Blue Jay (Crum Woods Biodiversity Guide)

Blue Jay

Cyanocitta cristata

Physical description ⁴

Blue jays are bright blue on top and whitish gray on the belly and chin. They have a gray-blue, feather crested head, which they can raise and lower. The feathers on their wings and tails are bright blue with white and black bands. Blue jays also have a collar of black feathers across the throat and continuing around the head. Their bills, legs, feet, and eyes are black. Males are just a little larger, on average, than females. Total body length ranges from 22 to 30 cm. (Reilly 1968)

Range mass: 65 to 109 g.

Range length: 22 to 30 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Conservation status ⁵

Blue jay populations are on the rise, and they are often very common where they occur. The range is expanding westward. Populations may have suffered somewhat in previous centuries as their wooded habitats were cleared and may suffer where epidemics of West Nile virus affect bird populations. Blue jays are corvids, which seem particularly susceptible to this virus. (Reilly 1968)

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Habitat ⁶

Blue jays prefer mixed woodlands, particularly those with clearings. They are also common in suburban areas and city parks. (Reilly 1968)

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Iucn red list assessment ⁷

Red List Category

Least Concern

Red List Criteria

Version

3.1

Year Assessed

2012

Assessor/s

BirdLife International

Reviewer/s

Butchart, S. & Symes, A.

Contributor/s

Justification

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

History

Least Concern (LC)
Least Concern (LC)
Least Concern (LC)
Lower Risk/least concern (LR/lc)
Lower Risk/least concern (LR/lc)
Lower Risk/least concern (LR/lc)

Sources and Credits

(c) Ralf Nowak, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/27815991@N08/3051282631
Ken Thomas, no known copyright restrictions (public domain), https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Blue_Jay-27527.jpg/460px-Blue_Jay-27527.jpg
(c) http://www.birdphotos.com, some rights reserved (CC BY), https://upload.wikimedia.org/wikipedia/commons/6/6c/Cyanocitta_cristata_2.jpg
(c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/25064400
(c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31389092
(c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31389082
(c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/34409245