The Ecology of Rattus lutreolus II*. Reproductive Tactics

1980 ◽  
Vol 7 (1) ◽  
pp. 53 ◽  
Author(s):  
RW Braithwaite
Keyword(s):  
Breeding Season ◽  
Litter Size ◽  
Reproductive Parameters ◽  
Reproductive Tactics ◽  
Mark Recapture ◽  
Selective Pressures ◽  
Breeding Female ◽  
South Eastern ◽  
Eastern Australia ◽  
Young Of The Year

Litter size and total number of placental scars were obtained by autopsy of specimens of Rattus lutreolus from south-eastern Australia. Mean litter size in Victoria was 5 - 0, whereas on Hogan I. it was 3 -9. Although mean litter size within Victoria did not appear to vary between populations, mean number of litters per reproductive female varied between habitats. It was 1 - 5 for riparian, 2 -4 for heathland, and 3 -7 for commensal populations. The proportion of young of the year breeding also increase in this order. With the aid of information from the mark-recapture studies, it is deduced that the usual number of litters per breeding female per full breeding season is one for riparian, two for heathland, two for Hogan I., and for or five for commensal populations. Demography of populations in these habitats is discussed and possible selective pressures moulding the reproductive parameters are identified.

Regional differences in the reproductive parameters of the sparsely-spotted stingaree, Urolophus paucimaculatus, from south-eastern Australia

2014 ◽  
Vol 65 (11) ◽  
pp. 943 ◽  
Author(s):  
Fabian I. Trinnie ◽  
Terence I. Walker ◽  
Paul L. Jones ◽  
Laurie J. Laurenson
Keyword(s):  
Life History ◽  
Annual Cycle ◽  
Regional Differences ◽  
Life History Traits ◽  
Size At Maturity ◽  
Reproductive Parameters ◽  
Maternal Condition ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Whether spatial variation occurs in the life-history traits of chondrichthyan species is important to fisheries modelling and assessments. A study on the reproductive parameters of Urolophus paucimaculatus from four separate regions across south-eastern Australia found regional differences in maximum total length (TL), size-at-maturity, size-at-maternity and litter sizes. Inshore embayments (Port Phillip Bay (PPB) and Corner Inlet (CI)) appear to allow for larger TLs (females and males) than do offshore areas (Lakes Entrance (LE) and Western Bass Strait (WBS)). Size-at-maturity and size-at-maternity decreased across longitude from west (PPB) to east (LE) and seasonality of parturition and ovulation occurred earlier in PPB (August–October) than in LE (September–December). Maximum litter size correlated with maximum TL (six in PPB, five in each of CI and LE, and four in WBS). There was uncertainty in classifying females for maternal condition because the reproductive cycle appears to range from a continuous annual cycle to a non-continuous biennial cycle. Much of the uncertainty arises from the ambiguity of observation of non-pregnant mature females, which have either aborted through capture and handling, or are in a ‘resting year’ between pregnancies. Most likely, the majority are reproducing annually with an unknown proportion of females non-continuous and resting between pregnancies.

Some aspects of the ecology of Paratya australiensis (Crustacea : Decapoda : Atyidae)

1977 ◽  
Vol 28 (4) ◽  
pp. 403 ◽  
Author(s):  
WD Williams
Keyword(s):  
Breeding Season ◽  
Hydrological Regime ◽  
Early Summer ◽  
Inland Waters ◽  
Running Waters ◽  
Australian Species ◽  
South Eastern ◽  
Eastern Australia ◽  
Coastal Streams ◽  
Paratya Australiensis

Three Australian species of Paratya have been described. However, only one, P. australiensis, can be accepted. It occurs in Australia in a broad south-eastern arc, and in a wide variety of permanent inland waters (coastal streams, rivers, lakes, farm dams and ponds). In these it favours vegetated areas. Young hatch as free-floating larvae and hatching occurs mainly in early summer in southern Victoria. Females breed in their second summer. In south-eastern Australia, at least, this breeding season appears adapted to the hydrological regime of running waters.

