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.

The Decline and Fall of the Pribilof Fur Seal (Callorhinus ursinus): A Simulation Study

1989 ◽  
Vol 46 (8) ◽  
pp. 1437-1445 ◽  
Author(s):  
Andrew W. Trites ◽  
Peter A. Larkin
Keyword(s):  
North Pacific ◽  
Survival Rates ◽  
Commercial Fishing ◽  
Juvenile Survival ◽  
Callorhinus Ursinus ◽  
Adult Males ◽  
The North ◽  
Adult Females ◽  
Fur Seal ◽  
The North Pacific

A mathematical model incorporating the basic life history features of the North Pacific fur seal (Callorhinus ursinus) approximated the decline of the Pribilof Islands population by reconstructing pup estimates and counts of adult males over the period 1950 to 1987. Simulation results suggest that commercial female harvesting and a series of poor juvenile survival rates were responsible for causing and maintaining the observed decline in pup production on St. Paul Island from 1956 to 1970. A more recent drop in pup production since 1976 is also attributed to poor juvenile survival, but with the addition of higher natural mortalities of adult females. It appears that the natural mortality of adult females may have increased by 2 to 5% beginning in the mid 1970s. We suspect reductions in the fur seal food base and entanglement-related mortality associated with commercial fishing in the North Pacific are contributing to the current decline, although neither possibility has yet been clearly demonstrated.

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.

scholarly journals Social and Behavioural Factors in Cetacean Responses to Overexploitation: Are Odontocetes Less “Resilient” Than Mysticetes?

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Paul R. Wade ◽  
Randall R. Reeves ◽  
Sarah L. Mesnick
Keyword(s):  
Life History ◽  
Mating Systems ◽  
Alloparental Care ◽  
Transfer Of Knowledge ◽  
Older Individuals ◽  
Adult Males ◽  
Baleen Whales ◽  
Social Nature ◽  
Adult Females ◽  
Behavioural Factors

Many severely depleted populations of baleen whales (Mysticeti) have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti). We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete life history. However, an additional factor may be the highly social nature of many odontocetes in which survival and reproductive success may depend on: (a) social cohesion and organization, (b) mutual defence against predators and possible alloparental care, (c) inter-generational transfer of “knowledge”, and (d) leadership by older individuals. We found little evidence of strong recovery in any of the depleted populations examined. Their relatively low potential rates of increase mean that odontocete populations can be over-exploited with take rates of only a few percent per year. Exploitation can have effects beyond the dynamics of individual removals. Four species showed evidence of a decrease in birth rates following exploitation; potential mechanisms include a deficit of adult females, a deficit of adult males, and disruption of mating systems. The evidence for a lack of strong recovery in heavily exploited odontocete populations indicates that management should be more precautionary.

Home-Range Size and Fidelity of Western Grey Kangaroos (Macropus Fuliginosus) Living in Remnants of Wandoo Woodland and Adjacent Farmland.

1992 ◽  
Vol 19 (2) ◽  
pp. 137 ◽  
Author(s):  
GW Arnold ◽  
DE Steven ◽  
A Grassia ◽  
J Weeldenburg
Keyword(s):  
Home Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
The Core ◽  
Adult Females ◽  
Radio Transmitters ◽  
Core Areas ◽  
Males And Females ◽  
Eucalyptus Wandoo ◽  
Older Males

The home ranges were studied from 1977 to 1981 of western grey kangaroos (Macropus fuliginosus) living in a 300-ha remnant of wandoo [Eucalyptus wandoo] surrounded by farmland at Baker's Hill, Western Australia. The M. fuliginosus population varied from 140 to 200 animals during the study. In 1979, four females (>30 kg) and 2 adult males (31 kg and 47 kg) were fitted with radio-transmitters and their movements recorded. The home ranges of these animals varied from 39 to 70 ha; the average overlap in the area used during the day and that used at night was 16.4%. Many of the kangaroos fed on farmland at night. The night ranges of 51 marked kangaroos were recorded using a spotlight. The animals showed a strong fidelity to their home ranges. Only 3 males (about 5-yr-old) shifted their night ranges; the centres of the ranges moved only 600-800 m. Older males had significantly larger night ranges than younger males and females. Individual females and the younger males showed preferences for using particular access points to get onto farmland; the older males showed no preferences. The core areas of the night ranges of many adult females overlapped closely in 'groups', but there was no evidence of 'mob' home ranges that were socially separated.

scholarly journals Home range of the Tropidurid lizard Liolaemus lutzae: sexual and body size differences

1999 ◽  
Vol 59 (1) ◽  
pp. 125-130 ◽  
Author(s):  
C. F. D. ROCHA
Keyword(s):  
Body Size ◽  
Home Range ◽  
Mutual Exclusion ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
Adult Females ◽  
The Mean ◽  
Janeiro State

