turns 50
In: Wildlife research, Band 50, Heft 1, S. 1-3
ISSN: 1448-5494, 1035-3712
6 Ergebnisse
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In: Wildlife research, Band 50, Heft 1, S. 1-3
ISSN: 1448-5494, 1035-3712
In: Wildlife research, Band 49, Heft 1, S. i-v
ISSN: 1448-5494, 1035-3712
Drones have emerged as a popular wildlife research tool, but their use for many species and environments remains untested and research is needed on validation of sampling approaches that are optimised for unpiloted aircraft. Here, we present a foreword to a special issue that features studies pushing the taxonomic and innovation boundaries of drone research and thus helps address these knowledge and application gaps. We then conclude by highlighting future drone research ideas that are likely to push biology and conservation in exciting new directions.
In: Wildlife research, Band 40, Heft 5, S. 349
ISSN: 1448-5494, 1035-3712
Context
Measures of intake and digestibility from captive feeding experiments are often used to evaluate the nutritional value of plant species to herbivores; however, there is question about how well plant-quality rankings from these trials predict foraging patterns of free-ranging animals. Studies addressing the alignment of results from feeding trials and herbivory in the field using captive and free-roaming conspecifics are needed.
Aims
Our goal was to compare the feeding patterns of snowshoe hares in captive intake and digestion trials with those of free-living conspecifics in the species' south-western range.
Methods
We conducted in vivo intake and digestion trials using captive hares to determine quality and consumption levels of the predominant conifer species in our study system. In the field, we quantified browsing intensity and over-winter depletion patterns of these conifers. We then compared voluntary intake and nutritional quality measured in captivity to consumption in the field.
Key results
Digestible energy (DE, kJ g–1) of conifers ranged from 11.0 (Pinus contorta) to 13.8 (Pseudotsuga menziesii) among six conifers, and digestible protein (DP, g protein per 100 g feed) from 1.2 (Thuja plicata) to 2.7 (P. contorta). During digestion trials, single-species intake was correlated with the content of digestible protein (DP) and digestible energy (DE). Hares maintained energy balance when fed two single-species diets (Pinus contorta, Pseudotsuga menziesii) and a mixed-species diet. Conifer species on which hares were able to maintain body mass (Pinus contorta, Picea engelmannii, Pseudotsuga menziesii) also tended to be the most heavily exploited by free-living hares. DP content of browse species predicted both browsing intensity and overwinter depletion of conifer species.
Conclusions
Voluntary intake and nutritional quality of browse, especially DP, successfully predicted foraging patterns of free-ranging conspecifics.
Implications
Intake and digestion trials can be a useful tool for better understanding patterns of herbivory in the field, and winter habitat quality for populations in this region is likely to be influenced by access to the most energy- and protein-rich conifers.
6 páginas, 2 figuras ; Efforts to conserve globally declining herbivorous green sea turtles have resulted in promising growth of some populations. These trends could significantly impact critical ecosystem services provided by seagrass meadows on which turtles feed. Expanding turtle populations could improve seagrass ecosystem health by removing seagrass biomass and preventing of the formation of sediment anoxia. However, overfishing of large sharks, the primary green turtle predators, could facilitate turtle populations growing beyond historical sizes and trigger detrimental ecosystem impacts mirroring those on land when top predators were extirpated. Experimental data from multiple ocean basins suggest that increasing turtle populations can negatively impact seagrasses, including triggering virtual ecosystem collapse. Impacts of large turtle populations on seagrasses are reduced in the presence of intact shark populations. Healthy populations of sharks and turtles, therefore, are likely vital to restoring or maintaining seagrass ecosystem structure, function, and their value in supporting fisheries and as a carbon sink. ; Studies in Shark Bay were funded byNSF grantsOCE0526065 and OCE0745606 and Florida International University.Work in India was supported by the Norwegian Institute of Nature Research, the Rufford Small Grants Programme and Spanish Ministry of Economia y Competitividad [projects: CTM2010-22273-C02-02 and PIE-201330E062 (CSIC)]. Work in Bermuda was funded by the Department of Conservation Services, Government of Bermuda and B. Dilke, a private benefactor. This is contribution # 681 of the Southeast Environmental Research Center, Florida International University, contribution # BBP218 of the BBP series at the Bermuda Department of Conservation Services library, and contribution 76 of the Shark Bay Ecosystem Research Project. ; Peer reviewed