Multi-scale site and landscape effects on the vulnerable superb parrot of south-eastern Australia during the breeding season

2006 ◽  
Vol 21 (7) ◽  
pp. 1119-1133 ◽  
Author(s):  
Adrian D. Manning ◽  
David B. Lindenmayer ◽  
Simon C. Barry ◽  
Henry A. Nix
Keyword(s):  
Breeding Season ◽  
Multi Scale ◽  
South Eastern ◽  
Landscape Effects ◽  
Eastern Australia ◽  
South Eastern Australia

Breeding of the Stubble Quail, Coturnix pectoralis, in South-Eastern Australia

1980 ◽  
Vol 7 (1) ◽  
pp. 117
Author(s):  
HJ Frith ◽  
SM Carpenter
Keyword(s):  
Breeding Season ◽  
Late Summer ◽  
Early Summer ◽  
Hunting Season ◽  
Annual Cycles ◽  
South Eastern ◽  
Eastern Australia ◽  
Gonad Size ◽  
The One ◽  
Latitudinal Trend

The gonad cycle, breeding season, proportion of the population in primary moult and the relative amount of body fat were examined through the year in stubble quail at eight localities covering seven degrees of latitude and including several types of habitat and climate. There were significant effects of annual cycles and rainfall on each character at each location. In gonad size the seasonal cycle accounted for 39-71% of the variability in males and 21-41% in females according to locality. Effects of rainfall accounted for 5-18 % of the variability in males and 5-19% in females. There was a suggestion of a latitudinal trend in the date of the beginning of the annual gonad cycle. Breeding at all localities was in spring and early summer with a very frequent second peak of gonad size and breeding in late summer and autumn. The timing, the relative values of the spring and summer peaks and the success of the breeding varied from place to place and from year to year in the one locality. In some years breeding was continuous virtually throughout the year. Although in some regions the hunting season is appropriately timed, considering the biology of the birds, in others it is not as it overlaps the breeding season. There is a case for standardization in the south-eastern States to May-July.

Catadromous migrations by female tupong (Pseudaphritis urvillii) in coastal streams in Victoria, Australia

2010 ◽  
Vol 61 (4) ◽  
pp. 474 ◽  
Author(s):  
David A. Crook ◽  
Wayne M. Koster ◽  
Jed I. Macdonald ◽  
Simon J. Nicol ◽  
Chris A. Belcher ◽  
...  
Keyword(s):  
Acoustic Telemetry ◽  
Mature Female ◽  
Home Ranges ◽  
River Systems ◽  
Moon Phases ◽  
Selective Pressures ◽  
South Eastern ◽  
Eastern Australia ◽  
Coastal Streams ◽  
Migratory Patterns

Understanding migratory requirements is critical for the conservation of diadromous fishes. Tupong (Pseudaphritis urvillii) are diadromous fishes found in freshwater and estuarine regions of south-eastern Australia. Previous studies have hypothesised that mature female tupong undertake downstream spawning migrations from freshwater to the estuary or sea, with a compensatory return of juveniles, and possibly spent fish, back upstream. We applied acoustic telemetry to test this hypothesis. We tagged 55 female tupong in two river systems in Victoria, Australia, and tracked movements for 4- to 6-month periods over 2 years. Thirty-one fish undertook rapid downstream migrations and then appeared to move through the estuary and out to sea between May and August in each year. Migration was associated with relatively high river discharges, and movement from the estuary to the sea tended to occur most frequently during intermediate moon phases. Low rates of movement between September and April suggested that tupong inhabited restricted home ranges outside of the spawning season. The apparently disparate migratory patterns of female (catadromous) and male (non-diadromous) tupong are rare amongst fishes globally. Differential exertion of a range of selective pressures may have resulted in the evolution of sexual differences in migratory modes in this species.

Oestrous Activity and Ovulation Rate in Rasa Aragonesa Ewes Maintained at two Different Body Condition Levels Implanted or Reimplanted in the Seasonal Anoestrus with Exogenous Melatonin

1994 ◽  
Vol 1994 ◽  
pp. 221-221
Author(s):  
L. Zarazaga ◽  
Z. Rondon ◽  
F. Forcada ◽  
J.A. Abecia ◽  
M.A. Sanz
Keyword(s):  
Nutritional Status ◽  
Breeding Season ◽  
Litter Size ◽  
Body Condition ◽  
Ovulation Rate ◽  
Sheep Breed ◽  
Reproductive Parameters ◽  
Melatonin Treatment ◽  
Exogenous Melatonin ◽  
Sheep Breeds

The effects of melatonin implants in advancing the breeding season and enhancing both ovulation rate (OR) and litter size in the ewe are well documented (Haresign et al., 1990; López and Inskeep, 1991). Likewise, oestrous activity and OR in the early breeding season can be stimulated by a moderately and constant body condition (BC) in Mediterranean sheep breeds (Forcada et al., 1992). However, little information is available in relation to the effect of nutritional status in ewes receiving exogenous melatonin on reproductive parameters. The present study was carried out to determine the effects of a constant BC throughout the year, and implant or reimplant of exogenous melatonin on onset of oestrous activity and OR in a reduced seasonality sheep breed.The experiment was designed as a 2x2 factorial. Factors were two constant BC levels (≤2.50; L, and ≥2.75; H) and two forms of melatonin treatment (one implant -Melovine™- placed the 8th April; M, and a second implant 49 days later; 2M).