The home range of the Tropidurid lizard Liolaemus lutzae, an endemic species of the costal sand dune habitats of Rio de Janeiro State, was studied in the beach habitat of Barra de Maricá restinga, Maricá County. Home ranges were studied using a mark-recapture technique in a delimited area at the beach habitat. I considered for estimates and analysis the home ranges of those lizards with a minimum of four positions. The size of L. lutzae home ranges varied according to the segment of the population. The mean home range size of adult males (x = 59.8 ± 33.7 m²) was significantly larger than that of adult females (x = 22.3 ± 16.1 m²). Juvenile mean home range size was significantly smaller than that of adult males, but did not differ from that of adult females (t = 1.058; p = 0.149). The overlap between male home ranges was usually low (3.6%), being in general only peripheral. Conversely, there was a considerable overlap between home ranges of adult females with those of adult males, the home range areas of two or three females being enclosed in the home range of one adult male. The small overlap between home ranges of adult males suggested mutual exclusion. The observed between-sex differences in the size of L. lutzae home range may be explained by the sexual dimorphism in body size in this species, and by the need of adult males to establish larger areas so as to include many females in their areas, during the reproductive season. The differences in home range along ontogeny probably result from differences in body size of the different segments of the population, due to trophic differences (carnivory and herbivory levels), and the dispersal of young after birth. Because L. lutzae is omnivorous, but primarily herbivorous when adult, and due to its sit-and-wait foraging behavior (mainly on arthropods), it does not need to move around over large areas to find food, which in turn reduces the area necessary for it to live.

A live-trapping of Australian brush-tailed possums, Trichosurus vulpecula (Kerr), in the Orongorongo Valley, Wellington, New Zealand

1973 ◽  
Vol 21 (1) ◽  
pp. 75 ◽  
Author(s):  
MC Crawley
Keyword(s):  
New Zealand ◽  
Home Ranges ◽  
Trichosurus Vulpecula ◽  
Adult Males ◽  
Adult Females ◽  
Capture Site ◽  
Live Trapping ◽  
Indigenous Forest ◽  
Autumn And Winter ◽  
Initial Capture

A live-trapping study of a population of Australian brush-tailed possums, Trichosurus vulpecula (Kerr), in indigenous forest of the Orongorongo Valley, Wellington, N.Z., was carried out from March 1966 to November 1968. In 14 ha of podocarp-mixed broadleaf forest, 301 possums (150; 151) were individually marked and repeatedly captured in a series of trapping periods. The population comprised residents and transients of both sexes with sub- adults forming the bulk of the latter, particularly in spring. The estimated population density varied from 10.6 per ha in November 1966 to 6.4 per ha in August 1968. There was one well-defined season of births each autumn and a few births in winter. On average, 73% (67-92%) of mature females produced pouch young each year. Females resident throughout the study had the highest breeding success (79%). Achievement of sexual maturity was delayed; no females bred until they were 2 yr old, and some not even at 3 yr. Losses occurred at all stages of the life history and averaged 62% between the pouch young and subadult stages; thus only 28 subadults per 100 females were recruited. Adult losses averaged 26% per annum. Adult males (mean weight 2.46 kg) were heavier than adult females (2.33 kg). Weights varied seasonally, with males heaviest in summer and lightest in spring, and females heaviest in winter and lightest in summer. Possums of both sexes were rather sedentary, with males (95% of captures within 115 m of the initial capture site) being less so than females (95 % of captures within 90 m of the initial capture site). More than half of the captures (55% for males, 62% for females) were made within 30 m of the site of initial capture. Males moved farther in autumn and summer than in other seasons, while females did so in autumn and winter. Subadults were apparently more sedentary than adults. Home ranges of adult males (mean 0.81 ha) were significantly larger than those of adult females (0.46 ha). Considerable overlapping of the ranges of both sexes occurred, and territorial behaviour was not conspicuous. The dispersion of the population remained the same throughout the study although the component individuals changed. The results of the present study are compared with those of similar studies in New Zealand and Australia, and the dynamics of the Orongorongo Valley possum population are discussed with reference to variable rates of reproduction and mortality.

The proximate causes of male-biased natal emigration in Columbian ground squirrels

1993 ◽  
Vol 71 (1) ◽  
pp. 204-218 ◽  
Author(s):  
Darwin R. Wiggett ◽  
David A. Boag
Keyword(s):  
Ground Squirrels ◽  
Home Ranges ◽  
Adult Males ◽  
Spermophilus Columbianus ◽  
Adult Females ◽  
Study Support ◽  
Proximate Causes ◽  
Natal Home ◽  
And Behavior ◽  
Columbian Ground Squirrels

The results of this study support the hypothesis that male-biased emigration of yearling male Columbian ground squirrels (Spermophilus columbianus) is socially induced. The likelihood of emigration from both the natal site and the natal colony was correlated with parameters of social structure and behavior. Agonism by the mother and (or) neighboring adult females, in association with parturition and lactation, apparently caused the initial shifts of yearling males away from their natal home ranges. After these shifts, yearling males that lived in areas where the number of neighboring males (both adult and yearling) was high relative to the number of females emigrated to areas within the natal colony that were more female-biased (intracolony emigration), or emigrated from the natal colony (intercolony emigration). Reduced numbers of adult males apparently resulted in lower rates of emigration by yearling males. Among the latter, emigrants appeared to be subordinate to non-emigrants. We discuss these findings in light of current hypotheses concerning the proximate and ultimate causes of emigration in ground-dwelling sciurids.

