A field study of Pseudocheirus occidentalis (Marsupialia : Petauridae) II. Population studies

1994 ◽  
Vol 21 (2) ◽  
pp. 189 ◽  
Author(s):  
BA Jones ◽  
RA How ◽  
DJ Kitchener

Field studies of the rare and endangered western ringtail possum (Pseudocheirus occidentalis) were undertaken at five main sites in south-western Australia. Population studies employing capture-markrelease and telemetry methods were concentrated at Abba River and Locke Estate, near Busselton, and supplementary telemetry records were obtained for three females at Yendicup, Perup, near Manjimup. The location of dreys and sightings were mapped at Geographe Bay (near Busselton) and Emu Point (Albany). Mature adults of both sexes weighed about 1000 g and attained maturity at 830-900 g. Young were estimated to spend about 104 days in the pouch and emerge at 130-150 g. Lactation ceased when young weighed 550-650 g. Most births were of single young, but at Locke 16.7% of females with pouch young carried twins. In the Busselton area some births occurred in all months, but there were few between December and March. Most births occurred during April-July, but a secondary peak occurred during September-November, especially at Locke. At Locke 69% of animals were females and this ratio was similar in all age classes, but at Abba the sex ratio was parity. At Locke hollows were rare and animals usually rested in dreys; at Abba hollows in Eucalyptus gomphocephala were the usual rest sites and dreys were rare, occurred only near the watercourse and were used only by males; at Yendicup no dreys were observed and hollows in eucalypts were the usual rest sites. Animals used 2-7 rest sites each. Home ranges of females at Yendicup averaged about 2.5 ha; in the Busselton area home ranges averaged less than 1 ha. Less than 1% of both day and night sightings were of animals at ground level. Plots of the location of dreys and sightings at three sites showed that possums were not evenly dispersed, and at two sites there were areas of apparently suitable habitat that were rarely used. Density was estimated for four sites: Abba River 3.7-4.3 ha-1, Locke Estate 2.4-4.5 ha-1, Geographe Bay 0.3-0.6 ha-1 and Emu Point 0.1-0.4 ha-1. Evidence of predation by foxes was found at Abba, Locke and Geographe Bay. Microscopic inspection of faecal pellets showed that, where Agonis flexuosa grew, its leaves accounted for 79-100% of diet. Small amounts of several other plants were also taken. At Perup A. flexuosa was absent and the diet consisted predominantly of leaves of the two common eucalypts (Eucalyptus calophylla and E. marginata).

2021 ◽  
Vol 13 (6) ◽  
pp. 3007
Author(s):  
Xiaojiong Zhao ◽  
Jian Wang ◽  
Junde Su ◽  
Wei Sun ◽  
Haoxian Meng

Quantitative assessment and evaluation of ecological parameters and biodiversity conservation are prime concerns for long-term conservation of rare and endangered species and their associated habitats in any ecological region. In this study, Gansu Province, a biodiversity hotspot, was chosen as the research area. We predicted the distribution patterns of suitable habitats for rare and endangered species. The replacement cost method was adopted to calculate the conservation value of rare and endangered species. The suitable habitat distribution area of rare and endangered wild animals reached 351,607.76 km2 (without overlapping area), while that of plants reached 72,988.12 km2 (without overlapping area). The conservation value of rare and endangered wildlife is US $1670.00 million. The high-value areas are mostly concentrated in the south and north of Gansu Province. The conservation value of rare and endangered wild plants is US $56,920.00 million. The high-value areas are mostly concentrated south of Gansu Province. The conservation value is US $58,590.00 million a year, and its distribution trend is gradually decreasing from northeast to southwest, with the highest in the forest area south of Gansu Province, followed by the Qilian Mountain area in the north. These results are of great significance for future improvement of the evaluation index system of ecosystem services and the development of ecosystem services and management strategies.


