Purple martins are the largest species of swallow in North America. These aerial insectivores are beloved by many homeowners for their graceful flight and aerial acrobatics. If you want to attract purple martins to your property, here are some key steps you can take.
Why Attract Purple Martins?
There are several benefits to attracting purple martins:
- Natural pest control – Purple martins are voracious consumers of flying insects like mosquitos, biting flies, moths, and more. A colony can consume thousands of flying insects each day.
- Entertainment value – Martins provide free “aerial shows” with their swift fluid flying and daring maneuvers.
- Help a declining species – Over the last few decades, purple martin populations have declined. Providing housing helps support their populations.
Getting Started
Here are some tips on getting your property ready to attract martins:
Location
– Place martin housing in an open area, preferably with a free flyway at least 30-60 feet around the housing. Avoid placing too close to trees, wires, fences, etc. that could impede their flight.
– Face the entrance holes eastwards. Martins prefer housing facing the morning sun.
– Elevate the housing 15-20 feet high on a pole, or under the eave of a building. This gives protection from predators.
Housing
– Install specially designed martin houses with multiple compartments (6-12 or more). Or install gourds securely mounted under eaves or on poles.
– Houses should be weatherproof and made to prevent entry by starlings, sparrows, and owls.
– Make sure holes are the appropriate size – 2 1/8″ diameter for purple martins.
– Houses must be able to open for annual cleaning and maintenance.
Attracting Martins to Your Site
Here are some key tactics to attract scouting martins to your new housing:
Start early
– Have housing up and ready by early spring before martins arrive. In most areas, this means having housing ready to go by February or March.
Use decoys and audio lures
– Place painted wooden martin decoys inside compartments or gourds to serve as “advertisements” to scouts.
– Play audio recordings of martin dawn song to grab the attention of scouts flying over.
Offer tasty insects
– Run a Purple Martin Party – capture a bag of live flying insects and release them above your martin house when scouts are in the area.
– Lure insects like crickets, dragonflies, flies to your yard with water features and native plants.
Be patient
– It can take 1-2 seasons before martins fully discover and occupy a new site. Persistence pays off!
Deterring Nest Competitors
Other cavity nesting birds can compete with martins for housing. Here are some tips to giving martins the advantage:
- Install porcupine wire around holes to discourage European starlings.
- Install owl guards over holes to keep out owls and squirrels.
- Frequently monitor houses and evict non-native nesters like house sparrows.
- Immediately remove alternate nesting sites like gourds or crates near martin housing.
Yearly Maintenance
It’s critical to do annual maintenance on your martin housing each fall/winter:
- Clean out old nests and debris.
- Remove parasite nests if present.
- Repair any damage.
- Paint/stain to refresh exterior.
This yearly cleaning prepares the housing for the next season’s arrivals.
Enjoying Your Martins
Once martins occupy your site, sit back and enjoy:
- Place chairs or a bench near the housing to observe activity.
- Watch aerial maneuvers as martins pursue insects or interact.
- Listen for martin chatter and gurgling sounds around the housing.
- Keep binoculars handy for close-up viewing.
- Consider streaming live video of the housing with a webcam to monitor activity.
Key Facts About Purple Martins
Here are some key facts about purple martin biology and behavior:
- The largest swallow species in North America.
- Exceptionally fast, agile fliers that feed exclusively on flying insects.
- Originally nested in tree cavities, but readily adapted to nesting in human-provided housing.
- Migratory songbirds that winter in South America.
- Nest in colonies, with multiple pairs often sharing a house.
- Male martins arrive first in spring to select the nest site.
- Females follow a week or two later to pair up and lay eggs.
- Martins are aerial insectivores and eat only insects caught in flight.
- A typical martin can consume 2000+ flying insects per day.
- Young martins require prodigious amounts of insects while nesting (up to 400 per day).
- Martins are extremely vulnerable while collecting mud nest materials.
- Parent martins tirelessly collect insects from dawn to dusk to feed their young.
- New martins take 2-3 years to reach full colorful adult plumage.
- Martins are highly social and interact with chatter and pursuit flights.
- Groups may mob owls, hawks, and crows that venture too close.
Ideal Habitat for Martins
Here are things martins look for in ideal nesting habitat:
- Open areas with wide flyways for foraging.
