos tiempos, asistimos a una recuperación parcial demográfica y de la distribución de la especie, gracias a la protección legal otorgada y al cumplimiento efectivo de la misma, pero en el reto de la conservación del castor y en la defensa de los intereses públicos, intervienen múltiples estamentos y actores (públicos y/o privados), con diferentes roles y responsabilidades. En un escenario de cambio global mundial, en el que los fenómenos climáticos se agudizarán, los responsables de la gestión y los profesionales de la información tienen un papel fundamental en la emisión de mensajes a la ciudadanía.
Una apuesta decidida por parte de los medios de comunicación debería integrar mensajes que demanden a nuestros gestores la restauración y el espacio a los ríos mediante la devolución de superficie inundable, y el respeto, o incluso el aumento, del Dominio Público Hidráulico.
Una sociedad comprometida con la conservación de la naturaleza, en términos generales, debiera buscar e implementar fórmulas realistas y eficaces para conjugar razonablemente tres objetivos plenamente complementarios: primero, el mantenimiento y restauración de la salud ambiental de nuestros ríos; segundo, el derecho a la información veraz; y por último, la ecuanimidad social, de tal manera, que sea la sociedad en su conjunto la que se haga cargo de esta tarea. Estamos convencidos de que esto no sólo es posible, sino que es una tarea a la altura de un país que presume de modernidad y respeto ambiental.
Por todo ello, hemos elaborado este modesto manual que pretende ofrecer información objetiva sobre el castor, informar con argumentos rigurosos contrastados para dar apoyo a los periodistas y a los comunicadores en general.

- by Jorge Echegaray
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- Environmental Education, Conservation Biology, Conservation, Riparian Ecology

In recent decades, ecological restoration and landscape architecture have focused on reintegrating ecological processes in the urban environment to support greater habitat complexity and increase biodiversity. As these values are more broadly recognized , new approaches are being investigated to increase ecosystem services and ecological benefits in urban areas. Ecosystem engineers, such as the North Ameri-can beaver (Castor canadensis), can create complex habitat and influence ecological processes in natural environments. Through dam building and wetland formation, beaver can create fish habitat, diversify vegetation in riparian zones, and aggrade sediment to increase stream productivity. As beaver populations have increased in urban areas across North America, their presence presents challenges and opportunities. Beaver can be integrated into the design of new and established urban green spaces to improve ecosystem functions. If managed properly, the conflicts that beaver sometimes create can be minimized. In this paper, we examine how landscape architects and restoration ecologists are anticipating the geomorphic and hydrological implications of beaver reintroduction in the design of wetlands and urban natural areas at regional and site levels. We present an urban beaver map and three case studies in Seattle, WA, USA, to identify various approaches, successes , and management strategies for integrating the actions of beaver into project designs. We make recommendations for how designers can capitalize on the benefits of beaver by identifying sites with increased likelihood of colonization, leveraging ecosystem engineers in design conception, designing site features to reduce constraints for the reintroduction and establishment of beaver, and anticipating and managing impacts.

- by ken yocom
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- Beavers, Ecological Urban Design

This report presents the results of an intensive archeological survey of 86 acres of Springer Reservoir located in Colfax County, New Mexico. The work was performed by the University of New Mexico’s Office of Contract Archeology at the request of the AECOM of Fort Collins, CO. to document all cultural resources within the project area prior to the beginning of the rehabilitation works at the reservoir. The project was designated Office of Contract Archeology Project No. 185-1086 under New Mexico CPRC General Permit No. State of New Mexico General Permit NM-10-017-S (expires December 31, 2012) and NMCRIS No. 120779.The survey identified two archeological sites and four isolated occurrences (IOs). The first site, LA 170053, is a low density lithic artifact scatter of unknown
temporal or cultural affinity. The second site is a previously documented water delivery system called Highline Canal which has operated from the late 19th century to present. The Highline Canal has already been recommended as eligible for listing in the National Register of Historic Places under Criterion A for its contributing role in the economic and agricultural development of the greater region of the Town of Springer. Based on our results of the survey, we concur with the original eligibility recommendation. The potential for subsurface cultural deposits at the other site (LA 170053) is very low and the site is recommended as not eligible for listing in the NRHP.

