Summer rest site selection by Appalachian eastern spotted skunks

2019 ◽  
Vol 100 (4) ◽  
pp. 1295-1304 ◽  
Author(s):  
Robin Y Y Eng ◽  
David S Jachowski

AbstractEastern spotted skunks (Spilogale putorius) have suffered a dramatic range-wide decline leading to concern that the species is likely vulnerable to extinction, but were recently discovered to persist in a portion of the southern Appalachian Mountains (United States). For 2 years we investigated habitat selection by eastern spotted skunks to develop an understanding of their habitat and conservation needs in northwestern South Carolina. We used a discrete choice modeling framework to evaluate vegetative and topographic features that we predicted would influence rest site selection by male and female spotted skunks. Using VHF telemetry, we tracked 15 spotted skunks (10 males and 5 females) to 215 day-time rest sites between the months of April and August. Spotted skunks selected rest sites in close proximity to drainage channels, where the relative probability of selection decreased 18% and 50% with every 20-m increase in distance to a drainage channel for males and females, respectively. Relative probability of selection by female spotted skunks increased 30% for every one-unit increase in coarse woody debris (CWD), and relative probability of selection by male spotted skunks increased 25% for every 10% increase in understory cover. These results are consistent with previous studies that have identified cover as important for protection from predators; however, we additionally identified CWD and drainage channels as important to habitat selection by spotted skunks. These latter attributes are likely selected based on prey availability, but alternate ecological functions of these features warrant further investigation. Preservation of understory vegetation and CWD within drainage networks might benefit conservation of eastern spotted skunks in the southern Appalachians.

Behaviour ◽  
2017 ◽  
Vol 154 (12) ◽  
pp. 1177-1196 ◽  
Author(s):  
Mallary Clay ◽  
Jim Stoeckel ◽  
Brian Helms

Environmental cues contain critical information for individuals while searching for mates and suitable habitat. Crayfish have well-developed chemosensory abilities for detecting environmental cues in water; much less is known about these abilities on land. The Devil crayfish (Cambarus diogenes) is a burrowing crayfish often found in dense floodplain colonies as adults. Juveniles however are released in surface water and must navigate overland to burrow. Previous work demonstrates juveniles use cues from conspecific adults, and to a lesser extent, soil cues, for burrow site selection. Using mesocosms, we build on this by examining burrowing cues associated with (1) congeneric adults, (2) excavated burrow material and (3) other juveniles. In contrast to conspecific adults, cues provided by congeneric adults did not override cues associated with soil type. Similarly, juveniles burrowed closer to conspecific adult burrow mounds than to congeneric and human-built mounds. Juveniles also showed significant grouping behaviour in the absence of all other cues. These results suggest juvenile crayfish integrate multiple terrestrial cues for burrow site selection.


1981 ◽  
Vol 59 (6) ◽  
pp. 1036-1039 ◽  
Author(s):  
R. Lloyd Gamble

The distribution of Mustela frenata longicauda was ascertained for Manitoba, Saskatchewan, and Alberta by examination of 91 labelled museum specimens and 186 carcasses provided by trappers from Manitoba. Collection records on site selection and distribution reaffirm the author's contention that M. frenata prefers late seral stages or ecotones in close proximity to free standing water. The transition between aspen parkland and the boreal forest or taiga is the northernmost distribution of this species in the Canadian prairies.


2011 ◽  
Vol 32 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Gerardo Leynaud ◽  
Julián Lescano ◽  
Laura Pereyra

AbstractDifferences among wetlands can have important consequences on reproductive success of amphibians; therefore habitat selection is expected to be of particular importance for anurans inhabiting heterogeneous environments. To investigate if the red-belly toad (Melanophryniscus stelzneri; Anura: Bufonidae) uses available habitats differentially and to determine the main factors influencing the use of certain water bodies as breeding habitat, we surveyed 30 spawning sites used by red-belly toads, and 30 adjacent unused sites, in an area of the Sierras of Córdoba, Argentina. We evaluated the relative importance of morphological and biotic features of ponds, and the presence of other organisms within the water body on the use of ponds as breeding sites by red-belly toads. Eight habitat variables related to important water body features were recorded and were used to fit a habitat selection model with GLM. Red-belly toads presented a positive selection to mallines, a wetland characteristic of the Sierras of Córdoba. They were associated with small, shallow ephemeral ponds with muddy banks and a high percent of vegetation cover. In general, the ponds used did not host other anuran species or potential predators. Breeding site selection by red-belly toads is largely consistent with records for other species of the genus in other parts of Argentina.


