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.

Spatial variability in the social organisation of the yellow-bellied glider (Petaurus australis) near Ravenshoe, north Queensland

2001 ◽  
Vol 49 (4) ◽  
pp. 397 ◽  
Author(s):  
Ross L. Goldingay ◽  
Darren G. Quin ◽  
Sue Churchill
Keyword(s):  
Adult Female ◽  
Social System ◽  
Dominant Male ◽  
Female Group ◽  
Sexually Dimorphic ◽  
Adult Males ◽  
Adult Females ◽  
The Social ◽  
Natal Home ◽  
Petaurus Australis

A detailed study was conducted over a 12-month period of 10 yellow-bellied glider groups at Nitchaga Creek in north Queensland. Adult gliders were sexually dimorphic in body size and were characterised by yellow ventral fur, which is consistent with southern populations. Gliders lived in groups of 3–6 individuals that occupied exclusive areas of about 50 ha. The structure of glider groups varied enormously: five contained one adult pair, three contained one adult male and 2–3 adult females, and two initially contained 2–3 adult males and one adult female but then persisted as bachelor groups after the death or disappearance of the adult female. Group size changed during the year as offspring matured and as individuals died. One male glider dispersed about 1 km from its natal home-range and became the dominant male in a nearby group. Young were born throughout the year, with a peak in the number of pouch-young in June. This study has confirmed the highly variable social system of the yellow-bellied glider, which appears to be mediated by local resource abundance.

Argulus canadensis from Cape Breton Island

1936 ◽  
Vol 2 (4) ◽  
pp. 355-358 ◽  
Author(s):  
Dr. C. B. Wilson
Keyword(s):  
Adult Males ◽  
Cape Breton Island ◽  
Young Males ◽  
Cape Breton ◽  
Males And Females ◽  
First Time ◽  
Secondary Sexual

Adult males, as well as young males and females, are described for the first time. The male has the most complicated secondary sexual apparatus so far described for species of Argulus. The immature differ markedly from the adults.

The social organisation and mating system of an Australian subalpine rodent, the broad-toothed rat, Mastacomys fuscus Thomas

1993 ◽  
Vol 20 (4) ◽  
pp. 405 ◽  
Author(s):  
TM Bubela ◽  
DCD Happold
Keyword(s):  
Mating System ◽  
Social Organisation ◽  
Home Ranges ◽  
Spatial Organisation ◽  
Nest Sites ◽  
Alpine Regions ◽  
The Social ◽  
Eastern Australia ◽  
The World ◽  
Males And Females

Mastacomys fuscus is a grass-eating rodent of south-eastern Australia that lives mainly in subalpine habitats where snow covers the ground for about four months of the year. Radiotelemetry revealed that in summer the females were territorial. Home ranges of males were larger than those of females and overlapped extensively with the home ranges of other males and with the home ranges of up to three females. In winter, males and females huddled together in communal nests. The locations of nest sites, cover, water and grass also determined the spatial organisation of individuals. The evidence suggests that M. fuscus is not monogamous, but there were insufficient data to determine whether polygyny or promiscuity is the preferred mating system. The social organisation of this species, solitary in summer and communal in winter, is a response to the cold snowy winters and the limited time for reproduction in summer. The social organisation of M, fuscus is different from that of the other conilurine rodents of Australia, but similar to that of rodents that live in other alpine regions of the world.

Natal dispersal of grizzly bears

2001 ◽  
Vol 79 (5) ◽  
pp. 838-844 ◽  
Author(s):  
Bruce N McLellan ◽  
Frederick W Hovey
Keyword(s):  
Home Range ◽  
Ursus Arctos ◽  
Natal Dispersal ◽  
Conservation Strategies ◽  
Grizzly Bears ◽  
Home Ranges ◽  
Adult Males ◽  
Gradual Process ◽  
The Social ◽  
Dispersal Distances

We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and farther still by 4 years of age. Dispersal of both sexes was a gradual process, occurring over 1–4 years. From the locations of death, or last annual ranges, it was estimated that 18 males dispersed 29.9 ± 3.5 km (mean ± SE) and 12 females dispersed 9.8 ± 1.6 km. Eleven of these males dispersed the equivalent of at least the diameter of 1 adult male home range, whereas only 3 of the females dispersed at least the diameter of 1 adult female home range. The longest dispersals recorded were 67 km for a male and 20 km for a female. Because the social system consists of numerous overlapping home ranges of both sexes, long dispersal distances may not be required to avoid inbreeding or competition with relatives. Simple models suggest that 61% of the ranges of brother and sister pairs would not overlap, but the home range of every daughter would overlap her father's range. The home range of an estimated 19 ± 4 (mean ± SD) adult males, however, would overlap at least a portion of each female's range, thereby reducing the chance of a female mating with her brother or father. Understanding the dispersal behaviour of grizzly bears is essential for developing conservation strategies. Our results suggest that meta-population reserve designs must provide corridors wide enough for male grizzly bears to live in with little risk of being killed.

scholarly journals Does Distance Still Matter For Internal Migration And, If So, How? Evidence From 1986 To 2006

2015 ◽  
Author(s):  
Omoniyi Alimi ◽  
David Mare ◽  
Jacques Poot
Keyword(s):  
Travel Time ◽  
Internal Migration ◽  
Urban Areas ◽  
Goodness Of Fit ◽  
Socioeconomic Differences ◽  
Straight Line ◽  
Straight Line Distance ◽  
Deterrence Effect ◽  
Migration Flows ◽  
Road Distance

In this paper we re-examine the structure of internal migration flows in New Zealand.  We use data on gross migration flows between the 39 main and secondary urban areas for the four intercensal periods between 1986 and 2006.  We confirm that the gravity model – in which migration is inversely related to distance – fits the data well, and that the way in which distance is measured (travel time, road distance or straight-line distance) matters to some extent for the goodness of fit of the model. We also show that some forms of socioeconomic differences influence migration in the same way as distance. Perhaps surprisingly, we find that the deterrence effect of distance on migration was increasing, at least until 2001. Improvements in connectivity through reduced travel time have not increased migration flows. 