(In Spanish)
Una sociedad comprometida con la conservación de la biodiversidad debe buscar e implementar fórmulas realistas y eficaces para conseguir objetivos loables como la gestión de los recursos naturales, la protección estricta de las especies salvajes y la ecuanimidad social, de tal manera que sea la sociedad en su conjunto la que se haga cargo de esta tarea. Estamos convencidos de que esto no sólo es posible, sino que es una tarea factible a la altura de países modernos que presumen de biodiversidad y compromisos con la conservación de la naturaleza. El castor (Castor fiber), por su condición de especie estrictamente protegida en España y por su rol ecológico sin parangón en el mundo animal, es uno de los exponentes y mejores indicadores del compromiso ambiental de nuestra sociedad.
Tres especialistas en la especie han elaborado la primera guía digital de conocimientos sobre los castores en España, con el fin de resaltar su papel fundamental como especie salvaje protegida nativa, clave para los ecosistemas, e ingeniero natural que promueve la restauración de la biodiversidad en zonas húmedas continentales (ríos, lagunas, etc.). Esta guía de índole divulgativo, pretende aportar información contrastable fundamentada en el mejor conocimiento disponible como alternativa a las leyendas y exageraciones que rodean a esta especie, contribuyendo así a divulgar positivamente sobre el papel ecológico de los castores en nuestros ríos y zonas húmedas. Está redactada con un lenguaje sencillo y ameno, cuenta con infografía de calidad, y su objetivo es ofertar una herramienta digital que pueda contribuir a ayudar a los profesionales de la información a la hora de tratar noticias sobre castores y sus hábitats, así como también a la ciudadanía en general, para que amplíe sus conocimientos sobre este animal estrictamente protegido.

- by Jorge Echegaray
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- Environmental Education, Teacher Education, Conservation Biology, Ecology

Beaver exploitation is little documented for the Lower Paleolithic, in the Caune de l'Arago (Tautavel, France) beaver remains are present in ten levels dated from the Middle Pleistocene. Levels Gs4 and J provide bones with cut-marks. These cut-marks are located on the long bones, indicating meat removal and also on the metapodials, indicating that the animals were skinned before defleshing. The few beaver remains in each level could lead us to think that its exploitation was opportunistic but the fact that this exploitation occurs in two levels shows that it was not an exceptional practice. Even if small game was proposed in addition to large mammal exploitation for the model of hominid subsistence, evidence is scarce for the Lower Paleolithic. Their exploitation, even occasional , shows that large mammals are not the only meat resource used in this site.

- by loic lebreton and +1
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- Beavers, Cut-Marks, Middle Pleistocene

