Targeted field testing of wildlife road-crossing structures: koalas and canopy rope-bridges

2017 ◽  
Vol 39 (1) ◽  
pp. 100 ◽  
Author(s):  
Ross L. Goldingay ◽  
Brendan D. Taylor

The suitability of structures installed to enable safe passage of wildlife across a road is most frequently determined by monitoring of structures after new roads are built. Rarely are new structures field tested before installation. We installed canopy rope-bridges in an area frequented by koalas (Phascolarctos cinereus) with the explicit aim of determining whether koalas might use such structures. Rope-bridges were of four different designs to maximise the likelihood that one might be used, as a precursor to further replication. Infrared cameras were installed on the rope-bridges as well as on two nearby reference trees to compare frequency of use. Over a monitoring period of 2.9 years no koalas were detected on the rope-bridges whereas koalas were recorded on the reference trees on 34 and 41 different 24-h periods. Rope-bridges may not be suited to an arboreal mammal that is inclined to travel along the ground to move between trees.

2018 ◽  
Vol 40 (1) ◽  
pp. 67 ◽  
Author(s):  
C. E. Dexter ◽  
R. G. Appleby ◽  
J. Scott ◽  
J. P. Edgar ◽  
D. N. Jones

The ability to predict the frequency with which koalas (Phascolarctos cinereus) cross roads is an important step in developing mitigation strategies aimed at maintaining metapopulation viability for this species. In south-east Queensland, Australia, rapid urban development, including fragmentation and vehicle-related mortality, has contributed to a dramatic decline in local koala populations. Assessment of wildlife crossing structures that mitigates the impact of roads demonstrates these to be beneficial for many species. However, building enough structures to enable animals to move freely across impacted landscapes may be prohibitive in complex urban landscapes. The focus for this study was to consider the role of differing characteristics for species at risk. We examined the frequency of road crossings by individual koalas among six subpopulations in south-east Queensland. We explored the influence of potential predictor variables including: age, sex, and distance from roads. We established that road crossings were limited to a subset of individuals, with only 18 of 51 (~35%) koalas studied ever crossing a road. We found that koalas were disproportionately more likely to cross a road if they had initially been found within a distance of 100 m of that road. Males were more likely to cross roads than females, as were koalas aged less than five years. We suggest that successful wildlife road mitigation can be improved by better understanding the road-crossing behaviour of species such as the koala.


1991 ◽  
Vol 18 (2) ◽  
pp. 125 ◽  
Author(s):  
AF Bennett ◽  
LF Lumsden ◽  
JSA Alexander ◽  
PE Duncan ◽  
PG Johnson ◽  
...  

A total of 1487 observations of nine species of arboreal mammal, Acrobates pygmaeus, Phascolarctos cinereus, Petauroides volans, Petaurus australis, P. breviceps, P. norfolcensis, Pseudocheirusperegrinus, Trichosurus caninus and T. vulpecula, were made during surveys of the vertebrate fauna of northeastern Victoria. Habitat use by each species was examined in relation to eight forest types that occur along an environmental gradient ranging from sites at high elevation with a high annual rainfall, to sites on the dry inland and riverine plains. Arboreal mammals were not evenly distributed between forest types. Three species (P. australis, P. volans and T. caninus) were mainly associated with moist tall forests; two species (P. norfolcensis and T. vulpecula) were primarily associated with drier forests and woodlands of the foothills; the remaining three species (A. pygmaeus, P. breviceps and P. peregrinus) occurred widely throughout the forests. The composition of the arboreal mammal assemblage changed along the environmental gradient, but species displayed gradual changes in abundance with forest type rather than marked discontinuities in distributional pattern. The highest overall frequencies of occurrence of arboreal mammals were in forests typically dominated by a mixture of eucalypt species. The position at first sighting of an animal, and the relative height in the forest stratum, were used to describe the micro-habitats utilised. In general, the microhabitats occupied by each species are consistent with the distribution of their known food resources.


