Isabela eps:Layout 1 - Advanced Conservation Strategies

FERAL GOATS
IN GALAPAGOS
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Capra hircus in Galapagos
“Nearly half of all terrestrial life forms in Galapagos
are found nowhere else on earth”
Introduced mammals are major drivers of extinction. Feral goats (Capra hircus) are particularly devastating to island
ecosystems, causing direct and indirect impacts through overgrazing, which often results in ecosystem degradation and
biodiversity loss. Goats and donkeys are the primary threat to Galapagos’ most endangered plants, and are believed
responsible for one plant extinction, an endemic from Santiago. Goats convert forest to grassland by stopping regeneration
and felling trees or girdling and killing them with their horns. In this way they eliminate entire forests and ecosystems from
islands they inhabit. Endemic birds, reptiles and other animals that rely on this habitat disappear; if these species are
restricted to those areas they are lost forever. As seen on Santiago, many palatable endemic plant species are often reduced to
individuals hanging on in inaccessible bluffs. Exclosures provide seed banks for safe keeping of these severely reduced
populations, but the threats must be removed for recovery to
occur.
Goat menace!
Removing goat populations from islands is a powerful conservation tool to prevent extinctions and restore ecosystems. Goats
have been eradicated successfully from 120 islands worldwide. With newly developed technology and techniques, island
size is perhaps no longer a limiting factor in the successful removal of introduced goat populations. Furthermore, the use of
global positioning systems (GPS), geographic information systems, aerial hunting by helicopter, specialized hunting dogs, and
Judas goats have dramatically increased efficiency and significantly reduced the duration of eradication campaigns.
Intensive monitoring programs are also critical for successful eradications. Eradication removes the entire population of a
given species from an area, compared to control efforts where a percentage of the population will be removed in perpetuity.
Eradication offers a permanent solution with a once-off investment, and given the clear biodiversity benefits, the introduced
goat populations should be permanently removed.
Because of the presence of humans with domestic goat populations on large islands, future island conservation actions will
require eradication programs that involve local island inhabitants in a collaborative approach with biologists, sociologists,
and educators.
FACT BOX
• Worldwide # of islands where goats have been eradicated: 120
• Range size of these islands: 1 to 132,000 ha
• Cumulated area of these islands: 600,000 ha
• Luxembourg = 50% of PI targeted islands
• Monaco = 0,04 % of PI targeted islands
• PI targeted islands = 20% of Massachusetts State
C. Azul
1,625 m.
TOPOGRAFIC PROFIL
Topographic profile of Isabela Island
S. Negra
1,100 m.
PI targeted islands
Pushing the limits to a total new scale
Alcedo
1,150 m.
Darwin
1,425 m.
Wolf
1,707 m.
Ecuador
875 m.
FERAL GOATS
IN GALAPAGOS
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