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71.
72.
Benjamin Cretois Emily G. Simmonds John D. C. Linnell Bram van Moorter Christer M. Rolandsen Erling J. Solberg Olav Strand Vegard Gundersen Ole Roer Jan Ketil Rd 《Ecology and evolution》2021,11(21):15191
Many publications make use of opportunistic data, such as citizen science observation data, to infer large‐scale properties of species’ distributions. However, the few publications that use opportunistic citizen science data to study animal ecology at a habitat level do so without accounting for spatial biases in opportunistic records or using methods that are difficult to generalize. In this study, we explore the biases that exist in opportunistic observations and suggest an approach to correct for them. We first examined the extent of the biases in opportunistic citizen science observations of three wild ungulate species in Norway by comparing them to data from GPS telemetry. We then quantified the extent of the biases by specifying a model of the biases. From the bias model, we sampled available locations within the species’ home range. Along with opportunistic observations, we used the corrected availability locations to estimate a resource selection function (RSF). We tested this method with simulations and empirical datasets for the three species. We compared the results of our correction method to RSFs obtained using opportunistic observations without correction and to RSFs using GPS‐telemetry data. Finally, we compared habitat suitability maps obtained using each of these models. Opportunistic observations are more affected by human access and visibility than locations derived from GPS telemetry. This has consequences for drawing inferences about species’ ecology. Models naïvely using opportunistic observations in habitat‐use studies can result in spurious inferences. However, sampling availability locations based on the spatial biases in opportunistic data improves the estimation of the species’ RSFs and predicted habitat suitability maps in some cases. This study highlights the challenges and opportunities of using opportunistic observations in habitat‐use studies. While our method is not foolproof it is a first step toward unlocking the potential of opportunistic citizen science data for habitat‐use studies. 相似文献
73.
Hoset Katrine S.; Galliard Jean-Francois Le; Gundersen Gry; Steen Harald 《Behavioral ecology》2008,19(1):139-145
In small mammals living in highly seasonal environments, observationalstudies show that female home range size and exclusiveness aresmaller in the nonbreeding winter season than in the breedingsummer season. This has led to the notion that nonbreeding femalesare more social and decrease territorial behavior during winter.However, because territoriality decreases with increasing populationdensity, and density normally increases during the breedingseason, the effects of density and season on social structureare usually confounded. To find out which of the 2 factors explainsspace use, we experimentally established 3 high-density and3 low-density root vole (Microtus oeconomus) populations inlate spring and monitored the populations into the nonbreedingwinter season. Population sizes were controlled throughout thebreeding period to minimize seasonal variation in density. Homerange sizes were larger in founder females than in field-bornfemales but did not change with season or density. Area exclusivelyused by individual females was lower in winter than summer,and founder females decreased exclusiveness as density increased.We argue that this seasonal pattern of space use might be causedby variation in benefits of group living, whereas founder femalesalso responded to density-dependent competition by reducingarea exclusively used. 相似文献
74.
Erling S. Nordøy Lars P. Folkow Vladimir Potelov Vitaly Prischemikhin Arnoldus Schytte Blix 《Polar Biology》2008,31(9):1119-1135
Eight adult female harp seals (Pagophilus
groenlandicus) of the White Sea–Barents Sea stock were tagged with satellite-linked dive recorders during the nursing period and followed
from breeding in late February 1995 until moulting in late April 1995. Another ten adult harp seals of both sexes were tagged
and followed from moult in early May 1996 until breeding in late February the following year. Between breeding and moult the
seals were distributed along the coasts of Kola of Russia and eastern Finnmark of Norway, coinciding in time and space with
the spawning capelin (Mallotus villosus). Between moulting and breeding they encircled the entire Barents Sea, mostly in open water, using the water column from
20 to 300 m, and in so doing by and large reflecting the annual migrations of the capelin. Capelin is therefore assumed to
be the main source of prey for the White Sea–Barents Sea stock of harp seals, to be substituted, in part, by amphipods (e.g.
Themisto libellula) in mid-summer and polar cod (Boreogadus saida) and herring (Clupea pallasii) in late autumn and winter. These data provide a baseline for the evaluation of the effects of future climatic change in
the rich Barents Sea ecosystem. 相似文献
75.
Sjögren M Dahlström M Hedner E Jonsson PR Vik A Gundersen LL Bohlin L 《Biofouling》2008,24(4):251-258
This study reports a screening study for antifouling (AF) activity of the natural compound agelasine D isolated from marine sponges of the genus Agelas and 20 synthesised analogs of agelasines and agelasimines. Agelasine D, together with two of the analogs, ie AV1003A and AKB695, displayed a strong inhibitory effect on settlement of Balanus improvisus cypris larvae. Agelasine D had an EC50 value of 0.11 microM while the two analogs AV1033A and AKB695 had EC50 values of 0.23 and 0.3 microM, respectively. None of these three compounds affected larval mortality as was the case with several of the analogs tested. Moreover, the effect of AV1033A and AKB695 was reversible. When cyprids after 24 h exposure to the compounds were transferred to fresh seawater, the settlement frequency compared with the controls was completely recovered. The properties of the agelasine D analogs AV1003A and AKB695 make them highly attractive candidates as AF agents in future marine coatings. 相似文献
76.
Keri C. Lestyk L. P. Folkow A. S. Blix M. O. Hammill J. M. Burns 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(8):985-996
Pinnipeds rely on muscle oxygen stores to help support aerobic diving, therefore muscle maturation may influence the behavioral
ecology of young pinnipeds. To investigate the pattern of muscle development, myoglobin concentration ([Mb]) and acid buffering
ability (β) was measured in ten muscles from 23 harp and 40 hooded seals of various ages. Adult [Mb] ranged from 28–97 to
35–104 mg g tissue−1 in harp and hooded seals, respectively, with values increasing from the cervical, non-swimming muscles to the main swimming
muscles of the lumbar region. Neonatal and weaned pup muscles exhibited lower (~30% adult values) and less variable [Mb] across
the body than adults. In contrast, adult β showed little regional variation (60–90 slykes), while high pup values (~75% adult
values) indicate significant in utero development. These findings suggest that intra-uterine conditions are sufficiently hypoxic
to stimulate prenatal β development, but that [Mb] development requires additional postnatal signal such as exercise, and/or
growth factors. However, because of limited development in both β and [Mb] during the nursing period, pups are weaned with
muscles with lower aerobic and anaerobic capacities than those of adults. 相似文献
77.
78.
Verrucophora farcimen is renamed Pseudochattonella farcimen , and V. farcimen should be regarded as a synonym of P. farcimen for reasons of priority. 相似文献
79.