Swift Foxes and Ideal Free Distribution: Relative Influence of Vegetation and Rodent Prey Base on Swift Fox Survival, Density, and Home Range Size

Swift foxes (Vulpes velox) are an endemic mesocarnivore of North America subject to resource and predation-based pressures. While swift fox demographics have been documented, there is little information on the importance of top-down versus bottom-up pressures or the effect of landscape heterogeneity. Using a consumable resource-based ideal free distribution model as a conceptual framework, we isolated the effects of resource-based habitat selection on fox population ecology. We hypothesized if swift fox ecology is predominantly resource dependant, distribution, survival, and space use would match predictions made under ideal free distribution theory. We monitored survival and home range use of 47 swift foxes in southeastern Colorado from 2001 to 2004. Annual home range size was 15.4 km2, and seasonal home range size was 10.1 km2. At the individual level, annual home range size was unrelated to survival. Estimates of fox density ranged from 0.03 to 0.18 foxes/km2. Seasonal survival rates were 0.73 and 1.0 and did not differ seasonally. Foxes conformed to the predictions of the ideal free distribution model during winter, indicating foxes are food stressed and their behavior governed by resource acquisition. During the rest of the year, behavior was not resource driven and was governed by security from intraguild predation.

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Could a rabies incursion spread in the northern Australian dingo population? Development of a spatial stochastic simulation model

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009124 ◽

2021 ◽

Vol 15 (2) ◽

pp. e0009124

Author(s):

Vanessa Gabriele-Rivet ◽

Michael P. Ward ◽

Julie Arsenault ◽

David London ◽

Victoria J. Brookes

Keyword(s):

Home Range ◽

Landscape Heterogeneity ◽

Indigenous Communities ◽

Home Range Size ◽

Range Size ◽

Domestic Dog ◽

Sensitivity Analyses ◽

Northern Australia ◽

Spread Model ◽

Increased Risk

Australia, home to the iconic dingo, is currently free from canine rabies. However northern Australia, including Indigenous communities with large free-roaming domestic dog populations, is at increased risk of rabies incursion from nearby Indonesia. We developed a novel agent-based stochastic spatial rabies spread model to evaluate the potential spread of rabies within the dingo population of the Northern Peninsula Area (NPA) region of northern Australia. The model incorporated spatio-temporal features specific to this host-environment system, including landscape heterogeneity, demographic fluctuations, dispersal movements and dingo ecological parameters—such as home range size and density—derived from NPA field studies. Rabies spread between dingo packs in nearly 60% of simulations. In such situations rabies would affect a median of 22 dingoes (approximately 14% of the population; 2.5–97.5 percentiles: 2–101 dingoes) within the study area which covered 1,131 km2, and spread 0.52 km/week for 191 days. Larger outbreaks occurred in scenarios in which an incursion was introduced during the dry season (vs. wet season), and close to communities (vs. areas with high risk of interaction between dingoes and hunting community dogs). Sensitivity analyses revealed that home range size and duration of infectious clinical period contributed most to the variance of outputs. Although conditions in the NPA would most likely not support a sustained propagation of the disease in the dingo population, due to the predicted number of infected dingoes following a rabies incursion and the proximity of Indigenous communities to dingo habitat, we conclude that the risk for human transmission could be substantial.

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Swift fox (Vulpes velox) home-range dispersion patterns in southeastern Wyoming

Canadian Journal of Zoology ◽

10.1139/z02-180 ◽

2002 ◽

Vol 80 (11) ◽

pp. 2024-2029 ◽

Cited By ~ 3

Author(s):

Travis L Olson ◽

Frederick G Lindzey

Keyword(s):

