The Ecology of Rattus lutreolus III*. The Rise and Fall of a Commensal Population

1980 ◽  
Vol 7 (2) ◽  
pp. 199 ◽  
Author(s):  
RW Braithwaite
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Free Living ◽  
Mark Recapture

A free-living population of R. lutreolus living in and around the zoo enclosures of the Sir Colin MacKenzie Fauna Park at Healesville was studied for 27 months by use of mark-recapture trapping techniques. The demography of this population is compared with that of a natural heathland population. The breeding season was 2-3 months longer, growth of juveniles was more rapid, sexual maturity earlier, minimum survival shorter, body size larger, and habitat use less restricted in the commensal population. The evolution of the population and its decline are discussed.

Sexual maturity, factors affecting the breeding season and breeding in consecutive seasons in populations of overabundant Victorian koalas (Phascolarctos cinereus)

2006 ◽  
Vol 54 (6) ◽  
pp. 385 ◽  
Author(s):  
Natasha McLean ◽  
Kathrine A. Handasyde
Keyword(s):  
Population Dynamics ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Island Population ◽  
Population Parameters ◽  
Free Living ◽  
Phascolarctos Cinereus ◽  
Factors Affecting ◽  
Reproductive Patterns ◽  
South West

It is important to have knowledge of basic population parameters to understand how these vary geographically and temporally and how they contribute to population dynamics. This paper investigates three of these parameters in Victorian koala populations: sexual maturity, aspects of the breeding season, and the continuity of individuals’ breeding. The investigation was carried out in koalas of known-age in two free-living (Redbill Creek on French Island and Brisbane Ranges) and one semi-captive (the Koala Conservation Centre on Phillip Island) population as well as koalas of unknown age in four Victorian populations of overabundant koalas: Mt Eccles and Framlingham in south-west Victoria, French Island in Western Port and Snake Island in south Gippsland. At sexual maturity, female koalas had a mean age (±95% confidence interval) of 24.4 months (23.5–25.3 months), a mean head length of 125 mm (124–127 mm) and a mean body mass of 6.6 kg (6.3–6.8 kg). Only 7.4% of independent females (of unknown age) were carrying young when they weighed less than 6 kg. The breeding season was more restricted in the south-west populations. At Framlingham and Mt Eccles 85% and 91% of births, respectively, occurred between December and March. At Snake and French Islands only 46% and 53% of births, respectively, were recorded in the same period. In the Chlamydia-free population (Red Bill Creek) none of the koalas that were monitored stopped breeding and then resumed breeding in a subsequent season whereas many females from Chlamydia-infected populations (Brisbane Ranges and the Koala Conservation Centre) did so. This variation in reproductive patterns is likely to make an important contribution to the variation in the demography observed in different koala populations.

Effects of commercial thinning on site occupancy and habitat use by spruce grouse in boreal Quebec

2011 ◽  
Vol 41 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Ambroise Lycke ◽  
Louis Imbeau ◽  
Pierre Drapeau
Keyword(s):  
Habitat Use ◽  
Boreal Forest ◽  
Breeding Season ◽  
Vegetation Cover ◽  
Forest Cover ◽  
Site Occupancy ◽  
Lower Proportion ◽  
Large Mammals ◽  
Dense Vegetation ◽  
Commercial Thinning

Partial cuts are increasingly proposed to maintain habitats for species negatively affected by clearcutting, even if their benefits on nonpasserine birds and large mammals are still poorly documented. Our main objective was to evaluate effects of commercial thinning (CT) on spruce grouse ( Falcipennis canadensis L.), a game bird of the boreal forest. Because this species is known to be associated with a dense vegetation cover, we hypothesized that habitat use would be lower in treated sites. In spring 2006, we evaluated site occupancy in 94 forest stands (50 CT and 44 uncut stands) in Quebec by visiting each on three occasions during the breeding season (March–May). Additionally, during the molting period (May–July), we used radiotelemetry to monitor habitat use by 19 males. As compared with uncut stands, results show that a lower proportion of CTs were used in spring (39% versus 60%, after accounting for detection). During the molting period, CTs were also used less than expected according to their availability. The significant reduction of lateral and vertical forest cover in CT may explain these results. We conclude that even if CT is perceived beneficial for wildlife, it does not completely fulfill the needs of species associated with dense understory vegetation, such as spruce grouse.

