Population Ecology and Physiology of the Common Rock Rat, Zyzomys argurus (Rodentia: Muridae) in Tropical Northwestern Australia

Bradley, A. J.; Kemper, CM; Kitchener, D. J.; Humphreys, W. F.; How, R. A.; Schmitt, Linc

doi:10.2307/1381630

Cited by 15 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unlike the situation in Antechinus sruarrii males, which show a great deal of movement during the mating period (Lee et al, 1977), there was no observable difference in the pattern or extent of movement between female and male D. hallucatus. Seasonal changes in the diameter of the tail base of D. hallucatus were similar in pattern to weight changes and suggest that this parameter may be an indicator of nutritional condition of individuals as has been shown for the murid rodent Zyzomys urgurus in the tropics (Begg, 1981b;Bradley, Kemper, Kitchener, Humphreys, How & Schmitt, 1988).…”

Section: Discussionsupporting

confidence: 56%

“…This study was principally designed to investigate the ecophysiology of D. hallucatus in diflerent habitats and is part of a larger study of the ecophysiology of tropical small mammals (Humphreys, How, Bradley, Kemper & Kitchener, 1984;Kemper, Kitchener, Humphreys, How, Bradley & Schmitt, 1987;Kemper, Kitchener, Humphreys, How, Schmitt & Bradley, In prep. ;Bradley, Kemper, Kitchener, Humphreys, How & Schmitt, 1988). Additionally, the physiological changes of post-mating males of this species were compared to those in other dasyurids that show either a complete or incomplete post-mating male mortality.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ecology and physiology of the northern quoll, Dasyurus hallucatus (Marsupialia, Dasyuridae), at Mitchell Plateau, Kimberley, Western Australia

et al. 1989

Self Cite

View full text Add to dashboard Cite

With 1 plate and 4 figures in the text) Breeding, population dynamics and seasonal changes in physical and physiological parameters were examined in the northern quoll (Dasyurus hallticatus) at Mitchell Plateau, Western Australia, between September 1981 and November 1982. Females gave birth to a single litter of young in July or August. Births were earlier on near-coastal sites than on inland sites. Litter size was greater on inland sites and litter size differed between years. By September all females were either carrying pouch young or were lactating. Lactation ceased by April. Testosterone levels in males peaked in July. There were significantly more male than female pouch young. However, in only one grid was the adult sex ratio different from parity, with an excess of females in September 1981 and 1982. Embryonic mortality was > 53% but loss of pouch young was small. Although males and females moved similar distances between successive recaptures, the extent of movement varied seasonally, being greatest in September. Males were generally larger and heavier than females. Seasonal variations were recorded for most physical and physiological parameters. The most pronounced changes occurred towards the end of the dry season (July to September) for both males and females. Over this period there was a significant decline in weight (males), haematocrit (males), plasma albumin (males) and leucocytes (both males and females) and significant elevations in values of haemoglobin and both free and protein-bound cortisol in both males and females. Few males survived the post-mating period from July to September. They appeared to decline in condition over this period more markedly than females: they lost more weight, their haematocrit and plasma albumin values declined to a greater extent, and they were more heavily infected with lice (Boopia uncinata). Males with lower testosterone and higher free and protein-bound cortisol had increased prospects of surviving the breeding season, which suggests that it is the dominant males that are less likely to survive the breeding season. Individuals in the three major populations at Mitchell Plateau differed greatly in their physiological values. The high-density population in a sandstone area had intermediate levels of free cortisol and higher haematocrit values than both the other populations, and higher levels of haemogl3bin than the population on laterite substratum.

show abstract

Section: Discussionsupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Ecology and physiology of the northern quoll, Dasyurus hallucatus (Marsupialia, Dasyuridae), at Mitchell Plateau, Kimberley, Western Australia

et al. 1989

Self Cite

View full text Add to dashboard Cite

show abstract

“…One of the most convincing examples of immunosuppression involvement in population regulation is found in the marsupial genus Antechinus where elevated glucocorticoids induce suppression of immune and inflammatory systems resulting in infectious disease and death (Bradley et al 1980, McDonald et al 1981. Similar associations have been described for the bush rat (Rattus fuscipes) and rock rat (Zyzomys argurus) in Australia (Bradley et al 1988, McDonald et al 1988). Current evidence indicates that density-de-pendent immunosuppression is not unique to neuroendocrine-stress physiology, but probably is an important component of other population-regulating factors such as food quality.…”

Section: Discussionmentioning

confidence: 64%

“…Seasonal changes in lymphoproliferative responsiveness have been reported for laboratory mice, dogs, and humans (Shifrine et al 1980, Brock 1983, Komada et al 1989. Seasonal changes in genetic variability within animal populations have also been reported (Dubach 197 5) and have occurred concomitantly with changes in measures of immune function such as incidence of Salmonella and lymphocyte counts (Bradley et al 1988).…”

