![]() Unpaired males will perform an aerial display to any nearby female. Males are very territorial and will aggressively defend nest sites from other males. The male often selects two nest sites for females to choose from. Males arrive at the breeding grounds first and will select nest cavities where he will display to potential mates. In Texas, 5% of purple martins that occupied more than one nest practiced polygamy. Purple martins are socially monogamous, but form a pair bond that rarely extends to subsequent seasons. Average basal metabolic rate 3.0 KJ*g^-1*day^-1 cm3.O2/g/hr.Range length 18 to 22 cm 7.09 to 8.66 in.This lighter coloration is hypothesized to be an adaptation to the desert climate and serves to absorb less heat. Populations residing in the southwest United States exhibit lighter coloration than purple martins in other regions. In flight, a juvenile's tail may have a narrow, slight fork whereas adult tails are distinctly forked and wider. In juveniles, there is a much clearer line between their gray throats and white bellies compared to females which will have a primarily gray belly. Juvenile purple martins are overall gray to black with a white belly and gray-streaked breast. Their legs and feet have a black brown coloration and their eyes are dark brown. Their gape tends to be yellow in young birds and a dull orangey-brown color in adults. Purple martins have a dark, black-brown bill and the average length is 8.2 mm for males and 8.5 mm for females. Western females are overall paler than eastern. Females are overall gray or gray-blue with darker wings and crown feathers, and feature a white breast smudged with varying degrees of gray. Purple martin males have less shine on their blackish wings and tails compared to their heads and backs. Males are a bit larger, entirely shiny, and deep purple or almost black in coloration. ![]() Purple martins are the largest North American swallow, measuring 20.3 cm long and weighing 56 g on average. Wintering habitats include rainforests, agricultural areas, and clearings of South America. They are often seen in cities and open areas while migrating south. ![]() They have been recorded in lowlands and the high mountain ranges of Venezuela and Columbia. They usually fly over coastal lines and cross the Gulf of Mexico. ( Brauning, 1992 Brown, 1997)ĭuring migration, these birds stopover in a variety of habitats. Some populations that breed in the western United States continue to live in these natural settings, however most utilize man-made martin houses. Historically, this species inhabited forest edges, montane forests, and deserts and nested in abandoned woodpecker cavities. They tend to find shelter in urban settlements, often living in specially made birdhouses called "martin houses". Due to colonization and human interactions in their natural habitats, purple martins are now accustomed to human interaction and live in close proximity with humans today. Purple martins also seem to avoid high elevations, for instance the Appalachian Mountains, but may be found at elevations from less than 100 m to 4,000 m. Purple martins prefer open spaces that are situated close to any water source, as they are insectivores and are attracted to the large populations of insects near wetlands, swamps, and wet meadows. There have been some records of purple martin populations found in the British Isles, but these birds rarely migrate outside of the Americas. Concentrated populations have been found to winter in Bolivia and some provinces of Brazil. Their winter range has been recorded to be South American lowlands anywhere east of the Andes Mountains. Purple martins overwinter across most of South America including the countries of Colombia, Venezuela, Guyana, Suriname, Ecuador, Peru, Brazil, Bolivia, Paraguay and Argentina. Purple martins breed across the eastern half of the United States, and also may be found along the Pacific coastline including the entire Baja Peninsula. The northern extent of the breeding range includes the Canadian provinces of Alberta, Saskatchewan, and southern Manitoba. They are migratory birds that breed in North and Central America and overwinter in South America. Progne subis, commonly known as purple martins, inhabits the Nearctic region and can be found across North and South America.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |