Posts Tagged ‘storm’

How do Purple Martins Know the Party is Over?

Tuesday, July 27th, 2010

Tropical Storm Bonnie Passes with a Whimper But Scoots Martins Out

tropical-stormbonnie-7-23The last nest of 2 martin fledglings (which were a complete surprise) fledged the same day that Bonnie was supposed to dump rain all along the coast. Fortunately for some, the rain was more of a short drizzle but amazingly the purple martins seemed to know something was up.

Every morning our colony would get a faithful dozen or so visitors that would sit on the housing and chatter away. By about 11 AM they would leave only to return again the next morning. But the day after Bonnie not a purple feather was to be seen. Many speculate that birds, being so sensitive to changes in barometric pressures and the weather , could avoid bad weather by delaying migration to an area of poor weather or vice versa. Could it be coincidence?

According to Melvin L. Kreithen and William T. Keeton of the Division of Biological Sciences, Langmuir Laboratory, Cornell University in Ithaca, New York,(23 October 1973) Homing pigeons were able to to detect air pressure changes. As purple martin landlords can tell you, a purple martins homing ability is at the very least equal to that of a homing pigeon. So the correlation is fair.

By any account, the season is over here in South Florida and all martins have left.

The factors that affect a birds migration are complex and not completely understood. Click this article for Neotropical Migratory Bird Basics from the Smithsonian National Zoological Park. If you want to learn more about Neotropical Migratory Birds read this article on Birds Built-in Barometer.

Not that my birds needed a Tropical Storm to end their party, migratory birds know when it is time to go based on known factors such as the length of day and for some types of birds, even star patterns. There is nothing to be done for purple martins (or any other migratory bird-for that matter) that linger on. Some folks will tell you to lower or remove housing, but don’t bother. Just like the old wives tales that persist that tell hummingbird aficionados to remove hummingbird feeders to push hummers to migrate, nothing needs to be done.

So keep the feeders full, leave the housing up till you feel like it. Birds have been migrating for a long time and the only thing we need to do for them is support them, by way of a beak full of nectar, a belly full of seed or perhaps a dry place to sleep at night.

Afternoon Storms and Brutal Heat

Wednesday, June 9th, 2010

With the heat index in the 100′s the fierce thunderstorms are ALMOST welcome. I say almost because with each of these storms severe winds of upwards of 45 MPH that would last past sunset, have inflicted some damage.

The nest of mockingbirds right outside our garage was blown down and the 2 partially feathered nestlings had perished. The large Sabal Palms lost a few fronds and the seed pods that the mockingbirds had made their nest in was woefully inadequate for the punishing winds.

The purple martins hung on to their perches well into the night seemingly afraid to detach themselves. I suspect an attempt to find protection within their nests would have had them blown away at some point during the storm. Fortunately the storm died down and all seemed quite but the previous week had these storms coming in almost on a daily schedule.

The winds were no problem for the martin poles. So other than the mockingbird casualties, all is well. Unfortunately the same can not be said for the laptop which ran the colony cam, so no live web cam at the moment. A new laptop is on the want list…any one???

June 18, 2008

Wednesday, June 18th, 2008

A huge Thunderstorm came through this afternoon. Luckily my boys slept without so much as a whimper, DESPITE a lightning strike somewhere outside their window. An electrical surge has destroyed our DVR and something is amiss with our electrical system. After the lightning hit a light came on in the living room and would NOT turn off! Needless to say, that had me very concerned. I tried to switch the light off at least a dozen times without any luck. Finally it shut off….only to turn back on. An emergency light came on a few times, even though we did not loose power. We did have a circuit breaker trip but we had already reset it. I REALLY should call an electrician to check things out! If the house goes up in flames, you will know why!

On a purple note. The pole that the house is on suffered a career ending bend even though I keep my poles lowered. I would hate to think what would have happened if the poles were up fully and if the housing was full of birds. Just further strengthens my believe that as soon as you have martins that are committed to your site, just keep the pole down 5 feet or so. No need to tempt fate.

The other pole that has a much heavier gourd rack suffered no ill effects at all. I wonder if having the pole cemented or not could exacerbate bending? I mean, if the ground wont give, the pole will have to…right? Maybe we should rethink concreting poles in the ground.