Moult, Movements, Age and Sex Composition of Mountain Duck, Tadorna tadornoides, Banded at Lake George, N.S.W

1976 ◽  
Vol 3 (2) ◽  
pp. 173 ◽  
Author(s):  
JL McKean ◽  
LW Braithwaite

Two samples of mountain ducks totalling 1001 birds were trapped and banded at Lake George,N.S.W. A highly significant difference in age structure between the two samples, taken in January 1965 and in February 1970, may be related to major differences in rainfall for the year preceding each sample. The sex ratio was markedly biased in favour of females. Recoveries of birds were nearly all to the south and west and 300-700 km from the banding site. Fully 99 % of recoveries were in States other than New South Wales. Examination of one sample of 679 mountain ducks for moult of primary and secondary wing feathers showed that approximately one-third of the adults were moulting. It was concluded that the birds were possibly normal residents of the region in which most recoveries occurred, and that they make an annual moult migration to Lake George.

Environments ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Peter Brimblecombe ◽  
Yonghang Lai

The COVID-19 pandemic made it critical to limit the spread of the disease by enforcing human isolation, restricting travel and reducing social activities. Dramatic improvements to air quality, especially NO2, have often characterised places under COVID-19 restrictions. Air pollution measurements in Sydney in April 2019 and during the lockdown period in April 2020 show reduced daily averaged NO2 concentrations: 8.52 ± 1.92 and 7.85 ± 2.92 ppb, though not significantly so (p1~0.15) and PM2.5 8.91 ± 4.94 and 7.95 ± 2.64 µg m−3, again a non-significant difference (p1~0.18). Satellite imagery suggests changes that parallel those at ground level, but the column densities averaged over space and time, in false-colour, are more dramatic. Changed human mobility could be traced in increasing times spent at home, assessed from Google Mobility Reports and mirrored in decreased traffic flow on a major road, suggesting compliance with the restrictions. Electricity demand for the State of New South Wales was low under lockdown in early April 2020, but it recovered rapidly. Analysis of the uses of search terms: bushfires, air quality, haze and air pollution using Google Trends showed strong links between bushfires and pollution-related terms. The smoke from bushfires in late 2019 may well have added to the general impression of improved air quality during lockdown, despite only modest changes in the ground level measurements. This gives hints that successful regulation of air quality requires maintaining a delicate balance between our social perceptions and the physical reality.


Behaviour ◽  
1988 ◽  
Vol 104 (3-4) ◽  
pp. 202-232 ◽  
Author(s):  
John G. Robinson

AbstractThe extent to which population demography determines the age and sex composition of primate groups was examined using data from a population of wedge-capped capuchin monkeys Cebus olivaceus in central Venezuela. Demographic parameters were derived from censuses of individually recognized, aged, and sexed individuals living in nine groups over a ten year period. Animals were aged by extrapolation from census data. Animals of both sexes were classed as infants during their first year, and juveniles until they reached six years of age. Females reach sexual maturity at this time, while males were classed as subadults until they reached full adult size at age 12. Adulthood lasts at least 30 years in females, at least 24 years in males. Age-sex class specific mortality and fecundity rates generated a life table which indicated that the population was increasing (r = 0.087) between 1977 and 1986. The age and sex composition of the nine groups was described annually. On average, non-adults made up 60% of a group, with this percentage increasing with group size. There were more females than males in all groups in all years. The strong female-biased adult sex ratio (1:4.4) was a consequence of a biased birth sex ratio (1:1.9), higher female than male survivorship especially between the ages of 3 and 7 when males were dispersing, and a pronounced sexual bimaturism. The stable age distribution derived from the life table successfully predicted the observed average distribution of age-sex categories in groups. This suggests that the group structure of Cebus olivaceus groups is not a consequence of intragroup social interactions, but results from demographic parameters.


Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 446 ◽  
Author(s):  
Hazel Farrell ◽  
Penelope Ajani ◽  
Shauna Murray ◽  
Phil Baker ◽  
Grant Webster ◽  
...  

