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CURATOR
A pinboard by
Leonardo Gubert

PhD Student, University of Exeter

PINBOARD SUMMARY

Investigation on hibernation behaviour, exploitation of roadside habitats, the effect of habitat fragmentation and dispersal of the hazel dormouse in southwest England

7 ITEMS PINNED

Mitigating impacts of roads on wildlife: an agenda for the conservation of priority European protected species in Great Britain

Abstract: Global increases in road networks have been matched by traffic flows and are implicated in declines of many sensitive species. Impacts on wildlife by linear development features such as roads include mortality due to vehicle collisions and secondary effects such as preventing traditional movements or severing links between populations. European legislation requires development activities to have ‘no detriment’ to the favourable conservation status of European protected species (EPS), including great crested newts (Triturus cristatus), hazel dormouse (Muscardinus avellanarius) and bats (Chiroptera). To protect these and other species, various mitigation measures are available. Within this review, we sought to identify best practice guidance for preventing and mitigating these impacts for EPS in Great Britain, evaluate the evidence underpinning these best practices and identity knowledge gaps that may impede progress in improving practices. Many current practices appear to be implemented at considerable cost despite limited evidence of their effectiveness. This is probably partly due to inadequate definition of effectiveness, which has most frequently been assessed as a reduction in absolute road mortality or increased frequency of safe road crossings. However, challenges in measuring benefits more appropriately, at spatial and temporal scales that are appropriate for population maintenance, may also have contributed. Evidence of the cost-effectiveness of mitigation works could underpin justification for the substantial investment required to implement many of the mitigation methods reviewed, could avoid the potentially wasteful use of ineffective methods and could better safeguard the conservation status of impacted EPS at local and national scales.

Pub.: 05 Feb '15, Pinned: 16 Aug '17

Take Only Photographs, Leave Only Footprints: Novel Applications of Non-Invasive Survey Methods for Rapid Detection of Small, Arboreal Animals.

Abstract: The development of appropriate wildlife survey techniques is essential to promote effective and efficient monitoring of species of conservation concern. Here, we demonstrate the utility of two rapid-assessment, non-invasive methods to detect the presence of elusive, small, arboreal animals. We use the hazel dormouse, Muscardinus avellanarius, a rodent of conservation concern, as our focal species. Prevailing hazel dormouse survey methods are prolonged (often taking months to years to detect dormice), dependent on season and habitat, and/or have low detection rates. Alternatives would be of great use to ecologists who undertake dormouse surveys, especially those assessing the need for mitigation measures, as legally required for building development projects. Camera traps and footprint tracking are well-established tools for monitoring elusive large terrestrial mammals, but are rarely used for small species such as rodents, or in arboreal habitats. In trials of these adapted methods, hazel dormice visited bait stations and were successfully detected by both camera traps and tracking equipment at each of two woodland study sites, within days to weeks of installation. Camera trap images and footprints were of adequate quality to allow discrimination between two sympatric small mammal species (hazel dormouse and wood mouse, Apodemus sylvaticus). We discuss the relative merits of these methods with respect to research aims, funds, time available and habitat.

Pub.: 21 Jan '16, Pinned: 16 Aug '17

A blind climber: The first evidence of ultrasonic echolocation in arboreal mammals.

Abstract: The means of orientation is studied in the Vietnamese pygmy dormouse Typhlomys chapensis, a poorly known enigmatic semi-fossorial semi-arboreal rodent. Data on eye structure are presented, which prove that Typhlomys (translated as "the blind mouse") is incapable of object vision - the retina is folded and retains no more than 2 500 ganglion cells in the focal plane, and the optic nerve is subject to gliosis. Hence, Typhlomys has no other means for rapid long-range orientation among tree branches other than echolocation. Ultrasonic vocalization recordings at the frequency range of 50-100 kHz support this hypothesis. The vocalizations are represented by bouts of up to 7 more or less evenly-spaced and uniform frequency-modulated sweep-like pulses in rapid succession. Structurally, these sweeps are similar to frequency-modulated ultrasonic echolocation calls of some bat species, but they are too faint to be revealed with a common bat detector. When recording video simultaneously with the ultrasonic audio, a significantly greater pulse rate during locomotion compared to that of resting animals has been demonstrated. Our findings of locomotion-associated ultrasonic vocalization in a fast-climbing but weakly-sighted small mammal ecotype add support to the "echolocation-first theory" of pre-flight origin of echolocation in bats. This article is protected by copyright. All rights reserved.

Pub.: 20 Dec '16, Pinned: 16 Aug '17

Whisker touch guides canopy exploration in a nocturnal, arboreal rodent, the Hazel dormouse (Muscardinus avellanarius).

Abstract: Dormouse numbers are declining in the UK due to habitat loss and fragmentation. We know that dormice are nocturnal, arboreal, and avoid crossing open spaces between habitats, yet how they navigate around their canopy is unknown. As other rodents use whisker touch sensing to navigate and explore their environment, this study investigates whether Hazel dormice (Muscardinus avellanarius) employ their whiskers to cross between habitats. We analysed high-speed video footage of dormice exploring freely in flat and climbing arenas in near darkness and using infrared light illumination. We confirm that, like rats and mice, dormice move their whiskers back and forth continuously (~10 Hz) in a motion called whisking and recruit them to explore small gaps (<10 cm) by increasing the amplitude and frequency of whisking and also the asymmetry of movement between the left and right whisker fields. When gaps between platforms are larger than 10-15 cm, dormice spend more time travelling on the floor. These findings suggest that dormice can actively and purposively move their whiskers to gather relevant information from their canopy at night. As this species is vulnerable to threats on the ground, we also provide evidence that joining habitat patches between dormouse populations is important for promoting natural behaviours and movement between patches.

Pub.: 21 Jan '17, Pinned: 16 Aug '17