Wildlife Research最新文献

Large carnivore reintroductions often face unique challenges, as they can conflict with human interests and face public opposition. To increase the probability of success, reintroduction programs can use strategic communications to increase public support and achieve conservation goals.

Although there is initial research testing theoretically-grounded messages on generating support for reintroductions, there is much to learn about the efficacy of messaging strategies, particularly how specific themes perform against each other. Despite the established importance of local support for successful reintroductions, there is little research examining local versus non-local communities’ responses to different messaging. This study fills these gaps by examining how strategic messaging can be employed to increase public support for a potential red wolf (Canis rufus) reintroduction in Ozark National Forest, Arkansas, USA.

We used an online survey panel of 844 Arkansas respondents to test five randomly assigned messages: a descriptive control and four treatments related to trust in the U.S. Fish and Wildlife Service (USFWS); red wolf benefits to humans; red wolf benefits to the ecosystem; and mitigating perceived red wolf risks. We compared Ozark National Forest-adjacent landowner (ONFALO) respondents to all other respondents to understand the effects of messaging on local versus non-local communities.

Our findings indicated significant differences among ONFALO respondents and other respondents. We found key differences in how messaging induced these two groups. Additionally, our pre-test-post-test approach demonstrated ONFALO were less influenced by messaging about a potential reintroduction than other respondents. Finally, we found that ONFALO respondents agreed with negative statements about red wolves more often than other respondents.

Overall, we conclude that messaging that highlights red wolf information may increase ONFALO respondents’ support for a potential red wolf reintroduction, and that efforts to increase self-efficacy in risk mitigation, and messaging related to ecosystem benefits of red wolves may also be beneficial.

Our results demonstrate the need for messaging related to wildlife reintroductions to be strategically tailored based on the audience, where specific attention should be paid to local community values and concerns.

Many vertebrate studies report predation from pit co-occupants as a source of mortality during pitfall surveys.

This study aims to assess the use of false-floors in pitfall traps to reduce the opportunistic predation of small reptiles by small mammals caught within the same pit.

Small-vertebrate surveys were conducted using pitfall traps in an arid landscape from 1998 to 2021. Between 2018 and 2021, wooden false-floors with 2 cm notches in their sides were placed inside pitfall traps to reduce the amount of reptile predation caused by small mammals co-occupying the same pit. The position of captured individuals, relative to the false-floor, were used to assess the capacity of false-floors to create an effective barrier between captured reptiles and mammals.

During the false-floor trial period (2018–2021), Pseudomys australis and Notomys alexis were identified as the key mammal species opportunistically predating on captured reptiles, collectively accounting for 54% of reptile predation incidents. Most of the N. alexis and P. australis captures were found above false-floors (92 and 70% of captures respectively), indicating that they were generally not able to access the prey refuge beneath. Reptile mortality from small mammal predation was significantly lower in pitfalls with false-floors (15% of reptile-mammal co-occupancy incidents) than in those without (60% of co-occupancy incidents). However, false-floors did not prevent all predation events because some mammals were able to access the compartment underneath the false-floors.

The false-floors provided an effective barrier between small reptiles and key mammal species caught in the same pit and reduced occurrences of small reptile predation.

False-floors can effectively be used as a tool to reduce reptile mortality during pitfall surveys. However, they also increased the time taken to set and check traps and we therefore suggest their use only during times of high mammal abundances, when the abundance of large rodents is high. The efficacy of false-floors at any particular site may be improved by trialling different-sized notches and construction materials.

Fire regimes are changing with ongoing climate change, which is leading to an increase in fire frequency and severity. Australia’s Black Summer wildfires burned >12 million hectares in 2019–2020, affecting numerous threatened animal species. One of the species predicted to be most impacted was the threatened southern greater glider, an arboreal, hollow-dependent folivore, endemic to eastern Australia’s eucalypt forests.

This study aimed to assess how the 2019–2020 wildfires affected greater glider abundance and the resources they depend on in Woomargama National Park, New South Wales, Australia.

We categorised 32 sites into four fire severity treatments with eight sites for each treatment: unburned (continuous unburned vegetation); refuges (unburned patches within the fire’s perimeter); low-moderate severity; and high severity. We carried out two spotlight surveys per site using the double-observer method, beginning 21 months after the fires. We also conducted vegetation assessments on the same transects. To analyse the data, we used Generalised Linear Models to compare habitat differences based on fire severity, and N-mixture models to model greater glider detectability and abundance in relation to habitat and fire severity.

We found that fire severity depleted several habitat variables including canopy cover and the number of potentially hollow-bearing trees, a resource that greater gliders rely on. Greater glider abundance also decreased in all burn categories, with the greatest decline experienced in areas burned at high severity. We also found that greater glider abundance was much lower in fire refuges than unburned habitat outside of the fire zone.

