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Effective Control of Non-Native American Mink by Strategic Trapping in a River Catchment in Mainland Britain.

Reynolds JC, Richardson SM, Rodgers BJ, Rodgers OR - J. Wildl. Manage. (2013)

Bottom Line: Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink.These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration.Persistence of this population through the 4 years of the project was considered indicative of effective mink control.

View Article: PubMed Central - PubMed

Affiliation: Game & Wildlife Conservation Trust Fordingbridge, Hampshire SP6 1EF, UK.

ABSTRACT
The introduction of American mink (Neovison vison; hereafter mink) into Europe has had severe impacts on many native wildlife species, including the water vole (Arvicola amphibius) in mainland Britain. Although trapping has been widely used to attempt to control mink, managers have little direct evidence of its effect on mink density or distribution, particularly where immigration of mink from nearby areas is inevitable. Such evidence is needed to justify the use of lethal methods in conservation policy. During 2006-2010 we removed mink from the River Monnow Catchment in western Britain, using track-recording rafts to monitor continuously for mink presence, guiding a strategic trapping effort. The area monitored and trapped was increased in stages, from a core sub-catchment with 109 km of water-course in 2006, to a 421-km(2) catchment with 203 km of water-course in 2009. In each successive sub-catchment, mink detection and capture rates declined rapidly to near-zero levels after trapping began. Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink. These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration. On average, we detected each mink 5.1 times before capture (daily probability of detection = 0.059 per mink and raft), and trapped them 3.4 days after deploying traps in response. On average, mink entering the area were likely to have been present for less than 13 days before capture. Water voles had been extinct in the Monnow Catchment since the 1980s. During 2006-2008 (starting 6 months after mink trapping commenced), we released 700 captive-bred water voles into the treatment area to re-establish a wild population. Persistence of this population through the 4 years of the project was considered indicative of effective mink control. This study demonstrates that, even in a mainland context, a systematic trapping strategy can have a substantial impact on the density and distribution of a damaging species, in this case allowing the restoration of a native prey species. © 2013 The Wildlife Society.

No MeSH data available.


Related in: MedlinePlus

Distribution of water voles within the core area (River Dore) on successive spring field-sign surveys (a) April 2007, (b) April 2008, (c) April 2009, and (d) May 2010. We mapped only unequivocal evidence of water vole presence (i.e., food caches or latrines). We did not survey side streams. Main releases of water voles took place in the northern half of the river during August 2006, and in the southern half of the river during August 2007.
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fig06: Distribution of water voles within the core area (River Dore) on successive spring field-sign surveys (a) April 2007, (b) April 2008, (c) April 2009, and (d) May 2010. We mapped only unequivocal evidence of water vole presence (i.e., food caches or latrines). We did not survey side streams. Main releases of water voles took place in the northern half of the river during August 2006, and in the southern half of the river during August 2007.

Mentions: After releases in 2007, water vole distribution remained fairly constant through to 2010 (Fig. 6). In April 2010, water voles were distributed along 13.3 km of the River Dore.


Effective Control of Non-Native American Mink by Strategic Trapping in a River Catchment in Mainland Britain.

Reynolds JC, Richardson SM, Rodgers BJ, Rodgers OR - J. Wildl. Manage. (2013)

Distribution of water voles within the core area (River Dore) on successive spring field-sign surveys (a) April 2007, (b) April 2008, (c) April 2009, and (d) May 2010. We mapped only unequivocal evidence of water vole presence (i.e., food caches or latrines). We did not survey side streams. Main releases of water voles took place in the northern half of the river during August 2006, and in the southern half of the river during August 2007.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675646&req=5

fig06: Distribution of water voles within the core area (River Dore) on successive spring field-sign surveys (a) April 2007, (b) April 2008, (c) April 2009, and (d) May 2010. We mapped only unequivocal evidence of water vole presence (i.e., food caches or latrines). We did not survey side streams. Main releases of water voles took place in the northern half of the river during August 2006, and in the southern half of the river during August 2007.
Mentions: After releases in 2007, water vole distribution remained fairly constant through to 2010 (Fig. 6). In April 2010, water voles were distributed along 13.3 km of the River Dore.

Bottom Line: Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink.These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration.Persistence of this population through the 4 years of the project was considered indicative of effective mink control.

View Article: PubMed Central - PubMed

Affiliation: Game & Wildlife Conservation Trust Fordingbridge, Hampshire SP6 1EF, UK.

ABSTRACT
The introduction of American mink (Neovison vison; hereafter mink) into Europe has had severe impacts on many native wildlife species, including the water vole (Arvicola amphibius) in mainland Britain. Although trapping has been widely used to attempt to control mink, managers have little direct evidence of its effect on mink density or distribution, particularly where immigration of mink from nearby areas is inevitable. Such evidence is needed to justify the use of lethal methods in conservation policy. During 2006-2010 we removed mink from the River Monnow Catchment in western Britain, using track-recording rafts to monitor continuously for mink presence, guiding a strategic trapping effort. The area monitored and trapped was increased in stages, from a core sub-catchment with 109 km of water-course in 2006, to a 421-km(2) catchment with 203 km of water-course in 2009. In each successive sub-catchment, mink detection and capture rates declined rapidly to near-zero levels after trapping began. Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink. These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration. On average, we detected each mink 5.1 times before capture (daily probability of detection = 0.059 per mink and raft), and trapped them 3.4 days after deploying traps in response. On average, mink entering the area were likely to have been present for less than 13 days before capture. Water voles had been extinct in the Monnow Catchment since the 1980s. During 2006-2008 (starting 6 months after mink trapping commenced), we released 700 captive-bred water voles into the treatment area to re-establish a wild population. Persistence of this population through the 4 years of the project was considered indicative of effective mink control. This study demonstrates that, even in a mainland context, a systematic trapping strategy can have a substantial impact on the density and distribution of a damaging species, in this case allowing the restoration of a native prey species. © 2013 The Wildlife Society.

No MeSH data available.


Related in: MedlinePlus