Reinforcing the native Otter Lutra lutra population in East Anglia: an analysis of the behaviour and range development of the first release group

Abstract

The British population of the Eurasian Otter Lutra lutra has shown a serious decline since 1957-1958. In England the surviving population is broken into small fragments which may not be viable. One way to strengthen the population to enable it to recover would be to insert breeding units into the gaps. A practical methodology using captive-bred Otters in groups of three is described. This was tested successfully in 1983-1985 in East Anglia, with the first two release groups now breeding. The male in the 1983 group was tracked using a radio harness to be sure of survival and to monitor behaviour and use the environment. Data were obtained on the development of a home range in the new environment. Also, useful information was gathered on swimming and hunting speeds, time of emergence, distance travelled each night, activity periods and time spent in each habitat. This behaviour is compared to that of previously tracked wild Otters in Scotland. The very close similarity of many features is encouraging and results may be taken as indicative of the behaviour of wild Otters in lowland Britain.

Genetic diversity and landscape genetic structure of otter (Lutra lutra) populations in Europe

“…We collected samples also from southern Sweden where otters were reintroduced in the past 20 years (Sjöåsen 1996). We did not use additional samples from East Anglia (UK) because those populations originated from the reintroduction of otters by the Otter Trust breeding centre (Jefferies et al 1986). Otters are widespread in north-west Austria where they are in contact with the Czech population.…”

A longer confinement period favors European wild rabbit (Oryctolagus cuniculus) survival during soft releases in low-cover habitats

“…Among the stages involved in translocation programs, capture, captivity, transportation, and release are the most stressful (Teixeira et al 2007). Many studies have assessed ways to reduce this problem, one of which is the use of "soft release," whereby rabbits are acclimated to their new environment in mammal holding pens (Jefferies et al 1986;Short et al 1992). Comparison of "soft" and "hard" (without an acclimation period) release methods have generally demonstrated improved survival and behavior benefits with soft releases (Bright and Morris 1994).…”

Sex identification of Eurasian otter (Lutra lutra) non-invasive DNA samples using ZFX/ZFY sequences

“…Recently otter populations started to expand again, naturally or sustained by local reintroduction projects (Jeffries et al 1986;Mason and Macdonald 2004). Non-invasive genetic methods (Waits and Paetkau 2005) are being increasingly integrated in otter monitoring projects, aiming to obtain information on distribution range, population size and genetic variability (Dallas et al 2003;Hung et al 2004;Hà jkovà et al 2006;Prigioni et al 2006).…”