As all gardeners know, working in the garden is not just about plants. Being outside with your hands in the soil makes you keenly aware of animal life, too. Over the years, I’ve gardened in tandem with a majestic blue heron, a band of three crows and a playful red fox. Now, with the arrival of warmer weather, I’m looking forward to the return of the purple martins.
Aside from being able to identify their houses (virtual mansions of the ornithological kind), I didn’t know much about these amazing birds until recently, when my garden club hosted two members of a local purple martin society. Ever since, I’ve been scanning the skies for the colorful species. That’s because, according to the experts, the first wave of arrivals are due to be hitting my area soon.
Purple martin house
PURPLE MARTINS HEAD NORTH IN THEIR WINTER
Of the eight swallow species, purple martins are the largest. The dark bluish-black birds arrive en masse to North America each spring, soaring on the jet stream from their native southern Brazil. It takes them about five weeks to fly the 10,000 miles, which is quite a feat for a bird that weighs only about 2 ½ ounces.
Female purple martin in flight
Like many neotropical birds, purple martins travel north to the United States and Canada to breed. The birds arrive at the height of the insect season, establishing themselves in colonies located close to water where there is the greatest food supply. In total, the migration can take up to 2 to 3 months to complete.
Meanwhile back in Brazil, they’re considered a public nuisance, mainly due to their large numbers and preference for roosting in trees around central plazas. As a result, some municipalities have gone so far as to install sirens and other devices to chase the birds away.
ONLY MAN-MADE HOUSING WILL DO
In the United States, on the other hand, it’s a different story. Here, the purple martin colonies return each year to establish neighborhoods in man-made housing only, usually large, multi-room houses or hollowed-out hanging gourds. In fact, they are the only bird species that is totally dependent on human-supplied housing. In other words, not only are they friendly towards people, but they actually prefer living in close proximity.
As a species, purple martins favor locations in wide-open terrain, usually pole-mounted martin houses or gourds. This keeps them out of reach of predators like owls and hawks that dwell in cavities in trees. Consequently, they’ll generally bypass congested suburban areas for broad open areas like meadows or fields located near lakes or other bodies of water.
Typically only one male and one female live together in a room or a gourd. However, the highly sociable birds house together in colonies, where they interact as a unit, sharing food and singing to each other. In fact, a group of houses or gourds can often host as many as 60 to 70 birds over a 2-month period.
Purple martin pair
THEY SEND SCOUTS
Now is the time of year when the first scouts (who are the oldest birds) begin arriving from Brazil to check out their nesting sites from the previous year. The scouts pave the way for the rest of the flock, which arrives 4 to 6 weeks later. Built like a glider, the birds can travel at speeds greater than 40 miles per hour.
THEY ONLY FEED ON THE FLY
Moreover, purple martins bring a whole new meaning to eating ‘on the fly.’ According to Mike Dickson of the Purple Martin Society of Frederick, Maryland, they only recognize food that is in flight, meaning that they primarily snatch insects in midair. Adept in performing complex aerial acrobatics, the birds even drink in the air. They accomplish this by flying low over lakes or ponds while scooping up water with their bills.
A female in flight
Indeed, you’ll never find purple martins foraging for food on the ground, or eating seed from a feeder. People who choose to feed the friendly birds will discover they’re quite open to the idea, but only if the food is flung to them. On occasion this is necessary since the birds are highly susceptible to bad weather. Prolonged periods of cold or rain can spell death to entire colonies when there are no insects available.
THEY SING REALLY WELL
One of only a few colony birds that love to sing, purple martins’ throaty chirps can be heard May through June during the breeding season. According to the Cornell Lab of Ornithology, males make a croaking song during courtship that can last up to 4 seconds. People say that once you’ve heard it, you’ll never forget it.
Males perform the dawn song
Purple martins sing in a combination of gurgles, clicks and song. The loudest singing occurs before daylight. Males perform this dawn song, possibly to attract other birds to the nesting site. Click here to hear a few of their beautiful songs.
AN EARLY DEPARTURE
All too soon, by the end of July or first week in August, the birds prepare to leave for their migratory roost. Many purple martin lovers describe this time as a sad one, when they awake to find the birds gone and their houses empty. It’s as if suddenly, the countryside has fallen silent.
Female purple martin
Once airborne, the birds fly south towards a prescribed spot to roost by the tens of thousands. The largest roosting colony on record was estimated to have 700,000 birds at one time. Usually located by water, groups of colonies will gather there over a few days, before heading on back to Brazil. There can be thousands of purple martins in the sky at one time, so many that they often show up on Doppler radar as giant rings.
Interested in attracting purple martins? Here’s a great article from the Purple Martin Conservation Association in Edinboro, PA, a non-profit conservation organization.