Activity area during the breeding season of Varanus gouldii (Reptilia : Varanidae) in an urban environment.

1994 ◽  
Vol 21 (6) ◽  
pp. 633 ◽  
Author(s):  
G Thompson
Keyword(s):  
Body Size ◽  
Urban Environment ◽  
Leaf Litter ◽  
Breeding Season ◽  
Western Australia ◽  
Activity Area ◽  
Mean Size ◽  
The Mean ◽  
Activity Areas

The activity area of ten Varanus gouldii in Karrakatta Cemetery, Perth, Western Australia, was measured by daily locations obtained by telemetry, during the breeding season (October-December) in 1992. The mean size of activity area was 8.91 ha; activity area was positively correlated with body size. There were significant overlaps in activity areas and no evidence of territoriality for male or female V. gouldii. The animals often foraged in areas of dense leaf litter near the periphery of their activity area and retreated to burrows that were more centrally located.

The effect of body size and body condition on the ovulation rate of ewes

1977 ◽  
Vol 24 (3) ◽  
pp. 377-385 ◽  
Author(s):  
M. J. Ducker ◽  
J. S. Boyd
Keyword(s):  
Body Size ◽  
Breeding Season ◽  
Body Condition ◽  
Live Weight ◽  
Ovulation Rate ◽  
Subjective Measure ◽  
Body Dimensions ◽  
The Mean ◽  
Per Se ◽  
Linear Body

SUMMARYBody size was estimated for 255 Greyface ewes using five linear body dimensions. On the basis of this calculated measure combined with a subjective measure of body size 50 small and 50 large ewes were selected for use in the experiment. Precise ovulation data were obtained by endoscopy and this technique allowed the ewes to be mated subsequently.Body size did not affect the mean ovulation rate of the ewes although, at the same level of body condition, the large ewes were 25% heavier than the small ewes. The ovulation rates and the numbers of lambs born were influenced by changes in live weight and body condition. For these reasons live weight per se was not a good indicator of ovulation rate as ewe live weight was a combination of both body size and body condition. At the same live weight small ewes in improving body condition had a significantly higher ovulation rate than large ewes in reducing body condition.The onset of the breeding season of the ewes was not affected by their body size. The mean date of onset of oestrous activity for both large and small ewes was 17 October 1972 at a latitude 55° 52′ N.

Variability in the drinking behaviour of individual emus Dromaius novaehollandiae

2016 ◽  
Vol 38 (5) ◽  
pp. 489
Author(s):  
S. J. J. F. Davies ◽  
T. A. Knight
Keyword(s):  
Western Australia ◽  
Individual Variation ◽  
Maximum Temperature ◽  
Drinking Behaviour ◽  
Time And Space ◽  
Water Influx ◽  
Dromaius Novaehollandiae ◽  
Mean Size ◽  
The Mean ◽  
Considerable Individual Variation

The drinking behaviour of four captive emus Dromaius novaehollandiae Latham 1790 was examined at the CSIRO Laboratory, Helena Valley, Western Australia. Considerable individual variation was found in the amount of water each emu drank daily, but for each bird the amount drunk was positively correlated with daily ambient maximum temperature. There was also considerable variation between individual birds in the number of sips of water taken daily, in the mean size of each sip and in the distribution of the size of sips taken in each drinking bout. Variability in drinking behaviour has been reported in other species of bird when their water influx has been calculated using double-labelled water. The availability of water to emus varies greatly in both time and space. More thirsty emus may do well when water is plentiful, whereas more abstemious ones may be favoured when water is scarce. Hence, variability in drinking behaviour would be maintained in populations.

Aspect of the reproductive biology of the Gummy Shark, Mustelus antarcticus Gunther, from waters off the South coast of Western Australia

1990 ◽  
Vol 41 (6) ◽  
pp. 807 ◽  
Author(s):  
RCJ Lenanton ◽  
DI Heald ◽  
M Platell ◽  
M Cliff ◽  
J Shaw
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
Seasonal Changes ◽  
Sexual Maturity ◽  
Post Partum ◽  
Target Species ◽  
Eastern Australia ◽  
Mean Size ◽  
The Mean ◽  
Major Target

