scholarly journals What wild dogs want: habitat selection differs across life stages and orders of selection in a wide-ranging carnivore

BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Helen M. K. O’Neill ◽  
Sarah M. Durant ◽  
Rosie Woodroffe

Abstract Background Habitat loss is a key threat to the survival of many species. Habitat selection studies provide key information for conservation initiatives by identifying important habitat and anthropogenic characteristics influencing the distribution of threatened species in changing landscapes. However, assumptions about the homogeneity of individual choices on habitat, regardless of life stage, are likely to result in inaccurate assessment of conservation priorities. This study addresses a knowledge gap in how animals at different life stages diverge in how they select habitat and anthropogenic features, using a free-ranging population of African wild dogs living in a human-dominated landscape in Kenya as a case study. Using GPS collar data to develop resource selection function and step selection function models, this study investigated differences between second order (selection of home range across a landscape) and third order (selection of habitat within the home range) habitat selection across four life history stages when resource requirements may vary: resident-non-denning, resident-heavily-pregnant, resident-denning and dispersing. Results Wild dogs showed strong second order selection for areas with low human population densities and areas close to rivers and roads. More rugged areas were also generally selected, as were areas with lower percentage tree cover. The strength of selection for habitat variables varied significantly between life stages; for example, dispersal groups were more tolerant of higher human population densities, whereas denning and pregnant packs were least tolerant of such areas. Conclusions Habitat selection patterns varied between individuals at different life stages and at different orders of selection. These analyses showed that denning packs and dispersal groups, the two pivotal life stages which drive wild dog population dynamics, exhibited different habitat selection to resident-non-breeding packs. Dispersal groups were relatively tolerant of higher human population densities whereas denning packs preferred rugged, remote areas. Evaluating different orders of selection was important as the above trends may not be detectable at all levels of selection for all habitat characteristics. Our analyses demonstrate that when life stage information is included in analyses across different orders of selection, it improves our understanding of how animals use their landscapes, thus providing important insights to aid conservation planning.

2020 ◽  
Author(s):  
B Cristescu ◽  
S Bose ◽  
LM Elbroch ◽  
ML Allen ◽  
Heiko Wittmer

© 2019 The Zoological Society of London Many predators specialize on one or several prey species that they select from the range of potential prey. Predator specialization on primary versus alternative prey is driven in part by encounter rates with prey and a predator’s habitat selection. Although habitat selection changes with behavioural state, this has not been well-recognized in the resource selection function (RSF) literature to date, often because auxiliary data on the predator’s behavioural states (e.g. hunting) are absent. We monitored habitat selection of pumas Puma concolor in a multi-prey system in northern California, where pumas specialized on black-tailed deer Odocoileus hemionus columbianus. We employed multiple RSF analyses on different datasets to test the following three hypotheses: (1) Pumas utilize habitats in proportion to their availability; (2) Pumas select specific habitat features when killing black-tailed deer, their primary prey; (3) Pumas do not select distinct habitats from those identified under hypothesis 1 when killing alternative prey. We found that pumas in our study selected for specific habitats and habitat features in general, but that their selection was more pronounced when killing black-tailed deer. In summer, kill sites of deer were associated with rugged terrain, but gentle slopes and northerly aspects. In winter, pumas killed deer at low elevations, on gentle slopes and on northerly and westerly aspects. Overall, evidence suggested that pumas tracked their primary prey across seasonal migrations, which were short in distance but resulted in pronounced changes in elevation. When killing alternative prey, pumas showed little evidence of habitat selection, suggesting they may kill alternative prey opportunistically. Our results hold implications for how data should be partitioned when modelling baseline habitat selection of predators, hunting habitat selection and predation risk for prey species, as well as for how we model ecological processes such as apparent competition.


