Population structure, turnover and movement of spotted-tailed quolls on the New England Tablelands

2004 ◽  
Vol 31 (5) ◽  
pp. 475 ◽  
Author(s):  
Gerhard Körtner ◽  
Shaan Gresser ◽  
Beth Mott ◽  
Bobby Tamayo ◽  
Phil Pisanu ◽  
...  

Between 2000 and 2002 two populations of the spotted-tailed quoll (Dasyurus maculatus) were studied on the New England Tablelands using trapping surveys and radio-tracking. Overall, 85 individuals were trapped, but only two individuals were trapped throughout the 26 months of the study. Trapping was male-biased (74%). Adult males (>1 year) were substantially larger than females. On average, males travelled longer distances than females, and the maximum distances recorded were 8.1 and 3.9 km for a male and female respectively. Home ranges of males overlapped substantially, whereas those of females appeared to be exclusive. Mortality rates and the turnover in the quoll populations appeared to be substantial and at the beginning of autumn the populations comprised ~50% juveniles.


1977 ◽  
Vol 55 (2) ◽  
pp. 465-468 ◽  
Author(s):  
Pierre Mineau ◽  
Dale Madison

Miniature radio transmitters and 'local' triangulation methods were used to monitor the movements of free-ranging Peromyscus leucopus. A sexually mature male and female were studied in detail during two sessions within a 6-week period. Positions were recorded on 107 occasions, giving home ranges of 1.26 ha for the male and 0.91 ha for the female. Extensive home range overlap, correspondence in patterns of movement, the bearing of a litter by the female, and the lack of other adults in the study area indicate pair activity. The equipment and methods described will enable more thorough studies of the ecology and behavior of small, highly mobile rodent species in the future.



1994 ◽  
Vol 72 (7) ◽  
pp. 1314-1324 ◽  
Author(s):  
D. G. Reid ◽  
T. E. Code ◽  
A. C. H. Reid ◽  
S. M. Herrero

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.



2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick

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.



1983 ◽  
Vol 61 (7) ◽  
pp. 1955-1958 ◽  
Author(s):  
Marvin P. Pritts ◽  
James F. Hancock

The population structure and growth patterns of two populations of Solidago pauciflosculosa, a woody goldenrod, were investigated. Populations consisted of even-aged contagious patches of individuals, a dispersion pattern likely caused by the periodic appearance of microsites suitable for seedling establishment. The density of individuals within the even-aged clumps varied considerably and was correlated with total plant biomass and reproductive output. Density was not correlated with either reproductive or nonreproductive allocation patterns.



2011 ◽  
Vol 89 (9) ◽  
pp. 831-839 ◽  
Author(s):  
H. Dawn Marshall ◽  
Edward S. Yaskowiak ◽  
Casidhe Dyke ◽  
Elizabeth A. Perry

We investigated population structure of black bears ( Ursus americanus hamiltoni Cameron, 1957) from insular Newfoundland using the microsatellite profiles of 12 loci from three broadly distributed areas (Northern, Baie Verte, and Bonavista peninsulas). Our goals were to revisit earlier findings of low heterozygosity in Newfoundland and increase knowledge of intraspecific variability in black bears, and make inferences about postglacial colonization and contemporary movements of island black bears. Ninety-three individuals (42 males) were identified among 543 hair samples: 21 from Bonavista, 25 from Northern Peninsula, and 47 from Baie Verte. Genetic diversity is relatively low (HE = 0.42) and decreases from northwest to southeast. Small but significant subpopulation differentiation revealed by F statistics is greatest between Northern and Baie Verte peninsulas; it is lower and comparable in the remaining pairwise comparisons. We hypothesize that postglacial colonization proceeded from the Northern Peninsula southeastward. Bears migrated from the Northern Peninsula to Baie Verte at some more distant time in the past, then diverged by genetic drift. More recently, migration occurred from these two populations to Bonavista, characterized by positive FIS indicative of admixture. Tests of biased dispersal and posterior probability of correct assignment to locality reveal contemporary movements of both males and females with historical dispersal attributable to males.



