Riverbank Purple Martin Sanctuary
Purple Martins are a beautiful bird with a unique history that migrate to North America all the way from the Amazon Basin in Brazil – and we are very lucky that so many have made their seasonal home at Brandon’s Riverbank!
This idyllic initiative features three Purple Martin Houses located right beside the Riverbank Discovery Centre patio and is managed by local naturalist Dave Barnes.
Stop by Sunday afternoons at 1:00pm throughout the summer for FREE Purple Martin learning sessions with Dave!
About Purple Martins
As the largest member of the swallow family in North America, Purple Martins have a broad chest and forked tail. In flight they are graceful and fast, able to easily out-maneuver predators. Adult males have glossy purple feathers covering their entire body, while adult females have a purple head and back with a grey/ white belly. These birds have what is called “delayed plumage maturation” meaning that they take more than one year to acquire their adult plumage. This can make ID of young martins (sub- adults) challenging.
Sometime after humans arrived in North America approximately 12,000 years ago, the first peoples began to hang hollowed- out gourds from poles to attract Puple Martins to their camps. It is thought that this practice began as a means to protect corn fields and racks of drying skins/ meats. This practice established a relationship between Purple Martins and humans that eventually saw the bird species become entirely dependant on humans to provide nesting spaces.
The gourds resembled hollow trees and natural cavities such as those that the martins had been pre-disposed to select for nesting. The gourds certainy offered more spacious living. Residing in such close proximity to human settlements would have also benefitted the Martins as predators were less inclined to approach human camps.
Today Martin enthusiasts build state of the art artificial gourds and/ or houses with nesting cavities often refered to as “apartments”. As Purple Martins prefer to nest in groups, structures are often built with 2- 12 apartments. To keep predators away these houses are placed high off the ground, and should be built to allow the house to be raised and lowered for maintenance.
Purple Martins are a long-distance migrant; breeding throughout North America during the Spring and Summer, and wintering in the Amazon basin area of South America. These birds typically arrive to southern Manitoba in May, and depart once their babies are able to fly – usually in mid- August.
Different ages and genders of Martins migrate at different times. Older males called “scouts” often migrate first and will usually choose the best nesting sites.
Martin nests are typically constructed of twigs, straw, and coarse grass, with a mud dam occassionally at the front. Before egg laying begins, martins will line the nest bowl with green leaves. The female lays one pure white egg a day; clutch size is usually 4-6 eggs. Only one brood is raised each summer.
Purple Martins have suffered from the introduction of European Starlings and House Sparrows. These non- native species of North America compete with Purple Martins for nest sites and easily take over these areas they so heavily rely on. Active management of a Martin House is important to help defend against these invasive species and ensure martin colony success.
Purple Martins are aerial insectivores, meaning their only food source is flying insects – but they do not eat mosquitos; an American businessman started that myth 50 years ago to sell more aluminum bird houses. In fact, martins feed high in the sky, capturing the largest insects available such as dragonflies, beetles, moths, flies, and mating swarms of ants, wasps, and bees. Come and watch on Sundays as we attempt to train our martins to catch live mealworms tossed in the air!