2013 ◽  
Vol 64 (11) ◽  
pp. 1058 ◽  
Author(s):  
Nils Teichert ◽  
Pierre Valade ◽  
Pierre Bosc ◽  
Marine Richarson ◽  
Philippe Gaudin

Freshwater-fish populations of the Indo-pacific region are characterised by a large proportion of amphidromous species. We analysed the spawning-habitat selection of Sicyopterus lagocephalus (Gobiidae: Sicydiinae) within two rivers of the Reunion Island. Reproduction traces are rare events, so a presence-only sampling procedure was performed to collect egg clutches and a random description of available habitat was conducted to generate pseudo-absence data. Logistic models showed a strong selection for microhabitat variables and mesohabitat units. S. lagocephalus selected areas where availability of potential nests was high (small cobble to small boulder) and where interstitial substratum allowed intragravel flow. Our results suggest that the availability of favourable substratum may be a limiting factor, which could result in occupancy of suboptimal areas. Water depth and velocity had less of an effect on the selection of a spawning area. Higher selection for shallow (<60 cm) and lotic (>30 cm s–1) geomorphic units, with an optimum for riffle and cascade, suggested that mesohabitat could be a satisfactory approach to quickly assess the availability of spawning areas within a watercourse for expertise studies.


2005 ◽  
Vol 83 (7) ◽  
pp. 983-988 ◽  
Author(s):  
Javier A Rodríguez-Robles ◽  
Manuel Leal ◽  
Jonathan B Losos

Habitat selection can directly affect the fitness of an individual and the evolutionary dynamics of the population to which that organism belongs. We studied habitat use of the Puerto Rican yellow-chinned anole (Anolis gundlachi Peters, 1876) to examine whether this arboreal lizard uses its environment in a nonrandom manner. Males and females preferred woody vegetation substrates over nonwoody plants and sierra palms (Prestoea acuminata var. montana (Graham) A. Henderson and G. Galeano) as perching sites, and they also selected wider vegetation than what was randomly available. Selection for minimizing conspicuousness to potential predators and for increased locomotion capacity may help explain the preference for woody substrates and broader surfaces, respectively. Anolis gundlachi relies almost exclusively on visual cues for foraging and social interactions, and using wider perches also increases an individual's ability to scan a larger proportion of its territory. Our findings thus indicate that the nonrandom habitat use of free-ranging A. gundlachi leads to the selection of perching substrates that may increase performance of ecologically relevant capabilities.


2020 ◽  
Author(s):  
B Cristescu ◽  
S Bose ◽  
LM Elbroch ◽  
ML Allen ◽  
Heiko Wittmer

© 2019 The Zoological Society of London Many predators specialize on one or several prey species that they select from the range of potential prey. Predator specialization on primary versus alternative prey is driven in part by encounter rates with prey and a predator’s habitat selection. Although habitat selection changes with behavioural state, this has not been well-recognized in the resource selection function (RSF) literature to date, often because auxiliary data on the predator’s behavioural states (e.g. hunting) are absent. We monitored habitat selection of pumas Puma concolor in a multi-prey system in northern California, where pumas specialized on black-tailed deer Odocoileus hemionus columbianus. We employed multiple RSF analyses on different datasets to test the following three hypotheses: (1) Pumas utilize habitats in proportion to their availability; (2) Pumas select specific habitat features when killing black-tailed deer, their primary prey; (3) Pumas do not select distinct habitats from those identified under hypothesis 1 when killing alternative prey. We found that pumas in our study selected for specific habitats and habitat features in general, but that their selection was more pronounced when killing black-tailed deer. In summer, kill sites of deer were associated with rugged terrain, but gentle slopes and northerly aspects. In winter, pumas killed deer at low elevations, on gentle slopes and on northerly and westerly aspects. Overall, evidence suggested that pumas tracked their primary prey across seasonal migrations, which were short in distance but resulted in pronounced changes in elevation. When killing alternative prey, pumas showed little evidence of habitat selection, suggesting they may kill alternative prey opportunistically. Our results hold implications for how data should be partitioned when modelling baseline habitat selection of predators, hunting habitat selection and predation risk for prey species, as well as for how we model ecological processes such as apparent competition.


1973 ◽  
Vol 4 (2) ◽  
pp. 134-154 ◽  
Author(s):  
Sven Almquist

AbstractThis paper deals with the habitat selection of I5 species of spiders on coastal sand dunes studied by the analysis of their spatial distribution of individuals correlated to some intrinsic factors and to environmental conditions. The data are based on a total of 82I samples of I m2 each collected in the course of I7 months at Sandhammaren, SE SkÅne, Sweden. The complicated interplay between the climatic and vegetational conditions of the area and the thermal tolerances, preferences and escape reactions, as well as the resistance to desiccation of the spider species was indicated in the variation of the distribution of the population densities in the biotopes of the dunes. The temperature proved to be a critical environment factor, a main cause of the distribution of the spiders, obvious for e.g. Clubiona trivialis C. Koch, while the humidity seemed to be more important for the habitat selection of Oedothorax apicatus (Bl.).