An end-product market survey on biotoxins in commercial wild harvest shellfish (Plebidonax deltoides, Katelysia spp., Anadara granosa, Notocallista kingii) during three harvest seasons (2015–2017) from the coast of New South Wales, Australia found 99.38% of samples were within regulatory limits. Diarrhetic shellfish toxins (DSTs) were present in 34.27% of 321 samples but only in pipis (P. deltoides), with two samples above the regulatory limit. Comparison of these market survey data to samples (phytoplankton in water and biotoxins in shellfish tissue) collected during the same period at wild harvest beaches demonstrated that, while elevated concentrations of Dinophysis were detected, a lag in detecting bloom events on two occasions meant that wild harvest shellfish with DSTs above the regulatory limit entered the marketplace. Concurrently, data (phytoplankton and biotoxin) from Sydney rock oyster (Saccostrea glomerata) harvest areas in estuaries adjacent to wild harvest beaches impacted by DSTs frequently showed elevated Dinophysis concentrations, but DSTs were not detected in oyster samples. These results highlighted a need for distinct management strategies for different shellfish species, particularly during Dinophysis bloom events. DSTs above the regulatory limit in pipis sampled from the marketplace suggested there is merit in looking at options to strengthen the current wild harvest biotoxin management strategies.


1998 ◽  
Vol 20 (2) ◽  
pp. 302
Author(s):  
D. Goldney

A long-term mark-recapture program has been carried out on the Duckmaloi Weir (near Oberon, New south Wales) and associated river over the period 1986 to the present. The pipehead weir creates a long shallow ·pool' about 2.5 ha in area, ideal for gill-netting platypuses. One hundred and eighty-two (182) individual animals have been captured in excess of 500 times. The majority of animals have been captured in the weir pool. A very dynamic situation exists with new adults and juveniles being captured on a regular basis and conversely captured animals "disappearing" on a regular basis from the system. Some individuals exhibit both transience and site attachment characteristics. However, relatively few animals remain site attached for long periods of time. Sixty nine percent of individuals are captured two or fewer times. Band loss cannot account for this phenomenon. Of the captured animals, 11.3% have been caught more than 5 times. The sex ratio of the population favours females in first capture adults (1:1.72) but males in first capture juveniles (1:0.73). Females are more likely to be recaptured than males. The sex ratio of juveniles varies significantly from year to year. The period between recaptures varies greatly and can be up to 6 years. Four animals have been captured over nine years (3 females/1 male) but no animal has been captured every year of the study. Recruitment has occurred at levels able to maintain the current population numbers. Thirty percent of available adults have been found lactating, including second year females. Seventy one percent of first year capture juveniles and 89.9% of first capture adults "disappear" within two years of first capture. Forty two percent of juvenile animals reach adult status before "disappearing".


2000 ◽  
Vol 6 (1) ◽  
pp. 18 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Rodney P. Kavanagh

Populations of arboreal marsupials were assessed in forests before and after logging at different levels of logging intensity to determine the sensitivity of these species to habitat disturbance. The logging treatments imposed were unlogged controls and two intensities of integrated logging for sawlogs and woodchips. The mean basal area of trees retained in logged blocks ranged from 83% to 35% of pre-logging levels. The objective of the study was to develop better methods for managing arboreal marsupials within the wood production forests of southeastern New South Wales. Seven species of arboreal marsupials were recorded during the study, but the Greater Glider Petauroides volans was the only species recorded in sufficient numbers for analysis (86% of all records). No significant differences were observed between the treatments in counts of the Greater Glider before and after logging. However, given the observed trend and an a priori expectation of a decline in numbers of this species following intensive logging, a one-tailed statistical test was applied which resulted in a significant difference at P = 0.08 for the contrast between the unlogged controls and the most intensively logged treatment. The existence of a threshold in logging intensity within the range of 21 % to 39% retention of tree basal area, below which numbers of the Greater Glider suffer a marked decline, was inferred on the basis of comparisons with the results of other studies. Factors other than logging were important in determining the distribution of the Greater Glider. Elevation, in particular, was a significant environmental variable, with Greater Gliders more likely to occur in forests above 845 m a.s.1. The presence and absence of particular tree species also influenced the distribution of the Greater Glider. Forests containing Manna Gum E. viminalis and Mountain Gum E. dalrympleana were highly preferred compared to forests with a high proportion of E. obliqua. The presence of E. cypellocarpa appeared to improve the quality of habitat for the Greater Glider in forests dominated by E. obliqua. This study has shown that Greater Glider populations can be maintained at or near pre-logging levels when at least 40% of the original tree basal area is retained thoughout logged areas and when the usual practice of retaining unlogged forest in riparian strips is applied.


