The ecology of a Mediterranean tortoise (Testudo hermanni): a declining population

1985 ◽  
Vol 63 (1) ◽  
pp. 169-180 ◽  
Author(s):  
David Stubbs ◽  
Ian R. Swingland
Keyword(s):  
Mixed Forest ◽  
Nest Density ◽  
Home Ranges ◽  
Adult Males ◽  
Active Season ◽  
Age Cohort ◽  
Nesting Sites ◽  
Testudo Hermanni ◽  
Evergreen Oak Forest ◽  
Evergreen Oak

In France, wild tortoises occur at low densities (< 3/ha) in the mixed forest and maquis of the Massif des Maures. In an evergreen oak forest with scattered, traditional cultivations, distinct subpopulations still exist at relatively high density (> 10/ha). The population structure is heavily skewed in favour of old adults and recruitment is low. The population is declining due to habitat loss, both from fire and through the decline in traditional horticultural practices, leading to a reduction in nest site availability. The increase in nest density in the few suitable sites remaining leaves the eggs highly vulnerable to predation and losses of over 90% cannot be sustained. The active season is from March to November, but there is evidence of some activity during the hibernation period. Adult males maintain small, fixed home ranges, while females undertake distinct migrations to and from nesting sites in the spring and can switch to new home ranges. Juveniles are sedentary up to the age of 4 or 5 years, after which they may wander considerable distances in no particular direction, until the onset of sexual maturity. Sex ratio does not differ significantly from parity within any age cohort.

Habitat selection by the wood turtle (Clemmys insculpta) at the northern limit of its range

2004 ◽  
Vol 82 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Martin Arvisais ◽  
Esther Lévesque ◽  
Jean-Claude Bourgeois ◽  
Claude Daigle ◽  
Denis Masse ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Habitat Use ◽  
Mixed Forest ◽  
Activity Period ◽  
Home Ranges ◽  
Aquatic Habitats ◽  
Active Season ◽  
Habitat Features ◽  
Wood Turtles ◽  
Wood Turtle

We characterized the chronology of habitat use by the wood turtle, Clemmys insculpta (LeC., 1829), in the Mauricie region of Quebec, Canada. We also determined if this species used habitats according to availability within a home range and identified habitat features influencing habitat selection. Habitats were characterized for 20 wood turtles followed weekly by telemetry during the active season of 1997. Turtles used a great diversity of terrestrial and aquatic habitats. Alder (Alnus rugosa (Du Roi) Spreng.) stands were the most used terrestrial habitats throughout the active season. Habitat use varied according to activity period. Indeed, wood turtles used aquatic habitats and alder stands during prenesting and prehibernation activity periods, whereas all habitat types were used during nesting and postnesting activity periods. Wood turtles did not use habitats randomly within their home ranges, suggesting that they selected them. Wood turtles seemed to select mixed forest stands that were relatively young (16 years), short (1–4 m), had low arborescent cover (25%), moderate cover of the upper shrub layer (35%), and low total canopy closure (0%–50%). This knowledge will be helpful in the establishment of future conservation measures.

Life history characteristics and movements of the woodland jumping mouse, Napaeozapus insignis, in Nova Scotia

1988 ◽  
Vol 66 (8) ◽  
pp. 1752-1762 ◽  
Author(s):  
Kristiina Ovaska ◽  
Thomas B. Herman
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Survival Rates ◽  
Home Ranges ◽  
Adult Males ◽  
Active Season ◽  
The North ◽  
Adult Females ◽  
Napaeozapus Insignis ◽  
Overwintering Survival

