Cobb's wren (''Troglodytes cobbi'') is a fairly small (12-13.5 cm)

wren Wrens are a family of brown passerine birds in the predominantly New World family Troglodytidae. The family includes 88 species divided into 19 genera. Only the Eurasian wren occurs in the Old World, where, in Anglophone regions, it is commonly ...

which is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

. It was formerly classified as a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of the

house wren The house wren (''Troglodytes aedon'') is a very small bird of the wren family, Troglodytidae. It occurs from Canada to southernmost South America, and is thus the most widely distributed native bird in the Americas. It occurs in most suburban ar ...

(''Troglodytes aedon'') but is now commonly considered to be a separate species due to differences in

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

, voice,

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

and

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...

. The scientific and common names commemorate Arthur Cobb, an author from the Falkland Islands.

Description

The plumage is brown, greyer on the head and breast and more rufous on the tail. There are dark bars on the

flight feathers Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...

and tail. The bill is long, blackish and slightly curved. The main confusion species is the

sedge wren The sedge wren (''Cistothorus stellaris'') is a small and secretive passerine bird in the family Troglodytidae. It is widely distributed in North America. It is often found in wet grasslands and meadows where it nests in the tall grasses and sed ...

which is smaller with a shorter bill, buff eyestripe and dark streaks on the back and head. Cobb's wrens have a number of buzzing calls and their song is a series of jumbled trills and whistles. The song can be heard from August to February and varies between individuals with different males having different song patterns.

Behaviour

The birds typically inhabit dense stands of

tussac grass ''Poa flabellata'', commonly known as tussac grass or just tussac, is a tussock grass native to southern South America, the Falkland Islands, South Georgia and other islands in the South Atlantic. There are also two isolated records from the her ...

near the coast. They are often found on beaches searching among

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwat ...

and debris to find small invertebrates such as insects and

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

s. They are tame and can often be approached closely. When disturbed they prefer to slip away like a mouse between boulders or tussac clumps rather than fly.

Breeding

The nest is a ball of grass lined with feathers and tussac root fibres. It is built on or near the ground among tussac or in a rock crevice. The eggs are pinkish with small reddish spots, three or four are laid in a clutch. The eggs are laid from early October to December and two broods are probably raised during the breeding season.

Status and conservation

This wren is restricted to small

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

-free islands with a population of only 4,500-8000 pairs (1997/1998 estimate). It is fragmented into small populations which could disappear if their islands were colonized by rats or cats. The birds' habit of feeding and breeding at ground level makes them very vulnerable to predation unlike the sedge wren which lives higher up and can coexist with predators. The plight of Cobb's wren was recently brought to broader attention by being featured as

Canon Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western can ...

's endangered species of the month for the February 2009 issue of

National Geographic Magazine ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widely ...

. It has been reclassified as

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

in 2017 by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

thanks to the control of invasive rats on nearby islands.

References

* Birdlife International (2006
Cobb's Wren - Birdlife Species Factsheet
, retrieved 24/10/06 * * Alvaro Jaramillo, Peter Burke & David Beadle (2003) ''Field Guide to the Birds of Chile including the Antarctic Peninsula, the Falkland Islands and South Georgia'',

Christopher Helm Christopher Alexander Roger Helm (born Dundee, 1 February 1937 – 20 January 2007) was a Scottish book publisher, notably of ornithology related titles, including the ''Helm Identification Guides''. Born in Dundee, he was raised in Forfar, w ...

, London * Robin W. Woods (1988) ''Guide to Birds of the Falkland Islands'', Anthony Nelson, Oswestry *

External links

*
Photos, videos and observations
at Cornell Lab of Ornithologys Birds of the World
Sounds
on the xeno canto collection {{Taxonbar, from=Q531002

Cobb's wren Cobb's wren (''Troglodytes cobbi'') is a fairly small (12-13.5 cm) wren which is endemic to the Falkland Islands. It was formerly classified as a subspecies of the house wren (''Troglodytes aedon'') but is now commonly considered to be a sep ...

Birds of the Falkland Islands