2017 ◽  
Author(s):  
Brent L. Lockwood ◽  
Tarun Gupta ◽  
Rosemary Scavotto

AbstractMany terrestrial ectothermic species exhibit limited variation in upper thermal tolerance across latitude. However, these trends may not signify limited adaptive capacity to increase thermal tolerance in the face of climate change. Instead, thermal tolerance may be similar among populations because behavioral thermoregulation by mobile organisms or life stages may buffer natural selection for thermal tolerance. We compared thermal tolerance of adults and embryos among natural populations of Drosophila melanogaster from a broad range of thermal habitats around the globe to assess natural variation of thermal tolerance in mobile vs. immobile life stages. We found no variation among populations in adult thermal tolerance, but embryonic thermal tolerance was higher in tropical strains than in temperate strains. Average maximum temperature of the warmest month of the year predicted embryonic thermal tolerance in tropical but not temperate sites. We further report that embryos live closer to their upper thermal limits than adultso—i.e., thermal safety margins are smaller for embryos than adults. F1 hybrid embryos from crosses between temperate and tropical populations had thermal tolerance that matched that of tropical embryos, suggesting dominance of heat-tolerant alleles. Together our findings suggest that thermal selection has led to divergence in embryonic thermal tolerance but that selection for divergent thermal tolerance may be limited in adults. Further, our results suggest that thermal traits should be measured across life stages in order to better predict adaptive limits.Impact SummaryClimate change may threaten the extinction of many ectothermic species, unless populations can evolutionarily adapt to rising temperatures. Natural selection should favor individuals with higher heat tolerances in hotter environments. But recent studies have found that individuals from hot and cold places often have similar heat tolerances. This pattern may indicate that the evolution of heat tolerance is constrained. If this were true, then it would have dire consequences for species persistence under novel thermal conditions.An alternative explanation for lack of variation in heat tolerance is that mobile organisms don’t need higher heat tolerances to survive in hotter places. The majority of studies have focused on heat tolerance of the adult life stage. Yet, adults in many species are mobile organisms that can avoid extreme heat by seeking shelter in cooler microhabitats (e.g., shaded locations). In contrast, immobile life stages (e.g., insect eggs) cannot behaviorally avoid extreme heat. Thus, mobile and immobile life stages may face different thermal selection pressures that lead to disparate patterns of thermal adaptation across life stages.Here, we compared heat tolerances of fruit fly adults and eggs (Drosophila melanogaster) from populations in temperate North America and tropical locations around the globe. Consistent with previous studies, we found no differences among populations in adult heat tolerance. However, eggs from tropical flies were consistently more heat tolerant than eggs from North American flies. Further, eggs had lower heat tolerance than adults. Consequently, fly eggs in the hotter tropics may experience heat death more frequently than adult flies later in life. This may explain why patterns of divergence in heat tolerance were decoupled across life stages. These patterns indicate that thermal adaptation may be life-stage-specific and suggest that future work should characterize thermal traits across life stages to better understand the evolution of thermal limits.


2019 ◽  
Author(s):  
David C. McNitt ◽  
Robert S. Alonso ◽  
Michael J. Cherry ◽  
Michael L. Fies ◽  
Marcella J. Kelly

