Morphometric differences between Australian wild rabbit populations

1977 ◽  
Vol 25 (4) ◽  
pp. 721 ◽  
Author(s):  
J Taylor ◽  
L Freedman ◽  
TJ Olivier ◽  
J McCluskey

Morphometric distances, based on 20 skull measurements, were determined between eight localized Australian wild rabbit populations and a sample from the British Isles. To minimize the influence of age-associated variation in the Australian series, only animals estimated to be at least 12 months old (based on epiphyseal and dry eye-lens aging techniques) were included. Sexes were pooled after univariate and multivariate testing for sexual dimorphism and eliminating bizygomatic breadth. By means of univariate statistics, Mahalanobis generalized distance and canonical analysis, the various Australian and British Isles samples were shown to differ appreciably, morphometric distance increasing clinally in eastern Australia with geographic distance from the point of introduction (Geelong, Vic.). Based on a plot of first and second canonical variates, differences between three Canberra area samples were comparable in magnitude to those between certain populations separated by much greater geographic distances. These findings are consistent with results of studies of blood protein variations in Australian wild rabbit populations.

1991 ◽  
Vol 39 (3) ◽  
pp. 285 ◽  
Author(s):  
WS Osborne ◽  
JA Norman

Reproductive compatibility and population genetic structure were examined in the corroboree frog, Pseudophryne corroboree, a species restricted to montane and subalpine environments in south-eastern Australia. The species comprises three geographic populations, represented by two morphological forms. Hybridisation experiments showed that the allopatric populations are interfertile, although crosses between the Snowy Mountains population (southern form) and each of the two northern populations (northern form) resulted in a significantly higher number of tadpoles with growth abnormalities. An electrophoretic examination of metamorphlings indicated that there was considerable genetic divergence between the two forms, with several loci approaching fixation of alternate alleles. The Snowy Mountains population also had substantially reduced levels of genetic variation compared to the two northern populations. Although genetic distances generally correlate with geographic distance, the genetic differences between the northern and southern populations form a pronounced step, not explicable by geographic distance alone. These findings have taxonomic implications which should be taken into account when considering the conservation management of this uncommon species.


1991 ◽  
Vol 39 (1) ◽  
pp. 85 ◽  
Author(s):  
P Leeton ◽  
YJ Fripp

The endangered plant species, Rutidosis leptorrhynchoides (button wrinklewort), is now known from only a few populations in each of two regions separated by approximately 500 km in south-eastern Australia. Plants were examined from several populations from each region. No differences in chromosome number or morphology were observed among plants or populations. All counts were diploid, 2n = 26. Viable progeny were obtained following self-pollination and allozyme analysis indicated that these progeny were the result of selfing and not agamospermy. This species is not an obligate outcrosser and does not have a classical pre-zygotic self-incompatibility system. However, outcross pollen may have an advantage over self pollen and this species may thus be preferentially outcrossing. The pollen: ovule ratios (mean 3186 ± 48.5) were consistent with this hypothesis. Allele frequencies at allozyme loci diferred little between populations, with an estimated 97% of the variation within populations. There was no correlation between genetic distance and geographic distance. In contrast, for the leaf dimensions of plants germinated and raised together in a glasshouse there were differences between plants from the two regions. It is recommended that populations from both regions should be conserved.


1974 ◽  
Vol 1 (1) ◽  
pp. 17 ◽  
Author(s):  
BS Parker ◽  
K Myers

Aerial surveys can be used to measure the distribution of rabbit warrens over large areas of arid and semiarid Australia. Clumped patterns of distribution of rabbit warrens found by ground surveys are also detected in aerial surveys, which further show that the highest density of warrens occurs in habitats containing shales or other fine-grained rocks overlain by recent sediments, or those closely related to drainage systems. A good picture of rabbit distribution is obtained when about 25% of the area has been overed by the aircraft. * Part IV, Aust. J. Zool., 1971, 19, 355–70.


1980 ◽  
Vol 7 (1) ◽  
pp. 79 ◽  
Author(s):  
SH Wheeler ◽  
DR King

Eye-lens weight-age relationships were determined for rabbits from a wild population and from an enclosed population (of the same stock) in south-western Australia. Previously published curves of lens weight v. age for rabbits in eastern Australia are not entirely satisfactory models for the western Australian data. However, the differences, though obvious, are minor, and for general aging any of the published curves are adequate. For accurate aging, regional curves may have to be determined.


1986 ◽  
Vol 60 (2) ◽  
pp. 92-98 ◽  
Author(s):  
B. Boag ◽  
G. Iason

ABSTRACTMountain hares were collected each month between April 1984 and March 1985 and their intestines examined for helminths. 26 rabbits were also collected between Juny and December 1984 and examined for gastro-intestinal helminths. Three nematode and two cestode species were found in the hares while only two nematode and one cestode species were found in the rabbits. Trichostronglylus retortaeformis was recorded form 88% of the 193 hares and 92% of the rabbits While comparable figures for Passalurus ambiguus were 0·5% and 54% and for Mosgovoyia pectinata 14% and 81%. Seasonal fluctuations were observed in the T. retortaeformis populations in the hare; numbers tended to be low during the winter months and high throughout the summer. Paranoplocephala wimerosa was reported for the first time from the British Isles and Trichostrongylus axei was recorded for the forst time in the mountain hare.


1961 ◽  
Vol 6 (2) ◽  
pp. 156 ◽  
Author(s):  
ML Dudzinski ◽  
R Mykytowycz
Keyword(s):  
Eye Lens ◽  

The Auk ◽  
1986 ◽  
Vol 103 (3) ◽  
pp. 575-585 ◽  
Author(s):  
Dennis M. Power ◽  
David G. Ainley

Abstract We assessed geographic variation in 13 locality samples of Leach's Storm-Petrel (Oceanodroma leucorhoa), 12 from the Pacific coast and 1 from the Atlantic coast of North America. Nine phenetic characters were used with canonical variates analysis to determine similarity among samples. Regression of phenetic distance on geographic distance measured the relation between similarity and interisland distance. We found a clinal pattern of population similarity from the Aleutian Islands in the north to the Farallon Islands in the south. Populations from Los Coronados and San Benitos islands make up a distinct subset when rump color and wing and tail shape indices are included in the analysis, but these populations were part of a dominant clinal trend when only five size characters were used. On Guadalupe Island separate populations breed in summer and winter; these are strongly differentiated from the others and from each other. The North Atlantic sample was aligned closely with that from the Aleutians. The degree of geographic variation was roughly similar to that in certain migratory land birds on the North American continent, but is less than what is found for certain nonmigratory land birds on islands. Our results suggest recognizing four subspecies of Leach's Storm-Petrel in the study area, including two on Guadalupe Island isolated by time of breeding.


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