Reproductive cycles, fat body cycles and socio-sexual behaviour in the Mallee dragon, Amphibolurus fordi (Lacertilia : Agamidae)

1978 ◽  
Vol 26 (4) ◽  
pp. 653 ◽  
Author(s):  
HG Cogger
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
Fat Body ◽  
New South ◽  
Reproductive Period ◽  
South Wales ◽  
Behavioural Types ◽  
Fat Bodies ◽  
Reproductive Cycles ◽  
Sexually Mature

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.

A study of breeding in grey kangaroos, Macropus giganteus Shaw and M. fuliginosus (Desmarest), in central New South Wales

1973 ◽  
Vol 21 (2) ◽  
pp. 183 ◽  
Author(s):  
WE Poole
Keyword(s):  
Mortality Rate ◽  
New South ◽  
Sympatric Species ◽  
Significant Excess ◽  
South Wales ◽  
Grey Kangaroo ◽  
Group A ◽  
Age Range ◽  
Sexually Mature ◽  
Old Females

A total of 2750 grey kangaroos were examined at Mt. Hope, N.S.W., over a period of 4 years, commencing in 1962. Two colour phases of grey kangaroo were recognized but it was not until late in the study that concurrent investigations revealed that two sympatric species occurred in the area in the approximate ratio 1 : 8. As it was not possible to distinguish the species accurately in retrospect, all the kangaroos were treated as one group. A few males became sexually mature at 20 months of age, most by 36 months, and all before they were 72 months old. Females generally became sexually mature when between 20 and 36 months of age but onset of breeding was dependent on the breeding season (September-March). Most females were breeding by their second summer, some by the third summer, and a few not until the fourth summer. Most births occurred between September and March but some occurred in all months of the year. Of the total females carrying pouch young, 5% had dormant embryos in the uterus and all of these had pouch young more than 180 days old. The highest per- centage of females carrying dormant embryos was found in late autumn, possibly because of improved nutrition after heavy rains. No western grey kangaroos apparently carried a dormant embryo but 30% of the total eastern grey females did. A significant excess of pouch young were attached to an anterior rather than a posterior teat in multiparous females. When an anterior teat was already being suckled by a young-at-foot, the posterior teat on the same side was apparently shielded and a significant excess of young born to such females attached to the anterior teat on the non-suckled side. If a posterior teat was enlarged, almost two-thirds of the newborn young attached to anterior teats; the greater number on the non-suckled side. One female had two young in the pouch, separated in age by the length of one gestation period, indicating that suckling by the first young had failed to inhibit the next expected ovulation. Disparity between 713 male and female young was not significant at 105: 100 for pouch young and 84: 100 for young-at-foot. For sets of pouch young through the age range 113-280 days there was an estimated constant mortality rate of 1.82% per 28 days. No between-sex or between season variation in the mortality rate was revealed.

A Decade of Mark-Recapture of Platypuses on The Duckmaloi River: Any New Insights into Population Dynamics?

1998 ◽  
Vol 20 (2) ◽  
pp. 302
Author(s):  
D. Goldney
Keyword(s):  
Sex Ratio ◽  
New South ◽  
First Year ◽  
Mark Recapture ◽  
South Wales ◽  
Adult Status ◽  
Second Year ◽  
Gill Netting ◽  
Population Numbers

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".

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
Keyword(s):  
Sex Ratio ◽  
Age Structure ◽  
New South ◽  
Sex Composition ◽  
South Wales ◽  
Two Samples ◽  
Significant Difference ◽  
Moult Migration ◽  
Lake George ◽  
Age And Sex

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.

Seasonal changes in Pelage of Miniopterus schreibersi blepotis (Chiroptera) in north-eastern NSW.