2015 ◽  
Vol 79 (5) ◽  
pp. 854-860 ◽  
Author(s):  
Marcello D'Amico ◽  
Anthony P. Clevenger ◽  
Jacinto Román ◽  
Eloy Revilla

2019 ◽  
Vol 12 (0) ◽  
pp. 37-44
Author(s):  
Yoichi SONODA ◽  
Masahiko MATSUE ◽  
Satoshi FUNAKUBO

2008 ◽  
Vol 88 (3) ◽  
pp. 407-415 ◽  
Author(s):  
C. Mata ◽  
I. Hervás ◽  
J. Herranz ◽  
F. Suárez ◽  
J.E. Malo

2010 ◽  
Vol 37 (4) ◽  
pp. 320 ◽  
Author(s):  
Brendan D. Taylor ◽  
Ross L. Goldingay

Roads can disrupt the population processes of vertebrate wildlife species through habitat fragmentation and vehicle collision. The aims of this review were to synthesise the recent literature on road impacts on wildlife, to identify gaps in our understanding of this topic and to guide future research and management in Australia. We reviewed 244 published studies from the last decade on road and vehicle impacts on wildlife conducted worldwide. A geographic bias was evident among the studies, with 51% conducted in North America, 25% in Europe, 17% in Australia and 7% across several other countries. A taxonomic bias was evident towards mammals (53%), with far fewer studies on birds (10%), amphibians (9%) and reptiles (8%), and some (20%) included multiple taxonomic groups. Although this bias is partly explained by large insurance and medical costs associated with collisions involving large mammals, it is also evident in Australia and signals that large components of biodiversity are being neglected. Despite a prevalence of studies on wildlife road mortality (34%), population impacts are poorly described, although negative impacts are implicated for many species. Barrier effects of roads were examined in 44 studies, with behavioural aversion leading to adverse genetic consequences identified for some species. The installation of road-crossing structures for wildlife has become commonplace worldwide, but has largely outpaced an understanding of any population benefits. Road underpasses appear to be an important generic mitigation tool because a wide range of taxa use them. This knowledge can guide management until further information becomes available. Global concern about the decline of amphibians should lead to a greater focus on road impacts on this group. Priorities for research in Australia include (1) genetic studies on a range of taxa to provide an understanding of life-history traits that predispose species to barrier effects from roads, (2) studies that examine whether crossing structures alleviate population impacts from roads and (3) studies that describe the behavioural response of frogs to crossing structures and that identify factors that may promote the use of suitable structures. A national strategy to mitigate the impacts of roads on wildlife populations is long overdue and must ensure that research on this topic is adequately funded.


Author(s):  
Nabilah Zainol ◽  
Taherah Mohd. Taher ◽  
Siti Nurfaeiza Abd. Razak ◽  
Nur Afiqah Izzati Noh ◽  
Nurul Adyla Muhammad Nazir ◽  
...  

The Felda Aring - Tasik Kenyir Road was identified as one of the most threatening roads to wildlife in Malaysia. The present study was conducted to assess the road crossing activities involving the medium- to large-mammal species due to the problem stated. The objectives of this study were to (1) predict the suitability of the road and its surroundings as the roaming areas for the Asian elephant (Elephas maximus, n = 104) and Malayan tapir (Tapirus indicus, n = 66), (2) identify the mammalian species inhabiting the forest beside the road, (3) compare the forest’s common species [photographic capture rate index (PCRI) > 10/ detection probability (P) ≥ 0.05] with the ones utilising the road crossing structures; the viaducts and the bridges, and (4) determine the most impacted species from traffic collisions. The road and its surroundings were classified as moderately suitable to the elephant and tapir (suitability values = 0.4 - 0.8). A total of 16 mammal species were recorded at the forest edges, in which the wild pig (Sus scrofa) (PCRI = 118.96, P = 0.3719 ± 0.027), barking deer (Muntiacus muntjak) (PCRI = 68.89, P = 0.2219 ± 0.0232), sun bear (Helarctos malayanus) (PCRI = 11.13, P = 0.0507 ± 0.0159), tapir (PCRI = 11.13, P = 0.0469 ± 0.0118), elephant (PCRI = 10.7, P = 0.0787 ± 0.0195) and Malayan porcupine (Hystrix brachyura) (PCRI = 10.7, P = 0.103 ± 0.0252) were the common species utilising the crossing structures. In contrast, the Asian palm civet (Paradoxurus hermaphroditus) and leopard cat (Prionailurus bengalensis) were the most frequently hit species on the road [F(7,398) = 28.53, p < 0.0005]. The present study found that large-mammal species were utilising the crossing structures at a higher frequency, whereas more medium-mammal species were involved in traffic collisions.


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