Home Range ◽

Home Range Size ◽

Geographic Range ◽

Range Size ◽

Home Ranges ◽

Vulpes Velox ◽

Swift Fox ◽

Dispersion Patterns ◽

Range Overlap ◽

Grassland Habitats

We monitored dispersion patterns of swift foxes (Vulpes velox) for 3 years in shrub-grassland habitats on the margin of the species' geographic range near Medicine Bow, Wyoming. Annual home-range size was 18.6 ± 1.6 km2 (mean ± SE, n = 13) and was similar to home-range estimates reported in other studies conducted within grassland habitats in other portions of the species' geographic range. Male home ranges were larger than those of their mates during pup-rearing periods (P < 0.04) but were similar in size during the dispersal period. The home ranges of both sexes were smallest during the pup-rearing period. The degree of home-range overlap for mates (biological periods combined) was high (range = 27.4100%, mean ± SE = 70.8 ± 0.03%, n = 26 pairs) but was minimal between adjacent pairs (range = 0.236%, mean ± SE = 11.9 ± 2.4%, n = 10 pairs), suggesting territorial behavior. Occupied home ranges were distributed similarly each year despite one or both pair members often being new. Swift fox home-range size varied seasonally, and home-range dispersion patterns appeared to be influenced by the presence of other fox pairs and the recent use of an area by other swift foxes.

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The generalized ideal free distribution model: Merging current ideal free distribution models into a central framework

Ecological Modelling ◽

10.1016/j.ecolmodel.2019.01.008 ◽

2019 ◽

Vol 397 ◽

pp. 47-54 ◽

Cited By ~ 2

Author(s):

Jorge F.S. Menezes ◽

Burt P. Kotler

Keyword(s):

Ideal Free Distribution ◽

Distribution Model ◽

Distribution Models ◽

Free Distribution ◽

Model Merging ◽

Ideal Free

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Density-dependent habitat selection in muskrats: a test of the ideal free distribution model

Oecologia ◽

10.1007/bf00329763 ◽

1990 ◽

Vol 84 (3) ◽

pp. 380-385 ◽

Cited By ~ 37

Author(s):

F. Messier ◽

J. A. Virgl ◽

L. Marinelli

Keyword(s):

Habitat Selection ◽

Ideal Free Distribution ◽

Distribution Model ◽

Density Dependent ◽

Free Distribution ◽

Density Dependent Habitat Selection ◽

Ideal Free ◽

The Ideal

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Home range size and resource use by swift foxes in northeastern Montana

Journal of Mammalogy ◽

10.1093/jmammal/gyaa030 ◽

2020 ◽

Vol 101 (3) ◽

pp. 684-696 ◽

Cited By ~ 1

Author(s):

Andrew R Butler ◽

Kristy L S Bly ◽

Heather Harris ◽

Robert M Inman ◽

Axel Moehrenschlager ◽

...

Keyword(s):

Home Range ◽

Great Plains ◽

Resource Use ◽

Vegetation Index ◽

Home Range Size ◽

Range Size ◽

Border Region ◽

Anthropogenic Factors ◽

Home Ranges ◽

Swift Fox

Abstract Swift foxes (Vulpes velox) are endemic to the Great Plains of North America, but were extirpated from the northern portion of their range by the mid-1900s. Despite several reintroductions to the Northern Great Plains, there remains a ~350 km range gap between the swift fox population along the Montana and Canada border and that in northeastern Wyoming and northwestern South Dakota. A better understanding of what resources swift foxes use along the Montana and Canada border region will assist managers to facilitate connectivity among populations. From 2016 to 2018, we estimated the home range size and evaluated resource use within the home ranges of 22 swift foxes equipped with Global Positioning System tracking collars in northeastern Montana. Swift fox home ranges in our study were some of the largest ever recorded, averaging (± SE) 42.0 km2 ± 4.7. Our results indicate that both environmental and anthropogenic factors influenced resource use. At the population level, resource use increased by 3.3% for every 5.0% increase in percent grasslands. Relative probability of use decreased by 7.9% and 7.4% for every kilometer away from unpaved roads and gas well sites, respectively, and decreased by 3.0% and 11.3% for every one-unit increase in topographic roughness and every 0.05 increase in normalized difference vegetation index (NDVI), respectively. Our study suggests that, to reestablish connectivity among swift fox populations in Montana, managers should aim to maintain large corridors of contiguous grasslands at a landscape scale, a process that likely will require having to work with multiple property owners.