Factors Affecting the Distribution of Mallards Wintering in the Mississippi Alluvial Valley

The Auk ◽  
1983 ◽  
Vol 100 (4) ◽  
pp. 932-946 ◽  
Author(s):  
James D. Nichols ◽  
Kenneth J. Reinecke ◽  
James E. Hines
Keyword(s):  
Population Size ◽  
Mississippi Alluvial Valley ◽  
Adult Males ◽  
Alluvial Valley ◽  
Factors Affecting ◽  
Young Males ◽  
Young Females ◽  
Winter Distribution ◽  
Wintering Areas ◽  
Males And Females

Abstract The Mississippi Alluvial Valley (MAV) is the principal wintering area for Mallards (Anas platyrhynchos) in the Mississippi Flyway. Here, we consider it a distinct habitat (sensu Fretwell 1972), i.e. fitness is relatively homogeneous among ducks within the MAV but different from that of ducks in other such habitats. We analyzed recovery distributions of Mallards banded preseason (July-September 1950-1980) to test hypotheses concerning the effects of winter temperatures, precipitation, and population levels on Mallard winter distribution. When two groups of years that comprised extremes of warm and cold winter weather were compared, recovery distributions of all four age and sex classes (adult males and females, young males and females) differed significantly; recoveries were located farther south in cold years. Recovery distributions also differed between wet and dry years in the MAV for all groups except adult males, higher proportions of recoveries of adult females and of young males and females occurring in the MAV during wet winters. Although differences in continental Mallard population size were associated with differences in recovery distributions only of adult males and young females, the proportion of young males and of all young Mallards recovered in the MAV increased during years of low populations. We conclude that temperature, water conditions, and population size affect the habitat suitability of Mallard wintering areas and that Mallards exhibit considerable flexibility in winter distribution associated with these factors.

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.

Spatial Organisation of Urban Feral Cats (Felis Catus) in Jerusalem.

1995 ◽  
Vol 22 (3) ◽  
pp. 299 ◽  
Author(s):  
V Mirmovitch
Keyword(s):  
Home Range ◽  
Home Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
Mating Season ◽  
Minimum Convex Polygon ◽  
Spatial Organisation ◽  
Similar Frequency ◽  
Feral Cats ◽  
Young Males

Feral cats were studied for 10 months in a residential area in Jerusalem and their spatial distribution compared during two 1-month periods, the first in the autumn prior to the mating season and the second during the mating season (winter). Cat locations were recorded by direct observations, and home-range sizes were calculated with the minimum convex polygon method. No significant change in home-range size of adult males or females was found between the 2 periods. Young males expanded their home ranges considerably during their first mating season. Home ranges of males were significantly larger than those of females in both periods (0.56 and 0.30 ha, respectively, in autumn; 0.75 and 0.27 ha in winter). The home ranges of both sexes overlapped considerably with individuals of the same sex. Overlap among home ranges of females indicated a group pattern. High overlap (80%) was found among females that fed from the same set of garbage bins with similar frequency. Lower overlap (20%) was found between individual females that shared only a subset of their food resources and used it with different frequency. It is suggested that the distribution of food patches (garbage bins), the amount of food available and the rate of food renewal determined the cats' spatial organisation.

An Ecological Study of Sminthopsis crassicaudata (Marsupialia : Dasyuridae) II.* Behaviour and Social Organization

1978 ◽  
Vol 5 (2) ◽  
pp. 163 ◽  
Author(s):  
SR Morton
Keyword(s):  
Social System ◽  
Ecological Study ◽  
Adaptive Significance ◽  
Breeding Period ◽  
Home Ranges ◽  
Nest Sites ◽  
Sminthopsis Crassicaudata ◽  
The Social ◽  
Males And Females ◽  
Nest Sharing

The behaviour of Sminthopsis crassicaudata was studied by mark-recapture techniques at Werribee, Vic., from 1972 to 1976. Observations of nocturnal behaviour were also made at Fowlers Gap Station, N.S.W. S. crassicaudata usually nest solitarily in the breeding period (August–March), but up to 70% of individuals share nests in groups of from two to eight during the non-breeding period (April–July). These nest-sharing groups are impermanent and appear to be random aggregations of individuals. Most nest-sharing in the breeding period involves pairs of a male with an oestrous female. Both males and females inhabit large overlapping ranges in the breeding and non-breeding periods. Males seem to move their nest sites more frequently than females; this supposition is supported by observations of nocturnal behaviour. The ranges of individuals are unstable in space and are best described as 'drifting home ranges'. The only animals that may become territorial are breeding females, and these probably defend only a small area around the nest. Males do not appear to defend their range at any time. The adaptive significance of the social system is discussed. * Part I, Aust. Wildl. Res., 1978, 5, 151–62.

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.

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