Guadalupe Junco
Encyclopedia
The Guadalupe Junco, Junco hyemalis insularis, is a bird
endemic
to Guadalupe Island
off Pacific Mexico
. It is often considered a subspecies
of the Dark-eyed Junco
, for example by the IUCN which lumps these taxa in the 2008 IUCN Red List
. Other sources treat it as a distinct species
Junco insularis.
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. It makes a high, sharp sik and a long series of chipping notes.
This bird is today found mainly in the Cupressus guadalupensis
cypress grove on the island of Guadalupe, with a few birds in the remaining Guadelupe Pine stands. Around 1900, it was known to utilize almost any habitat
for breeding. It ranged over the whole island for feeding then, and indeed still does theoretically, but actually only a handful of flocks exist. A testimony to the adaptability of this junco is the fact that today a few birds breed at the seashore in non-native Nicotiana glauca
tobacco shrub since this is dense enough to provide some protection from cats.
The breeding season is from February to June. Three to four eggs are laid in a bulky cup nest of dried
grass stems, which is either in a depression in the ground or in the lower branches of a tree. The eggs are greenish white with reddish brown spots. If food is plentiful, the birds apparently breed twice a year.
(nearly 2 per acre) being present around the 1870s. Feral cat
s also multiplied, and as the habitat was destroyed by the goats the cats wreaked havoc on the endemic fauna. In 1897, Kaeding found the Guadalupe Junco "abundant", but already decreasing due to cat predation. Anthony summed up 10 years of occasional visits in 1901 by noting that
He blamed the interaction of goats, destroying habitat, and cats, destroying the birds themselves.
W. W. Brown Jr., H. W. Marsden and Ignacio Oroso surveyed Guadalupe throughout May/June 1906, and collected numerous bird specimens for the Thayer Museum - among these a "large series" of the junco. They found the junco "fairly abundant" but despite the depredations of the cats still "a very tame, confiding little bird" - in other words, unwary of predators.
Feral goats were all but exterminated by 2006 by Grupo de Ecologia y Conservacion de Islas and Island Conservation, http://www.islandconservation.org permitting spectacular regeneration of the native flora. The island was recently protected as a biosphere reserve again by the above groups. As habitat regenerates and especially if the planned removal or containment of cats will be undertaken, the remaining juncos will find more protected breeding and feeding sites. Indeed, the future of the Guadalupe Junco looks better than it ever did during the last century, although it is still precariously close to extinction and could be wiped out by any chance event such as a violent storm or an introduced disease. As noted above, in 2008 the IUCN stopped listing this bird in its Red List, which only contains distinct species. Previously, it was listed as Critically Endangered
.
3(3): 73. PDF fulltext|year=2004|id=10945|title=Junco insularis|downloaded=08 October 2007}} (2008a) Guadalupe Junco Species Factsheet. Retrieved 2008-MAY-26. (2008b): [2008 IUCN Redlist status changes]. Retrieved 2008-MAY-23. (1905): Birds from the West Coast of Lower California and Adjacent Islands (Part II). Condor
7(4): 134-138. PDF fulltext (1995): A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, Oxford & New York. ISBN 0-19-854012-4 (2003): On the urgency of conservation on Guadalupe Island, Mexico: is it a lost paradise? Biodiversity and Conservation 12(5): 1073–1082. (HTML abstract) (1908): The Present State of the Ornis of Guadaloupe Island. Condor
10(3): 101-106. PDF fulltext
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to Guadalupe Island
Guadalupe Island
Guadalupe Island, or Isla Guadalupe is a volcanic island located 241 kilometers off the west coast of Mexico's Baja California peninsula and some 400 kilometers southwest of the city of Ensenada in Baja California state, in the Pacific Ocean...
off Pacific Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It is often considered a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Dark-eyed Junco
Dark-eyed Junco
The Dark-eyed Junco is the best-known species of the juncos, a genus of small grayish American sparrows. This bird is common across much of temperate North America and in summer ranges far into the Arctic...
, for example by the IUCN which lumps these taxa in the 2008 IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. Other sources treat it as a distinct species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
Junco insularis.
Description and ecology
This American sparrowAmerican sparrow
American sparrows are a group of mainly New World passerine birds, forming part of the family Emberizidae. American sparrows are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns....
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. It makes a high, sharp sik and a long series of chipping notes.