BASE
From the late Pleistocene to the Holocene and now the so-called Anthropocene, humans have been driving an ongoing series of species declines and extinctions (Dirzo et al. 2014). Large-bodied mammals are typically at a higher risk of extinction than smaller ones (Cardillo et al. 2005). However, in some circumstances, terrestrial megafauna populations have been able to recover some of their lost numbers because of strong conservation and political commitment, as well as human cultural changes (Chapron et al. 2014). Indeed, many would be in considerably worse predicaments in the absence of conservation action (Hoffmann et al. 2015). Nevertheless, most mammalian megafauna face dramatic range contractions and population declines. In fact, 59% of the world's largest carnivores (more than or equal to 15 kilograms, n = 27) and 60% of the world's largest herbivores (more than or equal to 100 kilograms, n = 74) are classified as threatened with extinction on the International Union for the Conservation of Nature (IUCN) Red List (supplemental tables S1 and S2). This situation is particularly dire in sub-Saharan Africa and Southeast Asia, home to the greatest diversity of extant megafauna (figure 1). Species at risk of extinction include some of the world's most iconic animals-such as gorillas, rhinos, and big cats (figure 2 top row)-and, unfortunately, they are vanishing just as science is discovering their essential ecological roles (Estes et al. 2011). Here, our objectives are to raise awareness of how these megafauna are imperiled (species in tables S1 and S2) and to stimulate broad interest in developing specific recommendations and concerted action to conserve them.
BASE
In: Ripple , W J , Chapron , G , López-Bao , J V , Durant , S M , Macdonald , D W , Lindsey , P A , Bennett , E L , Beschta , R L , Bruskotter , J T , Campos-Arceiz , A , Corlett , R T , Darimont , C T , Dickman , A J , Dirzo , R , Dublin , H T , Estes , J A , Everatt , K T , Goswami , V R , Galetti , M , Hayward , M , Hedges , S , Hoffmann , M , Hunter , L T B , Kerley , G I H , Letnic , M , Levi , T , Maisels , F , Morrison , J C , Nelson , M P , Newsome , T M , Painter , L , Pringle , R M , Sandom , C J , Terborgh , J , Treves , A , Van Valkenburgh , B , Vucetich , J A , Wirsing , A J , Wallach , A D , Wolf , C , Woodroffe , R , Young , H & Zhang , L 2016 , ' Saving the World's Terrestrial Megafauna ' , BioScience , vol. 66 , no. 10 , pp. 807-812 . https://doi.org/10.1093/biosci/biw092
From the late Pleistocene to the Holocene and now the so-called Anthropocene, humans have been driving an ongoing series of species declines and extinctions (Dirzo et al. 2014). Large-bodied mammals are typically at a higher risk of extinction than smaller ones (Cardillo et al. 2005). However, in some circumstances, terrestrial megafauna populations have been able to recover some of their lost numbers because of strong conservation and political commitment, as well as human cultural changes (Chapron et al. 2014). Indeed, many would be in considerably worse predicaments in the absence of conservation action (Hoffmann et al. 2015). Nevertheless, most mammalian megafauna face dramatic range contractions and population declines. In fact, 59% of the world's largest carnivores (more than or equal to 15 kilograms, n = 27) and 60% of the world's largest herbivores (more than or equal to 100 kilograms, n = 74) are classified as threatened with extinction on the International Union for the Conservation of Nature (IUCN) Red List (supplemental tables S1 and S2). This situation is particularly dire in sub-Saharan Africa and Southeast Asia, home to the greatest diversity of extant megafauna (figure 1). Species at risk of extinction include some of the world's most iconic animals—such as gorillas, rhinos, and big cats (figure 2 top row)—and, unfortunately, they are vanishing just as science is discovering their essential ecological roles (Estes et al. 2011). Here, our objectives are to raise awareness of how these megafauna are imperiled (species in tables S1 and S2) and to stimulate broad interest in developing specific recommendations and concerted action to conserve them.
BASE