Effect of flow on platypus (Ornithorhynchus anatinus) reproduction and related population processes in the upper Shoalhaven River

2017 ◽  
Vol 65 (2) ◽  
pp. 130 ◽  
Author(s):  
M. Serena ◽  
T. R. Grant

The platypus (Ornithorhynchus anatinus) occupies a wide range of aquatic habitats, feeding mainly on benthic macroinvertebrates. In this study, we investigated how flow affects platypus reproduction in the unregulated upper Shoalhaven River in rural New South Wales. In a mainly dry period, the population occurred at relatively high density (12.4 animals km–1) and was strongly female-biased (84% of resident animals); mean annual loss and recruitment of resident females were respectively estimated to be 12% and 14%. Percentage lactation was 17–71% (n = 23 years), and annual reproductive success (defined as the mean number of juveniles captured per adult/subadult female from February to April) varied from 0 to 1.5 juveniles female–1 (n = 21 years). A significant positive linear relationship was evident between percentage lactation and antecedent discharge in the five months before breeding (March–July) and a positive curvilinear relationship was evident between percentage lactation and mean litter size. Conversely, reproductive success was compromised by high poststorm discharge in the period when juveniles are confined to a nesting burrow, especially from late November to early January. The relationships identified in our study between flow and reproduction also appear to apply to platypus populations occupying urban streams in Victoria, suggesting that they may be widely relevant to this species.

1984 ◽  
Vol 32 (5) ◽  
pp. 631 ◽  
Author(s):  
RJ Whittington ◽  
TR Grant

Blood was collected from a bill sinus of nine conscious adult platypuses, Ornithorhynchus anatinus, caught in south-eastem New South Wales. Sexual dimorphisms were not found in the haematological and serum biochemical values measured. Results were compared with those obtained earlier from anaesthetized platypuses: ether anaethesia did not affect red cell parameters and the majority of biochemical values measured. It did, however, cause significant leukocytosis due to neutrophilia and monocytosis. The mean total leukocyte count in conscious platypuses was 28.63 X 10*9.1-�. The unusually high urea levels and low creatinine levels found in anaesthetized platypus were confirmed in this study (31.5 mmol.l-� and 26 �mol.l-� respectively). High values for erythrocyte count (9.96 X 10*12.l-�), packed cell volume (0.491.l-�) and haemoglobin (190 g.l-�) were found in conscious platypuses, confirming earlier findings and supporting the view that the erythrocyte parameters of the platypus show significant adaptations to hypoxia.


2017 ◽  
Vol 25 (5) ◽  
pp. 456-459
Author(s):  
Kevin Rourke ◽  
Coralie J Wilson

Objectives: To determine if adolescents perceive community-based exercise as beneficial to their well-being and in what ways. Methods: A New South Wales Police Citizens Youth Club ran a four-week fitness course. The classes involved: 1) sports including basketball and soccer, 2) non-contact boxing drills, and 3) games, both team games such as dodgeball and non-team games such as line tag. Parental consent to offer a survey at the completion of the course was requested during registration. The survey was the Warwick Edinburgh Mental Well-being Scale; it was minimally modified to measure perceived benefit to mental well-being instead of actual benefit. Results: Thirty-one high school adolescents, ages 13–18, completed the survey. As a group, participants reported that they believed their well-being had improved after the course. The mean score for each survey item showed an improvement in every area of mental well-being for this sample of adolescents. Thirty-two per cent of adolescents reported having less energy. Survey scores indicated a statistically significant improvement in perceived well-being ( p<0.0001). Conclusions: The results of this study suggest that four weeks of community-based exercise improves perceived mental well-being in adolescent participants.


2004 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
AD Bilton ◽  
DB Croft

Female reproductive success and the recruitment of offspring to the next generation are key components of animal population dynamics. With an annual commercial harvest of between 13 and 22% of the red kangaroo (Macropus rufus) population, it is increasingly important that these processes are understood. We used data on the reproductive success of 33 free-ranging female M. rufus on Fowlers Gap station in far western New South Wales to determine the expected lifetime reproductive success (LRS) of females within an unharvested population. We also designed a model to generate predictions about female LRS incorporating empirical relationships between a mother?s reproductive success and maternal age, environmental conditions and the sex and survivorship of a previous reproductive attempt. Results from observations on female LRS (calculated from annual weaning rates) and those generated by the model predict that female M. rufus on ?Fowlers Gap? wean, on average, 3.7 young in a lifetime (ranges 0 - 11 and 0 - 20, respectively); representing only 41% of their maximum reproductive potential. Manipulation of initial starting conditions allowed the effect of varying environmental conditions on female LRS to be explored. The condition of the environment when females commence breeding does not appear to significantly affect their overall lifetime reproductive output. However, the occurrence of drought does. Females experiencing two droughts in a lifetime did not live as long and weaned fewer offspring and grandoffspring (from their daughters) than those females experiencing only one drought in a lifetime. In addition to the adverse effect of drought on the reproductive success of female M. rufus in this study, we suggest that, given the relatively high and stable population densities of M. rufus on ?Fowlers Gap?, other mechanisms (acting primarily on juvenile survival) must exist which limit population growth.