ABSTRACTBobcats are an apex predator and a species of socio-cultural importance in the central Appalachian Mountains. Despite their importance, knowledge of bobcat spatial ecology in the region is sparse. We examined space use and resource selection of bobcats in the Appalachian Mountains of western Virginia during 3 biological seasons: breeding (January-March), kitten-rearing (April-September), and dispersal (October-December). We observed sex effects on all space use metrics, with male seasonal areas of use (SAU) approximately 3 times larger than female SAUs and male movement rates 1.5 times higher than females during all seasons. We found no seasonal effect on SAU size for either sex. Female movement rates increased during the kitten-rearing season, and male movement rates increased during the dispersal season. We examined seasonal bobcat resource selection at 2 hierarchical scales, selection of home ranges within the landscape (2nd order) and selection of locations within home ranges (3rd order). Female bobcats exhibited 2nd order selection for higher elevations and deciduous forest and avoidance of fields. Males exhibited 2nd order selection for higher elevations and fields. Male 2nd order selection appears to be driven largely by the spatial distribution of females, which is mediated through the valley and ridge topography of the study area. Sample size precluded 3rd order analysis for females, however males exhibited 3rd order selection for higher elevations, fields, and deciduous forest. Resource selection patterns varied seasonally for both sexes, possibly driven by seasonal shifts in prey availability. Our findings highlight the importance of forested ridges to bobcats in the region. Our findings also illustrate the differences in space use between sexes, which future research efforts should consider. Further research should investigate seasonal shifts in bobcat prey selection, which may further explain the seasonal resource selection shifts we observed, and highlight potential implications for prey species.


2019 ◽  
Vol 12 (1) ◽  
pp. 49-56
Author(s):  
Sulagna Dutta ◽  
Pallav Sengupta

Hamsters have unique physiological characteristics rendering them well-suited for biomedical research as experimental model. They match beneficial traits of both smaller rodents and larger mammals that make them suitable for laboratory use, such as availability, breeding ease, greater tissue proportions and the like. In experimental design, it is inevitable to select laboratory animals of accurate age that can mimic the target human age in a specific research. In this article, we have calculated that one human year equals 13.67 hamster days, considering their entire lifespan. This simplistic calculation may not find universal relevance in biomedical research, given the accelerated non-uniform life stages of hamsters when matched with human. To resolve this issue, this is the first ever article where we have provided a concise perception of hamster days in human years by correlating their age at every major life stage. This article will aid precision in biomedical research via selection of laboratory hamster of accurate age corresponding to human age, which is the most primary and essential criteria in animal based research.


2013 ◽  
Vol 40 (3) ◽  
pp. 217 ◽  
Author(s):  
Wen-Bo Yan ◽  
Zhi-Gao Zeng ◽  
Duo Pan ◽  
Tie-Jun Wang ◽  
Qiong Zhang ◽  
...  

Context Knowledge of the habitat selection of reintroduced species is crucial to successful re-establishment of viable populations and effective conservation decision-making. Aims The aim of our research was to examine habitat selection by reintroduced Eld’s deer (Cervus eldi) in a human-dominated landscape. Methods The study was conducted during the period from July 2005 to November 2007 in the Chihao region, a human-dominated area located in western Hainan Island, China. Radio-telemetry was used to monitor 15 collared deer to gain their location information. Resource selection functions were used to quantify habitat selection of the study population at the landscape and home-range scales in both wet and dry seasons. Key results At the landscape scale, Eld’s deer showed selection for habitats with scrubland, high elevation, gentle slope, close to water sources and roads. At the home-range scale, Eld’s deer showed selection for habitats with dense forest, scrubland, grassland, low elevation and far away from roads, but they randomly used habitats without special consideration to the distance to water sources. At both landscape and home-range scales, Eld’s deer showed strong avoidance of villages. In addition, Eld’s deer showed increased selection of sparse forests and decreased use of grasslands in the dry season, as compared with the wet season at both spatial scales. Sexual differences in habitat selection existed in reintroduced Eld’s deer. Males showed stronger avoidance to human disturbance, whereas females selected vegetation with higher forage availability but poor hiding cover, especially during the antler-growing period (i.e. wet season). Conclusions The habitat selection of reintroduced Eld’s deer was scale-dependent. As a non-fatal anthropogenic factor, human disturbance had a strong influence on habitat selection of Eld’s deer. They more strongly selected slope habitats at relatively high elevations. However, our results also indicated that the reintroduced Eld’s deer had certain adaptive ability and tolerance to the disturbed environment. Implications This work provides insight into the habitat selection of reintroduced Eld’s deer in a human-dominated landscape. If the essential food resources are available, the regions at a relatively high elevation with low human disturbance can be considered as potential sites of future Eld’s deer reintroduction.


Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.


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