1963 ◽  
Vol 11 (3) ◽  
pp. 290 ◽  
Author(s):  
PD Dwyer
Keyword(s):  
Seasonal Changes ◽  
New South ◽  
New South Wales ◽  
Age Groups ◽  
Adult Females ◽  
Early Autumn ◽  
South Wales ◽  
North Eastern ◽  
Reproductive Cycles

In M. s. blepotis, of north-eastern New South Wales, the annual moult occurs during the summer and early autumn and lasts about 14.5 weeks. Yearlings having their first moult usually initiate this some 3 weeks after the adults commence. In many adult females the moult is inhibited during lactation and again during the winter so that some individuals may be found moulting in all months of the year. The importance of considering annual pelage characters when using colour taxonomically in bats is emphasized, and possible relationships between moult and reproductive cycles are indicated. In addition the use of pelage characteristics, in conjunction with reproductive criteria as a means of recognizing age groups of M. s. blepotis, is discussed.

scholarly journals Reproductive biology of the Amazon Lava Lizard (Tropidurus torquatus) from the Wet Chaco of Corrientes (Argentina): congeneric comparisons of ecotypic and interspecific variations

2014 ◽  
Vol 92 (7) ◽  
pp. 643-655 ◽  
Author(s):  
M.A. Ortiz ◽  
J.M. Boretto ◽  
C. Piantoni ◽  
B.B. Álvarez ◽  
N.R. Ibargüengoytía
Keyword(s):  
Body Size ◽  
Reproductive Biology ◽  
Fat Body ◽  
Tail Length ◽  
Reproductive Activity ◽  
Hatching Time ◽  
Fat Bodies ◽  
Reproductive Cycles ◽  
Lava Lizard ◽  
Clutch Mass

Herein we describe the reproductive biology of a population of the Amazon Lava Lizard (Tropidurus torquatus (Wied-Neuwied, 1820)) from Corrientes, northeastern Argentina (Wet Chaco). We describe the male and female reproductive cycles, minimum body size for adults, reproductive output, mean relative clutch mass, fat body cycles, and sexual dimorphism. Our results were compared with data on the reproductive biology of Brazilian populations of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity. In contrast, females were reproductive only from winter to summer (July–February), laying at least two clutches each of six eggs, on average, per reproductive season. The relative clutch mass and egg size values in Corrientes were the highest reported for the species. The annual cycle of energy storage (as fat bodies) was inversely correlated with reproductive activity in both sexes. Males differed from females in snout–vent length, head size, interlimb length, and tail length. We observed interpopulational differences in relative clutch mass, egg volume and mass, incubation period and hatching time, and the minimum body size for sexual maturity probably as a result of phenotypic plasticity or adaptation to local environmental conditions and likely both.

Sex-Ratios and Related Characteristics in Spinifex sericeus (Poaceae)

1990 ◽  
Vol 38 (2) ◽  
pp. 153 ◽  
Author(s):  
KM Maze ◽  
RDB Whalley
Keyword(s):  
Sex Ratio ◽  
New Caledonia ◽  
New South ◽  
Sand Dunes ◽  
Sex Ratios ◽  
Experimental Period ◽  
North Coast ◽  
Male Bias ◽  
South Wales ◽  
Males And Females

Spinifex sericeus R.Br. is a dioecious, stoloniferous grass which occurs on sand dunes around much of the south-eastern coastline of Australia, New Zealand and New Caledonia. Sex ratios of ramets of S. sericeus and some associated characteristics were studied on the mid-north coast of New South Wales. Generally there was a male bias in the observed ramet sex ratio, although the extent of this bias varied with the beach investigated, the position in the dunes and the time of sampling. Male inflorescences matured and died more rapidly than females, and hence the observed male bias was greatest at the beginning of the flowering period. Male ramets were found to have more sexual tillers per clump than female ramets. The genet sex ratio was estimated from plants grown from seed and separated from each other throughout the experimental period. Males and females were found to be equal in number, although this equality may not be a true reflection of the genet sex ratio in the field.

