Tuesday, January 12, 2010

Good Day to Take it Easy

The temperature warmed into the 40Fs at the Audubon Center at Francis Beidler Forest with a promise of 60Fs by Thursday! However, the cool weather kept the number of visitors to seven and kept most of the wildlife out of sight or resting.

Black Vulture at Audubon's Francis Beidler Forest by Mark Musselman
Barred Owl at Audubon's Francis Beidler Forest by Mark Musselman

Not a single reptile, not even a lizard, was spotted around the boardwalk and only a few birds made their presence known. Two that remained quiet, but were spotted anyway, were the Black Vulture (Coragyps atratus) perched in the sunlight high atop a Bald Cypress (Taxodium distichum) snag and a Barred Owl (Strix varia) in an oak that the owl pair has adopted as their "digesting tree." Vultures often depend on warm rising air (thermals) to lift them high above the ground and limit the energy required to stay aloft. Cold days like today offer little in the way of thermals.
Crayfish loaded Barred Owl pellet at Audubon's Francis Beidler Forest by Mark Musselman
Owls do not digest all the parts of the prey that they eat and regurgitate those parts in a compact pellet. Barred Owls tend to select a feeding perch near their nest. The oak this pair selected is at #14 and across the boardwalk from their nesting tree. The pellets and waste on the boardwalk give away the feeding perch's location. Depending on the species and their dietary preferences, the pellets will be composed of differing material. Here in the swamp, the Barred Owls often eat the easy-to-spot-and-catch crayfish. The owl pellet in the image appears to be made up entirely of crayfish exoskeleton. However, in the past, we have found owl pellets on the boardwalk that contained small mammal bones and hair. Additionally, we have observed a Barred Owl catch and eat a Yellow-bellied Sapsucker!

Yellow-bellied Sapsucker at Audubon's Francis Beidler Forest by Mark Musselman

On the topic of sapsuckers, the two in the image spent an extraordinary amount of time chasing each other near the observation tower at Goodsen Lake. Several times, one bird drove the other into the water. They need to be careful...the owls look like they've finished digesting their last meal!

Images by Mark Musselman

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