scholarly journals Evaluation of Habitat Characteristics and the Appropriate Scale for Evaluating Diurnal Habitat Selection of Wintering American Woodcock in Louisiana

2019 ◽  
Vol 30 (6) ◽  
pp. 1725-1733 ◽  
Author(s):  
Antoine Duparc ◽  
Mathieu Garel ◽  
Pascal Marchand ◽  
Dominique Dubray ◽  
Daniel Maillard ◽  
...  

Abstract Most habitats are distributed heterogeneously in space, forcing animals to move according to both habitat characteristics and their needs for energy and safety. Animal space use should therefore vary according to habitat characteristics, a process known as the “functional response” in habitat selection. This response has often been tested vis-à-vis the proportion of a habitat category within areas available to individuals. Measuring sought-after resources in landscape where they are continuously distributed is a challenge and we posit here that both the mean availability of a resource and its spatial variation should be measured. Accordingly, we tested for a functional response in habitat selection according to these two descriptors of the resource available for a mountain herbivore. We hypothesized that selection should decrease with mean value of resources available and increase with its spatial variation. Based on GPS data from 50 chamois females and data on the actual foodscape (i.e., distribution of edible-only biomass in the landscape), we estimated individual selection ratio (during summer months) for biomass at the home range level, comparing edible biomass in individual home ranges and the mean and standard deviation of edible biomass in their available range. Chamois being a group-living species, available accessible ranges were shared by several individuals that formed socio-spatial groups (clusters) in the population. As expected, selection ratios increased with the standard deviation of edible resources in each cluster, but unlike our prediction, was unrelated to its mean. Selection of areas richer in resources hence did not fade away when more resources were available on average, a result that may be explained by the need for this capital breeder species to accumulate fat-reserve at a high rate during summer months. Low spatial variation could limit the selection of chamois, which highlights the importance of resource distribution in the process of habitat selection.


Author(s):  
Fabian Gaston Jara

The selection of breeding habitat is crucial for many ectotherms inhabiting aquatic environments. Giant water bugs offer an excellent model for analysis of how temperature affects breeding habitat selection and reproductive success. This work focuses on whether wetland temperature influences habitat selection and offspring success in the giant water bug Belostoma bifoveolatum Spinola 1852. To determine B. bifoveolatum breeding habitat characteristics, twenty-one wetlands lying on the environmental gradients of canopy cover and altitude were sampled in spring; water temperature was monitored and the presence or absence of adult belostomatids, incubating males, and nymphs were recorded. Several environmental variables were measured in sites where males incubated eggs, and compared with control sites. Field experiments were also conducted to evaluate the effect of site choice on hatching success. B. bifoveolatum Spinola 1852 was found up to 1545 m a.s.l. but reproduction was observed only in the warmest temporary wetlands, with low forest cover, from 300-1000 m a.s.l. Incubating males were found in the shallowest and warmest sites within the wetlands, where egg incubation time was shortest and hatching success highest. The selection of breeding habitat and incubation site, along with parental care, constitute important adaptations in B. bifoveolatum, and could explain its success in this cold region.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexis Grenier-Potvin ◽  
Jeanne Clermont ◽  
Gilles Gauthier ◽  
Dominique Berteaux

Abstract Background Movements and habitat selection of predators shape ecological communities by determining the spatiotemporal distribution of predation risk. Although intraspecific interactions associated to territoriality and parental care are involved in predator habitat selection, few studies have addressed their effects simultaneously with those of prey and habitat distribution. Moreover, individuals require behavioural and temporal flexibility in their movement decisions to meet various motivations in a heterogeneous environment. To untangle the relative importance of ecological determinants of predator fine-scale habitat selection, we studied simultaneously several spatial, temporal, and behavioural predictors of habitat selection in territorial arctic foxes (Vulpes lagopus) living within a Greater snow goose (Anser caerulescens atlantica) colony during the reproductive season. Methods Using GPS locations collected at 4-min intervals and behavioural state classification (active and resting), we quantified how foxes modulate state-specific habitat selection in response to territory edges, den proximity, prey distribution, and habitats. We also assessed whether foxes varied their habitat selection in response to an important phenological transition marked by decreasing prey availability (goose egg hatching) and decreasing den dependency (emancipation of cubs). Results Multiple factors simultaneously played a key role in driving habitat selection, and their relative strength differed with respect to the behavioural state and study period. Foxes avoided territory edges, and reproductive individuals selected den proximity before the phenological transition. Higher goose nest density was selected when foxes were active but avoided when resting, and was less selected after egg hatching. Selection for tundra habitats also varied through the summer, but effects were not consistent. Conclusions We conclude that constraints imposed by intraspecific interactions can play, relative to prey distribution and habitat characteristics, an important role in the habitat selection of a keystone predator. Our results highlight the benefits of considering behavioural state and seasonal phenology when assessing the flexibility of predator habitat selection. Our findings indicate that considering intraspecific interactions is essential to understand predator space use, and suggest that using predator habitat selection to advance community ecology requires an explicit assessment of the social context in which movements occur.