2020 ◽  
Author(s):  
Annalee M. Tutterow ◽  
Andrew S. Hoffman ◽  
John L. Buffington ◽  
Zachary T. Truelock ◽  
William E. Peterman

AbstractFood acquisition is an important modulator of animal behavior and habitat selection that can affect fitness. Optimal foraging theory predicts that predators should select habitat patches to maximize their foraging success and net energy gain, which predators can achieve by targeting spaces with high prey availability. However, it is debated whether prey availability drives fine-scale habitat selection for predators.We assessed whether an ambush predator, the timber rattlesnake (Crotalus horridus), exhibits optimal foraging site selection based on the spatial distribution and availability of prey.We evaluated the spatial concordance of radio-telemetered timber rattlesnake foraging locations and passive infrared game camera trap detections of potential small mammal prey (Peromyscus spp., Tamias striatus, and Sciurus spp.) in a mixed-use forest in southeastern Ohio from 2016–2019. We replicated a characteristic timber rattlesnake ambush position by focusing cameras over logs and modeled small mammal encounters across the landscape in relation to remotely-sensed forest and landscape structural features. To determine whether snakes selectively forage in areas with higher prey availability, we projected the estimated prey spatial relationships across the landscape and modeled their overlap of occurrence with observed timber rattlesnake foraging locations.We broadly predicted that prey availability was greatest in mature deciduous forests, but T. striatus and Sciurus spp. exhibited greater spatial heterogeneity compared to Peromyscus spp. We also combined predicted species encounter rates to encompass a body size gradient in potential prey. The spatial distribution of cumulative small mammal encounters (i.e. overall prey availability), rather than the distribution of any one species, was highly predictive of snake foraging.Timber rattlesnakes appear to select foraging locations where the probability of encountering prey is greatest. Our study provides evidence for fine-scale optimal foraging in a low-energy, ambush predator and offers new insights into drivers of snake foraging and habitat selection.


2020 ◽  
Vol 98 (11) ◽  
pp. 743-750
Author(s):  
S.D. Wallace ◽  
G.J. Forbes ◽  
J.J. Nocera

Wood Turtles (Glyptemys insculpta (Le Conte, 1830)) can use agricultural fields for basking and feeding, but hayfields can be an ecological trap due to mortality associated with agricultural machinery. It is unclear if hayfields are selected habitat or simply occur adjacent to used waterways. We sought to investigate Wood Turtle habitat selection at the third- and fourth-order scales in an agri-forested landscape and quantify food abundance (berries, fungi, and gastropods–worms) among habitat types. To quantify habitat selection by Wood Turtles, we radio-tracked 23 adults from May to November of 2018. We measured habitat features at each turtle location and three random sites within 50 m. At the third order, turtles primarily selected for edge habitat and selected hayfields over forest. At the fourth order, turtles selected for low canopy cover and presence of woody debris. Earthworms (suborder Lumbricina) were abundant within hayfields, and berries and fungi were abundant in forests. Turtles abandoned hayfields at the end of July, likely due to the emergence of food within the forest. Food availability likely influences their habitat use during the season, and hayfields provide a food source that entices Wood Turtles during the prime hay harvest period, which likely increases the risk of machinery-related mortality.


2008 ◽  
Vol 122 (1) ◽  
pp. 49 ◽  
Author(s):  
Jon R. Trapp ◽  
Paul Beier ◽  
Curt Mack ◽  
David R. Parsons ◽  
Paul C. Paquet

Because mortality of Wolves, Canis lupus, is highest during the first six months of life, den site selection may affect reproductive success of Wolf populations. We studied fine-scale denning habitat selection (within 100 m of den site) by comparing field-measured characteristics of 22 dens in Idaho, Montana, and Alberta with 22 paired random contrast locations within pack home ranges. In order of importance, Wolves denned in areas with greater canopy cover, hiding cover, herbaceous ground cover, and woody debris, and were closer to water than paired random sites. Thus Wolves may select den sites for physical protection and available water. We also studied coarse-scale denning habitat selection by comparing 35 Wolf dens with 35 paired contrast locations in Idaho, Montana, and Wyoming with respect to six remotely-sensed variables (elevation, slope, coniferous forest cover, solar radiation, distance to water, and distance to roads). Although these variables did not differ (univariate P > 0.10) between den and contrast locations, a Mahalanobis-distance model using four remotely-sensed variables (slope, elevation, coniferous forest cover, and solar radiation) suggested > 85% of dens would occur in potential denning habitat occupying < 12% of the Wolf recovery areas in the northern Rocky Mountains. This model may be useful for identifying likely den locations in areas not yet occupied by Wolves. Wolf core use areas, including den areas, showed higher intensity of use throughout the year when compared to the entire territory.