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An experimental investigation of a new ideal free distribution model

Evolutionary Ecology ◽

10.1007/bf01239345 ◽

1996 ◽

Vol 10 (1) ◽

pp. 45-49 ◽

Cited By ~ 8

Author(s):

Tom Tregenza ◽

Judith J. Shaw ◽

David J. Thompson

Keyword(s):

Experimental Investigation ◽

Ideal Free Distribution ◽

Distribution Model ◽

Free Distribution ◽

Ideal Free

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Effects of food and oxygen availability on habitat selection by guppies in a laboratory environment

Canadian Journal of Zoology ◽

10.1139/z86-014 ◽

1986 ◽

Vol 64 (1) ◽

pp. 88-93 ◽

Cited By ~ 23

Author(s):

André J. Talbot ◽

Donald L. Kramer

Keyword(s):

Food Supply ◽

Poecilia Reticulata ◽

Ideal Free Distribution ◽

Oxygen Availability ◽

Distribution Model ◽

Oxygen Effect ◽

Potential Cost ◽

Free Distribution ◽

Ideal Free ◽

The Ideal

Using the ideal free distribution model proposed in 1970 by S. D. Fretwell and H. L. Lucas, we investigated how local food and oxygen availability influenced the distribution of a group of guppies (Poecilia reticulata, Teleostei, Poeciliidae) among five habitats in a large tank. Our study differed from previous investigations of ideal free distributions in the larger number of habitats available, the presence of resource-free zones between habitats, the visual isolation of the different habitats, the availability of resources over an entire day rather than a short feeding period, and the systematic variation of a potential cost component (low oxygen). In our system, the ideal free distribution model was a poor predictor of fish distributions. Although the proportion of fish in a habitat was positively correlated with food supply, there were too few fish where the food supply was high and too many fish where the food supply was low to equalize average feeding rates in all habitats. The proportion of fish in a habitat was not affected by oxygen concentration, whether food was limited or superabundant. Large, stable differences in density occurred between habitats receiving identical treatments. Time spent by the fish in sampling alternative habitats and the ease with which some individuals could restrict the access of others to the habitats may have contributed to the failure of the ideal free distribution model. The effectiveness with which guppies use the surface film for respiration under hypoxic conditions may explain the lack of a dissolved oxygen effect. Our study demonstrates the need to understand conditions that promote or hinder the appearance of ideal free distributions before they can be used to predict the relationship between animal density and resource availability in nature.

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Space use in free-ranging canids: are gonadal hormones required for territory maintenance?

Canadian Journal of Zoology ◽

10.1139/cjz-2021-0085 ◽

2021 ◽

Vol 99 (10) ◽

pp. 939-947

Author(s):

Eric M. Gese ◽

Patricia A. Terletzky

Keyword(s):

Home Range ◽

Survival Rates ◽

Space Use ◽

Fertility Control ◽

Home Range Size ◽

Gonadal Hormones ◽

Range Size ◽

Annual Survival ◽

Range Overlap ◽

Free Ranging

Fertility control among carnivores has been used to reduce depredations on livestock and wild neonates, population control, modify behavior, inhibit genetic introgression, and reduce human–wildlife conflicts. Although there is considerable knowledge on techniques to sterilize carnivores, there is little information concerning how the absence of gonadal hormones influences behavior, space use, and survival of wild canids. We examined territorial fidelity, home-range size and overlap, and survival of 179 surgically sterilized free-ranging canids (124 coyotes (Canis latrans Say, 1823), 55 coyote – red wolf (Canis rufus Audubon and Bachman, 1851) hybrids) with gonadal hormones present (tubal-ligated females (n = 70), vasectomized males (n = 73)) versus absent (spayed females (n = 22), neutered males (n = 14)). The absence of gonadal hormones did not influence annual home-range size and home-range overlap, territory fidelity, and annual survival rates. Additionally, no differences were detected across sexes and hormonal treatments in annual home-range size, percent home-range overlap, annual home-range residency rates, and annual survival rates. Methods of fertility control that do not keep gonadal organs intact may prove useful for management without concern for changes in behavior, mainly territoriality, space use, and survival.

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