DSC2506 Crossbill... - a photo on Flickriver

            Red/Common Crossbill - Loxia Curvirostra (m)
  
The crossbill is a genus, Loxia, of birds in the finch family (Fringillidae), with six species. These birds are characterised by the mandibles with crossed 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.
 
Crossbills are specialist feeders on conifer cones, and the unusual bill shape is an adaptation which enables them to extract seeds from cones. These birds are typically found in higher northern hemisphere latitudes, where their food sources grow. They 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 specialise 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.
 
The mechanism by which the bill-crossing (which usually, but not always, occurs in a 1:1 frequency of left-crossing or right-crossing morphs) is developed, and what determines the direction, has hitherto withstood all attempts to resolve it.
 
It is very probable that there is a genetic basis underlying the phenomenon (young birds whose bills are still straight will give a cone-opening behavior if their bills are gently pressed, and the crossing develops before the birds are fledged and feeding independently), but at least in the red crossbill (the only species which has been somewhat thoroughly researched regarding this question) there is no straightforward mechanism of heritability.
 
Population:
 
UK breeding:

40,000 pairs

Taken on: December 14, 2018

Tags:

Crossbill

Crossbills

Avian

Animal

Animals

Wildlife.

Wildbirds

Woodlands

Wildlife Photography

Jeff Lack Photography

Forest

Finches

Finch

Pines

Pine-Forest

Trees

Countryside

Nature

NGC « less

Sets appears in: • Crossbill

Groups appears in: • Birds • Bird Lovers more » • Birds , Birds Birds • Bird Fanatics! (No Limits) • Bird Images • BIRDPIX (3/day) • *I Love Birds* • "Bird Brained" • A Guide To The Birds Of Europe • Bird and Nature Photography • Birds of the British Isles • Bird Watching Group (BWG): Post 1 : Award 2 • Beautiful Birds • BIRDS ARE BEAUTIFUL. • Birds and Wildlife UK • * Birds of Britain * • BIRDS - OISEAUX - AVES (POST 1 / COMMENT 1) • Bird Watchers • **Simply Superb (P 1- A 2)** • All birds all the time • Birding In The Wild • Birds birds birds birds! • Birds UK • Avian Photography • Birds and Wildlife Only!!! • #4 PLATINUM WILDLIFE/ Post 1 - Award 1 (P2-A2) with CODE • BBC Springwatch (Official) • Nature's Golden Carousel ~ Closed! • Amazing Birds ***No Rules, No Banning, No Sweepers*** • ! * Fantastic Nature Group *Moderated* » Post 1 and Award 1 « • AWESOME BIRDS ! (Award 2 Please) • 4 Birds only • The Galaxy & Stars 1 (P1/C5 - No Art Images • :: | Bird Photography |:: • #3 PALLADIUM WILDLIFE/ Post 1 - Award 5 (P2-A10) with CODE • Best Bird Photographers • Amazing Wildlife Photography (Invitation Only) • *Feathers & Beaks* P1 - A3 • Audubon magazine • #2 18K Gold wildlife/ Post 1 - Award 3 (P2-A6) with CODE • Avian Wonders • "Watch The Birdie" P2 C2***Only birds*** NO OTHER IMAGES • Birding World • AVES DEL MUNDO -- BIRDS OF THE WORLD -- OISEAUX DU MONDE • Our Wonderful and Fragile World - P1 - A4 • NATURE'S SPIRIT (by invitation) (post 1/award 1) • Birding for everyone! (Field Guide of the World) • Best Birds Worldwide • "Birds Flock Together" (one bird a day ♥ only birds) • Amateur Photographer Magazine • NATURE'S KALEIDOSCOPE P1 X A1 • Birds And Nature Of Britian • *Birds Photography* « less

Stats: 5,157 views / 185 comments