0 the crested auklet (aethia cristatella) is a small seabird of the family alcidae , distributed throughout the northern pacific and the bering sea .
1  the species feeds by diving in deep waters , eating krill and a variety of small marine animals .
2  it nests in dense colonies of up to 1 million individuals in the bering sea and the sea of okhotsk .
3  it often breeds in mixed-species colonies with the least auklet , a smaller congener .
4 the species is known for its sexual ornaments , found in both males and females .
5  these include colorful plumage with a forehead crest , a striking scent recalling citrus fruit , and a loud trumpet call , all of which appear to have evolved through sexual selection .
6  the total population is around 6 million , almost half in north america .
7  it is in general considered to be of least concern , though the alaskan population faces additional threats from predation and oil spills .
8 the crested auklet was first identified in 1769 by the german zoologist peter simon pallas , who named it aethia cristatella .
9  the genus aethia includes four auklet species .
10  there are no subspecies of crested auklet .
11  the family alcidae consists of many species of shorebirds including other auklets (not in the genus aethia), puffins , razorbills , guillemots , and murres .
12 the crested auklet can measure 1827 cm (7.110.6 in) in length , 3450 cm (1320 in) in wingspan and weigh 195330 g (6.911.6 oz) .
13  they have a reddish-orange and yellow tipped bill , yellowish white irises , and white auricular plumes from their eyes to their ears .
14  their bodies , wings , and tails are primarily dark sooty grey , while their legs and feet are grey and claws black .
15  the males and females are very similar , although the females have slightly smaller and less curved bills , additionally slightly smaller crests .
16 crested auklets are known for their forehead crests , which is made of black forward-curving feathers .
17  these forehead crests are highly variable , and can have between two and twenty three narrow forward curving feathers .
18  the average auklet has 12 crest feathers , which are of variable length , between 8.1 and 58.5 millimetres .
19  auklets have auricular plumes and a bright orange bill with curved accessory plates .
20  like forehead crests , these features vary widely within auklet populations .
21 the crested auklet is recognized primarily by two characteristics during the breeding season .
22  the first is its crest , a group of bristle feathers located on top of its head above its eyes .
23  the second is a social odor that the auklets produce during the breeding season , described as smelling like tangerines .
24  this odor originates from tiny wick feathers , located in a small patch of skin between the shoulder blades .
25  in winter plumage , their bills are smaller and dull yellow .
26  they lack accessory plates and their crest and auricular plumes are reduced .
27 juveniles are similar to winter adults , but without auricular and crest plumes .
28  their bills are smaller , and colored a dull brownish yellow .
29  juveniles take 33 days to reach adult size .