- Ponds, lakes, rivers, or marshes that attract aerial insects.
- Low, open grassy areas to forage close to the ground.
- An abundance of day-flying insects like flies, moths, mayflies, dragonflies, etc.
- Dead snags for morning singing/gathering spots.
- Mud puddles or wet soil for gathering nest materials.
- Suitable cavities for nesting, preferably elevated houses, gourds, or bird condos.
Martins thrive around open water, so sites near ponds or wetlands are ideal. Low-cut grass also allows them to swoop down and grab insects.
Range and Migration
Purple martins migrate huge distances each year:
- Breed across eastern North America, the Pacific Northwest, and southern Canada.
- Migrate to the rainforests of the Amazon Basin to overwinter.
- Travel 5000-7000 miles each way every spring and fall.
- Males arrive back at breeding sites first by mid-March.
- Females follow a week or two later.
- Most martins leave breeding grounds by late July/early August.
- Fall migration lasts from August through October.
Scout martins will arrive in an area and look for good nesting sites. If none are found, they may skip that area. This highlights the importance of having housing ready before the spring scouts arrive.
Diet and Feeding
Purple martins have a simple aerial insect diet, feeding exclusively on insects caught mid-flight:
- Consume a diverse range of flying insects – dragonflies, flies, moths, butterflies, bees, wasps, flying ants, etc.
- Will avoid noxious species like bald-faced hornets.
- Require open flyways for efficient foraging.
- Martins drink on the wing by skimming over ponds and wetlands.
- Require huge quantities of insects while breeding (up to 2000 per day for adults).
- Fledglings may consume 400 insects per day as they grow.
Landscaping with water gardens and native plants can help attract natural insect prey to your yard. Avoid pesticide use.
Major Threats
Purple martins face a variety of threats on their breeding and wintering grounds:
- Predators – martins vulnerable to owls, accipiter hawks, falcons, snakes.
- Weather – extended cold/wet weather can inhibit insect hatches.
- Habitat loss – filling of wetlands, removal of dead snags.
- Pesticides – chemical use reduces insect prey base.
- Competition – starlings, sparrows taking over nest sites.
- Amazon deforestation – threatening overwintering habitat.
Providing suitable housing protected from predators is key. Avoiding pesticide use around housing helps maintain an insect food source.
Attracting Martins to New Sites
Attracting martins to a brand new site takes patience and persistence. Some tips:
- Have suitable housing up in early spring before scouts arrive.
- Use decoys and audio lures to attract interest.
- Consider relocating a few pairs from another site.
- Repeatedly play dawn song over housing in morning when scouts are active.
- Release bags of live insects like crickets over housing when martins are near.
- Avoid trimming vegetation around housing during nesting.
- It may take several seasons of persistence before martins fully occupy a site.
Having pairs in residence will make the site more attractive to additional martins. Relocation from established sites can give new sites a jump start.
Nesting and Breeding
Key facts about purple martin nesting biology:
- Martins are colonial cavity nesters, nesting in aggregations.
- Prefer elevated cavities with dropoff at entrance.
- In the wild nested in tree cavities, but adapted to use human housing.
- Males arrive on breeding grounds first and select cavity nest sites.
- Females follow a week or two later to pair up and lay eggs.
- Typically lay 3-6 eggs per clutch.
- Incubation lasts 15-18 days.
- Chicks fledge around 26-32 days after hatching.
- Purple martins have 1-2 broods per season.
- New fledglings take 2-3 years to reach full adult plumage.
Providing housing that protects eggs and fledglings from predators and weather is key. Starling-resistant sites also help martins succeed.
Summary
Here are some final tips for attracting purple martins:
- Have weatherproof, predator-resistant housing ready in early spring.
- Place housing in open areas with wide flyways.
- Use decoys and audio lures to grab scouts’ attention.
- Manage vegetation and competing species around housing.
- Do annual maintenance and cleaning of houses.
- Landscape with water features and native plants to attract insects.
- Avoid pesticide use near martin housing.
- Be patient – it may take years for martins to fully occupy a new site.
With the right habitat and techniques, you’ll soon enjoy hosting these beautiful aerial acrobats on your property!
