Purple martins are the largest species of swallow in North America. These aerial acrobats have steel blue-black plumage and forked tails. They are extremely social birds that nest in colonies, roost in flocks, and feed on the wing in pursuit of flying insects. Purple martins migrate thousands of miles between their breeding grounds in North America and their wintering grounds in South America.
Do Purple Martins Live in Rhode Island?
Yes, purple martins do live in Rhode Island during the spring and summer months. However, they are not native residents. Purple martins rely on man-made nest boxes and gourds provided by humans. They were extirpated from much of their eastern breeding range in the early 20th century due to habitat loss and competition from introduced European starlings for natural cavities.
Purple martins arrive in Rhode Island in mid-April after making the long journey north from their wintering grounds in Brazil. The males precede the females by up to two weeks. Some birds may overwinter in Florida or Cuba before continuing their migration. Most purple martins leave Rhode Island by late July or early August to begin their southbound migration back to South America.
According to local experts, Rhode Island’s population of breeding purple martins is relatively small but seems to be growing in recent decades thanks to dedicated conservation efforts by individuals and groups who monitor and maintain colonies. Some of the best places to see purple martins in Rhode Island during summer include Rome Point in North Kingstown, Sachuest Point National Wildlife Refuge in Middletown, Trustom Pond National Wildlife Refuge in South Kingstown, and Fort Wetherill State Park in Jamestown.
Range and Habitat
The purple martin has an extremely large breeding range across most of North America. Their breeding habitat extends from central Alaska across Canada to Newfoundland and south throughout the United States. The only states where they do not nest are Hawaii and areas of the Southwest like New Mexico and Arizona.
Purple martins are flexible in their habitat needs but prefer open areas near water such as lakes, rivers, or coastal sites. They often nest in towns and suburban neighborhoods. Purple martins rely on natural cavities and human-provided nest boxes for breeding. Prime nesting locations provide open flying space void of obstructions with a nearby body of water that supplies insects.
During migration and winter, purple martins use a wider variety of habitats including forests, grasslands, savannas, and wetlands. Their winter range encompasses most of South America east of the Andes Mountains from central Brazil south to northern Argentina.
Population and Conservation Status
Purple martins remain common and widespread across North America though populations can fluctuate. An estimate in 2014 put the global breeding population at 13 million individuals. However, there are indications that numbers in some regions have declined from historical levels due to factors like increased pesticide use, habitat alteration, climate change, and nest site competition.
Loss of natural nesting cavities likely caused historical declines before human-supplied nest boxes allowed martins to rebound. Providing proper housing is still a conservation need today, especially with the invasive house sparrow displacing martins from nests. Predation pressure from raptors, crows, and snakes can also limit productivity.
Purple martins are protected in the United States under the Migratory Bird Treaty Act. They are not considered threatened or endangered at state, national, or global scales. However, local populations may be vulnerable and require active management to maintain. For example, in Rhode Island the Audubon Society of Rhode Island coordinates a statewide Purple Martin Monitoring Project to track the status of colonies.
Identification
Purple martins are impossible to miss during breeding season. With their dark coloration, swift flight, and habit of soaring in circles, they stand out from all other North American swallow species. Distinctive identification marks of purple martins include:
- Large size – 7.5 to 8 inches long with a wingspan around 18 inches
- Entire body has glossy steel blue-black plumage
- Forked tail
- White belly patch (can be hard to see)
- Makes a distinctive liquid gurgling song
Female purple martins are identical to males but tend to be slightly smaller in size. Juvenile martins have grayish plumage on the head, throat, and chest before molting into adult plumage by their first spring.
The only swallow species that comes close to resembling purple martins are tree swallows. However, tree swallows have white undersides, more streamlined bodies, and lack the white belly patch. Other dark swallows like cliff swallows have pale rumps and throats.
Nesting and Reproduction
Purple martins are a highly colonial species that prefers to nest in multi-compartment houses or clusters of gourds. Their nests consist of mud, grass, leaves, twigs, and feathers. Typical clutch size is 4-5 eggs that are incubated for about 15 days. After hatching, the nestlings will fledge in 4-5 weeks.
Purple martins produce 1-2 broods per year. Nest success is variable based on factors like weather, predation, and nest site competition. On average, each pair successfully raises around 2-3 young annually. Adult martins migrate south before their offspring and will reunite on the wintering grounds or following spring.
Diet and Feeding
Purple martins are aerial insectivores that feed exclusively on flying insects while in flight. They do most of their feeding during daylight hours. Analysis of regurgitated food boluses shows purple martins consume a wide variety of insects including:
- Dragonflies
- Damselflies
- Butterflies
- Moths
- Flies
- Midges
- Bees
- Wasps
- winged Ants
- Aerial spiders
Purple martins may forage up to several thousand feet in the air. But they generally feed closer to the ground near their colonies during breeding season. Martins adjust their diet based on which insects are most abundant at a given place and time.
Purple martins drink by skimming across the surface of open water bodies. Drinking sites are often located near nesting colonies.
Interactions with Humans
Purple martins have a long history of interaction with humans in North America. Some Native American tribes would hang gourd houses to attract martins. Early European colonists also exploited the martin’s appetite for flying insects by providing nest boxes to control mosquitoes and agricultural pests around homesteads.
Today, thousands of “martin landlords” maintain nest boxes or gourd racks specifically for purple martins. This housing allows martins to thrive in proximity to human development. Interest in attracting martins remains strong due to their aerial insectivory, elaborate aerial displays, colonial nature, and attachment to human-provided sites.
Some key considerations for successfully attracting and maintaining purple martins include:
- Siting houses in open, elevated locations away from trees/buildings
- Using multiple compartments at least 8-10 feet off the ground
- Annual maintenance and cleaning between seasons
- Stopping house sparrow and starling usurpation
- Monitoring and recording martin activity/productivity
- Using recommended designs likekeeMartins, seismic mounts,etc.
With proper housing and management, purple martins can be a joy to observe going about their daily routines in neighborhoods across Rhode Island each summer.
Conclusion
In conclusion, purple martins are part-time breeding residents of Rhode Island that rely on man-made nesting structures provided by dedicated conservationists and bird enthusiasts. Martins arrive in Rhode Island in April after migrating thousands of miles from South America and depart by late summer. Specially designed nest boxes and gourds allow these aerial acrobats to nest in suburban and coastal areas near open flying space. Monitoring and management of Rhode Island’s martin colonies is important for maintaining populations of these migratory songbirds in the state. Anyone can aid martin conservation by putting up suitable nesting houses, guarding against invasive competitors, and participating in citizen science surveys.
