Downtown Martin Roost

Twice now, once on our anniversary (5 years! and on a well deserved date night), and once with friends and their kids, we have gone to see the Purple Martins come in to roost downtown. This has been happening in this particular spot for enough years now that there is plenty of info on it online... so I guess we will add some too.

Along with numerous other birds, Purple Martins are flying south this time of year to over winter in Central/South America. The purple martin is a large swallow that many folks hang gourds/houses for in their yards. In fact, Native Americans did this too, in order to attract martins for their services as insect predators.
Throughout their fall migration, they stopover periodically for a few days in certain places. While there are many reasons that we humans don't fully understand, we can figure their choice of stopover location has to do with two major pressures that they face during migration: food abundance and predators. The broad floodplain of the James River provides an abundance of insects, the dominant component of this aerial insectivore's diet. Plus the roost trees and local surroundings must provide some relatively low densities of predators, such that migrating adults, and more importantly, first year juveniles, can benefit from a decreased risk of being depredated. The huge number of birds that congregate also decreases the chance that any one of them will be eaten...i.e., safety in numbers.

For the past few years a roost has established itself in downtown Richmond; a good sized one, estimated at between 5 and 10 thousand birds per night. There are many other roosts throughout eastern Va., and everywhere along the migration route. It is amazing to think about these bird's ancestors have been stopping over in this general area for many thousands of years despite the fact that this floodplain is dominated by human development. This roost is in a row of ten or so trees smack in the middle of downtown!

So basically around dusk, the birds flock in from the east and south mostly and begin to congregate way high, in several groups. Then one by one, each group moves lower towards this cluster of trees. And in about five groups, they dive into the trees, alarmingly fast and whizzing by your head. Once landed, the trees are shaking with thousands, competing for a place to perch for the night. Cool too that you can watch them take off in the morning on the dopplar radar.

This video doesn't do it justice, but it certainly gives you the idea. And we have been lucky enough both times to see an opportunistic red-tailed hawk come in for some dinner.



As for Alder, he is doing laps with his push toys with wheels around the house and up and down th street. He LOVES it! This and reading books are his favorite activities. And we are enjoying more communication from him all the time via signing. More on this later when we have pics.