A life cycle assessment approach to quantifying greenhouse gas emissions from land-use change for beef production in eastern Australia

2015 ◽  
Vol 37 (3) ◽  
pp. 273 ◽  
Author(s):  
Beverley K. Henry ◽  
D. Butler ◽  
S. G. Wiedemann
Keyword(s):  
Land Use ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Land Use Change ◽  
New South ◽  
Ghg Emissions ◽  
Beef Production ◽  
South Wales ◽  
Eastern Australia ◽  
Direct Land Use Change

In life cycle assessment studies, greenhouse gas (GHG) emissions from direct land-use change have been estimated to make a significant contribution to the global warming potential of agricultural products. However, these estimates have a high uncertainty due to the complexity of data requirements and difficulty in attribution of land-use change. This paper presents estimates of GHG emissions from direct land-use change from native woodland to grazing land for two beef production regions in eastern Australia, which were the subject of a multi-impact life cycle assessment study for premium beef production. Spatially- and temporally consistent datasets were derived for areas of forest cover and biomass carbon stocks using published remotely sensed tree-cover data and regionally applicable allometric equations consistent with Australia’s national GHG inventory report. Standard life cycle assessment methodology was used to estimate GHG emissions and removals from direct land-use change attributed to beef production. For the northern-central New South Wales region of Australia estimates ranged from a net emission of 0.03 t CO2-e ha–1 year–1 to net removal of 0.12 t CO2-e ha–1 year–1 using low and high scenarios, respectively, for sequestration in regrowing forests. For the same period (1990–2010), the study region in southern-central Queensland was estimated to have net emissions from land-use change in the range of 0.45–0.25 t CO2-e ha–1 year–1. The difference between regions reflects continuation of higher rates of deforestation in Queensland until strict regulation in 2006 whereas native vegetation protection laws were introduced earlier in New South Wales. On the basis of liveweight produced at the farm-gate, emissions from direct land-use change for 1990–2010 were comparable in magnitude to those from other on-farm sources, which were dominated by enteric methane. However, calculation of land-use change impacts for the Queensland region for a period starting 2006, gave a range from net emissions of 0.11 t CO2-e ha–1 year–1 to net removals of 0.07 t CO2-e ha–1 year–1. This study demonstrated a method for deriving spatially- and temporally consistent datasets to improve estimates for direct land-use change impacts in life cycle assessment. It identified areas of uncertainty, including rates of sequestration in woody regrowth and impacts of land-use change on soil carbon stocks in grazed woodlands, but also showed the potential for direct land-use change to represent a net sink for GHG.

Reproductive cycles in the eastern subspecies of the Australian salmon, Arripis trutta marginata (Cuvier & Valenciennes)

1977 ◽  
Vol 28 (3) ◽  
pp. 287 ◽  
Author(s):  
CA Stanley ◽  
WB Malcolm
Keyword(s):  
Sexual Activity ◽  
New South ◽  
Juvenile Fish ◽  
Gonad Weight ◽  
Spawning Activity ◽  
Similar Work ◽  
South Wales ◽  
Younger Age ◽  
Reproductive Cycles ◽  
Weight Data

To complement similar work carried out on the western subspecies of the Australian salmon (Arripis trutta esper), the known data on the reproductive cycle of the eastern subspecies (A. t. marginata) are summarized. The data (collected between 1961 and 1963) consisted of ovary and testis welghts, fish lengths, oocyte diameters from preserved ovaries, and information from histological material. The gonad weight data were analysed to show increases in ovary and testls weights, which were indicative of sexual activity. Supporting information was extracted from changes in maximum oocyte diameters, and from examination of histological sections. The onset of sexual maturity for juvenile fish in Tasmanian waters occurred at a length of approximately 39 cm (equivalent to the end of the fourth year of life). The corresponding length for the western subspecies is 54 cm (at approximately the same age), and 52-54 cm for New Zealand fish. There was no evidence of spawning activity in Tasmanian waters. Cycles of sexual activity were observed in fish from the Lakes Entrance area of Victoria and the Eden and Bermagul areas of southern New South Wales. Spawning activity was deduced to occur between December and January in the Lakes Entrance area, between January and February in the Eden area, and between November and February in the Bermagui area. Sexual maturation may commence in males at a slightly younger age than in females.