We examined abundance, reproduction, movements, and adult–juvenile interactions of Napaeozapus insignis in a 5-year mark–recapture study in Nova Scotia. Densities of N. insignis varied greatly between years, mainly as a result of variation in overwintering survival of juveniles and breeding success of females. Year-to-year survival rates of adults were relatively constant (approximately 26%), whereas those of juveniles fluctuated widely. Adult females produced only one litter per season, and no juvenile reproduced in the summer of her birth. Length of the active season was 12–17 weeks, and timing of emergence from hibernation varied little from year to year. Males emerged from hibernation 15–33 days earlier than females, and their captures were clustered along portions of the transects adjacent to steep slopes, which may have provided well-drained hibernation sites. The overall sex ratio did not differ from 1:1, but in May it was biased towards males, and in July and August adult females outnumbered adult males. Distances moved by adult males and females within 24 h were similar (mean for males = 97 m, for females = 61 m), but home ranges of males between June and August were greater than those of females (mean distance between two farthest captures for males = 447 m, for females = 175 m). Results from a removal experiment, as well as examination of trapping records, indicated that adult females inhibited early capture of juveniles when densities of adults were high. We suggest that the suite of life history traits (long life-span, late maturity, infrequent reproduction) that northern zapodids exhibit relative to southern zapodids is best explained by a bet-hedging hypothesis. Long winters and short summers in the north contribute to low and unpredictable overwintering survival of juveniles. By directing energy from reproduction into accumulation of hibernation fat, adults increase their chances of surviving to breed again the next summer and thus decrease the probability of leaving no young at all.

scholarly journals The benefits of being dominant: Health correlates of male social rank and age in a marmot

2021 ◽  
Author(s):  
Kenta Uchida ◽  
Rachel Ng ◽  
Samuel A Vydro ◽  
Jennifer E Smith ◽  
Daniel T Blumstein
Keyword(s):  
Body Mass ◽  
Physiological Stress ◽  
Social Rank ◽  
Health Indicators ◽  
Good Health ◽  
Dominant Male ◽  
Adult Males ◽  
Active Season ◽  
Handicap Hypothesis ◽  
Variation Explained

Abstract The benefits of dominance may not come without costs, particularly for males. For example, the “immunocompetence handicap hypothesis” states that males with enhanced mating success allocate resources to enhance reproductive output at a cost to their current health, whereas the “resource quality hypothesis” predicts that high-ranking males may benefit from increased reproduction and good health. While the predictions from each have been well tested in captive animals and in a variety of highly social primates, fewer studies have been carried out in free-living, facultatively social animals. Using adult male yellow-bellied marmots (Marmota flaviventer), we evaluated predictions of these hypotheses by examining the relationship between social rank and two health indicators–fecal corticosterone metabolite (FCM) levels, and neutrophil/lymphocyte (N/L) ratios–after accounting for variation explained by age, body mass, and seasonality. We found that higher-ranking males tended to have a lower N/L ratio (reflecting good health) than lower-ranking individuals, whereas FCM levels were not significantly related to rank. In addition, heavier male marmots had lower N/L ratios, while body mass was not associated with FCM levels. We also found that older adult males had lower FCM levels (reflecting less physiological stress) but higher N/L ratios than younger adults. Finally, we found that FCM levels decreased as the active season progressed and FCM levels were associated with the time of the day. Overall, our results suggest that socially-dominant male marmots enjoyed better, not worse health in terms of lower N/L ratios.

Spacing, movements, and habitat selection of the river otter in boreal Alberta

1994 ◽  
Vol 72 (7) ◽  
pp. 1314-1324 ◽  
Author(s):  
D. G. Reid ◽  
T. E. Code ◽  
A. C. H. Reid ◽  
S. M. Herrero
Keyword(s):  
Lontra Canadensis ◽  
Home Ranges ◽  
Adult Males ◽  
Movement Rates ◽  
River Otters ◽  
Aquatic Mammal ◽  
Adult Females ◽  
Two Factors ◽  
Bog Lakes ◽  
Selection Of

Seasonal spacing patterns, home ranges, and movements of river otters (Lontra canadensis) were studied in boreal Alberta by means of radiotelemetry. Adult males occupied significantly larger annual home ranges than adult females. Males' ranges overlapped those of females and also each other's. In winter, home ranges of males shrank and showed less overlap. Otters often associated in groups, the core members typically being adult females with young, or adult males. Otters tended to be more solitary in winter. In winter, movement rates of all sex and age classes were similar, and much reduced for males compared with those in other seasons. These data indicated a strong limiting effect of winter ice on behaviour and dispersion. We tested the hypothesis that otters select water bodies in winter on the basis of the suitability of shoreline substrate and morphology for dens with access both to air and to water under ice. Intensity of selection was greatest in winter, with avoidance of gradually sloping shorelines of sand or gravel. Adults selected bog lakes with banked shores containing semi-aquatic mammal burrows, and lakes with beaver lodges. Subadults selected beaver-impounded streams. Apart from human harvest, winter habitats and food availability in such habitats are likely the two factors most strongly limiting otter density in boreal Alberta.

