Assisted colonisation trial of the eastern barred bandicoot (Perameles gunnii) to a fox-free island

2017 ◽  
Vol 44 (7) ◽  
pp. 484 ◽  
Author(s):  
Rebecca Groenewegen ◽  
Dan Harley ◽  
Richard Hill ◽  
Graeme Coulson

Context Assisted colonisation has the potential to protect species from intractable threats within their historical ranges. The Australian mainland subspecies of the eastern barred bandicoot (Perameles gunnii) is extinct in the wild, with surviving populations restricted to small sites protected by predator–barrier fences. PVA modelling shows that a self-sustaining bandicoot population would require an area free of the introduced red fox (Vulpes vulpes) of at least 2500ha. French Island is outside the historic range of the species, but is fox-free and contains around 9000ha of potentially suitable habitat. Aims This study will assess the suitability of French Island as a potential site for a self-sustaining eastern barred bandicoot population by conducting a 1-year assisted colonisation trial to assess habitat use, body condition and survival. Methods Between July and September 2012, 18 adult bandicoots were released. We radio-tracked bandicoots using intraperitoneal radio-transmitters for up to 122 days and trapped fortnightly. Key results The release group met the three measures of success: (1) appropriate habitat use; (2) recovery of post-release bodyweight; and (3) founder survival exceeding 100 days. Habitat use and body condition throughout the trial reflected that of mainland populations, and seven bandicoots survived longer than 100 days. Mortality was greatest in the first month, with veterinary investigations confirming two deaths due to cat predation, two deaths from toxoplasmosis and one unknown cause of death. Bandicoots that survived longer than 100 days occupied higher, drier ground than those that did not. Toxoplasmosis cases were associated with lower topographic position on the site. Conclusions Our results suggest that French Island provides suitable habitat for the establishment of a population of eastern barred bandicoots. On French Island, toxoplasmosis was identified as an important source of mortality in addition to cat predation, and warrants further investigation. Implications Given the costs and challenges of predator control and the maintenance of predator exclusion fences, assisted colonisation to one or more fox-free islands remains the most viable option to establish self-sustaining bandicoot populations. Our results highlight the value in conducting trial releases ahead of major translocations.

2012 ◽  
Vol 90 (7) ◽  
pp. 875-884 ◽  
Author(s):  
A.B. Edworthy ◽  
K.M.M. Steensma ◽  
H.M. Zandberg ◽  
P.L. Lilley

Terrestrial molluscs have declined globally, often as a result of habitat loss and fragmentation. Many land snails are poor dispersers and exist in isolated habitat patches. The Oregon forestsnail ( Allogona townsendiana (I. Lea, 1838)) coincides with the most densely populated region of British Columbia and is listed as endangered in Canada. To investigate the dispersal distances and habitat-use patterns of Oregon forestsnails, we tagged and tracked 21 adult snails at Langley, British Columbia, for up to 3 years (2005–2008). The maximum daily dispersal distance for a snail was 4.5 m and the maximum displacement that we observed for a snail was 32.2 m during 3 years. Snails occupied home-range areas of 18.4–404.4 m2, often overlapping both forest and meadow habitat. Their home-range sizes were smaller in habitats with high availability of stinging nettle ( Urtica dioica L.), which may be an indicator of high-quality habitat. Our results suggest that the Oregon forestsnail is a relatively sedentary species with limited dispersal ability in its adult stage. Although Oregon forestsnails are likely unable to colonize suitable habitat independently, remnant forest–meadow mosaic patches such as our study site provide valuable habitat for Oregon forestsnail, which are supplementary to large tracts of intact forest where most of their populations are found.


2018 ◽  
Vol 132 (1) ◽  
pp. 46-52
Author(s):  
David M. Green ◽  
Katharine T. Yagi

We used radio-tracking to investigate movement patterns and habitat use of Fowler’s Toads (Anaxyrus fowleri) during late summer and early fall in a relatively undisturbed lakeshore dune and beach habitat at Long Point, Ontario. Small radio transmitters were fitted to 11 adult toads with an external harness made from fine surgical plastic tubing wrapped around the body behind the front limbs. We located radio-tagged toads morning and evening, for a maximum of 9 days, recording their locations using Global Positioning System units. Initially, the toads were located on the upper beach or in the fore-dunes during the day, either dug in under the sand or hiding beneath debris; in the evening, they were generally active on the lower beach close to the water line. After a storm and the onset of cooler autumn weather, the toads tended to move further from the water line. They also curtailed their nightly activity and retreated deeper into the sand. As this sort of behaviour was not observed during the summer, we interpret it as pre-hibernation movement to more stable sites away from the beach where the animals can burrow deeply into the sand to lie dormant during the winter.


