The crossbill is a bird in the finch family, Fringillidae.
The three to five (or possibly many more) species are all classified
in the genus Loxia. These birds are characterised
by the mandibles crossing at their tips, which gives
the group its English name. Adult males tend to be red or orange
in colour, and females green or yellow,
but there is much variation.
These are specialist feeders on conifer cones, and the unusual
bill shape is an adaptation to assist the extraction
of the seeds from the cone. These birds are typically found
in higher northern hemisphere latitudes, where their
food sources grows. They will erupt out of the breeding range
when the cone crop fails. Crossbills breed very
early in the year, often in winter months, to take advantage
of maximum cone supplies
The different species are each birds to specialising in feeding
on different conifer species, with the bill shape optimised
for opening that species of conifer. This is achieved by inserting
the bill between the conifer cone scales and twisting the lower
mandible towards the side to which it crosses, enabling the
bird to extract the seed at the bottom of the scale with its
tongue. |
Parrot Crossbill, Loxia pytyopsittacus
© http://www.ecosystema.ru/
This bird breeds in the pine forests of northwest
Europe and into western Russia. There is also a small population
in Scotland, adding to the difficulty of distinguishing it from
Common Crossbill and the endemic Scottish
Crossbill, both of which breed within its range.
This crossbill is mainly resident, but will irrupt south and
west if its food source fails. This species will form flocks
outside the breeding season, often mixed with other crossbills.
They are specialist feeders on conifer cones, and the unusual
bill shape is an adaptation to assist the extraction
of the seeds from the cone. The Parrot Crossbill is a specialist
feeder on the cones of Scots pine.
Male
Parrot Crossbill (Loxia pytyopsittacus) sitting in a
Spruce tree.
Picture taken at Smithska udden, Gothenburg, Sweden
Photo: Oskila, http://en.wikipedia.org/wiki/File:Loxia_pytyopsittacus071021.jpg
|
Adult males tend to be red or orange in colour, and females
green or yellow, but there is much variation.
This species is difficult to separate from Common
Crossbills and Scottish Crossbills,
and plumage distinctions are negligible. The head and bill are
larger than in either of the other species. The bill is thicker
than those of its relatives, and the crossed tips are often
not readily apparent. Extreme care is needed to identify this
species.
The deeper, harder choop or tyuup call is probably the best
indicator.
Some pine-feeding populations currently assigned to Common
Crossbill in southern Europe may possibly be better
referred to either this species or alternatively to new species
in their own right, but as yet, research into
them is still at a very early stage. |
Scottish
Crossbill, Loxia scotica
The Scottish Crossbill, Loxia scotica, It is endemic to the
Caledonian Forests of Scotland, and is the only
vertebrate unique to the United Kingdom. The Scottish Crossbill
was confirmed as a unique species in August 2006, on the basis
of having a distinctive bird song. |
Source: http://wild-scotland.org.uk/species/18/scottish-crossbill/
Scottish Crossbills have quite distinct flight
and excitement calls from other crossbills - some even stated
they
have "Scottish accents".
Research in Scotland has shown that Common
Crossbills, Parrot Crossbills
and Scottish crossbills are reproductively isolated, and the
diagnostic calls and bill dimensions have not been lost. They
are therefore good species.
The population is thought to be less than 2000 birds. It nests
in pines or other conifers, laying 2-5 eggs.
Pinus
sylvestris, Spittal of Glenmuick, Cairngorm National
Park, Scotland
http://en.wikipedia.org/wiki/File:Pinus_sylvestris_Glenmuick.jpg
|
The Scottish Crossbill breeds in the native Scots pine, Pinus
sylvestris, Caledonian forests of the Scottish Highlands,
but (perhaps surprisingly), often also in forestry plantations
of exotic conifers, notably Larch (Larix decidua and L. kaempferi)
and Lodgepole pine (Pinus contorta).
This species of crossbill is resident, and is not known to migrate.