1994 ◽  
Vol 72 (8) ◽  
pp. 1416-1419 ◽  
Author(s):  
Howard J. Kilpatrick ◽  
Paul W. Rego

We monitored 20 adult fishers (8 males, 12 females) to investigate the effects of season, sex, and site availability on rest-site selection by fishers at the southern extent of their range. Data on rest-site locations (n = 219) and random sites (n = 194) were collected from December 1989 through February 1991. Fishers rested in hardwood, softwood, and mixedwood forest types in proportion to their availability in summer; however, hardwoods were used less than expected in winter. Fishers used nests, cavities, and burrows in proportion to their availability in winter. In summer, however, nests were selected twice as often as expected, cavities were used less than expected, and burrows were not used. Male fishers tended to use larger cavity trees and mixed forest stands more often than females did. In winter, fishers were not restricted to coniferous forest types, as occurs at the northern extent of their range, because moderate snow depths did not restrict movement and prey may have been more available in other forest types. Fishers appeared to select rest-site types most suitable for thermoregulation and obtaining prey. Trees with diameter at breast height ≥ 32 cm may provide cavities for rest sites in hardwood-dominated forests.


Waterbirds ◽  
2021 ◽  
Vol 43 (3-4) ◽  
Author(s):  
Catherine E. Ricketts ◽  
Elizabeth Kurimo-Beechuk ◽  
William E. Mills ◽  
Robert J. Cooper ◽  
Sara H. Schweitzer ◽  
...  

The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Andrew N Stillman ◽  
Rodney B Siegel ◽  
Robert L Wilkerson ◽  
Matthew Johnson ◽  
Christine A Howell ◽  
...  

Abstract Recently burned coniferous forests host wildlife communities that respond to variation in burn severity, post-fire habitat structure, and patch configuration. Habitat selection theory predicts that birds inhabiting these variable post-fire landscapes will select nesting locations that confer an adaptive advantage through increased fitness and reproductive success. Understanding the effect of post-fire habitat on avian nesting ecology can provide valuable information to guide restoration and management after wildfire. The Black-backed Woodpecker (Picoides arcticus) is strongly associated with recently burned forests in the western United States, where it is used as an indicator species for the effects of post-fire forest management. Between 2011 and 2018, we located and monitored 118 Black-backed Woodpecker nests in burned forests of northern California. We evaluated the influence of habitat and nest characteristics on nest site selection and daily nest survival. Our results demonstrate a pattern of neutral congruence between habitat selection and fitness. Black-backed Woodpeckers showed strong selection for each of the nest habitat variables that we measured: woodpeckers selected moderately sized trees in areas of high snag density burned at high severity, but also in areas relatively close to low-severity or unburned edges. However, only nest initiation date affected nest survival, with decreased survival in late-season nests. Our results suggest that management actions aimed at maintaining breeding habitat for Black-backed Woodpeckers should prioritize retention and creation of pyrodiverse landscapes that include dense stands of snags (>5 snags per 100 m2) within ~500 m of forest that burned at low severity or remained unburned.


2021 ◽  
Vol 25 (9) ◽  
pp. 5315-5336
Author(s):  
Mohamad El Gharamti ◽  
James L. McCreight ◽  
Seong Jin Noh ◽  
Timothy J. Hoar ◽  
Arezoo RafieeiNasab ◽  
...  

Abstract. Predicting major floods during extreme rainfall events remains an important challenge. Rapid changes in flows over short timescales, combined with multiple sources of model error, makes it difficult to accurately simulate intense floods. This study presents a general data assimilation framework that aims to improve flood predictions in channel routing models. Hurricane Florence, which caused catastrophic flooding and damages in the Carolinas in September 2018, is used as a case study. The National Water Model (NWM) configuration of the WRF-Hydro modeling framework is interfaced with the Data Assimilation Research Testbed (DART) to produce ensemble streamflow forecasts and analyses. Instantaneous streamflow observations from 107 United States Geological Survey (USGS) gauges are assimilated for a period of 1 month. The data assimilation (DA) system developed in this paper explores two novel contributions, namely (1) along-the-stream (ATS) covariance localization and (2) spatially and temporally varying adaptive covariance inflation. ATS localization aims to mitigate not only spurious correlations, due to limited ensemble size, but also physically incorrect correlations between unconnected and indirectly connected state variables in the river network. We demonstrate that ATS localization provides improved information propagation during the model update. Adaptive prior inflation is used to tackle errors in the prior, including large model biases which often occur in flooding situations. Analysis errors incurred during the update are addressed using posterior inflation. Results show that ATS localization is a crucial ingredient of our hydrologic DA system, providing at least 40 % more accurate (root mean square error) streamflow estimates than regular, Euclidean distance-based localization. An assessment of hydrographs indicates that adaptive inflation is extremely useful and perhaps indispensable for improving the forecast skill during flooding events with significant model errors. We argue that adaptive prior inflation is able to serve as a vigorous bias correction scheme which varies both spatially and temporally. Major improvements over the model's severely underestimated streamflow estimates are suggested along the Pee Dee River in South Carolina, and many other locations in the domain, where inflation is able to avoid filter divergence and, thereby, assimilate significantly more observations.


Sign in / Sign up

Export Citation Format

Share Document