This bird is today found mainly in the Cupressus guadalupensis
Cupressus guadalupensis
Cupressus guadalupensis, the Guadalupe cypress, is a species of cypress from Guadalupe Island off western North America.-Distribution:...
cypress grove on the island of Guadalupe, with a few birds in the remaining Guadelupe Pine stands. Around 1900, it was known to utilize almost any habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
for breeding. It ranged over the whole island for feeding then, and indeed still does theoretically, but actually only a handful of flocks exist. A testimony to the adaptability of this junco is the fact that today a few birds breed at the seashore in non-native Nicotiana glauca
Nicotiana glauca
Nicotiana glauca is a species of wild tobacco known by the common names tree tobacco and incorrectly also Mustard tree. Its leaves are attached to the stalk by petioles , and its leaves and stems are neither pubescent nor sticky like Nicotiana tabacum...
tobacco shrub since this is dense enough to provide some protection from cats.
The breeding season is from February to June. Three to four eggs are laid in a bulky cup nest of dried
grass stems, which is either in a depression in the ground or in the lower branches of a tree. The eggs are greenish white with reddish brown spots. If food is plentiful, the birds apparently breed twice a year.
Decline to near-extinction
This bird used to be abundant, but now only 50-100 adult birds are thought to survive. Goats introduced to provide food for fishermen and to start a meat-canning plant in the early-mid 19th century became feral and overran the island towards the late 19th century, with more than 4 goats/haHectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
(nearly 2 per acre) being present around the 1870s. Feral cat
Feral cat
A feral cat is a descendant of a domesticated cat that has returned to the wild. It is distinguished from a stray cat, which is a pet cat that has been lost or abandoned, while feral cats are born in the wild; the offspring of a stray cat can be considered feral if born in the wild.In many parts of...
s also multiplied, and as the habitat was destroyed by the goats the cats wreaked havoc on the endemic fauna. In 1897, Kaeding found the Guadalupe Junco "abundant", but already decreasing due to cat predation. Anthony summed up 10 years of occasional visits in 1901 by noting that
"...the juncos are slowly but surely becoming scarce."
He blamed the interaction of goats, destroying habitat, and cats, destroying the birds themselves.
W. W. Brown Jr., H. W. Marsden and Ignacio Oroso surveyed Guadalupe throughout May/June 1906, and collected numerous bird specimens for the Thayer Museum - among these a "large series" of the junco. They found the junco "fairly abundant" but despite the depredations of the cats still "a very tame, confiding little bird" - in other words, unwary of predators.
Feral goats were all but exterminated by 2006 by Grupo de Ecologia y Conservacion de Islas and Island Conservation, http://www.islandconservation.org permitting spectacular regeneration of the native flora. The island was recently protected as a biosphere reserve again by the above groups. As habitat regenerates and especially if the planned removal or containment of cats will be undertaken, the remaining juncos will find more protected breeding and feeding sites. Indeed, the future of the Guadalupe Junco looks better than it ever did during the last century, although it is still precariously close to extinction and could be wiped out by any chance event such as a violent storm or an introduced disease. As noted above, in 2008 the IUCN stopped listing this bird in its Red List, which only contains distinct species. Previously, it was listed as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
.
Resources
(1901): The Guadalupe Wren. CondorCondor (journal)
The Condor is a peer-reviewed quarterly scientific journal covering ornithology and published by the Cooper Ornithological Society.-History:...
3(3): 73. PDF fulltext|year=2004|id=10945|title=Junco insularis|downloaded=08 October 2007}} (2008a) Guadalupe Junco Species Factsheet. Retrieved 2008-MAY-26. (2008b): [2008 IUCN Redlist status changes]. Retrieved 2008-MAY-23. (1905): Birds from the West Coast of Lower California and Adjacent Islands (Part II). Condor
Condor (journal)
The Condor is a peer-reviewed quarterly scientific journal covering ornithology and published by the Cooper Ornithological Society.-History:...
7(4): 134-138. PDF fulltext (1995): A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, Oxford & New York. ISBN 0-19-854012-4 (2003): On the urgency of conservation on Guadalupe Island, Mexico: is it a lost paradise? Biodiversity and Conservation 12(5): 1073–1082. (HTML abstract) (1908): The Present State of the Ornis of Guadaloupe Island. Condor
Condor (journal)
The Condor is a peer-reviewed quarterly scientific journal covering ornithology and published by the Cooper Ornithological Society.-History:...
10(3): 101-106. PDF fulltext