1993 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
R.J. Taylor

Aspects of the behaviour and ecology of Vombatus ursinus were studied in largely cleared agricultural land in a coastal area in northeast Tasmania. The average density of V. ursinus was 20 individuals.km-2 over the whole study area but around 60.km-2 in an intensively studied section. Burrows were concentrated in areas of sandy soil where a dense cover of native vegetation had been maintained. Only short, shallow burrows were present in areas of dolerite, probably because of the difficulty of digging. Home-ranges of different individuals overlapped. Wombats were not active continually through the night and varied in time of emergence from their burrow and the time spent above ground. Often more than one burrow was used on the same night, with more than one individual making use of a burrow, but usually not at the same time. Disputes over the use of burrows occurred. Individuals frequently sniffed around burrows and investigated for the presence of occupants. Males may use this as a strategy for finding females in oestrus. Mating behaviour was observed once. Wombats are solitary and actively avoid the presence of others. Odour in faecal pellets and from scent marking probably plays an important social role by providing information on the individuals sharing a home-range and the occurrence of strangers. Dominant animals may be intolerant of the presence of certain individuals within their home-range.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3612 ◽  
Author(s):  
Jessica L. Beckham ◽  
Samuel Atkinson

Texas is the second largest state in the United States of America, and the largest state in the contiguous USA at nearly 700,000 sq. km. Several Texas bumble bee species have shown evidence of declines in portions of their continental ranges, and conservation initiatives targeting these species will be most effective if species distributions are well established. To date, statewide bumble bee distributions for Texas have been inferred primarily from specimen records housed in natural history collections. To improve upon these maps, and help inform conservation decisions, this research aimed to (1) update existing Texas bumble bee presence databases to include recent (2007–2016) data from citizen science repositories and targeted field studies, (2) model statewide species distributions of the most common bumble bee species in Texas using MaxEnt, and (3) identify conservation target areas for the state that are most likely to contain habitat suitable for multiple declining species. The resulting Texas bumble bee database is comprised of 3,580 records, to include previously compiled museum records dating from 1897, recent field survey data, and vetted records from citizen science repositories. These data yielded an updated state species list that includes 11 species, as well as species distribution models (SDMs) for the most common Texas bumble bee species, including two that have shown evidence of range-wide declines: B. fraternus (Smith, 1854) and B. pensylvanicus (DeGeer, 1773). Based on analyses of these models, we have identified conservation priority areas within the Texas Cross Timbers, Texas Blackland Prairies, and East Central Texas Plains ecoregions where suitable habitat for both B. fraternus and B. pensylvanicus are highly likely to co-occur.


Sociobiology ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 480
Author(s):  
Angele Nicodenin Soro ◽  
Juan Lapuente ◽  
Abduoulaye Ngolo Kone ◽  
Kolo Yeo ◽  
Souleymane Konate

The goal of this study was to explain the patterns of diversity and distribution of arboreal social bees nesting in forest habitats of the Comoé National park, within the home-ranges of wild chimpanzees that consume their honey. Investigations were done using a total sixteen plots, one hectare each, established in three habitat types (mature forest island, secondary forest island and gallery forest). The diversity and distribution of arboreal social bees was estimated with visuals searches. The exploitation of the beehives of these bee by the chimpanzees was also evaluated using chimpanzees’ honey dipping tools as indicators. Results revealed five bees’ species belonging to two tribes; Meliponini (Meliponula ferruginea, Meliponula togoensis, Meliponula bocandei, Hypotrigona gribodoi) and Apini (Apis mellifera). Frequent exploitation of the honey of stingless bees by the chimpanzees was observed, except for H. gribodoi. Meliponula ferruginea was the most exploited species by chimpanzees. A total of 114 beehives were found in the overall established plots leading to an estimated density of 2.4 beehives/ha in the study area. Among the surveyed habitats, mature forest island was found to harbor the highest beehive density (4.2 beehives/ha), followed respectively by secondary-forest island (1.9 beehives/ha) and gallery forest (1.1 beehives/ha). Finally, all bee species were found nesting in cavities of trees with a DBH ranging from 15 to 87.3 cm, with a special preference for Dialium guinneense. However, the DBH of nesting trees and beehives’ height, measured from the ground level, did not significantly influence the honey exploitation by chimpanzees. In sum bee species diversity and distribution might be important in the survival of chimpanzees of a forest savanna landscape.


