Male Bias in Road-kills of Macropods

1997 ◽  
Vol 24 (1) ◽  
pp. 21 ◽  
Author(s):  
Graeme Coulson
Keyword(s):  
Population Structure ◽  
Sex Ratios ◽  
Insufficient Data ◽  
Road Mortality ◽  
Male Bias ◽  
Red Kangaroo ◽  
Significant Bias ◽  
Macropus Rufus ◽  
Wallabia Bicolor

I determined the sex of a total of 251 road-kills of six macropod species in southern Australia over a 13-year period. There was a significant bias towards males in five species, ranging from 65 to 92% males, but there was no difference from parity in the red kangaroo, Macropus rufus. Male eastern grey kangaroos, M. giganteus, and male western grey kangaroos, M. fuliginosus, probably behave in ways that expose them to vehicles more than females. Male-biased road-kills of swamp wallabies, Wallabia bicolor, may reflect skewed population sex ratios. There are insufficient data on the behaviour and population structure of the red-necked wallaby, M. rufogriseus, and rufous-bellied pademelon, Thylogale billardierii, to determine which explanation is responsible for male-biased road mortality in these species.

scholarly journals Assessing the Impacts of Urbanization on Sex Ratios of Painted Turtles (Chrysemys picta)

Diversity ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 72 ◽  
Author(s):  
John P. Vanek ◽  
Gary A. Glowacki
Keyword(s):  
Population Structure ◽  
Sex Ratios ◽  
Monitoring Program ◽  
Chrysemys Picta ◽  
Adult Survival ◽  
Sampling Location ◽  
Road Mortality ◽  
Population Declines ◽  
Road Density ◽  
Painted Turtles

Turtles are particularly susceptible to the negative impacts of urbanization due to low mobility and a life history strategy emphasizing long generation times and high adult survival. In addition to declines directly through habitat loss, urbanization has been hypothesized to limit populations of aquatic turtles through changes in population structure, as adult females are disproportionally killed on and near roads, leading to male-biased populations, which can lead to population declines or local extirpations. The purpose of this study was to better understand how urbanization impacts the sex ratios of painted turtles (Chrysemys picta) in an urban ecosystem, as empirical results linking male-biased turtle populations to roads and urbanization are mixed. Using eight years of trapping data from a long-term monitoring program in a suburb of Chicago, IL, USA, we report one of the most male-biased populations ( x ¯ = 75% male) of turtles in the USA, consistent with prevailing road mortality hypotheses. However, we found no evidence that male-biased populations were related to road density or the amount of protected area around a sampling location and found that impervious surface (a metric of urbanization) was weakly related to less male-biased populations. Our results highlight the importance of replicating ecological studies across space and time and the difficulty in assessing population structure in aquatic turtles. We suggest that active conservation measures may be warranted for the continued persistence of urban turtle populations.

Diagnosis and treatment of mesenteric volvulus in a red kangaroo (Macropus rufus)

2014 ◽  
Vol 244 (7) ◽  
pp. 844-850 ◽  
Author(s):  
S. Emmanuelle Knafo ◽  
Alana J. Rosenblatt ◽  
James K. Morrisey ◽  
James A. Flanders ◽  
Margret S. Thompson ◽  
...  
Keyword(s):  
Diagnosis And Treatment ◽  
Red Kangaroo ◽  
Macropus Rufus

Bilateral radial and ulnar fractures in a red kangaroo (Macropus rufus)

2019 ◽  
Vol 255 (8) ◽  
pp. 942-948 ◽  
Author(s):  
Katherine L. Ballor ◽  
Krista M. Gazzola ◽  
Karen L. Perry
Keyword(s):  
Red Kangaroo ◽  
Macropus Rufus

Unequal sex ratios in longline catches

2001 ◽  
Vol 81 (1) ◽  
pp. 187-188 ◽  
Author(s):  
P. Wirtz ◽  
T. Morato
Keyword(s):  
Sex Ratio ◽  
Feeding Behaviour ◽  
Sex Ratios ◽  
The Other ◽  
Size Difference ◽  
Longline Fishery ◽  
Significant Bias ◽  
Different Response ◽  
The Given

There is sometimes a significant bias in the sex ratio of fish caught by longline. Usually, more females than males are caught. The possible reasons for unequal sex ratios in longline catches are listed and discussed. One sex could be more common in the area where the fishery takes place because there really is an unequal sex ratio in the population or because the other sex preferentially occurs in different places. Alternatively, longline fishery might preferentially catch one of the sexes. This could be a result of size difference between the sexes and thus a different response to the given hook size or bait size. Finally, sexes could differ in their feeding behaviour. There is growing evidence that females—not only of fish—are ‘energy maximizers’: they find food faster and spend more time feeding than do males. Thus, fishing methods using bait are likely to catch a higher proportion of females than fishing methods that do not use bait.

