Survival, Age-Determination and Population Age Structure of the Common Ringtail Possum, Pseudocheirus-Peregrinus, in a Eucalyptus Woodland and a Leptospermum Thicket in Southern Victoria

1987 ◽  
Vol 35 (6) ◽  
pp. 625 ◽  
Author(s):  
LI Pahl
Keyword(s):  
Age Determination ◽  
Growth Curves ◽  
Tooth Wear ◽  
Adult Males ◽  
Lower Survival ◽  
Average Rainfall ◽  
Pseudocheirus Peregrinus ◽  
Drought Survival ◽  
Two Populations ◽  
Ringtail Possum

Juvenile ringtail possums in two populations were aged by comparison with growth curves based on head length and body weight, and adults were aged by comparing the degree of tooth wear with that of ringtails of known age. Survival to the end of pouch life, 3 months old, appeared high but dropped markedly thereafter. During years of 'average' rainfall, 26-80% of all offspring lived to the age of weaning (6 months), but as few as 6% survived to weaning in a year of drought. Approximately 30% survived to sexual maturity (1 year) during years of 'average' rainfall, compared with 2% during a drought. Survival of adult females was higher than that of adult males, and ringtails at Sandy Point (Leptospermum thicket) appeared to survive longer than ringtails at Lysterfield (Eucalyptus woodland). The lower survival of adult ringtails at Lysterfield was associated with higher rates of tooth wear, possibly due to their more abrasive diet, but may have also been influenced by the hotter climate at Lysterfield. The lower survival of ringtails at Lysterfield resulted in a population with a greater proportion of 1-year-old animals than in the Sandy Point population.

Age of road-killed common brushtail possums (Trichosurus vulpecula) and common ringtail possums (Pseudocheirus peregrinus) in an urban environment

2009 ◽  
Vol 31 (2) ◽  
pp. 137 ◽  
Author(s):  
R. A. Giffney ◽  
T. Russell ◽  
J. L. Kohen
Keyword(s):  
Population Ecology ◽  
Tooth Wear ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Pseudocheirus Peregrinus ◽  
Declining Populations ◽  
Age Trends ◽  
The Common ◽  
Common Brushtail Possum ◽  
Ringtail Possum

Road-associated mortality has been identified as having major ecological effects on small, fragmented and declining populations. Both the common brushtail possum (Trichosurus vulpecula) and common ringtail possum (Pseudocheirus peregrinus) appear to be in decline in some regions across their natural ranges. Urban populations may be an exception; however, little is known of their population ecology. This study investigates age trends in a subset of road-killed brushtail and ringtail possums collected along eight northern Sydney roads between March 2004 and March 2006. From a total of 591 recorded road-killed possums, 86 were collected for use in this study (36 brushtails, 50 ringtails). Age was estimated using tooth wear patterns on cleaned skulls. Both species showed trends associated with age, and younger possums of both species were more likely to be killed on roads than older animals. Male-biased dispersal of subadult possums is considered a major contributing factor to the over-representation of young brushtail possums in this road-kill sample.

scholarly journals Incisor tooth wear and age determination in mountain gorillas from Volcanoes National Park, Rwanda

2018 ◽  
Vol 167 (4) ◽  
pp. 930-935 ◽  
Author(s):  
Jordi Galbany ◽  
Thadée Muhire ◽  
Veronica Vecellio ◽  
Antoine Mudakikwa ◽  
Aisha Nyiramana ◽  
...  
Keyword(s):  
National Park ◽  
Age Determination ◽  
Tooth Wear ◽  
Incisor Tooth ◽  
Mountain Gorillas

Differences in skeletal characters between the disjunct eastern and western populations of ring-billed gulls (Larus delawarensis)

1984 ◽  
Vol 62 (6) ◽  
pp. 1067-1074 ◽  
Author(s):  
Beatrice M. Termaat ◽  
John P. Ryder
Keyword(s):  
Discriminant Function ◽  
Multivariate Analyses ◽  
Correct Identification ◽  
Adult Males ◽  
Lake Of The Woods ◽  
Larus Delawarensis ◽  
Males And Females ◽  
Two Populations ◽  
Univariate Analyses ◽  
Discriminant Function Analyses

Univariate analyses of variance, multivariate analyses of variance (Manova), and discriminant function analyses were performed on measurements of 51 skeletal characters of adult males and females from the disjunct eastern and western populations of the ring-billed gull (Larus delawarensis) in Canada. The analyses established sufficient differences in skeletal characters to permit correct identification of the origin of 34 of 38 males (90%) and 40 of 42 females (95%). The populations are now expanding in range to the extent where new colonies are established in the Lake of the Woods, Ontario region, the historical hiatus between the two populations. Further expansion and contact may well erase the existing skeletal differences of individuals in these populations.

Diet of an inland population of the common ringtail possum (Pseudocheirus peregrinus)

2016 ◽  
Vol 38 (1) ◽  
pp. 130 ◽  
Author(s):  
Eden Hermsen ◽  
Anne Kerle ◽  
Julie M. Old
Keyword(s):  
New South ◽  
Habitat Requirements ◽  
South Wales ◽  
Pine Trees ◽  
Pseudocheirus Peregrinus ◽  
The Common ◽  
Microhistological Analysis ◽  
Vegetation Samples ◽  
Cypress Pine ◽  
Ringtail Possum

Populations of the common ringtail possum (Pseudocheirus peregrinus) in inland New South Wales have declined or disappeared. Habitat requirements and diet of these populations are poorly understood. Determining the diet of inland ringtail possums is crucial to understanding the factors limiting their survival, and was the focus of this study. Spotlighting surveys were conducted to locate ringtail possums, and scat and vegetation samples were collected for microhistological analysis. Ringtail possums were most frequently observed in red stringybark followed by bundy box and black cypress pine trees, and this correlated with the most common dietary items consumed.