Sexual Health ◽  
2007 ◽  
Vol 4 (4) ◽  
pp. 306
Author(s):  
D. Mossman ◽  
C. Ooi ◽  
M. Loewenthal ◽  
M. Boyle

Background: Chlamydia Trachomatis is one of the most common sexually transmitted infections in Australia and world wide. This study was undertaken to map the frequency of Chlamydia genotypes in regional New South Wales (NSW), Australia, to explore the potential utility of genotype analysis in defining local sexual networks, and to investigate whether patterns of genotype frequency are correlated with demographic factors, including age and gender. Methods: We studied 204 urine samples infected with Chlamydia trachomatis, as determined by PCR analysis using the COBAS Amplicor system. Samples were collected from wide geographic area of regional New South Wales (Hunter, New England, Northern Rivers, South Eastern New South Wales). Sequencing and genotyping were performed after nested PCR of the omp1 gene. Results: Genotype E was found in 42.6% of infections, with genotypes F (23.5%) and G (16.7%) other common causes of infection. Mixed infection occurred in only 3 cases. There was no significant difference in genotype frequency based on gender or geographic location. There was a significant difference in gender frequency based on patient age, with older patients significantly more likely to demonstrate infection with genotype G (mean age (years) 23.7+/-7.29 sd, E: 21.7 +/-5.7 sd; G: 28.9; sd 10.18; p�=�0.022). Conclusions: There was no significant difference in genotype frequency in the various regions of New South Wales, suggesting genotype analysis is of limited use in defining sexual networks in regional NSW. The finding of a higher frequency of genotype G in older patients raises the possibility that genotypic variation may be driven by immune responses to genotypes that occur more frequently at a younger age. These results may have implications for the future design of a chlamydial vaccine.


1997 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt

The distribution and abundance of ground-dwelling mammals in the major vegetation alliances in the eucalypt forests within an area of c. 24000 km2 in north-eastern New South Wales were examined. Data for 33 species of mammal from 21 areas containing 30 vegetation alliances were collected. Four notable aspects of the data were the absence or low abundance of the introduced fox (Vulpes vulpes), the widespread distribution and abundance of the cat (Felis catus), the diversity and abundance of medium-sized native mammals and the diversity of small mammals. Although differences occurred between areas and alliances, there was no significant difference in the number of native and introduced species. The ground-dwelling mammals present in the eucalypt forests of north-eastern New South Wales were more diverse and in greater abundance than those found in forests of south-eastern New South Wales. However, some species, such as the spotted-tailed quoll (Dasyurus maculatus), appear to be in urgent need of protection and management if they are to persist.


1978 ◽  
Vol 26 (4) ◽  
pp. 653 ◽  
Author(s):  
HG Cogger

A field study of the reproductive and fat cycles of the small agamid lizard Amphibolurus fordi was undertaken in two areas of mallee in central western New South Wales. The development of the gonads, including the histology of the testicular cycle, is described, together with correlated changes in the size of the inguinal fat bodies. The males emerge from winter torpor some 4-5 weeks before the females. The sex ratio approximates unity throughout the life cycle. Mating occurs from October to December; up to three clutches each of two or three eggs are laid in a season. The eggs hatch in 7-9 weeks after laying. The construction of the nesting chamber by the female is described. Apart from behaviour specifically geared to thermoregulation, two other behavioural types have been identified: male-female interactions involving only sexually mature individuals during the reproductive period, and non-sex-specific patterns which occur in both immature and mature individuals of either sex. Males are not territorial.


2012 ◽  
Vol 52 (7) ◽  
pp. 675 ◽  
Author(s):  
R. D. Bush ◽  
R. Barnett ◽  
I. J. Links ◽  
P. A. Windsor

The prevalence of Caseous lymphadenitis (CLA) in Australia was estimated to be 5.2% using 2009 abattoir surveillance data from all States supplied by Animal Health Australia involving 5029 lines comprising 1 339 463 sheep. This is a decrease from the 26% estimated in a similar study in 1995. There was a significant difference (P < 0.001) in CLA prevalence between all states except Tasmania and Victoria (P = 0.75) with prevalences of 12.8 and 12.9%, respectively. Western Australia recorded the lowest prevalence with 1.0%. The average CLA prevalence for New South Wales was 5.3% and within three surveyed Livestock Health and Pest Authority regions (Tablelands, Central North and Central West) was 2.9, 4.9 and 4.4%, respectively. The attitude of the majority of producers surveyed in these three Livestock Health and Pest Authority areas was that CLA was of little or no significance (75%) but were aware of the need for CLA control with ~68% using 6-in-1 vaccine, though only 39.9% as recommended. It appears that the prolonged use of CLA vaccination has been successful in reducing the prevalence of CLA across Australia and particularly in New South Wales. Further improvements in communication of information on preventative management practices associated with lice control, importance of using an approved vaccination program, plus increasing producers’ awareness of the importance of CLA control, are indicated.


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