2003 ◽  
Vol 9 (1) ◽  
pp. 141-153 ◽  
Author(s):  
Mayumi Sakuragi ◽  
Hiromasa Igota ◽  
Hiroyuki Uno ◽  
Koichi Kaji ◽  
Masami Kaneko ◽  
...  

Paléorient ◽  
1981 ◽  
Vol 7 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Amiel Brosh ◽  
M. Ohel

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2454
Author(s):  
Yue Sun ◽  
Yanze Yu ◽  
Jinhao Guo ◽  
Minghai Zhang

Single-scale frameworks are often used to analyze the habitat selections of species. Research on habitat selection can be significantly improved using multi-scale models that enable greater in-depth analyses of the scale dependence between species and specific environmental factors. In this study, the winter habitat selection of red deer in the Gogostaihanwula Nature Reserve, Inner Mongolia, was studied using a multi-scale model. Each selected covariate was included in multi-scale models at their “characteristic scale”, and we used an all subsets approach and model selection framework to assess habitat selection. The results showed that: (1) Univariate logistic regression analysis showed that the response scale of red deer to environmental factors was different among different covariate. The optimal scale of the single covariate was 800–3200 m, slope (SLP), altitude (ELE), and ratio of deciduous broad-leaved forests were 800 m in large scale, except that the farmland ratio was 200 m in fine scale. The optimal scale of road density and grassland ratio is both 1600 m, and the optimal scale of net forest production capacity is 3200 m; (2) distance to forest edges, distance to cement roads, distance to villages, altitude, distance to all road, and slope of the region were the most important factors affecting winter habitat selection. The outcomes of this study indicate that future studies on the effectiveness of habitat selections will benefit from multi-scale models. In addition to increasing interpretive and predictive capabilities, multi-scale habitat selection models enhance our understanding of how species respond to their environments and contribute to the formulation of effective conservation and management strategies for ungulata.


2019 ◽  
Vol 98 ◽  
pp. 111-118
Author(s):  
Samukelisiwe P. Ngcobo ◽  
Amy-Leigh Wilson ◽  
Colleen T. Downs

Author(s):  
Svein Dale

AbstractIn boreal forests, food supplies typically have cyclic variations, and many species here fluctuate in numbers from year to year. One group of species showing large variations in population size is birds specialized on seeds from masting trees. Here, I analyze spatial patterns of a mass occurrence and habitat selection of the Common Redpoll (Carduelis flammea) during the breeding season in southeastern Norway in 2020 after a year with large seed crops from Norway Spruce (Picea abies) and Downy Birch (Betula pubescens). I found that Common Redpoll numbers increased with elevation and towards the northwest. Numbers were also strongly and positively correlated with snow depth in early April when snow was present mainly above 400 m elevation. Sites with snow cover in early April (30% of all sites) held 96.4% of all individuals recorded. Field observations indicated that Common Redpolls foraged extensively for spruce seeds on the snow until the end of May when young were independent. I suggest that the mass occurrence was due to a unique combination of exceptionally large seed crops of two tree species coinciding in the same year. The masting produced large amounts of food both for overwintering (birch seeds) and for breeding (spruce seeds), and during the breeding season snow cover facilitated access to food resources. Dependency of Common Redpolls on snow cover suggests that climate change may negatively impact some seed-eaters in boreal regions. On the other hand, higher temperatures may induce more frequent masting which may be beneficial for seed-eaters. Thus, climate change is likely to lead to complex ecosystem changes in areas where snow cover may disappear.


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