The life history of Trichosurus vulpecula hypoleucus (Phalangeridae) in the jarrah forest of south-western Australia

2005 ◽  
Vol 53 (4) ◽  
pp. 265 ◽  
Author(s):  
A. F. Wayne ◽  
C. G. Ward ◽  
J. F. Rooney ◽  
C. V. Vellios ◽  
D. B. Lindenmayer
Keyword(s):  
Life History ◽  
Western Australia ◽  
The Body ◽  
Summer Drought ◽  
Testis Size ◽  
Trichosurus Vulpecula ◽  
Adult Males ◽  
Eucalyptus Marginata ◽  
Adult Females ◽  
Western Australian

The common brushtail possum (Trichosurus vulpecula) is noted for its morphological, biological and ecological variability across its range. Despite having suffered substantial population declines since European settlement, relatively little has been published on the south-western Australian subspecies, the koomal (T. v. hypoleucus). This study reports morphological, reproductive and general life-history data from an 18-month study of a population in the southern jarrah (Eucalyptus marginata) forest at Chariup (part of Perup), near Manjimup, in south-western Australia. As one of the smallest subspecies, adult males of T. v. hypoleucus averaged 1616 g and females averaged 1470 g. Sexual dimorphism also occurred with head length and pes length, but not tail length. A single autumn breeding season occurred in both 2002 and 2003, in which all adult females bred and produced a single young between February and May. The onset of autumn births was associated with the end of the summer drought. Unlike many other Trichosurus populations, no spring breeding pulse or ‘double-breeding’ events were observed. At least 83% of pouch young survived to pouch emergence. The growth rate of offspring was initially linear, but became curvilinear and approached an asymptote after ~5 months. Most females bred for the first time when they were 1 year old. On the basis of testis size, males also matured at 1 year old. The body condition of adult males, but not adult females, changed significantly over time and followed an apparently seasonal pattern in which their condition was poorest in winter and best in summer. While many of the life-history traits of the Chariup population were similar to those of other south-western Australian populations of T. v. hypoleucus, the most striking variations included age at maturity, extent of spring breeding pulse and female fecundity. Further comparisons with conspecifics elsewhere in Australia and New Zealand also highlight the variability exhibited by T. vulpecula across its range. Some aspects of the biology of T. v. hypoleucus were particularly similar to those observed for T. v. arnhemensis in northern Australia.

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.

Gonadal and hormonal phenology in free-living male rufous whistlers, Pachycephala rufiventris (Passeriformes : Pachycephalidae)

2001 ◽  
Vol 49 (6) ◽  
pp. 651 ◽  
Author(s):  
P. G. McDonald ◽  
L. B. Astheimer ◽  
W. A. Buttemer
Keyword(s):  
Life History ◽  
Hormone Secretion ◽  
Temperate Zone ◽  
Nest Building ◽  
Adult Males ◽  
Migratory Species ◽  
The North ◽  
South Wales ◽  
Gonad Size ◽  
Incubation Feeding

The hormonal and gonadal profiles of the few Australian old endemic passerine species studied to date have exhibited less annual variation in gonad size, reduced amplitude in testosterone (T) and luteinising hormone (LH) levels in comparison with those exhibited by many predominantly migratory species from the north temperate zone. Because none of the Australian endemics studied to date were migratory species, we studied a migratory population of rufous whistlers in central western New South Wales to determine whether differences in life history might be associated with different gonadal and hormonal profiles. Breeding stages were classified into five functional categories: territory/pair establishment, nest building, incubation, feeding nestlings/fledglings and post-breeding. We captured adult males at all breeding stages, examined their gonadal status through unilateral laparotomy, collected a blood sample and assessed this for plasma T and LH content using radioimmunoassay. Both hormones peaked early in the breeding season: LH levels during territory/pair establishment at 2.8 ng/mL 1.7 (s.d.) and T levels during nest building at 1.8 ng/mL 1.6 (s.d.). Following incubation LH and T (in particular) levels decreased substantially with the onset of parental duties – whilst feeding nestlings/fledglings T was 0.1 ng/mL 0.1 (s.d.), and LH was 1.6 ng/mL 1.2 (s.d.). This temporal variation in hormone secretion and an observed synchronous peak in gonad size at nest-building is reminiscent of migratory species from the north temperate zone displaying biparental care. Peak concentrations of both plasma T and LH in whistlers were intermediate between those reported for passerines from the north temperate zone with a similar life history and sedentary Australian old endemic passerines examined to date. This possibly reflects differences in life-history traits, the functional use of T in this species and/or possible phyletic effects.

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