Spatial organization of a lynx population

1995 ◽  
Vol 73 (4) ◽  
pp. 632-641 ◽  
Author(s):  
Kim G. Poole

I examined the home-range relationships and spatial organization of an untrapped lynx (Lynx canadensis) population in the southern Northwest Territories, Canada. I determined annual home ranges and static and dynamic interactions among 30 radio-collared adult lynx from April 1989 to April 1993. Densities of snowshoe hares (Lepus americanus), the main prey, declined during winter 1990–1991. There was extensive range overlap between sexes, and between certain pairs of female lynx. Ranges among most males and among other individual or pairs of females were more exclusive. Most intrasexual dynamic interactions indicated neither attraction nor avoidance, suggesting that home-range boundaries were maintained by passive means. Two male–female pairs showed some positive attraction during the early part of the first winter of low hare density. Home ranges of three male and three female lynx monitored for 3 consecutive years were stable. Spatial organization broke down during winter 1991 – 1992, when all resident lynx died or dispersed; this was concomitant with the first full winter of low hare density. Spatial organization observed prior to low hare densities may be described as a land-tenure system, based on prior residency, and may have served to regulate the density of this untrapped population during peak prey levels.

1997 ◽  
Vol 243 (1) ◽  
pp. 163-189 ◽  
Author(s):  
P. Ferreras ◽  
J. F. Beltrán ◽  
J. J. Aldama ◽  
M. Delibes

1992 ◽  
Vol 70 (8) ◽  
pp. 1614-1621 ◽  
Author(s):  
Robert J. Small ◽  
Lloyd B. Keith

We tested the relative vulnerability of arctic (Lepus arcticus) and snowshoe (Lepus americanus) hares to predation by red foxes (Vulpes vulpes) in experimental trials on three islands off Newfoundland's southwest coast. Arctic hares were significantly more vulnerable than snowshoe hares to fox predation: they were killed at a higher rate, and though the probability of death increased slightly for arctic hares over a trial period, it decreased for snowshoe hares. Rates of fox predation on arctic hares were inversely related to home-range size and nutritional status, whereas predation on snowshoe hares was inversely related to the percentage of home-range core areas with dense understory cover. We believe the arctic hare's greater vulnerability to fox predation, found in this study, coupled with its apparent inability to utilize food resources in forested areas that support snowshoe hares, which we found in an earlier study, largely accounts for the current restriction of arctic hares in Newfoundland to certain mountain and coastal barrens. The status of arctic hare populations before the introduction of snowshoe hares is unclear. However, distribution and abundance likely decreased as red foxes and lynx (Lynx canadensis) increased and began to cycle with snowshoe hares. Dispersal of foxes, and perhaps of lynx, from forested areas following snowshoe hare declines would have periodically intensified predation on the barrens.


1994 ◽  
Vol 72 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Christine R. Maher

Pronghorn (Antilocapra americana) vary in spatial organization. A literature review revealed that males occupied undefended home ranges in 12 populations and maintained territories in 11 populations. Low-productivity habitats and high or low population density could preclude territoriality. Using activity budgets, interaction rates, and home-range overlap, male social organization was described for a translocated pronghorn population in central California and compared with that of another population studied at Sheldon National Wildlife Refuge, Nevada, to determine if males were organized differently. Interaction rates were highest during spring, decreased in summer, then increased in late summer coincident with the rut. Home-range overlap ranged from 0 to 85% and averaged 30.6%; small amounts of overlap resulted from geographical features rather than from behavioral interactions. Males joined groups of females and fawns during summer; few behavior patterns associated with territoriality were observed. Males occupied undefended home ranges and this spacing system may have been influenced by food abundance and distribution, population density, or a combination of these factors. Comparisons between Sheldon and Carrizo males indicated that, while neither population was territorial, the behavior of Sheldon males was closer to the territoriality end of a continuum between territoriality and undefended home range than was that of Carrizo males. Behavior patterns were very similar between the populations but some occurred more frequently among Sheldon males. Both populations lived in semi-arid habitats, where low primary productivity would make the costs of maintaining territories greater than the benefits. Differences between the populations could be based on differences in population density. The Carrizo population was small and widely dispersed and male–male competition appeared low; therefore, the opportunity to interact with other males was lower than in areas of higher population density. Comparisons with other populations were difficult to make because of a lack of quantified data on behavioral and ecological variables. Such data are required if more is to be learned about the effects of ecology and demography on social organization.


Author(s):  
Justin M. Calabrese ◽  
Christen H. Fleming ◽  
Michael J. Noonan ◽  
Xianghui Dong

ABSTRACTEstimating animal home ranges is a primary purpose of collecting tracking data. All conventional home range estimators in widespread usage, including minimum convex polygons and kernel density estimators, assume independently sampled data. In stark contrast, modern GPS animal tracking datasets are almost always strongly autocorrelated. This incongruence between estimator assumptions and empirical reality leads to systematically underestimated home ranges. Autocorrelated kernel density estimation (AKDE) resolves this conflict by modeling the observed autocorrelation structure of tracking data during home range estimation, and has been shown to perform accurately across a broad range of tracking datasets. However, compared to conventional estimators, AKDE requires additional modeling steps and has heretofore only been accessible via the command-line ctmm R package. Here, we introduce ctmmweb, which provides a point-and-click graphical interface to ctmm, and streamlines AKDE, its prerequisite autocorrelation modeling steps, and a number of additional movement analyses. We demonstrate ctmmweb’s capabilities, including AKDE home range estimation and subsequent home range overlap analysis, on a dataset of four jaguars from the Brazilian Pantanal. We intend ctmmweb to open AKDE and related autocorrelation-explicit analyses to a wider audience of wildlife and conservation professionals.