1998 ◽  
Vol 46 (2) ◽  
pp. 153 ◽  
Author(s):  
Damon L. Oliver

The regent honeyea ter, Xanthomyza phrygia, is an endangered woodland bird whose range and population size have decreased in the last thirty years. Suggested reasons for this decline include abnormal breeding behaviour, poor reproductive output, and excessive inter- and intra-specific aggression. This study investigated the breeding behaviour and aggressive interactions of regent honeyeaters during the nest construction, incubation, nestling, and fledgling stages in two consecutive breeding seasons in the Bundarra–Barraba region near Armidale, New South Wales. The female was entirely responsible for nest construction and incubation, which is typical of many honeyeaters. Both parents fed the nestlings, and at a similar rate, although only the female brooded chicks on the nest. Both parents fed the fledglings. The mean frequency at which nestlings (23 times per hour) and fledglings (29 times per hour) were fed is the highest published rate of any non-cooperative honeyeater. Breeding males were involved in significantly more aggressive interactions with conspecifics and other nectarivores than were females, although the overall percentage of day-time spent in aggression for both sexes was low (2.5%). It appears that abnormal breeding behaviour, poor reproductive effort, or excessive aggression are not experienced by this species in northern New South Wales, and that other factors are likely to be responsible for its current low population level.


1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.


1978 ◽  
Vol 18 (92) ◽  
pp. 370 ◽  
Author(s):  
JM George ◽  
RA Pearse

Merino ewes were grazed for 10 years at stocking rates of 8, 12 and 16 ha-1, lambing in winter, spring or summer on a phalaris/white clover pasture on the Northern Tablelands of New South Wales. Wool production, wool yield and count, and lambing and weaning rates were established for the wide range of climatic conditions experienced. A spring lambing is indicated under the within-year price relationships experienced. Under a wide range of wool and lamb prices the optimum stocking rate varied from 12 to 16 ewes ha-1 depending on labour costs.


1999 ◽  
Vol 21 (2) ◽  
pp. 177
Author(s):  
T.R. Grant ◽  
P.C. Gehrke ◽  
J.H. Harris ◽  
S. Hartley

Data from the New South Wales Rivers Survey on the occurrence of platypuses have provided the most recent and comprehensive record of platypus distribution in the State. The species was most commonly reported from the montane and coastal regions, being less common on the western slopes and uncommon in the rivers of the western lowlands. The observations confirmed those from earlier community-based surveys. In contrast to the distribution of native fish species, there appears to have been little change in the overall state-wide distribution of the platypus in response to degrading processes in the rivers of New South Wales, although nothing is known of the stability of their population numbers.


2006 ◽  
Vol 28 (1) ◽  
pp. 77
Author(s):  
P. D. Wilson

Concepts of the distribution of the greater broad-nose bat (Scoteanax rueppellii) have changed significantly as occurrence records have accumulated over the years. Early accounts of the species' distribution suggested that it was restricted to the heavily timbered areas of eastern Australia, and occurred over a wide range of altitudes. However, recent summaries of the distribution of the species differ significantly from these early accounts. To reconcile these discrepancies, I collated records from museum collections and wildlife databases. These data clearly indicate that stated altitudinal limits for the species are not correct. The currently known southern limit of the species is near Eden, New South Wales (NSW). The distribution of the species was modelled using the DOMAIN climate matching algorithm. The model indicates that S. rueppellii may occur in East Gippsland, Victoria, suggests its likely occurrence in inland Queensland and northern NSW, but a low likelihood of occurrence in inland southern NSW. However, the data show strong spatial and temporal biases that restrict the confidence that may be placed in the model. It is argued that species distributions must be regarded as open and evolving hypotheses.


1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.


1963 ◽  
Vol 3 (9) ◽  
pp. 114 ◽  
Author(s):  
JD Colwell

The effects of the different sowing rates of 20, 40, and 60 lb of seed an acre on the yield, bushel weight, composition, and response to fertilizers, of wheat grown on soils of high fertility has been studied in seven field experiments in the wheat-belt of southern New South Wales. Seasonal conditions ranged from drought to lush growing conditions and in addition one experiment was irrigated to reduce the effects of moisture stress on plant growth. Yields ranged from 10 to 70 bushels of wheat an acre and fertilizer treatments gave both positive and negative effects. For the wide range of growth conditions, variation in seeding rate had only small and non-significant effects on grain yields, with the exception of the irrigated experiment where a consistent trend indicated the need for higher seeding rates for maximum yield. Effects of the seeding rates on grain size and composition and fertilizer response, were negligible. Losses in potential grain yield, caused by the exhaustion of soil moisture reserves by excessive vegetative growth of high fertility soils before grain development has been completed, does not seem to be reduced appreciably by the use of low seeding rates.


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