The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 201-210 ◽  
Author(s):  
Kevin M. Hartke ◽  
James B. Grand ◽  
Gary R. Hepp ◽  
Travis H. Folk

Abstract In waterfowl, reproduction is physiologically demanding and females are exposed to varying risks of mortality at different periods of the breeding cycle. Moreover, differences among females may influence survival within breeding periods. We captured and fitted female Wood Ducks (Aix sponsa) with radio-transmitters before nest initiation during two breeding seasons to estimate survival and investigate sources of variation in survival. We partitioned the breeding season into three periods (preincubation, incubation, postnesting) according to breeding status of individual females, and used information-theoretic methods to compare models in which daily survival varied among periods, between successful and failed nesting females, and with parameters describing individual heterogeneity. Our analysis suggested that daily survival was best modeled as a function of breeding period, differences between successful and failed nesting females during postnesting, and early incubation body condition of successful females during postnesting. Model-averaged daily survival was 0.9988 (95% CL: 0.9963–0.9996) during preincubation and 1.0 during incubation. Postnesting daily survival was 1.0 for failed nesting females and 0.9948 (0.9773–0.9988) for successful females, suggesting a trade-off between current reproduction and survival. Female age, body condition at capture, nest initiation date, and brood size generally were not useful for explaining variation in survival. Only early incubation body condition was important for modeling survival of successful females during postnesting; however, weight of evidence was limited and the effect on survival was weak. Mortality was greatest for females during preincubation and for females that nested successfully. Results support the hypothesis that brood care is costly for females.


2009 ◽  
Vol 31 (2) ◽  
pp. 123 ◽  
Author(s):  
Lindsay A. Hogan ◽  
Clive J. C. Phillips ◽  
Allan Lisle ◽  
Alan B. Horsup ◽  
Tina Janssen ◽  
...  

The nocturnal nature of wombats makes it difficult to learn about their behavioural ecology and activity rhythms in the wild. A facility was established at Rockhampton Zoo to house 12 adult southern hairy-nosed wombats in order to monitor their behaviour by means of video surveillance and provide detailed information on their activity patterns using movement-sensitive radio-transmitters. After one year of monitoring it was established that the wombats spent, on average, as a proportion of total time 69.9% sleeping, 8.8% lying resting, 5.2% feeding, 5.2% exploring, 4.3% performing stereotyped behaviour, 2.5% sitting resting and 4.1% in other activities. Feeding, lying resting and sleeping varied with season by ~5%. Temporal patterns were bimodal for 8 of the 12 behaviours described, with most ‘active’ behaviours being expressed between 1800 and 2000 hours and 0200 and 0500 hours. The activity pattern was characterised by a strong circadian rhythm, with most activity occurring nocturnally. Within active periods there was an alternating rhythm of active and rest periods and activity peaks at the beginning and end of each night. Comprehensive and reliable information on the behavioural ecology, as well as captive management, of southern hairy-nosed wombats was obtained from the remote video and radio-transmitter recordings.


2019 ◽  
Vol 100 (4) ◽  
pp. 1263-1273
Author(s):  
Youngsang Kwon ◽  
Anna C Doty ◽  
Megan L Huffman ◽  
Virginie Rolland ◽  
Daniel R Istvanko ◽  
...  

AbstractNorth American bats are experiencing declines in part due to anthropogenic impacts resulting in habitat loss and disturbance. In eastern deciduous forests, bats rely on forest resources for all or part of the year. Therefore, to promote conservation of bats, it is essential to determine whether current forest management techniques are compatible with habitat use by bats. We evaluated the relative effect of landscape characteristics, including forest management variables, on sex-specific foraging habitat of an insectivorous forest-dwelling bat species, the evening bat (Nycticeius humeralis), and predicted areas of suitable habitat for N. humeralis. A total of 18 variables were assessed using a maximum-entropy (Maxent) machine-learning approach: eight land use–land cover classes, three stand types, two topography measures, normalized difference vegetation index, and four forest management variables. Females showed the highest probability of presence closer to stands treated with prescribed fire, whereas males showed the highest probability of presence closer to reforested stands. In general, males exhibited more flexibility than females in their habitat selection. The Maxent model further indicated that habitat associated with suitability of > 70% was ~4 times larger for males than females, and predicted an additional area of suitable foraging habitat where no presence locations had been recorded. Our modeling approach may be suitable for other researchers to derive models appropriate for a wide range of bat species.


2013 ◽  
Vol 154 (3) ◽  
pp. 803-811 ◽  
Author(s):  
F. Casas ◽  
F. Mougeot ◽  
M. E. Ferrero ◽  
I. Sánchez-Barbudo ◽  
J. A. Dávila ◽  
...  

ARCTIC ◽  
2016 ◽  
Vol 69 (1) ◽  
pp. 19
Author(s):  
Paul L. Flint ◽  
John A. Reed ◽  
Deborah L. Lacroix ◽  
Richard B. Lanctot

From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (<em>Clangula hyemalis</em>) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.


2003 ◽  
Vol 30 (2) ◽  
pp. 111 ◽  
Author(s):  
Gerhard Körtner ◽  
Shaan Gresser ◽  
Bob Harden

In Australia, baiting with 1080 (sodium fluoroacetate) is widely used to reduce predation of native wildlife by the red fox. However, such control programs may place some native carnivores at risk, particularly the spotted-tailed quoll in eastern Australia. We measured the mortality in a total of 57 quolls fitted with mortality radio-transmitters during four experimental fox baitings with Foxoff® 1080 baits containing Rhodamine B in north-east New South Wales. In all experiments quolls visited bait stations regularly and removed a total of 20 baits. All but one of these baits was found in the vicinity of the bait station, indicating that quolls did not ingest baits. This was confirmed by the absence of Rhodamine B in the vibrissae of all quolls retrapped after baiting. The only quoll that may have died from a bait had eaten a cached bait some six weeks after baiting concluded. Thus, baiting did not threaten any of the quoll populations sampled. Therefore it appears that most restrictions imposed to protect spotted-tailed quolls during fox baiting are unnecessary as long as this bait type is used.


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