The gummy shark (Mustelus antarcticus) is a major target species in two substantial shark fisheries that operate in temperate Australian waters. Data on the reproductive biology of M. antarcticus in the waters off south-western Australia were obtained from samples collected by commercial vessels operating from Albany to Esperance, Western Australia. The samples contained a ratio of four females to one male. M. antarcticus is a viviparous, aplacental species. Males mature at a smaller size than females. Since the overwhelming majority of sharks sampled were mature, it was not possible to estimate precisely the mean size at which sexual maturity was attained. Examination of seasonal changes in the development of ova and testes, in uterine contents, and in embryo growth established that the period of parturition, mating and ovulation occurred over the 3 months between early November and early February. The gestation period was 11-12 months. Full-term embryos ranged in size from 30 to 36 cm total length and occurred in a sex ratio of one male to one female. The ovarian and gestational cycles proceed concurrently, with reproduction occurring annually. Only one of the 224 females analysed for uterine content was considered to be in a true post-partum condition. The number of embryos (N) per mother increased with the length of the mother (L) according to the regression N = exp(-4.13398 + 0.049171L). The reproductive biology of females collected off Albany and Esperance differed in some respects from that of females collected off south-eastern Australia.

The evolution of sexual dimorphism in the skink Eumeces laticeps: an example of sexual selection

1985 ◽  
Vol 63 (5) ◽  
pp. 995-1002 ◽  
Author(s):  
Laurie J. Vitt ◽  
William E. Cooper Jr.
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Breeding Season ◽  
Prey Size ◽  
Maximum Size ◽  
Head Size ◽  
Sexually Dimorphic ◽  
Eumeces Laticeps ◽  
Aggressive Male ◽  
The Mean

Adults of the skink Eumeces laticeps are sexually dimorphic in coloration, body size, head size, and relative head size. Males have larger heads at a given body size than females and the divergence in relative head size is coincident with the size at which sexual maturity is reached. Although there were no differences between sexes in tail loss frequencies, there were substantial differences in frequencies of body and head scars, a consequence of aggressive male–male interactions. Prey size was correlated with body and head size and males tended to eat larger prey items than females. However, both sexes are capable of eating prey much larger than the mean or maximum size of prey found in stomachs, suggesting that resource partitioning is a consequence of sexual size differences rather than a cause. The heads of males at a given body size increase during the breeding season, and a combination of head and body size apparently determines the outcome of intrasexual aggressive encounters. Moreover, small males were never observed with females during the breeding season, and those males observed "guarding" females were significantly larger than males observed in the absence of females. We conclude that sexual selection accounts for many of the differences in morphological traits between sexes of E. laticeps.

scholarly journals Shrinking fish: comparisons of prehistoric and contemporary salmonids indicate decreasing size at age across millennia

2014 ◽  
Vol 1 (2) ◽  
pp. 140026 ◽  
Author(s):  
Pablo Turrero ◽  
Eva García-Vázquez ◽  
Carlos Garcia de Leaniz
Keyword(s):  
Body Size ◽  
Life Histories ◽  
Upper Palaeolithic ◽  
Age Classes ◽  
Mean Size ◽  
The Mean ◽  
Selection For ◽  
Dependent Growth ◽  
Size At Age ◽  
Endemic Distribution

A comparison of Upper Palaeolithic and contemporary salmonid vertebrae from the Iberian Peninsula indicates that there has been a significant decrease in the mean body size for a given age among Atlantic salmon and brown trout inhabiting the southernmost range of their endemic distribution. Mean size at age was greater in prehistoric specimens for all age classes during the freshwater phase of their life histories. Fisheries-induced evolution (selection for smaller sizes) is an obvious explanation for the observed reduction in fish body size, but recent changes in the aquatic habitat affecting density-dependent growth cannot be ruled out.

Temporal patterns in the size of the main commercial shark species of Western Australia

2017 ◽  
Vol 68 (6) ◽  
pp. 1112 ◽  
Author(s):  
Matias Braccini
Keyword(s):  
Western Australia ◽  
Gradual Increase ◽  
Temporal Patterns ◽  
Shark Species ◽  
Management Actions ◽  
Mean Size ◽  
The Mean

Declines in the mean size of harvested organisms may indicate overexploitation. In the present study, temporal patterns in the mean size of the four main commercial shark species of Western Australia were evaluated. Unlike commonly observed for other shark populations, there were no strong temporal patterns in the mean size of gummy, dusky and whiskery sharks, whereas the mean size of sandbar sharks showed a gradual increase since 1993. These observations add further evidence that sharks can be fished sustainably when adequate monitoring, assessment and management actions are implemented.

