July 9, 1999

     Purple Martins

From April to September, many of us in Minnesota enjoy the gurgling chatter of purple martins in and over our neighborhoods.  Some of us provide apartments, thoughtfully placed and maintained for them.  In return, these largest members of the swallow family give us pleasure with their aerial displays and songs during the spring and summer months.

Now both male and female purple martins are busy feeding their young.  The diet of the martin could almost be covered by one word - insects - but this is not quite true as they eat a few spiders also.  Their food is generally procured on the wing and in the usual swallow fashion of darting, swooping and wheeling in streamlined flight.  Sometimes they can be seen flying close to the surfaces of lakes or rivers, dipping down for drinks.

One brood of young is raised each summer by martins in the Upper Midwest.  The nest is started about a month before the eggs are laid, with both sexes building the nest.  Usually four or five eggs are laid, and incubation apparently is performed by the female only.  She is similar in color to the dark steel-blue males but has a light-colored belly.  The eggs hatch in about 15 days, and the young remain in the nest for nearly a month.

After the nesting season has ended each summer, martins gather into assembly groups before leaving the area.  The early migration of martins comes to a peak the second half of August in Minnesota as the birds leave for their winter home in Brazil.  While there they feed on insects in the air, as before, but they do not nest.  Their homing instincts are strong, and many will return to the same nesting area the following spring.