Herbivory is a fundamental process that controls primary producer abundance and regulates energy and nutrient flows to higher trophic levels. Despite the recent proliferation of small-scale studies on herbivore effects on aquatic plants, there remains limited understanding of the factors that control consumer regulation of vascular plants in aquatic ecosystems. Our current knowledge of the regulation of primary producers has hindered efforts to understand the structure and functioning of aquatic ecosystems, and to manage such ecosystems effectively. We conducted a global meta-analysis of the outcomes of plant–herbivore interactions using a data set comprised of 326 values from 163 studies, in order to test two mechanistic hypotheses: first, that greater negative changes in plant abundance would be associated with higher herbivore biomass densities; second, that the magnitude of changes in plant abundance would vary with herbivore taxonomic identity. We found evidence that plant abundance declined with increased herbivore density, with plants eliminated at high densities. Significant between-taxa differences in impact were detected, with insects associated with smaller reductions in plant abundance than all other taxa. Similarly, birds caused smaller reductions in plant abundance than echinoderms, fish, or molluscs. Furthermore, larger reductions in plant abundance were detected for fish relative to crustaceans. We found a positive relationship between herbivore species richness and change in plant abundance, with the strongest reductions in plant abundance reported for low herbivore species richness, suggesting that greater herbivore diversity may protect against large reductions in plant abundance. Finally, we found that herbivore–plant nativeness was a key factor affecting the magnitude of herbivore impacts on plant abundance across a wide range of species assemblages. Assemblages comprised of invasive herbivores and native plant assemblages were associated with greater reductions in plant abundance compared with invasive herbivores and invasive plants, native herbivores and invasive plants, native herbivores and mixed-nativeness plants, and native herbivores and native plants. By contrast, assemblages comprised of native herbivores and invasive plants were associated with lower reductions in plant abundance compared with both mixed-nativeness herbivores and native plants, and native herbivores and native plants. However, the effects of herbivore–plant nativeness on changes in plant abundance were reduced at high herbivore densities. Our mean reductions in aquatic plant abundance are greater than those reported in the literature for terrestrial plants, but lower than aquatic algae. Our findings highlight the need for a substantial shift in how biologists incorporate plant–herbivore interactions into theories of aquatic ecosystem structure and functioning. Currently, the failure to incorporate top-down effects continues to hinder our capacity to understand and manage the ecological dynamics of habitats that contain aquatic plants.

- by Kevin Wood
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- Botany, Zoology, Environmental Science, Ecosystems Ecology

Recent museum, archaeological, and observer record evidence suggests that North American beaver (Castor canadensis) were historically native to the watersheds of California's coast, including San Francisco Bay. A wide variety of animals are abundantly represented in Native American petroglyphs and pictographs with their representations fulfilling intentions ranging from the mundane to ceremonial and mythological purposes. However, beaver symbols are poorly represented in California rock art and absent from the San Francisco Bay Area. A novel record, in the form of Western Message Petroglyphs, suggests that a beaver lodge was present in the late nineteenth century in the Alameda Creek watershed, potentially the last evidence of beaver prior to their extirpation in the region by the fur trade.

- by Leigh Marymor
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- Rock Art (Archaeology), California History, Prehistoric Rock Art, Rock Art

W kulturze uczonej średniowiecza bóbr był przedstawiany jako zwierzę, które dokonuje na sobie aktu kastracji. Korzenie tego toposu sięgają literatury antycznej, w której przedstawienie to było tylko jednym z wielu sposobów opisu tego zwierzęcia. Starożytne wzmianki o bobrze ukazują różne podejścia autorów do zoologii, które jednak we wczesnym średniowieczu zostały zarzucone na rzecz jednego nurtu – alegorycznych opisów pochodzących z Fizjologów – wczesnochrześcijańskich tekstów moralizatorskich. Recepcja literatury antycz nej w pełnym średniowieczu i ówczesne ożywienie intelektualne pozwoliły na wykrystalizowanie się pluralizmu podejść do przyrody, co ma swoje silne odzwierciedlenie w opisie bobra. Bliższe przyjrzenie się powiązaniom między dziełami zawierającymi wzmianki o bobrze pozwala na dokładniejsze poznanie mechanizmu przekazy wania wiedzy: zarówno w starożytności, jak również między starożytnością a średniowieczem. Waga tego zagadnienia nie może zostać niedoceniona ze względu na podejście kultury średniowiecznej do starożytnych auctores i auto rytetów chrześcijańskich. Kwestia interpretacji zachowań bobrów przez autorów reprezentujących odmienne podejścia do przyrody pozwala na wysnucie ogólniejszych wniosków na temat sposobu podejścia ludzi średniowiecza do świata zwierząt. Lektura źródeł skłania do refleksji, czy pod nazwą castor nie wyobrażano sobie wielu różnych istot – zarówno prawdziwych, jak również fantastycznych.