Reproductive cycles and fecundities of two species of Siphonaria (Mollusca : Pulmonata) in south-eastern Australia

1980 ◽  
Vol 31 (1) ◽  
pp. 37 ◽  
Author(s):  
RG Creese
Keyword(s):  
Breeding Season ◽  
Egg Mass ◽  
Egg Masses ◽  
Rocky Substratum ◽  
South Eastern ◽  
Eastern Australia ◽  
Reproductive Cycles ◽  
South Eastern Australia

The reproductive cycles of Siphonaria denticulata and S. virgulata were determined by measuring the length or weight of the spawn of each species. S. denticulara lays a typical. coiled, gelatinous egg ribbon, cemented to the rocky substratum. S. virgulata lays a globular egg mass which is released directly into the water. This latter form of spawning is apparently unique amongst pulmonate molluscs. S. denticulata has a long breeding season, extending from November-December to the following April-May. Spawning usually occurs every 2 weeks for large adults, but smaller (i.e. younger) limpets spawn less frequently. Periods of spawning correspond to periods of full or new moons. The exact length of the breeding season of S. virgulata is unknown. Estimates of fecundity were obtained from counts of eggs within egg masses. There were differences in the fecundity of S. denticulata between localities, but S. denticulata and S. virgulata from the same locality had similar fecundities for similar-sized animals. Egg ribbons of S. denticulata experimentally placed high on the shore were found to suffer higher mortality from desiccation than those lower on the shore. This may explain why S. virgulata, which generally lives higher on the shore than its congener, has pelagic egg masses.

Use of Den Trees by Leadbeater's Possum (Gymnobelideus Leadbeateri)

1996 ◽  
Vol 44 (6) ◽  
pp. 625 ◽  
Author(s):  
DB Lindenmayer ◽  
RA Meggs
Keyword(s):  
Radio Tracking ◽  
Eucalyptus Regnans ◽  
Breeding Female ◽  
South Eastern ◽  
Risk Of Predation ◽  
Eastern Australia ◽  
Mountain Ash ◽  
Central Highlands ◽  
Leadbeater's Possum ◽  
South Eastern Australia

The results of a radio-tracking study of the uses of den trees by Leadbeater's possum (Gymnobelideus leadbeateri McCoy) at Cambarville in the mountain ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, south-eastern Australia, are described. Animals were radio-tracked for three periods of 5-20 days in July 1990, November 1990 and July 1991. A total of 14 individuals was tracked and they occupied 11 different trees with hollows on the 10-ha study site. Preliminary findings showed that some animals moved between hollows in different trees, and most animals used two or more trees. The distances between utilised trees usually exceeded 50 m. Possible reasons for the den-swapping behaviour include attempts to either or both relieve burdens of ecto-parasites and to reduce the risk of predation. There were several examples, in each of the three radio-tracking periods, of two or more radio-collared adult breeding female animals simultaneously co-occupying the same nest tree. This result was different from some of the general findings of an earlier study of G. leadbeateri at Cambarville.

Life-History of the Feathertail Glider, Acrobates-Pygmaeus (Acrobatidae, Marsupialia) in South-Eastern Australia

1990 ◽  
Vol 38 (5) ◽  
pp. 503 ◽  
Author(s):  
SJ Ward
Keyword(s):  
Life History ◽  
Litter Size ◽  
Maternal Investment ◽  
Seasonal Fluctuation ◽  
North West ◽  
South Eastern ◽  
North East ◽  
Eastern Australia ◽  
History Of ◽  
Maximum Field

Acrobates pygmaeus was captured in nestboxes in three areas of central and southern Victoria: the Gembrook-Cockatoo area and Nar Nar Goon North east of Melbourne, and Daylesford north-west of Melbourne. Breeding was strictly seasonal and females produced two litters between July and February each year. Males also showed seasonal fluctuation in testes sizes. Mean litter size was 3.5 at birth and 2.5 at weaning. Pouch life lasted 65 days and young were weaned at approximately 100 days of age. Growth was slow and maternal investment in each young was high, and continued after weaning. Most individuals matured in the season following their birth, but some males did not mature until the second season after their birth. Maximum field longevity was at least three years. Comparisons are made with other small diprotodont marsupials.

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