2019 ◽  
Vol 286 (1916) ◽  
pp. 20192230 ◽  
Author(s):  
H. N. Abernathy ◽  
D. A. Crawford ◽  
E. P. Garrison ◽  
R. B. Chandler ◽  
M. L. Conner ◽  
...  

Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer ( Odocoileus virginianus seminolus ) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change.


2016 ◽  
Vol 129 (4) ◽  
pp. 379
Author(s):  
T. L. Imlay ◽  
J. Saroli ◽  
T. B. Herman ◽  
S. W. Mockford

The disjunct Eastern Ribbonsnake (Thamnophis sauritus) population in southwest Nova Scotia is listed as “threatened” by the committee on the Status of Endangered Wildlife in Canada. A study of the movements of the species at two lakeshore locations known to support a high density of Eastern Ribbonsnakes was undertaken in 2007 and 2008. Average seasonal movements at both sites ranged from 17 m to 84 m for juvenile snakes and 21 m to 130 m for adults; one neonate was recaptured during the study after travelling 32 m. The maximum distance travelled by an individual snake was 391 m in one season. The best-fit model to explain differences in daily movement patterns included year (P = 0.041), indicating that there is annual variation in the movements of this species. Low recapture rates precluded accurate estimates of home-range size, which varied roughly from 0.16 ha to 0.78 ha. Both movements and home ranges were larger than previously documented in Nova Scotia, but maximum distances travelled were consistent with a previous study in Michigan. Most documented movements were along the lakeshore within contiguous, suitable habitat. More work is needed to understand the frequency of large movements and triggers that initiate movements, e.g., changes in water levels, habitat suitability, or prey availability.


2011 ◽  
Vol 59 (1) ◽  
pp. 9 ◽  
Author(s):  
Michael D. Craig ◽  
Angela M. Benkovic ◽  
Andrew H. Grigg ◽  
Giles E. St J. Hardy ◽  
Patricia A. Fleming ◽  
...  

If we are to accelerate the recolonisation of restored areas by slow-recolonising species, we must provide suitable microhabitats at appropriate densities. Previous research in south-western Australia has shown that Napoleon’s skink (Egernia napoleonis) rarely recolonises restored areas. We trapped Napoleon’s skink in restoration and unmined forest to confirm the species was late successional. We also radio-tracked six skinks in unmined forest, to determine types and characteristics of used microhabitats, and estimated home ranges to determine required microhabitat densities, with the aim of accelerating skink recolonisation of restored areas. All tracked skinks used logs and hollow-bearing trees. Used logs were larger, and used trees were larger and taller than random samples, probably because large logs and trees were more likely to contain cracks and hollows that provide a refuge from predators. Extrapolations from home-range estimates indicated that a minimum of four logs ha–1 are required in restored areas to facilitate recolonisation by skinks, with skink densities likely to increase with log densities. Our study demonstrated that not all fauna will naturally recolonise restored areas and management of these areas is required to provide suitable habitat for late-successional species. Our approach could potentially be applied to other ecosystems or species.


