112 research outputs found
Healthy Western Lands: a proposal for healthy rangelands, wildlife, and free-roaming horses and burros
The Coalition for Healthy Nevada Lands, Wildlife and Free-roaming Horses (CHNL) is dedicated to proper management of free-roaming horses (Equus caballus) and burros (E. asinus) so rangelands are healthy, which benefits wildlife and the horses and burros themselves. The CHNL proposes the rapid reduction of horses and burros on designated public lands to achieve appropriate management levels (AML). After these reductions, the use of fertility control, supplemented with some gathers and adoption of gathered horses, should allow the Bureau of Land Management to economically maintain horse and burro populations at AML. The CHNL believes this approach will be the most expeditious to restoring rangeland to health and cost-effective as it reduces handling of horses and burros. Herein, we describe CHNL’s rationale for this approach and our effort to have the Nevada Legislature pass a resolution supporting the proposal
Change in Abundance of Pacific Brant Wintering in Alaska: Evidence of a Climate Warming Effect?
Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from low-temperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of the wintering populations. Mean surface air temperatures during winter at the end of the Alaska Peninsula increased about 1°C between 1963 and 2004, resulting in a 23% reduction in freezing degree days and a 34% decline in the number of days when ice cover prevents birds from accessing food resources. Trends in the wintering population fluctuated with states of the Pacific Decadal Oscillation, increasing during positive (warm) phases and decreasing during negative (cold) phases, and this correlation provides support for the hypothesis that growth in the wintering population of brant in Alaska is linked to climate warming. The size of the wintering population was negatively correlated with the number of days of strong northwesterly winds in November, which suggests that the occurrence of tailwinds favorable for migration before the onset of winter was a key factor in whether brant migrated from Alaska or remained there during winter. Winter distribution of brant on the Alaska Peninsula was highly variable and influenced by ice cover, particularly at the heavily used Izembek Lagoon. Observations of previously marked brant indicated that the Alaska wintering population was composed primarily of birds originating from Arctic breeding colonies that appear to be growing. Numbers of brant in Alaska during winter will likely increase as temperatures rise and ice cover decreases at high latitudes in response to climate warming.Au cours des 42 dernières années, la répartition de la bernache cravant du Pacifique (Branta bernicla nigricans) s’est déplacée vers le nord en hiver, passant ainsi de régions faiblement tempérées à des régions subarctiques. Nous avons évalué l’abondance et la répartition de la bernache en Alaska l’hiver afin de tenter de déterminer si le réchauffement climatique contribue aux tendances positives au sein des populations d’hivernage les plus au nord. Les températures moyennes de l’air à la surface en hiver se sont accrues d’environ 1°C entre 1963 et 2004, ce qui s’est traduit par une réduction de 23 % du nombre de jours atteignant le point de congélation et d’une diminution de 34 % du nombre de jours pendant lesquels la couverture de glace empêche les oiseaux d’avoir accès aux ressources alimentaires. Les tendances caractérisant la population d’hivernage fluctuaient en fonction des états de l’oscillation pacifique décennale en ce sens qu’elles augmentaient pendant les phases positives (tièdes) et qu’elles baissaient pendant les phases négatives (froides). Cette corrélation vient appuyer l’hypothèse selon laquelle la croissance de la population d’hivernage de la bernache en Alaska est liée au réchauffement climatique. L’effectif de la population d’hivernage a été négativement corrélé au nombre de jours de vents forts en provenance du nord-ouest en novembre, ce qui laisse croire que l’occurrence de vents arrières favorables à la migration avant le début de l’hiver constituait un facteur-clé déterminant si une bernache migrait de l’Alaska ou y restait pendant l’hiver. Dans la péninsule de l’Alaska, la répartition de la bernache en hiver variait énormément et dépendait de la couverture de glace, surtout à la lagune Izembek particulièrement achalandée. Les observations de bernaches déjà marquées ont permis de constater que la population d’hivernage de l’Alaska était principalement composée d’oiseaux provenant des colonies de reproduction de l’Arctique qui semblent prendre de l’ampleur. Le nombre de bernaches en Alaska pendant l’hiver augmentera vraisemblablement au fur et à mesure que les températures augmenteront et que les couvertures de glace diminueront en haute latitude en raison du réchauffement climatique
Archiving primary data: solutions for long-term studies
The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers
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