Section: Discussionmentioning

confidence: 98%

Temporal Variation in Humoral and Cell‐Mediated Immune Response in a Sigmodon Hispidus Population

Lochmiller¹,

Vestey²,

McMurry³

1994

Ecology

View full text Add to dashboard Cite

We examined the hypothesis that environmentally induced alteration of immunocompetence is a primary physiological mechanism by which population survival is regulated. The involvement of disease and immunocompetence in the regulation of small mammal populations is not well understood but a strong relationship between physiological stress and immunity has been demonstrated. Its involvement is further supported by several studies, which have provided evidence that survival, incidence of disease, and selected gross measures of immunity change temporally with density and season. We examined this hypothesis by documenting the existence of temporal alterations in selected measures of both humoral and cell—mediated immune function in a population of cotton rats (Sigmodon hispidus), a species known to fluctuate widely in density, inhabiting a tallgrass prairie in central Oklahoma. A total of 310 cotton rats was collected from August 1989 to May 1991 (10 collections) using conventional live—trap methods. In addition to morphological characteristics of primary and secondary lymphoid organs, the ability of splenocytes to produce specific antibody in response to a single injection of sheep erythrocytes and to proliferate in response to in vitro exposure to mitogens was measured to assess immunocompetence. Whole blood was collected for the determination of total peripheral blood leukocyte counts, packed cell volume, and total serum proteins. Statistically significant differences in all variable except total serum protein existed among the 10 collections and most of this variability was independent of specific seasonal time periods. Bimodal thythmicity was characteristic of temporal changes for several measures of immunocompetence. Changes over time in the average immunocompetence of this population could have reflected a shift in genotypic polymorphism; several other plausible explanations are offered to explain the observed temporal patterns.

show abstract

“…High levels of corticosterone may be costly to an organism since chronic elevated levels of this hormone can produce kidney diseases, stomac tumors and reproduction failures (Bronson 1967, McDonald et al 1981, Bradley et al 1988. If chronic levels of corticosterone occurred in Westray mice, one would have expected these mice to have heavy adrenals (Christian and Davis 1956).…”

Section: Comparing Island-populationsmentioning

confidence: 99%

Behavioural and physiological characteristics of standard and chromosomally divergent populations of house mice from the Orkney archipelago (Scotland)

Ganem¹

1998

Acta Theriol.

View full text Add to dashboard Cite

Behavioural and physiological characteristics of standard and chromosomally divergent populations of house mice from the Orkney archipelago (Scotland) Guila GANEM Ganem G. 1998. Behavioural and physiological characteristics of standard and chromosomally divergent populations of house mice from the Orkney archipelago (Scotland). Acta Theriologica 43: 23-38. (Schwartz and Schwartz, 1943) from Orkney are closely related on the basis of mandible morphology and allozyme variation. In three of the twenty islands where house mice occur populations have diverged from the standard 2n = 40 karyotype through fixation of Robertsonian (Rb) chromosomal mutations. Mice from Westray island carry 36 chromosomes and share one Rb fusion with those from Eday and Faray (2n = 34; 2n = 34-36). These islands are geographically very close to each other and to islands carrying standard mice. Behavioural and ecophysiological analyses were performed on the three chromosomally divergent populations of mice as well as on two nearby standard populations (Sanday and Papa-Westray). The aim of the study was to assess whether divergences attributable to chromosomal changes occur, and to discuss whether behavioural divergences may explain the non-mixing of karyotypes. The study does not reveal any divergence between islands attributable to karyotype or habitat differences. The non-blending of the different karyotypes present in Orkney is discussed with reference to history of colonisation, human behaviour, and the consequences of site saturation. Particular characteristics displayed by the different island-populations suggest that in the near future the present pattern of karyotype variation observed in Orkney could change. House mice Mus musculus domesticus

show abstract

Population Ecology and Physiology of the Common Rock Rat, Zyzomys argurus (Rodentia: Muridae) in Tropical Northwestern Australia

Cited by 15 publications

References 0 publications

Ecology and physiology of the northern quoll, Dasyurus hallucatus (Marsupialia, Dasyuridae), at Mitchell Plateau, Kimberley, Western Australia

Ecology and physiology of the northern quoll, Dasyurus hallucatus (Marsupialia, Dasyuridae), at Mitchell Plateau, Kimberley, Western Australia

Temporal Variation in Humoral and Cell‐Mediated Immune Response in a Sigmodon Hispidus Population

Behavioural and physiological characteristics of standard and chromosomally divergent populations of house mice from the Orkney archipelago (Scotland)

Contact Info

Product

Resources

About