- by Igor Rosa
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- Animal Studies, Albert the Great, Pliny the Elder, Beavers

New excavations at the mid-Holocene Stone Age site of Dąbki 9 in northern Poland provided not only evidence for imported pottery vessels over distances of c. 900 km at c. 4000 calBC, but also a mammal bone assemblage which is unique in its composition for the southern Baltic Sea area. Beaver (Castor fiber) is by far dominating, and altogether, primary fur-bearing species constitute 77 percent of the identified animal bones. Both the dominance of subadult game individuals in the dietary waste (wild boar, aurochs) and the distinct seasonality (between April and July) suggest a special function for the site. Since contacts to southern Neolithic cultures are proven, the furs could have been used as exchange goods.
Although people from Dąbki 9 were in regular contact with farming cultures, there is no evidence for husbandry at the site. Ancient DNA analyses of questionable bovid remains show that all successfully sampled remains are from aurochs and not from cattle. Therefore, it is assumed that Dąbki was part of the general development in the southwestern Baltic Sea coastal area with a successive onset of cattle husbandry concurrent with the appearance of the first funnel beaker about 4000 calBC.

Potential for habitat restoration is increasingly used as an argument for reintroducing ecosystem engineers. Beaver have well known effects on hydromorphology through dam construction, but their scope to restore wetland biodiversity in areas degraded by agriculture is largely inferred. Our study presents the first formal monitoring of a planned beaver-assisted restoration, focussing on changes in vegetation over 12 years within an agriculturally-degraded fen following beaver release, based on repeated sampling of fixed plots. Effects are compared to ungrazed exclosures which allowed the wider influence of waterlogging to be separated from disturbance through tree felling and herbivory. After 12 years of beaver presence mean plant species richness had increased on average by 46% per plot, whilst the cumulative number of species recorded increased on average by 148%. Heterogeneity, measured by dissimilarity of plot composition, increased on average by 71%. Plants associated with high moisture and light conditions increased significantly in coverage, whereas species indicative of high nitrogen decreased. Areas exposed to both grazing and waterlogging generally showed the most pronounced change in composition, with effects of grazing seemingly additive, but secondary, to those of waterlogging.
Our study illustrates that a well-known ecosystem engineer, the beaver, can with time transform agricultural land into a comparatively species-rich and heterogeneous wetland environment, thus meeting common restoration objectives. This offers a passive but innovative solution to the problems of wetland habitat loss that complements the value of beavers for water or sediment storage and flow attenuation. The role of larger herbivores has been significantly overlooked in our understanding
of freshwater ecosystem function; the use of such species may yet emerge as the missing ingredient in successful restoration.

- by Alan Law and +2
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- Restoration Ecology, Beavers, Rewilding, Grazing Ecology

Digital screens and spaces are crowded with animal bodies, from cat videos to corporate logos. In Virtual Menageries, Jody Berland examines the role of animals in the spread of global networks. Her richly illustrated study links today's proliferation of animals on social media to the aristocratic collection of exotic animals in the formative years of transcontinental exploration. By tracing previously unseen parallels across this history, Berland shows how and why animals come to bridge peoples, territories and technologies in colonial and capitalist cultures. Berland's genealogy of the virtual menagerie begins in 1414 when Bengal sent a Kenyan giraffe to join a Chinese emperor's menagerie. It revisits the beaver's role in the colonial settlement of Canada and maps the crucial appearances of animals in early moving pictures, computing software, cell phone marketing, social media, and relaxation soundtracks. The menagerie is reinvented for the digital age, Berland shows, when image and sound designers use parts or images of animals to ensure the affective promise and commercial spread of an emergent digital infrastructure. These animal emissaries enliven and domesticate the ever-expanding field of mediation. Virtual Menageries offers a unique account of animals and animal images as mediators that encourage complicated emotional, economic and aesthetic investment in changing practices of connection.

- by Jody Berland
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- History, Musicology, Media Studies, New Media

The American Beaver and His Works.