2007 ◽  
Vol 34 (3) ◽  
pp. 177 ◽  
Author(s):  
Robyn F. Wilson ◽  
Helene Marsh ◽  
John Winter

Roads and powerline corridors destroy canopy connectivity in the rainforest of north-east Australia. We tested the hypotheses that linear barriers affect (a) the alignment of home ranges, (b) use of habitat either side of linear barriers, and (c) the crossing of them by the strictly arboreal lemuroid ringtail possum (Hemibelideus lemuroides), which is known to be vulnerable to habitat fragmentation. Radio-tracking and a translocation experiment were conducted at a narrow 7-m-wide road and an 80-m-wide powerline. Homes ranges of lemuroid ringtails ranged from 0.15 to 1.67 ha (minimum convex polygon) and were aligned with the road but not powerline corridors. When lemuroid ringtails were experimentally translocated, wider canopy clearings over roads reduced their capacity to return to their original home range, and the powerline corridor was a nearly insurmountable barrier. No possums were observed crossing roads or the powerline corridor at ground level or residing in the intervening matrix, indicating that loss of canopy connectivity has a negative impact on their movements.


1993 ◽  
Vol 20 (4) ◽  
pp. 457 ◽  
Author(s):  
G Lundie-Jenkins

A 2-year study was conducted to investigate two aspects of the local distribution of the rufous harewallaby, Lagorchestes hirsutus, in a region of the Tanami Desert. These were: (a) patterns of habitat use in response to changing environmental conditions and (b) environmental parameters influencing 'local' choice of habitat. Counts of faecal pellets and tracks were used to obtain indices of hare-wallaby activity within occupied sites and to gain an insight into the movements by individuals. Local choice of habitat was analysed by assessment of numerous habitat features at occupied and unoccupied sites in the region. Previous surveys over the greater part of the study area provide evidence of a significant local decline and local contraction of range by L. hirsutus during recent times. Hare-wallabies showed seasonal trends in the relative use of different vegetation systems in response to the relative availability of food items within each habitat. The home ranges of hare-wallabies consisted of two distinct areas of activity: a large sparsely used area within the dense Triodia pungens vegetation and a small concentrated feeding area within the neighbouring caliche system. Hare-wallabies were dependent upon a specialised form of spinifex habitat. Patchiness, hummock size, food diversity and the degree of floral senescence affected suitability for hare-wallabies. Within the Tanami Desert site, suitable combinations of these characters were associated with tight mosaics of different regenerative stages after fire. Fire is therefore clearly implicated as an important force in creating a greater diversity of feeding and sheltering habitats for the hare-wallabies in the otherwise uniform spinifex sandplains. There is an obvious role for the application of controlled burns as a means of managing habitats to favour L. hirsutus in the Tanami Desert.


1998 ◽  
Vol 88 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J. B. Jones ◽  
H. Bouzar ◽  
G. C. Somodi ◽  
R. E. Stall ◽  
K. Pernezny ◽  
...  

Until recently, tomato race 1 (T1) of Xanthomonas campestris pv. vesicatoria was the only race causing bacterial spot of tomato in Florida. In 1991, tomato race 3 (T3) was first identified in 3 of 13 tomato production fields surveyed. By 1994, T3 was observed in 21 of 28 fields and was the only race identified in 14 fields. In field studies, tomato genotypes with resistance to either T1 or T3 or susceptibility to both were co-inoculated with strains of both races. Lesions on 10 plants in each of three replications for each genotype were sampled three times during the experiment; bacterial isolations were made from each lesion, and tomato race identifications were made for each strain. At the third sampling date, T3 was isolated from 97% of the lesions on the susceptible genotype Walter and the T1-resistant genotype Hawaii 7998, while T3 was isolated from 23% of the lesions and T1 from the remaining 77% on the T3-resistant genotypes PI 128216 and PI 126932. In surface population studies done in growth rooms, suspensions of T1 and T3 were applied alone and in combination to the leaf surfaces of susceptible and resistant genotypes. T1 populations were reduced more than 10-fold when applied in combination with T3, compared with populations that developed when T1 was applied alone. T3 populations were not affected when applied in combination with a T1 strain. In greenhouse studies with the T3-resistant genotype Hawaii 7981, disease was significantly reduced in plants inoculated with T3 in combination with T1, compared with plants inoculated with T1 alone. These results clearly demonstrate the competitive nature of T3 in the presence of T1 and help explain the emergence of T3 as a prevalent race in Florida.


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