Greater glider declines following severe wildfire can be at least partly attributed to the level of vegetation loss and the associated loss of key habitat resources. The contribution of direct mortality to population declines remains unknown.

Greater glider conservation will rely heavily on protecting expansive unburned areas of suitable habitat and maintaining hollow-bearing trees.

In New Zealand and Australia, rural landowners believe that local control of invasive predators aimed at protecting the indigenous biota exacerbates European rabbit (Oryctolagus cuniculus) problems on their land.

We tested this using rabbit index data collected in replicated areas with and without predator control in rural landscapes of the Hawke’s Bay region of New Zealand.

Spotlight data were available from two ecological restoration areas. For the Cape to City area, data were collected from 2016 to 2021, with three sites subjected to ongoing predator control (traps deployed in 2016 and 2017) and two sites untreated. For the Poutiri Ao ō Tāne area, data were collected from 2012 to 2021, with two sites subjected to ongoing predator control (beginning in 2012) and three sites untreated. Generalised linear mixed-effects models were used to assess whether predator control was a statistically significant predictor of rabbit counts. Cameras were also deployed annually, beginning in 2015, in the treatment and non-treatment areas in Cape to City. Mixed-effects models were fitted to the camera detection data using a ‘Before After Control Impact’ framework to assess whether camera detection rates of rabbits changed with predator control.

Contrary to landowner expectations, fewer rabbits were counted under spotlight at the predator control sites at Cape to City, although no effect was detected in the camera detection data. More rabbits were counted on the predator control sites at Poutiri Ao ō Tāne, but this effect was not statistically significant and only became apparent in the last 2 years of the 9-year monitoring period.

The effects of predator control on rabbit abundance indices in the Hawke’s Bay region were contradictory and inconclusive. This suggests that the influence of predators on rabbit populations is minor compared with other sources of population limitation or regulation, such as disease and poor food quality.

The absence of a definitive predator effect should reassure landowners concerned about potential rabbit population outbreaks following predator control.

The incorporation of invasive plants into novel ecosystems often has negative effects, but it can also sometimes enhance ecosystem function. The threatened native rodent species Leporillus conditor (greater stick-nest rat) is extinct on the Australian mainland and now lives primarily on small islands off the coast of southern Australia. Many of these are degraded novel ecosystems invaded by African boxthorn (Lycium ferocissimum), a weed of national significance. However, L. conditor does not appear to be negatively affected by the presence of boxthorn, raising the question of how the two species co-exist.

To understand how L. conditor uses African boxthorn, we evaluated dietary composition of L. conditor on parts of Reevesby Island by comparing consumption of invasive boxthorn with that of native vegetation.

We identified three key vegetation types on the centre of the island and used point-intercept vegetation surveys to estimate relative availability of plant species in each. We then used micro-histological faecal analysis to estimate the proportions of each species in the diet of L. conditor, and quantified plant species selection by using selection ratios (use/availability).

Qualitative evidence of L. conditor activity suggested that it was mostly confined to vegetation with greater abundance of boxthorn than the other vegetation types (13.5%, compared with 5.7% total sampled vegetation). Furthermore, 51.7% of the faecal plant content and 11.8% of total sampled vegetation was African boxthorn, resulting in a selection ration for boxthorn of 4.4. Native species that appeared to be favoured food sources of L. conditor included Olearia axillaris, Myoporum insulare and Enchylaena tomentosa.

Stick-nest rats of Reevesby Island demonstrate a clear selection for African boxthorn, both in terms of diet (tested quantitatively) and nesting (from previous research and our field observations).

The strong selection of stick-nest rats for a declared noxious weed as its main food source and persistence of stick-nest rats on Reevesby Island require consideration with regards to vegetation management on islands where L. conditor occurs. More broadly, it highlights that some elements of novel ecosystems may have unexpected positive impacts on parts of original ecosystems.

The black rat (Rattus rattus) is an invasive species found throughout much of the globe, including in many agricultural areas, where they cause significant damage to many crops including citrus. Understanding how black rats move in these orchards would substantially aid the development of management programs to combat this pest species.

Our goal was to determine the home-range size and mean maximum distance moved over a 24-h period, as well as to determine the activity period for black rats in orchards.

We used innovative cellular tracking technology to provide a more complete assessment of home-range size and maximum daily movements than previously reported in other investigations. We also used remote-triggered cameras to assess activity periods for black rats to better inform management actions.

We observed large home ranges for black rats in citrus orchards (x¯=2.36ha). Although mean home-range size did not differ between males and females, we did identify an effect of sex on the mean maximum daily distance moved by black rats (males: x¯=201m; females: x¯=148m). Black rats were most active during the early evening, with all observations made during night-time.