- by Stéphane RENNESSON
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- Ethology, Anthropomorphism, Beavers, Lewis Henry Morgan
- by Lee Raye
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- Evolutionary Biology, Geology, Medieval Literature, Medieval History

Recent museum, archaeological, and observer record evidence suggests that North American beaver (Castor canadensis) were historically native to the watersheds of California’s coast, including San Francisco Bay. A wide variety of animals are abundantly represented in Native American petroglyphs and pictographs with their representations fulfilling intentions ranging from the mundane to ceremonial and mythological purposes. However, beaver symbols are poorly represented in California rock art and absent from the San Francisco Bay Area. A novel record, in the form of Western Message Petroglyphs, suggests that a beaver lodge was present in the late nineteenth century in the Alameda Creek watershed, potentially the last evidence of beaver prior to their extirpation in the region by the fur trade.

- by Leigh Marymor
- •
- Geography, Rock Art (Archaeology), California History, Prehistoric Rock Art

The European beaver Castor fiber is well-known as an ecosystem engineer that greatly affects landscape structure, biodiversity as well as physical and chemical properties of surface water bodies. Beaver ponds alter surface water bodies by raising water elevation, decreasing flow velocity and altering the morphology of streams or drainage ditches, which can reduce the concentrations of organic carbon (OC) and nutrients (N, P). Recent studies indicated that mercury transforms into hazardous and neurotoxic methylmercury (MeHg) in beaver impoundments by biological processes in anaerobic conditions.
However, the knowledge about nutrients and MeHg levels in impounded forest waterbodies is scarce in Lithuania. We aimed to ascertain the alteration in concentrations and stocks of OC, nutrients and MeHg in water and sediments from upstream and downstream, as well as within beaver dams and ponds during the growing seasons of 2016–2018. Results showed higher concentrations of dissolved organic carbon (DOC) and nutrients (P and N) in upstream water samples compared to those of downstream from beaver dams. Meanwhile, in sediments mean stocks of OC, P and N were the highest in the middle part of the ponds and in beaver dams. Moreover, the concentrations and stocks of MeHg in sediments were higher in beaver dams than in any other parts of beaver impoundments (upstream, mid-pond, pond periphery and downstream). We conclude that dam bottom sediments were rich in OC, N and P, and at the same time, contained toxic MeHg. Therefore, beaver dams could act as a trickle filter by improving water quality, in our case, DOC, N and P leaching, from riparian forests and soils, but may also act as hotspots of mercury methylation.

- by Egidijus Vigricas and +2
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- Beavers, Methylation, Sediments, Water Impoundment
- by Sébastien Barbara
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- Ancient Medicine, Beavers, Scythians, Basiliscus
- by Andrei V . Zinoviev
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- Zooarchaeology, Medieval Studies, Morphometry, Russia
- by Theo de Jong
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- Prehistoric Landscapes, Beavers, Animal Bones, Aurochs

A review of the video, Beaver Trapping: A Complete Guide to Trapping & Snaring Beaver. Open Water and Under Ice Sets. by Scotty "Trapper" Mackner of Beaver Club Productions. TrappersTV.com. 2 Disc Set. 209 minutes of video. Castor... more

- by Christopher B. Anderson
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- Invasive species ecology, Ecosystem Engineering, Beavers

À partir du XIXe s., une partie de la faune sauvage passe du statut de « nuisible » à celui de « protégée ». Concentrer le regard sur les naturalistes français ainsi que sur les cas des oiseaux et du castor permet de révéler et de comprendre les dynamiques qui ont mené à ce renversement des valeurs et à la redéfinition – toujours en cours - des assemblages entre humains et autres qu’humains. Deux cheminements principaux conduisent les savants vers la protection de la nature. D’abord la nécessité de préserver un « équilibre naturel » perturbé par l’homme, dans une perspective plus biocentrée, s’impose. Ensuite, à l’orée du XXe s., une logique de patrimonialisation, scientifique, esthétique et éthique, associée à la crainte des extinctions, débouche sur la protection des premiers « nuisibles ». Ainsi le paradigme dominant de l’utilité/nuisibilité des espèces sauvages se trouve vivement contesté. Face à ces mutations les animaux ne sont pas restés passifs mais au contraire développent des capacités d’adaptation.

