The fine structure of home ranges of male Chelydra serpentina: are snapping turtles territorial?

1987 ◽  
Vol 65 (11) ◽  
pp. 2623-2629 ◽  
Author(s):  
David A. Galbraith ◽  
Mark W. Chandler ◽  
Ronald J. Brooks
Keyword(s):  
Home Ranges ◽  
Chelydra Serpentina ◽  
Intraspecific Aggression ◽  
Aggressive Interactions ◽  
Lake Algonquin ◽  
Snapping Turtles ◽  
Intensive Use ◽  
Core Areas ◽  
One Year ◽  
Average Size

Four male snapping turtles (Chelydra serpentina) were located by radiotelemetry during the summers of 1985 and 1986 in 5.5-ha Broadwing Lake, Algonquin Park, Ontario. We measured sizes and overlaps of home ranges and core areas. Average size of home range did not differ greatly between years, and location of individual home ranges remained stable from one year to the next in two of three turtles studied both years. Within individual home ranges, the distribution of locations of most turtles was aggregated, but was not significantly different from Poisson distributions. Home ranges overlapped, but the proportion of areas used intensively by individuals was not different in overlapping and nonoverlapping areas, indicating that the areas of intensive use were not exclusive. However, the turtles spaced themselves farther apart than expected from the geometry of the home ranges, possibly the result of intraspecific aggression. If territory is defined as a fixed, exclusive, defended area, then male snapping turtles are not territorial during the summer, but occupy relatively stable home ranges which overlap, and whose spacing may in part be determined by aggressive interactions.

Influence of land development on home range use dynamics of female elk

2011 ◽  
Vol 38 (2) ◽  
pp. 163 ◽  
Author(s):  
S. L. Webb ◽  
M. R. Dzialak ◽  
S. M. Harju ◽  
L. D. Hayden-Wing ◽  
J. B. Winstead
Keyword(s):  
Cervus Elaphus ◽  
Site Fidelity ◽  
Forest Cover ◽  
Land Development ◽  
Home Ranges ◽  
Gps Collars ◽  
Range Use ◽  
Adaptive Kernel ◽  
Core Areas ◽  
One Year

Context Many ungulate species exhibit strong site fidelity to previously established areas, particularly females. However, development of the landscape may cause animals to shift their distribution to more secure areas. Aims To determine range use dynamics (i.e. size and overlap of core areas and home ranges) of female elk (Cervus elaphus) relative to land development features (e.g. roads, well pads, buildings, developments, towns, etc.) after controlling for environmental features (i.e. forest cover). Methods During the four-year study, we fitted elk (n = 165) with GPS collars annually and programmed collars to attempt one location fix every 3 h (eight locations per day) for one year. Females (n = 18) were subsequently recaptured and refitted with GPS collars to provide range use dynamics of individual elk over two to three years. We calculated sizes of core areas and home ranges using adaptive kernel estimators, overlap between annual ranges, and establishment of ranges relative to land development. Key results Overlap of annual core areas (48.6%) and home ranges (67.9%) was high despite annual increases in land development. Sizes of core areas and home ranges and annual overlap (i.e. site fidelity) were negatively influenced by land development after controlling for forest cover. Conclusions These data reveal that female elk show high levels of site fidelity even in the presence of increasing annual land development. Females did not appear to abandon previously established areas, but used ranges in a manner that minimised interaction with development within these areas based on reductions in range use size and fidelity as land development increased. Implications To help mitigate impacts on elk, land development should be minimised and large areas of forest protected so elk can avoid areas associated with human activity.

Koalas continue to occupy their previous home-ranges after selective logging in Callitris - Eucalyptus forest

2007 ◽  
Vol 34 (2) ◽  
pp. 94 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Matthew A. Stanton ◽  
Traecey E. Brassil
Keyword(s):  
Home Range ◽  
Basal Area ◽  
Selective Logging ◽  
Home Ranges ◽  
Phascolarctos Cinereus ◽  
Eucalyptus Forest ◽  
South Wales ◽  
Callitris Glaucophylla ◽  
One Year ◽  
Cypress Pine

The koala (Phascolarctos cinereus) is a charismatic, high-profile species whose conservation needs are commonly perceived to be incompatible with logging. However, koala biology and the results of chronosequence studies elsewhere suggest that this species may tolerate a degree of habitat alteration caused by logging. In this study, 30 koalas, five in each of six areas available for logging within a mixed white cypress pine (Callitris glaucophylla)–Eucalyptus forest in north-western New South Wales, were radio-tracked for one year during 1997–1998 to determine their movements, home-range sizes and tree preferences. Five months after the study began, three of these areas were logged selectively for sawlogs and thinnings of the white cypress pine, a tree that is important to koalas for daytime shelter. This removed about one-quarter of the stand basal area, but the eucalypt component was unaffected. The remaining three areas were left undisturbed as controls. Radio-tracking continued in all six areas for another seven months. Koalas continued to occupy all or part of their previous home-ranges after selective logging, and home-range sizes remained similar between logged and unlogged areas. Home-ranges for both sexes overlapped and were ~12 ha for males and 9 ha for females. Koala survival and the proportions of breeding females were similar in logged and unlogged areas. The principal food trees of the koala were red gums, mainly Eucalyptus blakelyi and E. chloroclada, and the pilliga box (E. pilligaensis), none of which were logged in this study. These results suggest that selective logging for white cypress pine does not appear to adversely affect koala populations and that koalas may not be as sensitive to logging as previously thought. Further work is required to determine thresholds in the level of retention of koala food trees in logging operations.