Black rats moved relatively large distances within orchards, with activity occurring exclusively at night.

This information on black rat activity patterns will greatly assist in the development of management programs by informing ideal spacing between traps and bait stations to minimise cost, while still yielding efficacious results. A reliance on trapping or baiting during night-time would ensure access by black rats, while eliminating access to diurnal non-target spe

Introduced predators pose a significant threat to biodiversity. Understanding how predators interact with other threats such as fire is crucial to developing effective conservation strategies.

We investigated interactions between the greater bilby (Macrotis lagotis) and two introduced predators, the European red fox (Vulpes vulpes) and feral cat (Felis catus), in response to fire management in a remote part of the Tanami Desert, Australia.

We used motion-sensor cameras and non-invasive genetic sampling to monitor bilbies and predators. We compared activity profiles to determine the level of temporal overlap among species, and used generalised linear modelling to assess the correlation between activity and average normalised difference vegetation index (NDVI; as a proxy for fire-associated environmental change). Finally, we used spatially explicit capture–recapture modelling to estimate cat and bilby densities before and after fire.

Cat and bilby activity declined following fire, whereas fox activity increased (despite only a small proportion of the study area being burnt). Bilbies and foxes showed the greatest overlap in temporal activity (76%), followed by bilbies and cats (71%) and cats and foxes (68%). Bilbies and cats were more likely to be captured in areas with a lower NDVI, whereas foxes were more likely to be captured in areas with a higher NDVI. Bilby density declined significantly following fire, whereas cat density remained constant through time.

Declines in bilby activity and density following fire may be attributed to emigration from the study area and/or increases in fox activity. Post-burn emigration could be due to wide scale destruction of important food resources. However, given much of the study area where bilbies were detected remained unburnt, it is more likely that observed declines are related to increases in fox activity and associated increases in predation pressure. Improved understanding may be gained by experimentally manipulating both fire and predator densities.

Increases in fox activity following fire are likely to have devastating consequences for the local bilby population. It is thus vital that appropriate management activities are put in place to protect bilbies from foxes. This may be achieved through a combination of lethal control and indirect methods.

There is a global move to advocate for the incorporation of Indigenous Knowledges into conservation and land management programs. In Australia this is being reflected in some programs and also regularly in strategy documents. However, we argue that this rarely reflects self-determination for Traditional Custodians. In this article we use two Culturally Significant Entities (CSEs), the humpback and southern right whales, to demonstrate how the regulatory framework that is in place to support species conservation does not adequately allow for Traditional Custodians to extend culturally appropriate levels of care for Country or preserve the knowledge held or associated with a species. Our aim is that the Australian Government and people will work with us to find a way to support the care of CSEs.

We, the authors, are Indigenous Australians. We have familial connections to whale Lore Holders and/or hold traditional whale Lore/Law as part of our cultural obligations. It is from this position that we advocate for greater care of the whales with which we have Ancestral kinship and reciprocal responsibility.

Some insectivorous bats are some of the smallest flying endotherm. They have a high energy demand to maintain body temperature. Therefore, one can expect that larger animals of a species and larger species occur in colder environments as a result of improved energy conservation related to reduced surface to volume ratio in larger endotherm animals. Evidence of this general rule is scarce in bats, although Bergmann predicted this some 175 years ago for closely related species.

In this work, I investigated whether bat body size increases with above-sea-level elevation-related temperature decrease for three closely related Australian bat species of the genus Vespadelus. The purpose of this was two-fold. First, to investigate whether there is a relationship between bat size and elevation by using more recent computational techniques of Bayesian multilevel modelling (BMM). Second, to provide an example of applying recent advances in BMMs to wildlife research and to predict potential consequences of climate warming for these bats.

I investigated whether bat size relates to elevations of bat-capture locations. I included measurement errors for elevation and forearm length measurements by using a BMM in an high-performance computing environment. This model uses measurements of 775 bats from locations in the western slopes of the Australian Alps.

The BMM analysis showed that bat forearm length increased 0.11 mm for every 100 m elevation, with a low standard error of 0.01 mm, indicating a high precision. The standard deviations of the variables species and sex within species were large. This means that they did not provide sufficient explantory power for the overall model and predictions to warrant inclusion.

This study showed that there is a linear increase of bat size with elevation. This is the first study to show that bat size is related to elevation (and associated temperature decline) in three sympatric, closely related species of the same genus and it confirmed what Bergmann predicted over 175 years ago.

Under a warming climate, the results predict that bats become smaller on average. When incorporating average temperature-lapse rate to calculate elevations that assume a 1.5 and 3°C change in future average climate, the study coarsely quantified reduction in suitable habitat for the largest of the three species, V. darlingtoni, of up to 3%.