Friday, May 10, 2019

Species Profile: Anna's hummingbird

Hello again, welcome back to animals under threat. Today, we will be covering a bird that is named after Anne Debelle, Duchess of Rivoli. Please welcome, Anna's hummingbird (Calypte anna).


This hummingbird is one of two species of hummingbird that belongs to the genus Calypte, the other is the Costa's hummingbird (Calypte costae). Both species look similar to each, but male Anna’s hummingbird is characterized by their gorget (patch of coloured feathers on the throat) which is a crimson/magenta colour while Costa's hummingbird gorget is a purple colour (National Geographic, 2006). Females are less brightly coloured than the males, although both have bronze-green feathers on their back, pale grey chest/belly and green flanks (Giraldo et al, 2018). Their current geographic range includes Canada, Mexico and the United States and prefer tropical/subtropical forest for their habitat (BirdLife International, 2016).
Male (right) by Robert McMorran and female (female) by Matthew Field.
 
Unlike most species of hummingbirds that perform courtship dances to impress females, the male Anna’s hummingbird performs sings (Stiles, 1982) to impress the female that enters his territory. If she doesn’t leave, he will perform a display dives at high speed over the female making dive sounds (Clark and Feo, 2010). Below are two videos of Anna’s hummingbird, one is by Timothy Barksdale of birds feeding and perching on a feeder and the other is an Anna’s hummingbird perch and singing by Larry Arbanas.
 
 


The biggest threat to this species of hummingbird are diseases introduced to their environment. The most common disease that affect the Anna’s hummingbird is the avian pox virus. Avian pox virus is transferred by mosquitoes, contaminated surfaces and airborne particles. Birds affected with this virus gain wart like growths around areas free of feathers or can characterized as raised, yellow blemishes around the mouth, lungs, trachea and esophagus. This can lead to blindness, decreased egg production, poor growth, reduced male mating success and death (Godoy et al, 2014).

Next time, we will be covering a newt that spends most of its life on dry land.
 
 
References
BirdLife International 2016. Calypte anna. The IUCN Red List of Threatened Species 2016: e.T22688199A93186783.
 
Clark, C.J. & Feo, T.J. 2010, "Why Do Calypte Hummingbirds "Sing" with Both Their Tail and Their Syrinx? An Apparent Example of Sexual Sensory Bias", American Naturalist, vol. 175, no. 1, pp. 27-37.
 
Giraldo, M., Parra, J. & Stavenga, D. 2018, "Iridescent colouration of male Anna's hummingbird (Calypte anna) caused by multilayered barbules", JOURNAL OF COMPARATIVE PHYSIOLOGY A-NEUROETHOLOGY SENSORY NEURAL AND BEHAVIORAL PHYSIOLOGY, vol. 204, no. 12, pp. 965-975.
 
Godoy, L.A., Tell, L.A. & Ernest, H.B. 2014, "Hummingbird health: pathogens and disease conditions in the family Trochilidae", Journal of Ornithology, vol. 155, no. 1, pp. 1-12.
 
National Geographic book, Complete Birds of North America, 2006
 
Stiles, F.G. 1982, "Aggressive and Courtship Displays of the Male Anna's Hummingbird", The Condor, vol. 84, no. 2, pp. 208-225.
 
Picture and video references
 
 

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