In Great Numbers

Posted on July 23, 2011 by Meredith

Last week I shared a video of our Austin Purple Martin Roost, where many thousands of Purple Martins soar together through the July sky before settling in for the night. These large flocks are called roosts, and eventually the birds will migrate together group by group to South America, where they will fatten up on insects during the winter before heading back to North America next year to nest once again. I went back a few days ago, this time with a functioning battery in my regular camera, to capture a series of images of the birds.

When we first arrived, the birds were still mostly in the sky.

But as the sky darkened, the birds began to come in to land. They had only a few trees, maybe three in all, that were the choice resting spot. Other trees nearby remained empty.

The sheer numbers of Purple Martins continue to astonish me, and the very loud zzzhhhhh sound of the birds in the trees could rival the worst summer cicada population.

It can be tricky to find for the birds to find a place to perch as they join their companions.

Just look at how many birds eventually gather together on each branch! It amazes me the trees manage to stay upright under all that weight.

This time, there was a crowd of bird watchers gathered in the nearby mall parking lot for the occasion. They oohed and aahed, too. Most of them stayed farther back, while a few brave souls joined me by the trees. For the sake of these pictures, I got pooped on three times — thank goodness for my giant floppy hat!

Purple Martin Party

Posted on July 9, 2011 by Meredith

Last night I piled my family into the car to partake in the social event of the summer season — the annual mass congregation of Purple Martins. The birds gather in numbers from tens of thousands to hundreds of thousands in such roosts all over the eastern half of North America. The groups are so large that they actually can be monitored with Doppler radar. Austin is lucky enough to have a large roosting spot right here.

In a typical summer, the Purple Martins will start gathering in our area around mid-July, with birds migrating toward South America group by group, until by August they are gone, off to their winter home. However, with the extended drought we’ve been having, this is no typical summer. The birds are roosting earlier than usual, and I suspect they’ll leave earlier than usual, as well. Only the birds know how long they intend to stick around.

Most roosts can be found near water sources, as the numbers of insects are far greater there. I’m not sure why our Purple Martins roost near Highland Mall in the middle of urban central, but they’ve been going there for years. Of course, their roosting locale is also a favorite grackle and starling spot, contributing to many a person’s confusion about what kinds of birds they are seeing, especially because Austinites are used to the familiar gatherings of grackles and starlings each evening at dusk. However, the tell-tale graceful swoops and dives of the Purple Martins as they soar in the sky to find insects make them easy to distinguish from the clumsier flights of the larger dark birds, which instead forage on the ground for food.

If you watch the video above, you’ll get a sample of how utterly incredible the Austin roost is. Purple Martins, by the way, are North America’s largest swallow. And if you want to see some absolutely adorable baby Purple Martins, check out my previous Purple Martin post.

Chirp If You Love Purple Martin Families

Posted on May 1, 2011 by Meredith

I have a newfound passion, and that’s Purple Martins.

Purple Martins are the largest North American swallow, and they share a special relationship with humans — those birds living east of the Rockies, for example, are completely dependent on humans for housing. This history starts long ago with Native Americans setting out gourds to attract the PMs, which in turn offered alerts to snakes and other dangers. Today, because invasive English House Sparrows and European Starlings aggressively compete for natural cavities, the Eastern Purple Martins fully shifted to human-made housing. However, House Sparrows and Starlings try to occupy these as well, so it’s important that humans actively manage the housing to keep out the aggressive species.

Yesterday, we had the pleasure of participating in nest checks down at Hornsby Bend with Andy and Julia, the landlords of the Purple Martin gourds there. What all do PM landlords do? They help ensure the success of Purple Martin nests by evicting House Sparrows and Starlings, keeping the housing systems in shape, providing pine straw or other nesting material, monitoring egg and young counts, providing protection from predators, replacing mite-infested nests, closing housing after migration, and cleaning and reopening housing in late winter for the next PM season.

As you view these photos, remember that Purple Martins have a unique relationship with humans which enables landlords to keep a close eye on the health of the birds. Please don’t handle other bird species’ nests, eggs, hatchlings, or fledglings you have at home. However, if you find a fallen fledgling, it’s okay to try to put it back into or near the nest, disturbing the nest or family as little as possible.

The Purple Martin young at Hornsby Bend were in different stages of development, from egg to about 11-13 days old. Many were newly hatched.

Here are the eggs of one nest — their solid-looking appearance indicates that hatching time is near.

When the babies hatch, they are tiny and featherless, and they have closed eyes and a transparent belly.

You can the see the yolk sac here, which the baby will use for additional nutrients in addition to the insects the parents provide.

In just a few days, the babies’ skin darkens, and they start to grow feathers.

These babies are about 5 days old, with visible feather tracts , darkened skin, and pin feathers beginning to show. Their eyes are just hinting at starting to open — if you look closely, you can see the slits.

Over the next few days, the eyes will fully open and the pin feathers will emerge even farther.

Pretty soon they actually start to look like birds, though my first thought when I saw this picture was that someone had stuck a Lost-World Pteranadon in the nest. I guess that mouth gets big fast to take on bigger insects.

To determine the age of some of the babies, we compared them to a set of photo charts. The babies of this nest are likely 11 days old, based on this one’s feather development and size. Its tail feathers are just now emerging from their sheaths.

It was Hatching Day in one nest, and this was soooooo exciting.

This little baby is still wearing its egg “diaper.”

The other three eggs in the same nest were getting ready to hatch — we could feel movement inside the eggs, and the joy of it was beyond words.

As heart-thrilling as the whole experience was for me, the best part was watching my almost-eleven-year-old son help count and determine the age of the birds, as well as getting to feel the tiny movements of the soon-to-hatch eggs. He was clearly moved by the whole experience, and he’s eager to go back to help Andy and Julia. By the way, we’re actually PM managers ourselves — we’re helping to get the Purple Martin colony established in the new gourds at my son’s school. I can’t wait to have a full colony of Purple Martins there!

To find out how you can help protect Purple Martins and whether your site is a good place to set up PM housing, be sure to visit the Purple Martin Conservation Association for a tremendous amount of information.

Oh, and… chirp! (see title)