Backyard Birds

Guadalupe Junco (Junco insularis)

The Guadalupe Junco (Junco insularis) is a critically endangered bird endemic to Guadalupe Island, Mexico. It is sometimes thought to be a subspecies of the Dark-eyed Junco.


This sparrow has a dull grayish head with a gray bill and brownish upperparts. Its wings and tail are blackish, though the tail has white edges. Its underparts are white with a rufous fringe at the bottom of the wings.

Calls / Vocalizations

It makes a high, sharp sik and a long series of chipping notes.

Distribution / Range

This bird is found mainly in the Cupressus guadalupensis cypress grove on the island of Guadalupe, with a few birds in the remaining Guadelupe Pine stands.

Breeding / Nesting

Three to four eggs are laid in its nest, either a depression in the ground or in the lower branches of a tree, from February to June. The eggs are greenish white with reddish-brown spots. If food is plentiful, the birds breed twice a year (Kaeding, 1905).


This bird used to be abundant, but now only 50-100 birds are thought to survive. Goats were introduced to provide food for fishermen and to start a meat-canning plant that became feral and overran the island in the late 19th century.

Feral cats also multiplied and as the habitat was rapidly destroyed by the goats wreaked havoc on the endemic fauna. In 1897, Kaeding (1905) found the species “abundant”, but already decreasing due to cat predation.

Feral goats were all but exterminated by 2006, permitting regeneration of what is left of the original flora. The island is now protected as a biosphere reserve, and the eradication of feral cats may be completed by 2010.

As the habitat regenerates, the remaining juncos will find more protected breeding sites.

Indeed, the future of the species looks better than ever before during the last century, although it is still critically endangered and could be wiped out by any chance event, such as a storm or an introduced disease.


Gordon Ramel

Gordon is an ecologist with two degrees from Exeter University. He's also a teacher, a poet and the owner of 1,152 books. Oh - and he wrote this website.

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