30 September, 2011

This Just In.....

Here is a quick summary from Don McCall, hot off the presses...well, off my screen anyway.

"We now have Island Girl's roost site from last night, as well as her first morning signal today from 10:00 (local time).  She spent the night in southwestern Mississippi, roughly 40 km (25 mi) south of Jackson.  At 10 a.m. she was about 65 km (40 mi) northwest of New Orleans, Louisiana and  flying south at a speed of 78 km/h (48 mph), approaching the shoreline of Lake Maurepas, which adjoins Lake Pontchartrain.

She has probably reached the coast of the Gulf of Mexico by now, but we probably won't know what happened next until later this evening or tomorrow morning.  If we receive any more signals indicating whether she started across the Gulf or followed the shoreline, I'll post another update as soon as that's available".


I would add that she covered 168 miles (271 km) for the day, still taking her time and not rushing south yet.

Incidentally, as she was flying south across Simpson County, Mississippi, yesterday afternoon, she did a hard turn to the SE towards the small town of Hazlehurst. She flew there and roosted between a major road (Interstate Highway 55) and a railroad track. Closer examination of the Google Earth image shows she chose another tower to sleep on again (cell tower/radio antenna?).

Did she see this tower in the distance and change her course to sleep there? It looked like it from the track but we can't say for certain. The distance was 17 miles. Can a peregrine see a tower from 17 miles away? Good question.

She finally reached Louisiana today, the eighth state on her journey (Michigan, Wisconsin, Iowa, Illinois, Kentucky, Tennessee, Mississippi and now Louisiana). It is possible that this is the first time she has been in these states.

Peregrines (and other long distance migrant hawks) can make a living catching their prey over a wide range of habitats. They must be able to do so if they are migrationg across such varied territory as the Arctic tundra, the Canadian boreal forest, the farmlands of the Mid-West, cities large and small, the sub-tropical regions of Mexico, the tropics of Central and South America, the intense Atacama Desert and the pine forests of southern Chile.

They must be adaptable enough to survive in each of these situations. They must have a flexible approach to hunting in different situations. They must be able to recognize, hunt and catch new prey species (do peregrines eat toucans?) and avoid all of the ever-present mortality sources.

Are these "slow migrant" peregrines that we have discovered during this study taking their time so that they can become familiar with these habitats and how to hunt them? Are they "familiarizing" themselves with their migratory route and what they can find there? Is this advantageous to them?

The complexity of peregrine migratory behavior is both deeply impressive and humbling. What a remarkable organism to fit into all of this and flourish.

1 comment:

Dan Brekke said...

Wonderful summary of the challenges these birds routinely manage. Amazing adaptability.