1985 ◽  
Vol 63 (12) ◽  
pp. 2817-2824 ◽  
Author(s):  
Richard M. P. Ward ◽  
Charles J. Krebs

The behavioural responses of lynx (Lynx canadensis) to declines in snowshoe hare (Lepus americanus) abundance were examined in the southwestern Yukon. Between April 1982 and June 1984, 11 lynx were radio tagged and monitored in and near the Kluane Game Sanctuary. Lynx home range size increased from 13.2 to 39.2 km2 concurrent with a decline in snowshoe hare abundance from 14.7 to 0.2 hares/ha. Below about 0.5 hares/ha, several lynx abandoned their home ranges and became nomadic, although they remained within the general study area. Lynx concentrated their foraging efforts in areas of relatively high snowshoe hare abundance and abandoned these areas after hares declined. Straight-line daily travel distance remained constant at 2.2−2.7 km/day above 1.0 hare/ha. Below 1.0 hares/ha, straight-line daily travel distances increased rapidly, reaching 5.5 km/day at 0.2 hares/ha. Three of seven radio-tagged lynx dispersed 250 km or more from the study area during the 1982 period of rapid hare decline. No similar long-distance emigrations were recorded after hare densities stabilized at less than 1.0 hares/ha. Trapping mortality was responsible for the loss of seven of nine radio-tagged lynx that travelled outside the game sanctuary. One lynx probably starved during the winter or spring of 1984. The high rate of trapping mortality outside the game sanctuary suggests that refugia in wilderness areas are important in maintaining lynx populations during periods of low recruitment.


2002 ◽  
Vol 80 (11) ◽  
pp. 2024-2029 ◽  
Author(s):  
Travis L Olson ◽  
Frederick G Lindzey

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 = 27.4–100%, mean ± SE = 70.8 ± 0.03%, n = 26 pairs) but was minimal between adjacent pairs (range = 0.2–36%, 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.


2006 ◽  
Vol 84 (3) ◽  
pp. 404-411 ◽  
Author(s):  
A J Edelman ◽  
J L Koprowski

We compared home ranges of introduced Abert's squirrels (Sciurus aberti Woodhouse, 1853) in mixed-conifer forests of Arizona during non-mating and mating seasons. Because Abert's squirrels are reported to depend on ponderosa pine (Pinus ponderosa P. & C. Lawson) forests, the mixed-conifer forest in our study represented a novel habitat. Home-range size, home-range overlap with females, and movement distances increased for males from non-mating to mating seasons. Home-range size and overlap characteristics of females remained consistent between seasons, but movement distances were reduced during the mating season. Males probably increased home-range size, home-range overlap with females, and movement distances during the mating season to maximize contact with scarce females. Home-range size and overlap characteristics of female Abert's squirrels likely remained stable between seasons because females do not search for mates. Restricted movements by females during the mating season may be due to changes in resource use in preparation for reproduction. Non-mating season home ranges in our study were smaller than home ranges observed in ponderosa pine forest. Abert's squirrels in mixed-conifer forest may have small home ranges because resource quality is higher than in ponderosa pine forest or competition for space with co-occurring Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis (J.A. Allen, 1894)).


1993 ◽  
Vol 71 (5) ◽  
pp. 869-875 ◽  
Author(s):  
Lui Marinelli ◽  
François Messier

We investigated the space-use patterns of adult muskrats in a small (77 ha) marsh on the Canadian Prairies during two breeding seasons. During the study, population size was relatively low and the adult sex ratio was biased towards females. Adult muskrats were territorial with little intrasexual home-range overlap. The exclusivity of home ranges was maintained throughout the breeding season, and appeared to decrease at the end of the season. Male movements often extended over the territory of more than one female, but the overlap was more extensive with primary than with secondary females. Lactation appeared to reduce the space use and mobility of female muskrats. Male muskrats tended to range over smaller areas when weaned young were present within their home range. The results suggest that the sexual pair is the basic social unit of muskrats but that polygyny was common. A female-biased sex ratio appeared to be responsible for the tendency of males to mate polygynously during this study, thus illustrating the plasticity of this social system.


2000 ◽  
Vol 78 (12) ◽  
pp. 2087-2095 ◽  
Author(s):  
Michael J Chamberlain ◽  
Charles D Lovell ◽  
Bruce D Leopold

Recently, coyotes (Canis latrans) have expanded their range to include most areas of the southeastern United States. However, most research on coyotes has been conducted in western and northern regions of North America. We radio-monitored 38 adult coyotes from 1993 to 1997 in central Mississippi. Home-range sizes (P = 0.681) and core-area (area of concentrated use) sizes (P = 0.736) were similar across seasons, but females maintained larger home ranges (P = 0.006) and core areas (P < 0.001) than males. Male-male, female-female, and male-female home-range overlap was greatest during whelping and pup rearing. Except for mated pairs, core-area overlap was negligible across all seasons for adults maintaining neighboring home ranges. Coyote habitat selection varied across spatial scales, though selection was similar between males and females at all scales. Coyote movement rates differed (P < 0.001) temporally, being highest during nocturnal periods. Overall, the highest movement rates for the monitored population were observed for females during summer. Two males and 2 females were suspected of forming pair bonds and frequently traveled together within shared home ranges, as did 2 adult males. Our data indicate that interactions among individual adults are influenced by sex, as most confirmed instances of direct contact occurred between pairs or suspected social groups. In our study area, neighboring adult coyotes exhibited territoriality at the core-area level.


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