Overwinter survival and post-release movements of translocated water voles

implications for current mitigation guidance

Rowenna Baker, Dawn Scott, Chris Keeling, Charlie Dwight

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Translocation is currently used as a last resort mitigation strategy for water voles (Arvicola amphibius) in the UK (Dean et al. 2016), where populations have undergone widespread declines during the past century. To increase the chances of success, current guidance suggests translocation of voles during autumn should not be carried out as individuals may be at higher risk of overwinter mortality, and instead should be overwintered in captivity for release the following spring. To verify this guidance, we carried out a mark recapture and radiotracking study of an autumn translocated and resident population in lowland England. Whilst we found translocated voles undertook longer exploratory movements than residents and those previously recorded in spring, there was no evidence from our study that translocated voles suffered higher mortality rates compared to the resident individuals. The turnover in both populations was high with 25% and 8% of the translocated and resident individuals being recaptured in spring. Younger voles that were not collared had a significantly higher chance of being recaptured in spring and their survival and settlement on the receptor channel is considered important as this is the age class that will produce most of the following years’ young. Mean weekly distances moved by collared voles showed no pattern of stabilisation, in either sex, over the 10-week monitoring period and combined dispersal from both study populations accounted for 26% of those that were not recaptured in spring. However, due to low sample size, we were unable to distinguish between the effects of dispersal and mortality. We conclude that where individuals or populations will be negatively impacted by planned development, autumn translocations in lowland England may offer a feasible alternative to housing animals in captivity, given the high financial cost and additional health and welfare risks associated with a captive environment. The receptor site and adjacent habitat (> 1 km) would need to support a seasonal abundance of food and cover, be connected to existing populations and be part of a wider landscape that is mink free and under an effective mink control programme to help secure long-term population viability. We advise, however, that due to our small sample size, further studies are undertaken to confirm our findings
Original languageEnglish
Pages (from-to)1-13
JournalEuropean Journal of Wildlife Research
Volume64
Issue number56
DOIs
Publication statusPublished - 20 Sep 2018

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water
mink
autumn
England
lowlands
receptors
captive animals
voles
age structure
viability
sampling
monitoring
gender
habitats
Arvicola amphibius

Bibliographical note

This is a post-peer-review, pre-copyedit version of an article published in European Journal of Wildlife Research. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10344-018-1216-8

Keywords

  • Arvicola amphibius
  • Radiotracking
  • Mitigation
  • Survival Translocation
  • Water vole

Cite this

Baker, Rowenna ; Scott, Dawn ; Keeling, Chris ; Dwight, Charlie. / Overwinter survival and post-release movements of translocated water voles : implications for current mitigation guidance. In: European Journal of Wildlife Research. 2018 ; Vol. 64, No. 56. pp. 1-13.
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abstract = "Translocation is currently used as a last resort mitigation strategy for water voles (Arvicola amphibius) in the UK (Dean et al. 2016), where populations have undergone widespread declines during the past century. To increase the chances of success, current guidance suggests translocation of voles during autumn should not be carried out as individuals may be at higher risk of overwinter mortality, and instead should be overwintered in captivity for release the following spring. To verify this guidance, we carried out a mark recapture and radiotracking study of an autumn translocated and resident population in lowland England. Whilst we found translocated voles undertook longer exploratory movements than residents and those previously recorded in spring, there was no evidence from our study that translocated voles suffered higher mortality rates compared to the resident individuals. The turnover in both populations was high with 25{\%} and 8{\%} of the translocated and resident individuals being recaptured in spring. Younger voles that were not collared had a significantly higher chance of being recaptured in spring and their survival and settlement on the receptor channel is considered important as this is the age class that will produce most of the following years’ young. Mean weekly distances moved by collared voles showed no pattern of stabilisation, in either sex, over the 10-week monitoring period and combined dispersal from both study populations accounted for 26{\%} of those that were not recaptured in spring. However, due to low sample size, we were unable to distinguish between the effects of dispersal and mortality. We conclude that where individuals or populations will be negatively impacted by planned development, autumn translocations in lowland England may offer a feasible alternative to housing animals in captivity, given the high financial cost and additional health and welfare risks associated with a captive environment. The receptor site and adjacent habitat (> 1 km) would need to support a seasonal abundance of food and cover, be connected to existing populations and be part of a wider landscape that is mink free and under an effective mink control programme to help secure long-term population viability. We advise, however, that due to our small sample size, further studies are undertaken to confirm our findings",
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Overwinter survival and post-release movements of translocated water voles : implications for current mitigation guidance. / Baker, Rowenna; Scott, Dawn; Keeling, Chris; Dwight, Charlie.

In: European Journal of Wildlife Research, Vol. 64, No. 56, 20.09.2018, p. 1-13.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Overwinter survival and post-release movements of translocated water voles

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AU - Baker, Rowenna

AU - Scott, Dawn

AU - Keeling, Chris

AU - Dwight, Charlie

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AB - Translocation is currently used as a last resort mitigation strategy for water voles (Arvicola amphibius) in the UK (Dean et al. 2016), where populations have undergone widespread declines during the past century. To increase the chances of success, current guidance suggests translocation of voles during autumn should not be carried out as individuals may be at higher risk of overwinter mortality, and instead should be overwintered in captivity for release the following spring. To verify this guidance, we carried out a mark recapture and radiotracking study of an autumn translocated and resident population in lowland England. Whilst we found translocated voles undertook longer exploratory movements than residents and those previously recorded in spring, there was no evidence from our study that translocated voles suffered higher mortality rates compared to the resident individuals. The turnover in both populations was high with 25% and 8% of the translocated and resident individuals being recaptured in spring. Younger voles that were not collared had a significantly higher chance of being recaptured in spring and their survival and settlement on the receptor channel is considered important as this is the age class that will produce most of the following years’ young. Mean weekly distances moved by collared voles showed no pattern of stabilisation, in either sex, over the 10-week monitoring period and combined dispersal from both study populations accounted for 26% of those that were not recaptured in spring. However, due to low sample size, we were unable to distinguish between the effects of dispersal and mortality. We conclude that where individuals or populations will be negatively impacted by planned development, autumn translocations in lowland England may offer a feasible alternative to housing animals in captivity, given the high financial cost and additional health and welfare risks associated with a captive environment. The receptor site and adjacent habitat (> 1 km) would need to support a seasonal abundance of food and cover, be connected to existing populations and be part of a wider landscape that is mink free and under an effective mink control programme to help secure long-term population viability. We advise, however, that due to our small sample size, further studies are undertaken to confirm our findings

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KW - Radiotracking

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KW - Survival Translocation

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