Study

Removal of introduced Arctic foxes Alopex lugopus, captive breeding and reintroductions lead to recovery of cackling goose Branta hutchinsii populations in the Aleutian Islands, Alaska, USA

Actions

This study is summarised as evidence for the following.

Action Category

Control mammalian predators on islands for wildfowl

Action Link
Bird Conservation

Release birds in ‘coveys’

Action Link
Bird Conservation

Clip birds’ wings on release

Action Link
Bird Conservation

Release captive-bred individuals into the wild to restore or augment wild populations of wildfowl

Action Link
Bird Conservation

Release birds as adults or sub-adults, not juveniles

Action Link
Bird Conservation
  1. Control mammalian predators on islands for wildfowl

    A before-and-after study from the Aleutian Islands, Alaska, USA on the cackling goose Branta hutchinsii recovery programme (USFWS 2001) found that geese bred on four islands from 1984 onwards after Arctic foxes Alopex lugopus were eradicated from them. Together with releases of captive-bred individuals, the programme resulted in the population increasing to 6,000 birds by 1991, compared with fewer than 1,000 in the 1970s, and birds were breeding on eight fox-free islands. The effects of different release techniques are discussed in ‘Release captive-bred individuals into the wild to restore or augment wild populations’, ‘Release birds as adults or subadults, not juveniles’ and ‘Clip birds’ wings on release’.

     

  2. Release birds in ‘coveys’

    A before-and-after study from the Aleutian Islands, Alaska, USA on the cackling goose Branta hutchinsii recovery programme (USFWS 2001) found that releasing geese in family groups proved a better strategy than releasing young geese (captive or wild, see ‘Release birds as adults or sub-adults, not juveniles’). The authors note that the release of captive-bred geese was not very successful overall. This study also investigates the effect of Arctic fox Alopex lugopus control on breeding islands (see ‘Predator control on islands’).

     

  3. Clip birds’ wings on release

    A before-and-after study from the Aleutian Islands, Alaska, USA on the cackling goose Branta hutchinsii recovery programme (USFWS 2001) found that releasing wing-clipped or moulting wild adult geese proved a better strategy than releasing young geese (captive or wild, see ‘Release birds as adults or sub-adults, not juveniles’). The authors note that the release of captive-bred geese was not very successful overall. This study also investigates the effect of Arctic fox Alopex lugopus control on breeding islands (see ‘Predator control on islands’).

     

  4. Release captive-bred individuals into the wild to restore or augment wild populations of wildfowl

    A before-and-after study from the Aleutian Islands, Alaska, USA on the cackling goose Branta hutchinsii recovery programme (USFWS 2001) found that the goose population increased from fewer than 1,000 birds in the 1970s to over 6,000 by 1991, following the release of captive-bred birds and the eradication of Arctic foxes Alopex lagopus from breeding islands (see ‘Predator control on islands’). The authors note, however, that the release of captive-bred geese was not very successful overall. Release techniques are discussed in ‘Release birds as adults or sub-adults, not juveniles’ and ‘Clip birds’ wings on release’.

     

  5. Release birds as adults or sub-adults, not juveniles

    A before-and-after study from the Aleutian Islands, Alaska, USA on the cackling goose Branta hutchinsii recovery programme (USFWS 2001) found that releasing young geese was less successful than other strategies (see ‘‘Clip birds’ wings on release’ and ‘Release birds in ‘coveys’). However, the authors note that the release of captive-bred geese was not very successful overall. This study also investigates the effect of Arctic fox Alopex lugopus control on breeding islands (see ‘Predator control on islands’).

     

Output references

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