Dispersal patterns in a regional koala population in south-east Queensland

2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick
Keyword(s):  
Urban Areas ◽  
Home Ranges ◽  
Adult Males ◽  
Dispersal Patterns ◽  
Young Males ◽  
Straight Line ◽  
The Social ◽  
Straight Line Distance ◽  
Males And Females ◽  
Natal Home

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

scholarly journals Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

2014 ◽  
Vol 60 (6) ◽  
pp. 700-711 ◽  
Author(s):  
Nina A. Vasilieva ◽  
Ekaterina V. Pavlova ◽  
Sergey V. Naidenko ◽  
Andrey V. Tchabovsky
Keyword(s):  
Body Size ◽  
Ground Squirrel ◽  
Life History Theory ◽  
Social Activity ◽  
Indirect Evidence ◽  
Adult Size ◽  
Adult Males ◽  
Mating Season ◽  
Active Season ◽  
Good Physical Condition

Abstract Life-history theory predicts that in hibernators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: “active” males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than “passive” males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

Observations on Activity Patterns, Population and Den Characteristics of The Water Rat Hydromys chrysogaster Along Badger Creek, Victoria.

1995 ◽  
Vol 18 (1) ◽  
pp. 71
Author(s):  
J.L. Gardner ◽  
M. Serena
Keyword(s):  
Population Density ◽  
Activity Patterns ◽  
Home Ranges ◽  
Adult Males ◽  
Fish Farms ◽  
Age Classes ◽  
Irrigation Channels ◽  
In Captivity ◽  
In The Wild ◽  
Hydromys Chrysogaster

The Water Rat Hydromys chrysogaster is Australia&apos;s largest amphibious rodent, occupying freshwater rivers, lakes, and coastal and estuarine habitats throughout the continent (Watts and Aslin 1981). Little is known of the species&apos; social organisation or use of space in the wild although Harris (1978) suggested that adults might be intrasexually aggressive. The home ranges of all sex and age classes overlap to some extent but home ranges of adults of the same sex appear to overlap less (Harris 1978). Adult males occupy the largest home ranges which overlap those of one or more females. In captivity individuals kept in groups form hierarchies in which only the dominant females usually breed successfully (Olsen 1982). Fighting occurs primarily among males, with the highest incidence of injuries observed at the beginning of the main September-March breeding season (Olsen 1980, 1982). The results of trapping studies indicate that population density may vary considerably, with the greatest numbers of animals typically occupying man-modified habitats such as irrigation channels or fish farms (McNally 1960, Watts and Aslin 1981, Smales 1984). Aggressive behaviour appears to be related to pelage colour (phenotype) and population density; the higher the density the greater the number of injured individuals (Olsen 1980).

scholarly journals Movements of Subadult Male Grizzly Bears, Ursus arctos, in the Central Canadian Arctic

2004 ◽  
Vol 118 (2) ◽  
pp. 239 ◽  
Author(s):  
Robert J. Gau ◽  
Philip D. McLoughlin ◽  
Ray Case ◽  
H. Dean Cluff ◽  
Robert Mulders ◽  
...  
Keyword(s):  
Home Range ◽  
Long Range ◽  
Rangifer Tarandus ◽  
Ursus Arctos ◽  
Canadian Arctic ◽  
Grizzly Bears ◽  
Home Ranges ◽  
Adult Males ◽  
Subadult Male ◽  
Daily Movement

Between May 1995 and June 1999, we equipped eight subadult male (3-5 yrs old) Grizzly Bears (Ursus arctos) with satellite radio-collars within a study area of 235,000 km2, centred 400 km northeast of Yellowknife, Northwest Territories, Canada. Subadult male annual home ranges were extraordinarily large (average = 11,407 km2, SE = 3849) due, in part, to their movement's occasional linear directionality. We believe their long-range linear movements may reflect some individuals tracking the migration of Caribou (Rangifer tarandus). Seasonal daily movement patterns were similar to adult males that were previously reported. The areas used by these bears are the largest ranges reported for any Grizzly Bears and the scale of their movements may put individual bears in contact with humans even when developments are hundreds of kilometres from the central home range of an animal.

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