Birds of the Week # 10
The Blue Jay is a noisy, bold, and aggressive passerine. It is a moderately slow flier (roughly 32–40 km/h (20–25 mph)) when unprovoked. It flies with body and tail held level, with slow wing beats. Its slow flying speeds make this species easy prey for hawks and owls when it flies in open areas. Virtually all the raptorial birds sympatric in distribution with the blue jay may prey upon it, especially swift bird-hunting specialists such as the Accipiter hawks. Diverse predators may prey on jay eggs and young up to their fledgling stage, including tree squirrels, snakes, cats, crows, raccoons, opossums, other jays and possibly many of the same birds of prey who attack adults.
Brown-headed Cowbirds seem to periodically check on their eggs and young after they have deposited them. Removal of the parasitic egg may trigger a retaliatory reaction termed “mafia behavior”. According to one study the cowbird returned to ransack the nests of a range of host species 56% of the time when their egg was removed. In addition, the cowbird also destroyed nests in a type of “farming behavior” to force the hosts to build new ones. The cowbirds then laid their eggs in the new nests 85% of the time.
The blue grosbeak was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Loxia caerulea. The specific epithet caerulea is the Latin word for “blue”, “azure-blue”, “sky-blue” or “dark-blue”. Linnaeus based his own description on the “blew gross-beak” described and illustrated by Mark Catesby in his The Natural History of Carolina, Florida and the Bahama Islands. The book had been published in 1729–1732. Catesby gave the location as Carolina and Linnaeus specified America. The type location is now restricted to South Carolina.
The Northern Mockingbird is known for its intelligence. A 2009 study showed that the bird was able to recognize individual humans, particularly noting those who had previously been intruders or threats. Also birds recognize their breeding spots and return to areas in which they had greatest success in previous years. Urban birds are more likely to demonstrate this behavior.
The mockingbird is influential in United States culture, being the state bird of five states, appearing in book titles, songs and lullabies, and making other appearances in popular culture.
© HJ Ruiz – Avian101