It will form flocks outside the breeding season, often mixed
with other crossbills. |
The crossbills are characterised by the mandibles crossing
at their tips, which gives the group its English name. They
are specialist feeders on conifer cones, and the unusual bill
shape is an adaptation to assist the extraction of the seeds
from the cone. The Scottish Crossbill appears to be a specialist
feeder on the cones of pines (Scots pine and Lodgepole pine)
and larch.
Adult males tend to be red or orange in colour, and females
green or yellow, but there is much variation.
The Scottish Crossbill is extremely difficult to separate from
the Common and Parrot, and plumage distinctions are negligible.
The head and bill size is intermediate between and overlapping
extensively with the other two, and extreme care is needed to
identify this species. The metallic jip call is probably the
best indicator, but even this needs to be recorded and analysed
on a sonogram to confirm the identity. |
Red Crossbill - Common Crossbill, Loxia curvirostra
© http://www.ecosystema.ru/
The Common Crossbill, Loxia curvirostra breeds
in the spruce forests of North America, where it is known
as Red Crossbill, as well as Europe and Asia; some populations
(possibly different species) breed in pine forests
in certain areas of all three continents, and in North America,
also in Douglas-fir.
Left:
Red Crossbill, Female, Both: Loxia curvirostra, Right:
Red Crossbills. Males
Cabin Lake Viewing Blinds, Deschutes National Forest,
Near Fort Rock, Oregon
Photo: Left:http://www.naturespicsonline.com/ Right:
Elaine R. Wilson
|
This crossbill is mainly resident, but will regularly irrupt
south if its food source fails. This species will form flocks
outside the breeding season, often mixed with other crossbills.
They are specialist feeders on conifer cones, particularly the
various spruce species, and the unusual bill shape is
an adaptation to assist the extraction of the seeds from the
cone. Some populations, which may be different
species, also feed on Douglas-fir and various pine species.
Adult males tend to be red or orange in colour, and females
green or yellow, but there is much variation. |
Common
crossbill feeding chicks on nest
Video credits © Graham Horder udio credits Natural FX ©
BBC Natural History Unit
www.arkive.org
This species is difficult to separate from Parrot
Crossbill and Scottish Crossbill,
both of which breed within its Eurasian range. The identification
problem is less severe in North America, where only Red Crossbill
and
White-winged Crossbill occur.
However, the South Hills Crossbill, occurring in the South Hills
and Albion
Mountains in Idaho has recently been described as a new species,
Loxia sinesciuris. It is virtually identical to
the Red Crossbill differing slightly in body dimensions and
calls and shows a very low degree of hybridization
with the Red Crossbill.
Plumage distinctions from Parrot Crossbill
and Scottish Crossbills are negligible.
The head and bill are smaller
than in either of the other species. Care is needed to identify
this species. The glip or chup call is probably the
best indicator.
|
Common
crossbill - overview
Video credits© Graham HorderAudio credits© Natural FX©
BBC Natural History Unit
www.arkive.org
According to the page about the Red Crossbill at http://en.wikipedia.org/wiki/Common_Crossbill
there are a lot of sub-species. Their names can be viewed there. |
White-winged Crossbill - Two-barred Crossbill, Loxia leucoptera
© http://www.ecosystema.ru/
The Two-barred Crossbill, Loxia leucoptera, known
as the White-winged Crossbill in North America.
It has two subspecies, White-winged Crossbill, Loxia
leucoptera leucoptera in North America, and Two-barred
Crossbill Loxia leucoptera bifasciata
in NE Europe and N Asia.
This bird breeds in the coniferous forests of Alaska, Canada,
northernmost USA and across Asia extending into northeast Europe.
It nests in conifers, laying 3-5 eggs.
