Purple Martin

Purple Martins on Martin House

The Purple Martin (Progne subis) is a member of the Hirundinidae family.   It is our largest swallow.  In flight it appears long-winged.  The adult male is a uniform glossy blue-black.  The adult female and juvenile are more grayish.  All plumages show dark above with dark head and breast (although grayish in female and juvenile).  In flight the underwing coverts are very dark and the tail is forked.  The photo above shows a male on the top row and a female or juvenile peeking out of the bottom row.  

The Purple Martin is 18 cm (7.5 inches) long and has a wingspan of 45 cm (18 inches).  The male, to the untrained eye, could be confused with a Starling but the shape and bill length is quite different.  In some geographical areas it could be confused with other martin species but we have only the Purple Martin here in New Brunswick.  

Martins are very vocal frequently making a chur sound.  Their song is a series of chortles and gurgles.  The range of this species is widespread in North America.  They breed in most of the eastern half of southern Canada and all of the eastern US.  They also breed in isolated pockets of the western US and also along the west coast.  In New Brunswick Purple Martins are not common but are fairly common locally along the St. John River and other parts of southern NB, especially where martin houses are provided.  Cold, wet springs can be hard on them and competition for housing with Starlings and Tree Swallows can lead to a decline in local populations.  Purple Martins lay 3 to 8 white eggs.  Their nests are lined with mud and plant material.  The eggs are incubated 15 to 18 days by the female.  

Purple Martins feed on flying insects which they catch in flight.  Their feeding frenzies provide good entertainment since they fly up to 72 kph ( 45 mph).  If there are adverse feeding conditions for more than 3 days the birds are in danger of starvation.  

In eastern North America the Purple Martin nests almost exclusively in martin houses provided by humankind.  This species prefers to be in colonies.  In the west they are more solitary and often nest in cavities in forested areas and in the southwest in cavities in saguaro cacti.  They use cavities excavated previously by another species.  

The population numbers of this species have been in serious decline over the last 50 years.  It is thought that competition for nest cavities has contributed to the decline.  In the west they have lost nesting cavities by logging operations.  There are likely other serious unknown causes of this decline.  

Purple Martins leave our area in August and September.  At that time large aggregations of individuals can be seen.  In August 1985, an aggregation of about 5000 birds was seen at Fredericton and later at Cambridge Narrows.  

The Purple Martin as a species was first described by Carolus Linnaeus, a famous Swedish botanist, physician and zoologist.  Purple Martins were recognized by our First Nations peoples.  They hung up empty gourds for them to nest in even before Europeans came to North America.  

The Purple Martin is a beautiful bird.  We need to be diligent in finding and correcting the causes of their population declines.  We can start by erecting martin houses and learning how to care for them properly.  There are many books and brochures showing how this can be done.