Effects of water deficit on yield of wheat and triticale

1980 ◽  
Vol 20 (106) ◽  
pp. 594 ◽  
Author(s):  
BG Sutton ◽  
EA Dubbelde
Keyword(s):  
Life Cycle ◽  
Water Deficit ◽  
New South ◽  
Water Status ◽  
Maximum Efficiency ◽  
Yield Response ◽  
Grain Production ◽  
Water Deficits ◽  
South Wales ◽  
Complete Life Cycle

The yield response of two commercial bread wheat cultivars and one triticale to water deficits imposed before anthesis, after anthesis, or during the complete life cycle was studied in a large bin (55l) experiment under rain shelters at Camden, New South Wales. Water status was managed by weekly water replacement to allow withdrawal to 25 and 0% remaining available soil water for the well-watered and deficient treatments, respectively. The three cereals performed similarly under continuously well-watered conditions (89.9, 91.1, and 100.7 g grain/bin) but under continuous water deficit the triticale produced significantly less than the bread wheats (31.2 cf 53.1 g grain/bin), respectively. The reason for this was the greatly reduced yield per plant from tillers in the triticale. Efficiency of water use over the complete life cycle for grain production was greater for the wheats than for the triticale (1.351 cf 0.954 g l-1, respectively), and maximum efficiency resulted from provision of adequate water before anthesis (an average of 1.310 g l-1 for treatments well watered before anthesis, cf an average of 1.130 g l-1 for those growing under water deficits). Post-anthesis water status had no significant effect on these values.

Greenhouse gas emissions profile for 1 kg of wool produced in the Yass Region, New South Wales: A Life Cycle Assessment approach

2013 ◽  
Vol 53 (6) ◽  
pp. 495 ◽  
Author(s):  
Philippa M. Brock ◽  
Phillip Graham ◽  
Patrick Madden ◽  
Douglas J. Alcock
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
New South ◽  
New South Wales ◽  
Single Issue ◽  
Gas Emissions ◽  
South Wales ◽  
On Farm

The use of Life Cycle Assessment (LCA) to determine environmental impacts of agricultural production, as well as production by other industry sectors has increased. LCA provides an internationally accepted method to underpin labelling and marketing of agricultural products, a valuable tool to compare emissions reduction strategies and a means to identify perverse policy outcomes. A single-issue LCA focussing on greenhouse gas emissions was conducted to determine the emissions profile and carbon footprint of 19-micron wool produced in the Yass Region on the Southern Tablelands of New South Wales. Greenhouse gas emissions (in carbon dioxide equivalents; CO2-e) from the production of all enterprise inputs and from the production of wool on-farm were included. Total emissions were found to be 24.9 kg CO2-e per kg of greasy wool at the farm gate, based on a 4941 breeding ewe enterprise on 1000 ha, with a total greasy wool yield of 65.32 t per annum. The co-products included 174 t sheep meat as liveweight from wethers and cull ewes plus 978 maiden ewes sold off-farm as replacement stock. Total emissions from all products grown on 1000 ha were 2899 t CO2-e per annum. The relative contribution of greenhouse gas emissions from different components of the production system was determined. Direct emission of methane on-farm (86% of total) was the dominant emission, followed by nitrous oxide emitted from animal wastes directly (5%) and indirectly (5%), and decomposition of pasture residue (1%). Only 2% of total emissions were embodied in farm inputs, including fertiliser. The emissions profile varied according to calculation method and assumptions. Enteric methane production was calculated using five recognised methods and results were found to vary by 27%. This study also showed that calculated emissions for wool production changed substantially, under an economic allocation method, by changing the enterprise emphasis from wool to meat production (41% decrease) and by changing wool price (29% variability), fibre diameter (23% variability) and fleece weight (11% variability). This paper provides data specific to the Yass Region and addresses broader methodological issues, to ensure that future livestock emissions calculations are robust.

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