This crossbill is mainly resident, but will irregularly irrupt
south if its food source fails. The American race seems to wander
more frequently than the Eurasian subspecies. This species will
form flocks outside the breeding season, often mixed with other
crossbills. It is a rare visitor to western Europe, usually
arriving with an irruption of Common Crossbills. |
White-winged
Crossbill, Loxia leucoptera, male. Mount Auburn Cemetery, Massachusetts
Photo: John Harrison, http://en.wikipedia.org/wiki/File:Whitewingedcrossbillmale09.jpg
They are specialist feeders on conifer cones,
and the unusual bill shape is an adaptation to assist the extraction
of the seeds from the cone. Two-barred Crossbill has a strong
preference for larch, Larix, in Eurasia using
Siberian larch, Larix sibirica, and Dahurian larch, Larix
gmelinii, and in North America Tamarack larch,
Larix laricina. It will also take Rowan Sorbus berries,
and in North America, also Eastern Hemlock,
Tsuga canadensis) and White spruce, Picea glauca
cones.
Adult males tend to be red or pinkish in colour, and females
green or yellow, but there is much variation.
Two-barred is easier to identify than other crossbills, especially
in North America, where only Red Crossbill
and this species occur, but some care is still needed.
|
White-winged
Crossbill, Loxia leucoptera, female
Photo: dominic sherony, http://en.wikipedia.org/wiki/File:White-winged_Crossbill_-_female.jpg
Within its Eurasian range, this species is smaller-headed
and smaller-billed than Parrot Crossbill
and Scottish Crossbill, so the main
confusion species both there and in North America is Common
or Red Crossbill.
The main plumage distinction from Common Crossbills is the white
wingbars which give this species its English
and scientific names. There are also white tips to the tertials.
The adult male is also a somewhat brighter (pinker) red than
other male crossbills. Some Common Crossbills occasionally show
weak white wingbars, so care is needed with the correct identification
of this species. The chip call is weaker and higher than that
of Common Crossbill. |
Hispaniolan Crossbill, Loxia megaplaga
The Hispaniolan Crossbill, Loxia megaplaga,
is a crossbill that is endemic to the island of Hispaniola in
the Caribbean and therefore only found in Haiti and the Dominican
Republic.
The bird feeds almost exclusively on the seeds from Hispaniolan
Pine (Pinus occidentalis) cones.
Medium-sized finch, 15 cm, with distinctive crossed mandibles
and two white wing-bars. Male pale red with
black wings. Female dull olive with blackish wings, yellowish
rump and breast, and fine dark streaking on breast.
Voice High, emphatic chu-chu-chu-chu call. Also soft warble.
Hints Best located by calls of small foraging
groups. Regularly visits water to drink. |
Hispanola
Crossbill, Loxia megaplaga
Source: http://www.planetofbirds.com/passeriformes-fringillidae-hispaniolan-crossbill-loxia-megaplaga
Loxia megaplaga occurs primarily in Haiti and the Dominican
Republic, where it was not recorded from 1930-1970. Several
birds were found in the Blue Mountains of Jamaica in the early
1970s, but there have been no subsequent records. In Haiti,
it is known from the Massifs de la Selle and de la Hotte, including
the Macaya Biosphere Reserve where small flocks were recorded
in 2004.
In the Dominican Republic, it occurs mostly in the Sierra de
Baoruco, with occasional records from the Cordillera Central.
Numbers presumably declined between the mid-1920s and mid-1960s
in response to habitat loss, but
by 1978 the species was thought to be recovering. The population
apparently fluctuates depending on food
availability but was estimated as c.3,375 individuals following
surveys in the Sierra de Baoruco between 1996-1999. |
It is restricted to pine Pinus occidentalis forests, mostly
at high elevations, and feeds exclusively on pine-seeds. There
is a large pine-cone crop about every three years, but crops
in other years are small or fail altogether. Fluctuations in
pine-cone abundance are not synchronous, and birds are nomadic
in response to food availability, the species has been recorded
as low as 540 m and as high as 2,600. It breeds between January
and April, with the timing probably depending on the cone crop.
The nest is usually built high up in the branches of pine trees.
Source: BirdLife International
(2012) Species factsheet: Loxia megaplaga. Downloaded from http://www.birdlife.org
on 15/02/2012. Recommended citation for factsheets for more
than one species: BirdLife International (2012)
IUCN Red List for birds. Downloaded from http://www.birdlife.org
on 15/02/2012. |
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