The ecology of an Australian reptile icon: how do blue-tongued lizards (Tiliqua scincoides) survive in suburbia?

2001 ◽  
Vol 28 (3) ◽  
pp. 214 ◽  
Author(s):  
Jennifer Koenig ◽  
Richard Shine ◽  
Glenn Shea
Keyword(s):  
Ecological Factors ◽  
Home Ranges ◽  
Minimal Risk ◽  
Body Temperatures ◽  
Avoided Crossing ◽  
In Captivity ◽  
Radio Transmitters ◽  
Core Areas ◽  
Study Sites ◽  
Gravid Females

Although most species of large reptiles in the Sydney region are now restricted to remnant bushland, the blue-tongued lizard (Tiliqua scincoides) remains abundant. How has this large, slow-moving reptile managed to persist in the suburbs? We implanted radio-transmitters into 17 adult blue-tongued lizards and tracked them for six months (October 1998 to March 1999). Radio-tracked animals utilised 5–17 suburban backyards, but each lizard spent most of its time in a few ‘core’ areas near 2–7 shelter sites. Males had larger home ranges than females (mean of 12700 v. 5100 m 2 ) and moved further between shelter sites. Gravid females (mean home range 1000 m 2 ) were more sedentary. Lizards used corridors of dense vegetation to move between retreat sites, and actively avoided crossing roads. In sunny weather, lizards typically basked close to their overnight shelter for 1–4 h each morning until they obtained body temperatures of approximately 32°C. They maintained high body temperatures while moving about in the afternoon. In combination, the following ecological factors may facilitate persistence of blue-tongued lizards at our suburban study sites. (i) The most important subgroup of the population in terms of conservation are gravid females, which are highly sedentary and, thus, less likely to encounter the dangers of suburbia. (ii) The more ‘expendable’ males move about much more, but mostly in times and places that involve minimal risk from humans and their domestic pets. (iii) Lizards show strong site fidelity, spending up to 70% of their time in ‘safe’ locations; importantly, they avoid roads. (iv) Blue-tongued lizards readily utilise ‘artificial’ shelter sites and the commensal prey species (e.g. snails) found in most gardens. (v) These lizards can grow rapidly, mature early, and produce large litters. Because blue-tongued lizards have a long life span (over 30 years in captivity), populations of adults may persist for many years in the absence of recruitment.

The Adaptive Strategy for Overwintering by Hatchling Snapping Turtles (Chelydra serpentina)

2001 ◽  
Vol 35 (3) ◽  
pp. 514 ◽  
Author(s):  
Paul A. Sims ◽  
Gary C. Packard ◽  
Philip L. Chapman
Keyword(s):  
Adaptive Strategy ◽  
Chelydra Serpentina ◽  
Snapping Turtles

Mercury concentrations in snapping turtles (Chelydra serpentina) correlate with environmental and landscape characteristics

Ecotoxicology ◽  
2011 ◽  
Vol 20 (7) ◽  
pp. 1599-1608 ◽  
Author(s):  
Madeline A. Turnquist ◽  
Charles T. Driscoll ◽  
Kimberly L. Schulz ◽  
Martin A. Schlaepfer
Keyword(s):  
Chelydra Serpentina ◽  
Landscape Characteristics ◽  
Snapping Turtles

Effects of a sudden increase in natural mortality of adults on a population of the common snapping turtle (Chelydra serpentina)

1991 ◽  
Vol 69 (5) ◽  
pp. 1314-1320 ◽  
Author(s):  
Ronald J. Brooks ◽  
Gregory P. Brown ◽  
David A. Galbraith
Keyword(s):  
Clutch Size ◽  
Research Area ◽  
Effective Density ◽  
Egg Mass ◽  
Sudden Increase ◽  
Chelydra Serpentina ◽  
Density Dependent ◽  
Snapping Turtles ◽  
The Mean ◽  
Clutch Mass