Daily distance travelled and foraging areas of Varanus gouldii (Reptilia : Varanidae) in a semi-urban environment

1992 ◽  
Vol 19 (6) ◽  
pp. 743 ◽  
Author(s):  
G Thompson
Keyword(s):  
Urban Environment ◽  
Western Australia ◽  
Daily Temperature ◽  
Maximum Daily Temperature ◽  
Positive Correlation ◽  
Foraging Area ◽  
Weak Positive Correlation ◽  
Daily Sunshine ◽  
The Mean ◽  
Daily Distance

The foraging areas of Varanus gouldii were monitored by the spool-and-line technique over 51 consecutive days during October and November 1990 in Karrakatta Cemetery, Perth, Western Australia. The daily distance travelled by lizards varied markedly. The mean distance travelled was 111 -6m for days that varanids moved from their burrows. There was a weak positive correlation between the daily distance travelled and the maximum daily temperature and hours of daily sunshine. Some varanids moved their foraging areas from open unshaded sections of the cemetery into a more heavily treed area in November. The size of the daily foraging area for small varanids (<600g) was extremely variable (estimated median 300m*2); areas were greater in November than October. Some varanids moved to different foraging areas every few days.

scholarly journals Trends in body size across an environmental gradient: A differential response in scavenging and non-scavenging demersal deep-sea fish

2005 ◽  
Vol 272 (1576) ◽  
pp. 2051-2057 ◽  
Author(s):  
M.A Collins ◽  
D.M Bailey ◽  
G.D Ruxton ◽  
I.G Priede
Keyword(s):  
Body Size ◽  
Environmental Gradient ◽  
Environmental Gradients ◽  
Food Distribution ◽  
North East ◽  
The North ◽  
Specific Effects ◽  
Mean Size ◽  
The Mean ◽  
Sea Fish

Body size trends across environmental gradients are widely reported but poorly understood. Here, we investigate contrasting relationships between size (body mass) and depth in the scavenging and predatory demersal ichthyofauna (800–4800 m) of the North-east Atlantic. The mean size of scavenging fish, identified as those regularly attracted to baited cameras, increased significantly with depth, while in non-scavengers there was a significant decline in size. The increase in scavenger size is a consequence of both intra and inter-specific effects. The observation of opposing relationships, in different functional groups, across the same environmental gradient indicates ecological rather than physiological causes. Simple energetic models indicate that the dissimilarity can be explained by different patterns of food distribution. While food availability declines with depth for both groups, the food is likely to be in large, randomly distributed packages for scavengers and as smaller but more evenly distributed items for predators. Larger size in scavengers permits higher swimming speeds, greater endurance as a consequence of larger energy reserves and lower mass specific metabolic rate, factors that are critical to survival on sporadic food items.

A Correction Factor for Counting Emus from the Air, and its Application to Counts in Western Australia

1982 ◽  
Vol 9 (2) ◽  
pp. 253 ◽  
Author(s):  
G Caughley ◽  
D Grice
Keyword(s):  
Drinking Water ◽  
Correction Factor ◽  
Western Australia ◽  
True Density ◽  
Mark Recapture ◽  
Mean Size ◽  
The Mean ◽  
The Difference

We used the mathematics of the mark-recapture model to derive a factor correcting counts of emus surveyed from the air. The emus were neither marked nor recaptured, the correction factor being derived from the number of emu groups counted independently by two observers simultaneously scanning the same transect. The analysis suggests that about 68% of emu groups on the transect are counted by a given observer during a standard survey, and that his counts must therefore be multiplied by 1.47 before they estimate true density of groups. Having determined independently the mean size of emu groups as 3.75 at that time of the year, we applied this factor to counts from a survey of 1480000 km2 in Western Australia. Overall density was 0.074 emus km-2, being highest in the pastoral zone at 0.103 km-2 and lowest in unoccupied land at 0.008 km-2. The difference probably reflects availability of drinking water.

A new species of the subgenus Scheloribates (Topobates) (Acari: Oribatida: Scheloribatidae) from Panama

2020 ◽  
Vol 29 (2) ◽  
pp. 278-283
Author(s):  
S.G. Ermilov
Keyword(s):  
New Species ◽  
Body Size ◽  
Leaf Litter ◽  
Related Species ◽  
Large Body ◽  
Oribatid Mite ◽  
Neotropical Region ◽  
Large Body Size ◽  
First Time ◽  
A New Species

The oribatid mite subgenus Scheloribates (Topobates) Grandjean, 1958, is recorded from the Neotropical region for the first time. A new species of this subgenus is described from the leaf litter collected in Cayo Agua Island, Panama. Scheloribates (Topobates) panamaensis sp. nov. differs from its related species by the very large body size and presence of a strong ventrodistal process on the leg femora II–IV.

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