- by LUGLIA Rémi
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- Beavers, Birds, History of Animals, Nature protection
- by María Vanessa Lencinas
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- Zoology, Invasive species ecology, Natural History, Ecology

- by Elena A Nikulina and +1
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- Archaeology, Prehistoric Archaeology, Zooarchaeology, Bioarchaeology

In the summer of 1946, a landowning bourgeoisie organized the II Livestock Exhibition of Tierra del Fuego, and the Argentinian Navy filmed the introduction of twenty Canadian beavers in the region. Both events echoed power disputes between a military government seeking to nationalize lands and capitals and the European landowners whose privileges were threatened. The events show that landowners and state officers negotiated their interests by articulating Argentina's white exceptionalism with animals and against racialized others. Interrogating the interspecies articulation of whiteness in Tierra del Fuego during the 1940s, I examine how sheep and beavers helped secure white privilege through land concentration, breeding, racial purification, nature modernization, and eugenic moralities. To answer these questions, I analyze documents and films from local and national archives. My analysis shows the entangled racialization of humans and animals and its effects, including the appropriation of the Fuegian and native identification categories by settlers and the state. This article demonstrates that 'White Argentina' is a project desiring to live not only among white citizens but also among white animals. More broadly, I argue that including animals in race and ethnicity studies can better explain the intersectional production of race inequalities.

Trap modification tips gleaned from Dr. Richard Buech and his research on using suitcase style traps like the Bailey Beaver Trap to capture beavers (Castor canadensis). Suggestions on using the Hancock beaver trap are given as well.... more

We evaluated habitat selection by European beaver Castor fiber L. across a spatial gradient from local (within the family territory) to a broad, ecoregional scale. Based on aerial photography, we assessed the habitat composition of 150 beaver territories along the main water bodies of the Vistula River delta (northern Poland) and compared these data with 183 randomly selected sites not occupied by the species. The beavers preferred habitats with high availability of woody plants, including shrubs, and avoided anthropogenically modified habitats, such as arable lands. Within a single family territory , we observed decreasing woody plant cover with increasing distance from a colony centre, which suggests that beaver habitat preferences depend on the assessment of both the abundance and spatial distribution of preferred habitat elements. We tested the importance of spatial scale in beaver habitat selection with principal coordinates of neighbour matrices analysis, which showed that the geographical scale explained 46.7% of the variation in habitat composition, while the local beaver density explained only 10.3% of this variability. We found two main spatial gradients that were related to the broad spatial scale: first, the most important gradient was related to the largest distances between beaver sites and was independent of woody plant cover and the local beaver site density. The second most important gradient appeared more locally and was associated with these variables. Our results indicate that European beaver habitat selection was affected by different scale-related phenomena related 1) to central place foraging behaviour, which resulted in the clumped distribution of woody plants within the territory, and 2) local population density and woody plant cover. Finally, 3) habitat selection occurs independently across the largest spatial scale studied (e.g. between watersheds), which was probably due to the limited natal dispersal range of the animals.

- by Paul Ramsay
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- Restoration Ecology, Multidisciplinary, Beavers, Rewilding
- by Andrei V . Zinoviev
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- Morphometrics, Beavers