Geographic variation in the diet of the powerful owl (Ninox strenua) at a local scale

2013 ◽  
Vol 61 (5) ◽  
pp. 372 ◽  
Author(s):  
Rohan J. Bilney
Keyword(s):  
Coastal Forests ◽  
Forest Sites ◽  
Sugar Glider ◽  
Pseudocheirus Peregrinus ◽  
The Common ◽  
Dietary Variation ◽  
Conservation Concern ◽  
Petaurus Breviceps ◽  
Ringtail Possum

This study reports the diet of the powerful owl (Ninox strenua) in East Gippsland, from a dataset of 2009 vertebrate prey items collected from 53 sites. Mammals dominated the diet at all sites, but birds were also consumed regularly. The greater glider (Petauroides volans) was the dominant dietary item across the region in terms of both frequency of consumption and biomass contribution. There was geographical dietary variation between coastal and foothill forest sites, with the sugar glider (Petaurus breviceps) and birds consumed more frequently in foothill forests, whereas the common ringtail possum (Pseudocheirus peregrinus) was frequently consumed only in coastal forests. Typically, a higher percentage of powerful owl diet comprised birds closer to cleared land. The dietary reliance upon hollow-dependent mammals in foothill forests (averaging >70%) is of conservation concern, especially when non-hollow-dependent prey are rare. Forest management activities, especially logging, that reduce densities of hollow-bearing trees in the landscape are therefore likely to decrease the long-term carrying capacity of the landscape for the powerful owl.

Age Determination in the Dingo and Crossbreeds.

1991 ◽  
Vol 18 (1) ◽  
pp. 75 ◽  
Author(s):  
PC Catling ◽  
LK Corbett ◽  
M Westcott
Keyword(s):  
Age Estimation ◽  
Canis Familiaris ◽  
Age Determination ◽  
Growth Curves ◽  
Growth Patterns ◽  
Birth Date ◽  
Eye Lens ◽  
Body Measurements ◽  
Confidence Limits ◽  
Regular Body

Growth curves were derived for captive known-age dingoes, Canis familiaris dingo, and their crosses with similarly sized domestic dogs, C. f. familiaris. Regular body measurements including weight and dried eye-lens weights were used. Age calibration curves and confidence limits were then produced to enable age estimation of animals of unknown birth date. Head length was the better predictor of age up to about 120 days, and eye-lens weight to about 500 days. The only difference in growth patterns in dingoes and crossbreeds from central and southern Australia was between sexes.

scholarly journals Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods

2005 ◽  
Vol 62 (4) ◽  
pp. 655-670 ◽  
Author(s):  
Christoph Stransky ◽  
Sif Gudmundsdóttir ◽  
Thorsteinn Sigurdsson ◽  
Svend Lemvig ◽  
Kjell Nedreaas ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Age Determination ◽  
Growth Curves ◽  
Age And Growth ◽  
Preparation Methods ◽  
Irminger Sea ◽  
Coefficients Of Variation ◽  
Commercial Species ◽  
Almost All

Abstract Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.

scholarly journals Skeletochronological Age Determination and Comparative Demographic Analysis of Two Populations of the Gold-spotted Pond Frog (Rana chosenica)

2007 ◽  
Vol 30 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Seok-Wan Cheong ◽  
Dae-Sik Park ◽  
Ha-Cheol Sung ◽  
Jung-Hyun Lee ◽  
Shi-Ryong Park
Keyword(s):  
Age Determination ◽  
Demographic Analysis ◽  
Two Populations

scholarly journals Sarcoptes scabiei: an important exotic pathogen of wombats

2005 ◽  
Vol 26 (2) ◽  
pp. 79 ◽  
Author(s):  
Lee F Skerratt
Keyword(s):  
Native Species ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
High Morbidity ◽  
Phascolarctos Cinereus ◽  
Recent Emergence ◽  
Common Wombat ◽  
Pseudocheirus Peregrinus ◽  
Exotic Pathogen ◽  
Ringtail Possum

Sarcoptes scabiei is a parasitic astigmatid mite, which causes scabies in people and sarcoptic mange in mammals. Importantly, it is an emerging disease in wildlife throughout the world. The mite originates from a human ancestor and is thought to have spread to domestic and then free-living animals. Based on the recent emergence of sarcoptic mange in Australian wildlife and Aboriginal communities, it is thought that Sarcoptes scabiei was probably introduced to Australia by the Europeans and their animals. The mitochondrial genetic similarity of mites from Australian wildlife and domestic animals supports this. In Australian wildlife, sarcoptic mange has been reported in the common wombat Vombatus ursinus, southern hairy-nosed wombat Lasiorhinus latifrons, koala Phascolarctos cinereus, common ringtail possum Pseudocheirus peregrinus and in 2003 in the agile wallaby Macropus agilis. Compared with other native species, sarcoptic mange has by far its greatest impact on wombats, particularly common wombats, and is capable of causing high morbidity and mortality rates.

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