Koedoe ◽  
1990 ◽  
Vol 33 (2) ◽  
Author(s):  
I.L. Rautenbach ◽  
M.B. Fenton ◽  
A.C. Kemp ◽  
S.J. Van Jaarsveld

Winter radio-tracking of three African goshawks Accipiter tachiro showed that they each occupied well-wooded home ranges of at least 28 hectares. They perched and roosted mainly within densely foliaged trees and an adult female changed perches on average 4,7 times per hour. No crepuscular predation of bats was recorded, in contrast to regular summer predation on colonies of little free-tailed bats, Tadarida pumila, but winter emergence rates of these bats at dusk had dropped to < 5 of the previous summer. We predict that many accipiters will be regular predators of bats and that skewed sex ratios and high fecundity may be two means by which bats counter this predation.



2017 ◽  
Vol 24 (3) ◽  
Author(s):  
A Romanova ◽  
O Krasko

Aim of the study: to evaluate the dynamics and to make a comparative analysis of male and female mortality among the population of Belarus Republic during 1959 – 2015.Materials and methods. The data on natural population movement in the Republic of Belarus during 1959 – 2015 have been analyzed in the research work. Crude and standardized mortality rates have been calculated using the direct standardization according to the world standard (Standard “World”), approved by WHO. JoinPoint software was used to investigate time trends as well as office suite MSEXCEL 2010.Results of the study. The minimum values of male and female crude and standardized mortality rates were established in 1964. Throughout the study period, the male population mortality rate grew 1.8-fold (based on crude rates – 2.4-fold), the female population mortality rate – 1.6-fold (based on crude rates – 2.2-fold). During 1985 – 2005, the differences in crude mortality rates among men and women grew 1.2-fold, and during 1962 – 2011, the differences in standardized rates increased 1.8-fold. Since 2003, the mortality rate among men and since 1999, the death rate among women has declined with an annual decrease rate to be more than twice as high as compared to an annual mortality increase registered during its growth.Conclusion. Since the 1960s, the changes in population age structure of the male and female population affected the crude mortality rates. The male and female mortality growth is due to an increased unfavorable impact of combined environmental factors. The adaptive capacity of women to sustain environmental changes contributed to their later entry into the period of mortality growth, as compared to men. The mortality rate reduction in men since 2003 and the excess of a decrease over an increase rate is associated with a set of state measures aimed at protecting and strengthening the public health in the republic.



2014 ◽  
Vol 15 (3) ◽  
pp. 1-8
Author(s):  
Leandro V. Ferreira ◽  
Denise A. Cunha ◽  
Pia Parolin

Virola surinamensis is a dioecious timber species of Amazonian floodplain forests. It is threatened by extinction and a priority species in the conservation program of genetic resources with high economic value for Brazil. The present study was aimed to assess the population structure of Virola surinamensis and the impact of logging in the estuary region of Brazilian Amazonia. Our data suggest that altering the dioecious population structure by logging likely creates the imbalance of male and female individuals in the population. New policies are needed to protect Virola trees with a special regard on reproductive matriarch trees.



1993 ◽  
Vol 71 (3) ◽  
pp. 660-663 ◽  
Author(s):  
Daniel K. Rosenberg ◽  
Robert G. Anthony

We described trapping mortality rates of northern flying squirrel (Glaucomys sabrinus) populations in western Oregon, U.S.A., and evaluated the effects of sex, age, body mass, and number of times an individual was recaptured on these rates. Although the overall trapping mortality rates were relatively low (7%) during 16–21 day trapping sessions, we observed differential mortality rates among the sex and age cohorts. The order of mortality rates was: juvenile females (32.3%) > juvenile males (11.1%) > adult females (5.1%) = adult males (4.1%). Overall trapping mortality rates were not affected by the number of times an individual was captured. We hypothesize that the differences we found were due to extrinsic factors (weather-related) acting on differential behavioral responses to trapping and thresholds of stress an animal can tolerate.



1995 ◽  
Vol 18 (1) ◽  
pp. 71
Author(s):  
J.L. Gardner ◽  
M. Serena

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).



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