According to optimal foraging theory, consumers make choices that maximize their net energy intake per unit of time. We used foraging theory as a framework to understand the foraging behaviour of North American beavers (Castor canadensis Kuhl, 1820), an important herbivore that engineers new habitats. We tested the hypothesis that beavers are energy maximizers by verifying the prediction that they allocate time to foraging activities independently of habitat quality in Kouchibouguac National Park of Canada in New Brunswick, where nearly five decades of unabated colonization by beavers led to family units established in habitats of varying quality. We observed the behaviour of 27 beavers at seven ponds from May to August 2001, at dusk and dawn. Habitat quality did not influence time that beavers allocated to foraging. This finding supported our hypothesis. The only factor in the best model explaining time spent foraging was the progression of spring and summer seasons (weekly periods). Limiting factors such as infrastructure maintenance and intermittent reactions to danger remain poorly understood for this important herbivore. Future research should focus on establishing the importance that habitat quality (food availability) and environmental stress (weather, predators) have on shaping its time budget and, consequently, its survival and reproductive success. Résumé : Selon la théorie de l'approvisionnement optimal, les consommateurs font des choix qui maximisent leur apport énergétique net par unité de temps. Nous avons utilisé la théorie de l'approvisionnement comme cadre pour comprendre le comportement d'approvisionnement du castor (Castor canadensis Kuhl, 1820), un important herbivore qui crée de nouveaux habitats. Nous avons testé l'hypothèse selon laquelle les castors sont des maximisateurs d'énergie en vérifiant la prédiction voulant que leur attribution de temps aux activités d'approvisionnement ne dépende pas de la qualité de l'habitat dans le parc national du Canada Kouchibouguac, au Nouveau-Brunswick, où près de cinq décennies de colonisation soutenue par les castors ont mené a ` l'établissement d'unités familiales dans des habitats de qualité variable. Nous avons observé le comportement de 27 castors dans sept étangs, de mai a ` août 2001, a ` la brunante et a ` l'aube. La qualité de l'habitat n'avait pas d'influence sur le temps alloué a ` l'approvisionnement par les castors. Cette constatation appuie notre hypothèse. Le seul facteur dans le modèle expliquant le mieux le temps alloué a ` l'approvisionnement est l'avancée du printemps et de l'été (périodes hebdomadaires). Des facteurs limitants comme l'entretien des infrastructures et des réactions intermittentes au danger demeurent mal compris pour cet important herbivore. Des travaux futurs devraient viser a ` établir le rôle que jouent la qualité de l'habitat (disponibilité de nourriture) et les stress environnementaux (météo, prédateurs) sur le budget-temps et, conséquemment, la survie et le succès de reproduction des castors. [Traduit par la Rédaction]

- by Nicolas Lecomte
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- Beavers, Ecolgy, Foraging Behavior
- by Guillermo José Martínez Pastur
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- Zoology, Invasive species ecology, Natural History, Ecology

The late Miocene (Vallesian, Lower Pannonian, MN9 Zone) lacustrine and swampy sediments of Rudabánya contain a large sample of one beaver taxon, Trogontherium minutum (Meyer 1838). The study of this material included an analysis of discrete morphology and metric variation, as well as age categories. Beavers are abundant at Rudabánya, especially in the black clay layer. This layer represents a marshy environment with some fluviatile transportation. These animals lived in the valleys when ponds developed. Rudabánya’s beaver assemblage shows a normally distributed age structure: between ages 1 and 4 are the most abundant. All of Rudabánya beaver material is referable to Trogontherium minutum (Meyer 1838).

- by László Kordos
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- the Carpathian Basin, Beavers, Late Miocene, Rudabanya

Background: Twenty beavers Castor canadensis (Castoridae) were initially introduced in the Argentinean portion of
Tierra del Fuego Island, from where they have occupied most of the Fuegian Archipelago and even reached the
continent. This invasion is causing great damage to the subantarctic forest ecosystems, and it is not known how
fast the species is spreading. While there is an estimation of this advance using interviews, it is not known how
reliable these are and they cannot be made in remote areas.
On the mainland, where beavers were present, their date of arrival was estimated using interviews and
dendrochronology, and the dates obtained by both methods were compared for each site.
Results: Differences were found among the groups of respondents, according to property size, in their ability to
detect changes in the environment made by beavers.
The dates of arrival estimated through dendrochronology are 23 years prior to those determined through surveys,
and they generate a potential route of arrival from the Fuegian Archipelago and migration in the mainland. This
route is more parsimonious than the route of dispersal generated through interviews.
Conclusions: Since it was determined that there is no relationship between the dates estimated through surveys
and dendrochronology, it is not possible to determine how much lag there is from the time when changes in the
environment are produced by beavers and the time when people notice this change. Our results indicate that this
lag may not be constant among different groups of people.

