Population dynamics and life history of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps, in north Queensland

Mahogany gliders, Petaurus gracilis, and sugar gliders, Petaurus breviceps, were trapped in an area of open woodland in north Queensland between 1994 and 1996 to examine their population ecology and life history. This study area contained two smaller areas, one consisting of continuous habitat and the other an area of fragmented habitat adjacent to the continuous habitat. Within the continuous area, the mahogany glider had an average density of 0.24 ha–1 whereas the sugar glider had an average density of 0.27 ha–1. In contrast, the density of mahogany gliders in the fragmented habitat averaged only 0.16 ha–1 whereas the density of sugar gliders was higher, at 0.46 ha–1. Both the mahogany glider and the sugar glider showed sexual dimorphism in their weight, head length and head width. The average body weight of both species fluctuated throughout the year with no consistent pattern. The mahogany glider showed a distinct breeding season, with births being recorded between April and October, whereas the sugar glider showed no pattern, with births being recorded during all months except February and April. During the study, all adult females of both species were observed to have bred, with an average litter size of 1.55 and a natality rate of 2.09 for the mahogany glider, and an average litter size of 1.83 and a natality rate of 2.14 for the sugar glider. The sugar glider was able to raise two litters of young within a single year whereas a second litter was raised by the mahogany glider only if the first litter was lost.

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On the differential topology of space-time

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s030500410004665x ◽

1971 ◽

Vol 69 (2) ◽

pp. 295-296 ◽

Cited By ~ 1

Author(s):

J. Wolfgang Smith

Keyword(s):

General Relativity ◽

Life History ◽

Space Time ◽

Average Density ◽

Relativity Theory ◽

General Relativity Theory ◽

Differential Topology ◽

Cosmology Theory ◽

History Of

It has often been assumed in cosmology theory(1) that there exists an average density of matter in space which is everywhere greater than zero. Under this assumption the space-time M will be foliated by curves each of which represents the life history of a particle. In keeping with the postulates of general relativity theory we shall refer to these curves as geodesics. Letting X denote the space of particles one obtains a projection f: M → X which assigns to every P ∈ M the particle found at P. Conversely, given the projection f:M → X, one can recover the geodesics: they are precisely the fibres f−1(x), x∈X.

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Relationships between size of stream insects and current velocity

Canadian Journal of Zoology ◽

10.1139/z78-027 ◽

1978 ◽

Vol 56 (2) ◽

pp. 178-186 ◽

Cited By ~ 20

Author(s):

William P. Kovalak

Keyword(s):

Life History ◽

Habitat Selection ◽

Dry Weight ◽

Growth Cycle ◽

Head Width ◽

Differential Growth ◽

Growth Cycles ◽

Frequency Distributions ◽

Stream Insects ◽

History Of

Size frequency distributions and dry weight – head width relationships for six insect species from two habitats with differing current velocities in the Pigeon River, Michigan, were compared. Early in their growth cycles, Ephemerella subvaria, Ephemerella lata, Rhithrogena jejuna, and Glossosoma nigrior generally were larger at the slow station, but near the end of the growth cycles they generally were larger at the fast station. For Paraleptophlebia mollis, early in the growth cycle size differences between stations were small but near the end of the growth cycles nymphs were larger at the fast station, whereas nymphs of Ephemerella deficiens were slightly larger at the slow station throughout the growth cycle. Larger size at the slow station probably was due to differential growth whereas larger size at the fast station probably was due to differential habitat selection controlled by oxygen requirements.There were no significant differences in dry weight – head width relationships between habitats or between sexes. Sex ratios generally were similar at the two stations and did not deviate appreciably from 50:50.The life history of each species is briefly described.

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Does encephalization correlate with life history or metabolic rate in Carnivora?

Biology Letters ◽

10.1098/rsbl.2009.0787 ◽

2009 ◽

Vol 6 (3) ◽

pp. 350-353 ◽

Cited By ~ 17

Author(s):

John A. Finarelli

Keyword(s):

Life History ◽

Metabolic Rate ◽

Body Mass ◽

Litter Size ◽

Brain Size ◽

Recent Analysis ◽

Size Evolution ◽

Gestation Time ◽

History Of ◽

History Variable

A recent analysis of brain size evolution reconstructed the plesiomorphic brain–body size allometry for the mammalian order Carnivora, providing an important reference frame for comparative analyses of encephalization (brain volume scaled to body mass). I performed phylogenetically corrected regressions to remove the effects of body mass, calculating correlations between residual values of encephalization with basal metabolic rate (BMR) and six life-history variables (gestation time, neonatal mass, weaning time, weaning mass, litter size, litters per year). No significant correlations were recovered between encephalization and any life-history variable or BMR, arguing against hypotheses relating encephalization to maternal energetic investment. However, after correcting for clade-specific adaptations, I recovered significant correlations for several variables, and further analysis revealed a conserved carnivoran reproductive strategy, linking degree of encephalization to the well-documented mammalian life-history trade-off between neonatal mass and litter size. This strategy of fewer, larger offspring correlating with increased encephalization remains intact even after independent changes in encephalization allometries in the evolutionary history of this clade.

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Life-History of the Feathertail Glider, Acrobates-Pygmaeus (Acrobatidae, Marsupialia) in South-Eastern Australia

Australian Journal of Zoology ◽

10.1071/zo9900503 ◽

1990 ◽

Vol 38 (5) ◽

pp. 503 ◽

Cited By ~ 18

Author(s):

SJ Ward

Keyword(s):

Life History ◽

Litter Size ◽

Maternal Investment ◽

Seasonal Fluctuation ◽

North West ◽

South Eastern ◽

North East ◽

Eastern Australia ◽

History Of ◽

Maximum Field

Acrobates pygmaeus was captured in nestboxes in three areas of central and southern Victoria: the Gembrook-Cockatoo area and Nar Nar Goon North east of Melbourne, and Daylesford north-west of Melbourne. Breeding was strictly seasonal and females produced two litters between July and February each year. Males also showed seasonal fluctuation in testes sizes. Mean litter size was 3.5 at birth and 2.5 at weaning. Pouch life lasted 65 days and young were weaned at approximately 100 days of age. Growth was slow and maternal investment in each young was high, and continued after weaning. Most individuals matured in the season following their birth, but some males did not mature until the second season after their birth. Maximum field longevity was at least three years. Comparisons are made with other small diprotodont marsupials.

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