PETERS ANOMALY IN A RED KANGAROO (MACROPUS RUFUS)

2014 ◽  
Vol 45 (3) ◽  
pp. 715-718 ◽  
Author(s):  
Wm. Kirk Suedmeyer ◽  
Jacqueline Pearce ◽  
Meredith Persky ◽  
Marlys L. Houck
Keyword(s):  
Red Kangaroo ◽  
Peters Anomaly ◽  
Macropus Rufus

Daily changes in plant water content in western Queensland: implications for red kangaroo foraging times

2004 ◽  
Vol 26 (1) ◽  
pp. 102 ◽  
Author(s):  
S. Underhill ◽  
G. C. Grigg ◽  
D. J. Yates
Keyword(s):  
Water Content ◽  
National Park ◽  
Plant Water ◽  
Forage Plants ◽  
Red Kangaroo ◽  
Macropus Rufus ◽  
Daily Changes ◽  
Semi Arid

We measured daily changes in plant water content to see if red kangaroos (Macropus rufus), in foraging at night, may gain more water than foraging by day. If so, it could be influential in dictating their time of foraging. The study was stimulated by work in Africa which showed that, by choosing to feed at night, gazelles are able to take advantage of increased plant water content. Daily changes in water content of 15 known forage plants were examined at Idalia National Park in semi-arid western Queensland in February, April and July 2002, during progressive drying of the country in an extraordinarily dry year. Of 29 day-night comparisons of plant water content, thirteen showed no difference, two (both of red spinach, Trianthema triquetra) showed a substantial increase at night, eight showed small but statistically significant increases, and six showed small but statistically significant decreases. We conclude that the choice of red kangaroos to forage at night is unlikely to be explained by nightly increases in plant water content.

Habitat Selection by Sex, Age and Reproductive Class in the Red Kangaroo, Macropus rufus, in Western New South Wales

1981 ◽  
Vol 8 (3) ◽  
pp. 465 ◽  
Author(s):  
CN Johnson ◽  
PG Bayliss
Keyword(s):  
Habitat Selection ◽  
National Park ◽  
Mating Systems ◽  
New South ◽  
New South Wales ◽  
Vegetation Types ◽  
Red Kangaroo ◽  
South Wales ◽  
Macropus Rufus ◽  
Lactating Females

The kangaroo populations of Kinchega National Park respond differently to shifts in pasture productivity, red kangaroos Macropus rufus being mobile and unevenly distributed with respect to soil and vegetation types, by comparison with the more evenly dispersed western grey kangaroos M. fuliginosus and the sedentary and localized euros M, robustus erubescens. Red kangaroo population classes tend to be differentially distributed, so that large males and heavily lactating females predominate on the seasonally preferred pastures, while other classes tend to predominate elsewhere. This finding has several implications for the management of red kangaroos and for our understanding of their resource ecology and mating systems.

scholarly journals Transferrin Polymorphism in the Australian marsupial mouse Sminthopsis crassicaudata (Gould)

1968 ◽  
Vol 21 (3) ◽  
pp. 587 ◽  
Author(s):  
RM Hope ◽  
GK Godfrey
Keyword(s):  
Personal Communication ◽  
Iron Binding ◽  
Trichosurus Vulpecula ◽  
Protein Patterns ◽  
Red Kangaroo ◽  
Sminthopsis Crassicaudata ◽  
Macropus Rufus ◽  
Starch Gel ◽  
Australian Marsupial ◽  
Transferrin Polymorphism

A number of polymorphisms involving characteristics of the blood have been described in Australian marsupials, but the genetical control of these has been established only for variation in the iron-binding serum protein transferrin in the red kangaroo Macropus rufus (Desmarest) (= Megaleia rufa) (Cooper and Sharman 1964), and the eastern and western grey kangaroos Macropus giganteus (Shaw) and Macropus fuliginosus (Desmarest) (Kirsch and Poole 1967). Transferrin variation in the brush-tail possum Trichosurus vulpecula (Kerr), first detected by Kirsch (personal communication), is being studied in this laboratory. The inheritance of the protein patterns developed on a starch gel after electrophoresis may be ascribed to the actions of two or more autosomal allelic genes without dominance.

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