Space fit for a king: spatial ecology of king cobras (Ophiophagus hannah) in Sakaerat Biosphere Reserve, Northeastern Thailand

2019 ◽  
Vol 40 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Benjamin Michael Marshall ◽  
Colin Thomas Strine ◽  
Max Dolton Jones ◽  
Taksin Artchawakom ◽  
Ines Silva ◽  
...  
Keyword(s):  
Habitat Use ◽  
Breeding Season ◽  
Protected Area ◽  
Spatial Ecology ◽  
Radio Telemetry ◽  
Biosphere Reserve ◽  
Adult Males ◽  
Anthropogenic Pressures ◽  
Anthropogenic Landscapes ◽  
Ophiophagus Hannah

Abstract A species’ spatial ecology has direct implications for that species’ conservation. Far-ranging species may be more difficult to conserve because their movements increase their chances of encountering humans. The movements can take them out of protected areas, which is especially risky for species that are routinely persecuted. The king cobra (Ophiophagus hannah), a large venomous elapid, is subject to anthropogenic pressures, such as persecution and habitat loss. Here we present results from a study using radio telemetry to quantify movements and habitat use of nine king cobras in and around a protected area in Northeast Thailand. This study is the first investigation into the movements and habitat use of king cobras outside of the Western Ghats, India. On average, the tracked king cobra’s use areas of 493.42 ± 335.60 ha (95% fixed kernel), moving 183.24 ± 82.63 m per day. King cobras did not remain in intact forested area. Five of the individuals frequently used the human-dominated agricultural areas surrounding the protected area, appearing to make regular use of irrigation canals. Two adult males showed increases in movements during the breeding season. One male’s increased breeding season range caused him to venture beyond the protected area, shifting his habitat use from intact forests to scrub in human-dominated areas. King cobras’ large home range and willingness to use anthropogenic landscapes merits special consideration from conservation planners.

Intra-population variability of the non-breeding distribution of southern giant petrels Macronectes giganteus is mediated by individual body size

2018 ◽  
Vol 30 (5) ◽  
pp. 271-277
Author(s):  
Lucas Krüger ◽  
Vitor H. Paiva ◽  
Julia V.G. Finger ◽  
Elisa Petersen ◽  
José C. Xavier ◽  
...  
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Population Level ◽  
Total Body Length ◽  
South Shetland Islands ◽  
Latitudinal Distribution ◽  
The North ◽  
Wing Load ◽  
Breeding Distribution ◽  
Individual Body

AbstractLiterature reports that body size can be associated with latitudinal distribution, for instance larger animals inhabit higher latitudes and colder habitats. This rule can be applied for species and populations within a species. The potential influence of body size on non-breeding distribution and habitat use at the intra-population level was investigated for southern giant petrels Macronectes giganteus (Gmelin) from Elephant Island, South Shetland Islands. The non-breeding distribution of 23 individuals was tracked, and total body length, culmen length, wing length, wing load and body mass were measured. Positions of core areas were used to estimate the latitudinal distribution of each individual. Smaller individuals were found to be associated more with lower latitudes, where warmer conditions and more coastal and productive waters prevail, whereas large males were associated more with higher latitudes, with colder conditions near sea ice caps, presumably feeding on carrion or preying on penguins. This association reflects a latitudinal gradient, with smaller individuals positioning themselves towards the north, and larger individuals towards the south. In this case, body size, individual distribution and habitat use were found to be associated, highlighting the importance of studying potential effects of individual body size on the ecology of seabirds.

Body Size and the Timing of Sexual Maturity

2017 ◽  
pp. 341-374
Author(s):  
Kim Hill ◽  
A. Magdalena Hurtado
Keyword(s):  
Body Size ◽  
Sexual Maturity

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.

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