A northern population of snapping turtles (Chelydra serpentina) centred around Lake Sasajewun in the Wildlife Research Area in Algonquin Park, Ontario, has been studied and individually marked since 1972. From 1972 to 1985, annual mortality and survivorship of adult females had been estimated at 1 and 96.6%, respectively, and only six dead turtles were found. Lake Sasajewun's population of C. serpentina was estimated in 1978–1979 and 1984–1985 at 38 and 47 adults, respectively. From 1976 to 1987, total number of nests found in the study area remained fairly constant and there were no significant changes in mean clutch size, mean clutch mass, or mean egg mass. On the main nest site, recruitment from 1976 to 1987 was 1.15 (1.8%) new females per year. From 1987 to 1989, we found 34 dead adult snapping turtles in the Wildlife Research Area. Observations of freshly dead animals indicated that most were killed by otters (Lutra canadensis) during the turtles' winter hibernation. A few uninjured turtles also died of septicemia in early spring shortly after emerging from hibernation. The estimated number of adults in Lake Sasajewun was 31 in 1988–1989, and the minimum number of adult residents known to be alive in the lake dropped from 47 in 1986 to 16 in 1989. In 1986 and 1987, annual adult female survivorship was estimated at 80 and 55%, respectively, and estimated numbers of nesting females declined from 82 in 1986 to 71 and 55 in 1987 and 1988, respectively. The actual number of nests found declined by 38 and 20% over the same periods. Although no significant differences occurred in mean egg mass or mean clutch size between 1987 and 1989 and earlier years, the mean clutch mass in 1988 was larger than in 1977 or 1978. This difference appeared to be due to a gradual increase in the mean age and body size of breeding females rather than to density-dependent changes. Recruitment into the adult breeding female population in 1987–1989 remained less than two individuals per year. Hatchling survival and number of juveniles were low throughout the study. Our observations support the view that populations of species with high, stochastic juvenile mortality and long adult life spans may be decimated quickly by increased mortality of adult animals, particularly if numbers of juveniles and immigrants are low. Recovery of such populations should be very slow because of a lack of effective density-dependent response in reproduction and recruitment.

Home range of the allied rock-wallaby, Petrogale assimilis

1994 ◽  
Vol 21 (1) ◽  
pp. 65 ◽  
Author(s):  
A Horsup
Keyword(s):  
Home Range ◽  
Major Effect ◽  
Home Range Size ◽  
Home Ranges ◽  
Temporal Separation ◽  
Dry Tropics ◽  
Shelter Site ◽  
Significant Difference ◽  
Mean Size ◽  
Core Areas

The home range and movements of the allied rock wallaby, Petrogale assimilis, a small macropod of the seasonally wet-dry tropics of Queensland, were studied over a 22-month period. There was no significant difference in the size of home ranges (95% isopleth) or core areas (65% isopleth) of males and females. Home ranges were generally elliptical with a mean size of 11.9 ha. Season had a major effect on home ranges. The following measures were all significantly greater in the dry seasons than in the wet seasons: home-range size (larger), home-range shape (more elongate), distance moved by females when feeding (longer), distance between shelter site and home-range centre of activity (longer). Feeding movements of males did not vary seasonally and were as long as dry-season movements of females, suggesting that movements of males are primarily determined by behavioural rather than physiological considerations. The overlap of rock-wallaby home ranges varied little between the sexes or seasons and averaged 38%. Core areas overlapped by an average of 22%; however, feeding adult rock-wallabies rarely met other conspecifics, except their partners. A comparison of the fixes of unpaired wallabies that had overlapping home ranges showed that temporal separation was occurring. In contrast, the home ranges of consort pairs showed extremely high temporal and spatial overlap. Rock-wallabies exhibited strong fidelity to their home ranges. The overlap of the seasonal home ranges and core areas of each individual rock wallaby averaged 68% and 52%, respectively. However, the seasonal home range of a socially immature adult male altered in location and size as he matured socially until it stabilised when he obtained a permanent consort.

scholarly journals Over-wintering Characteristics of West-Central Wisconsin Blanding's Turtles, Emydoidea blandingii

2010 ◽  
Vol 124 (2) ◽  
pp. 134 ◽  
Author(s):  
Richard P. Thiel ◽  
Timothy T. Wilder
Keyword(s):  
Chrysemys Picta ◽  
Anoxia Tolerance ◽  
Chelydra Serpentina ◽  
Emydoidea Blandingii ◽  
Anoxic Conditions ◽  
Painted Turtles ◽  
West Central ◽  
Remarkable Degree ◽  
Snapping Turtles

Hibernation of adult-sized Blanding's Turtles was studied at two west-central Wisconsin sites between 1991 and 2008. Turtles arrived at hibernacula from mid September to early October, spending 126 to 216 days at these sites, and generally emerged in early April yearly. Sixty percent of females and 30 percent of males hibernated in natural over man-made structures as hibernation sites. Anoxic conditions near five hibernation sites ranged from 78 to 100 days. Shell temperatures of three turtles monitored over five winters remained at <1°C a mean of 2,274 hours each winter. Over the same period, four turtles' temperatures were between 0° and -1°C a mean of 302 hours. During the course of our study, hibernating west-central Wisconsin Blanding's Turtles demonstrated a remarkable degree of both cold and anoxia-tolerance similar to that observed among Painted Turtles (Chrysemys picta) and Snapping Turtles (Chelydra serpentina).

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