- by Giorgia Graells and +1
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- Natural Resource Management, Dendrochronology, Qualitative Research, Beavers

In the mid-1820s, Anglo-American fur trappers. known as "mountain men," entered Arizona and began trapping beaver (Coslor calladensis). [n Arizona there have been a number of famous mountain men such as Sylvester and James Pattie. Ewing Young. lededia Smith. and Bill Williams who lrapped along the waterways in northern and southern Arizona. Although the heyday of mountain men lasted only a few decades due to a population decline of beaver, management of Ihese animals continues to this day. The purpose of managing beavers shifted from monetary gain 10 controlling wildlife damage. During the late 1900s, beaver were still widely distributed in limited numbers throughout much of the state. We provide a historical overview of beaver management in Arizona with emphasis on the mountain men, recreational trapping, wildlife damage management, and beaver research in Arizona.

- by Owen Nevin
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- Evolutionary Biology, Monogamy, Behavioral Ecology, Mammals
- by David Benson
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- Aquatic Ecology, Ecology, Beavers

"This is a wide-ranging book that provides a compendium of sources linking theoretical
approaches to visual representation and theory about animals. It has much to offer those working in cultural studies and thinking about animals in visual culture and screen media. I am reviewing this book within that disciplinary context although Virtual Menageries also contains selective references to animals held in historical menageries. While in some parts Berland switches rapidly between different epochs, examples and cultures, the book utilizes authoritative theorists and deftly weaves a spectrum of conceptual approaches into the discussion.
"[...] I welcome explorations of how perceptual and bodily felt responses develop in relationto viewing nonhuman animals and I was pleased to find Berland’s explanation foregrounding the emotions and affect in several places. The emotive appeal of animal species emerges from the book’s selection of engaging images and to confirm hierarchies of human attention. The book’s discursive overview effectively charts how selected animal species become virtually dominant in modes of representation ranging from photographic imagery to drawn illustration to animation such as Pokemon."

- by Jody Berland
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- Cultural Studies, Media Studies, Internet Studies, Critical Animal Studies

Bernard Allaire « La mise en marché des pelleteries canadiennes en Europe du 16e au 17e siècle » dans Mickaël Augeron et Dominique Guillemet, Champlain ou les portes du Nouveau Monde, Paris, Geste, 2004.
La commercialisation des pelleteries provenant de la traite avec les Amérindiens est un sujet relativement connu qui, malgré de nombreuses études, n'a jamais été analysé dans sa globalité en y incluant tous les points de chutes, les destinataires, les circuits de vente et ce, pour les différentes variétés animales existantes. Les envois de pelleteries en provenance du Canada ont bien sûr fait l'objet de quantifications précises mais pour diverses raisons, ces analyses ont toujours été limitées dans l'espace et le temps ou n'ont souvent concerné qu'une seule et même variété : le castor. La circulation de ces pelleteries sur le territoire français et leur réexportation vers les marchés extérieurs est l'aspect le plus négligé de la recherche en ce domaine et dont nous avons l'intention de retracer l'origine au 16 e siècle et les transformations au cours des deux siècles suivant. Une approche de longue durée s'impose car loin d'être statique et immuable, ce secteur essentiel de l'activité économique canadienne fluctue constamment en fonction des mouvements de l'offre nord-américaine et de la demande européenne.

- by Bernard Allaire
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- Economic History, Maritime History, 17th-Century Studies, 16th Century (History)
- by Heiner Schwarzberg and +1
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- Prehistoric Archaeology, Zooarchaeology, Bronze Age Europe (Archaeology), Late Bronze Age archaeology

A cost-effective way to prevent beavers (Castor canadensis) from obstructing water culverts and drainage pipes by using fences and beaver deceiver type devices. This method does not require killing or moving of beavers to be effective... more

- by Bjørn Bandlien
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- Medieval Culture, Beavers