Dwarf jay (Cyanolyca nana)

Description

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Dwarf jay fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Dwarf jay description

The small, slender dwarf jay (Cyanolyca nana) is an attractive bird, with greyish-blue plumage and a distinct black ‘face mask’ ⁽⁴⁾. A whitish ‘eyebrow’ stripe extends above each reddish-brown eye and the bill is black ^{(4) (5)}. The throat is whitish and is separated from the rest of the underparts by a darker line. Juvenile dwarf jays have a much smaller, less defined throat patch, which blends gradually into the rest of the plumage ⁽⁴⁾.

The dwarf jay often appears in flocks with Steller’s jay (Cyanocitta stelleri) but the dwarf jay can be easily distinguished by its smaller size, lighter plumage and the lack of a prominent crest of feathers on top of the head ⁽⁶⁾.

Compared with other jay species, the dwarf jay has a fairly small vocal repertoire, with just two main, nasal-sounding calls, either a “shree-up” in units of two or three or a single cry of “shiev-a shiev-a” ⁽²⁾.

Size

Length: 22 - 24.5 cm ⁽²⁾

Weight

41 g ⁽³⁾

Dwarf jay biology

Thought to be a largely insectivorous bird, the dwarf jay is known to feed on weevils, bark beetles, crane flies and wasps, but it may also consume some plant fibre ⁽⁸⁾.

The dwarf jay forages in groups containing between four and ten individuals, often in a flock with other bird species. It is an agile bird and may be seen hanging upside down as it searches amongst vegetation for food.  It also investigates tree stumps, searches under peeling bark, and will break open plant galls in search of hidden larvae, as well as pursuing slow flying insects ⁽⁸⁾.

In March, the male dwarf jay presents food to the female as part of the courtship ritual. Once a pair has formed, a tightly woven cup-shaped nest of mosses and lichen, lined with pine needles, is usually constructed in an oak tree at a height of about seven metres. The female dwarf jay typically lays two to three eggs, which are a pale greenish-blue, marked with olive spots. The eggs are incubated for around 20 days by the female alone, but the newborn chicks are fed by both parents ⁽⁶⁾.

It is thought that the grey-barred wren (Campylorhynchus megalopterus) and Steller’s jay (Cyanocitta stelleri) may prey on the eggs and chicks of the dwarf jay, and a sharp-shinned hawk (Accipiter striatus) has been observed attacking an adult dwarf jay ⁽⁶⁾.

Dwarf jay range

The dwarf jay has a small and fragmented distribution in south-eastern Mexico. It was once thought to be restricted to southern Veracruz and northern Oaxaca, but recent surveys have also found small numbers of the dwarf jay in northern Hidalgo, eastern Querétaro and central Veracruz ⁽⁷⁾.

Dwarf jay habitat

The dwarf jay inhabits humid pine, oak and fir forest ⁽⁸⁾, at elevations between 1,400 and 3,200 metres ⁽⁷⁾.

Dwarf jay status

The dwarf jay is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

Dwarf jay threats

The greatest threat to the dwarf jay is habitat loss, due to human activities such as logging, agriculture, firewood gathering, road construction and cattle grazing. The dwarf jay is particularly sensitive to human presence, and any disturbance typically leads to the dwarf jay abandoning its nest ^{(7) (9)}.

Climate change poses a long-term threat to this species, as it is likely to alter the dwarf jay's preferred habitat ⁽⁷⁾. For example, it has been predicted that climate change will result in tropical forest in southern Mexico being replaced by savanna ⁽¹⁰⁾.

Dwarf jay conservation

This endangered species is not currently known to be the focus of any specific conservation action. It has been recorded in Benito Juárez National Park, but this is believed to offer the dwarf jay little protection in practice ⁽⁷⁾.

Effective protection of this National Park has been recommended, as has the protection of other sites where this attractive bird has recently been recorded ⁽⁷⁾.

Find out more

Learn more about bird conservation:

• BirdLife International:
  http://www.birdlife.org/

Find out more about conservation in Mexico:

• The Nature Conservancy:
  http://www.nature.org/ourinitiatives/regions/northamerica/mexico

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

This species information was authored as part of the ARKive and Universities Scheme.

Glossary

Incubated

Kept warm so that development is possible.

Insectivorous

Feeds primarily on insects.

Larvae

Stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

Plant galls

Abnormal outgrowths of plant tissues caused by various parasites, such as fungi, bacteria, and insects.

References

1. IUCN Red List (November, 2010)
   http://www.iucnredlist.org/
2. Howell, S.N.G. and Webb, S. (1995) A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, Oxford.
3. Dunning, J.B. (2008) CRC Handbook of Avian Body Masses. CRC Press, Boca Raton, Florida.
4. Ridgway, R. (1904) The Birds of North and Middle America. Part III. Bulletin of the United States National Museum 50, Government Printing Office, Washington.
5. Madge, S. and Burn, H. (1994) Crows and Jays. A Guide to the Crows, Jays and Magpies of the World. Houghton Mifflin Company, New York.
6. Foote, D. (2010) Dwarf Jay (Cyanolyca nana). In: Schulenberg, T.S. (Ed.) Neotropical Birds Online. Cornell Lab of Ornithology, Ithaca. Available at:
   http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=518636
7. BirdLife International (November, 2010)
   http://www.birdlife.org/
8. Hardy, J.W. (1971) Habitat and habits of the dwarf jay, Aphelicoma nana. Wilson Bulletin, 83: 5-30.
9. Collar, N.J., Gonzaga, L.P., Krabbe, N., Madroño Nieto, A., Naranjo, L.G., Parker, T.A. and Wege, D.C. (1992) Threatened Birds of the Americas: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, Cambridge, U.K.
10. WWF: Climate Change Impacts in Mexico (May, 2011)
    http://wwf.panda.org/about_our_earth/aboutcc/problems/rising_temperatures/hotspot_map/mexico.cfm