When approaching their nesting site, they will dive from the sky at great speeds with their wings tucked, just like the peregrine falcon does when hunting smaller birds.

In 1750 the English naturalist George Edwards included an illustration and a description of the purple martin in the third volume of his A Natural History of Uncommon Birds.

Edwards based his hand-coloured etching on a preserved specimen that had been brought to London from the Hudson Bay area of Canada by James Isham.

[4] When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the purple martin with swallows and swifts in the genus Hirundo.

The specific epithet subis is Latin for a bird mentioned by the Roman author Nigidius Figulus that could break eagles' eggs.

Subadult males look very much like females, but solid black feathers emerge on their chests in a blotchy, random pattern as they molt to their adult plumage.

[13] Their breeding habitat is open areas across eastern North America, and also some locations on the west coast from British Columbia to Mexico.

[17][18] Wintering in Brazil, Bolivia, and parts of Peru,[3] purple martins migrate to North America in the spring to breed.

Spring migration is somewhat staggered, with arrivals in southern areas such as Florida and Texas in January, but showing up in the northern United States in April and in Canada as late as May.

[3] Research published in 2015, however, does indicate that the purple martin feeds on invasive fire ants (Solenopsis invicta) and that they may make up a significant portion of their diet.

[21] Purple martins (nominate form P. s. subis) are considered synanthropic, meaning they have developed an association with humans over time and benefit from living in close proximity to them.

[23] The human-avian relationship was in place even before the population crash in the 20th century; Cherokee were known to have hollowed out gourds and hung them on wooden snags and posts in the pre-colonial era.

They erected them so that the adult birds would build nests and then feed thousands of insects to their young each day that would otherwise be eating their crops.

In 1808, Chickasaws and Choctaws were observed hanging gourds for martins on stripped saplings near their cabins, as African Americans were doing likewise on long canes on the banks of the Mississippi.

Many people believe purple martins will defend their nesting sites against competitor species such as the house sparrow and European starling.

The house sparrow and European starling are known to kill adult martins, take over the nest, and remove eggs or remaining young.

Purple martins suffered a severe population crash in the 20th century widely linked to the release and spread of European starlings in North America.

Nearly all eastern members of the species exclusively nest in artificial gourds and 'condo' units provided by human 'landlords', and this practice has been experiencing a steady decline.

One study found that nearly 90% of landlords were 50 years of age or older and that younger generations were not exhibiting the same enthusiasm nor possessing the resources to provide martin housing.