Circleville Owl Pellet Dissection

On November 12th I visited the 3rd grade classes at Circleville Elementary School in the Pine Bush CSD and did an owl ecology program. After discussion on how ornithologists might do a survey of the common owls of the Circleville area we dissected owl pellets. Here are the results.

Feuerstack’s class 14 pellets – 26 mice, 7 shrews, 0 moles, 0 birds
Eller’s class 12 pellets – 25 mice, 2 shrews, 0 moles, 4 birds
DelMoro’s class 11 pellets – 23 mice, 4 shrews, 1 mole, 1 bird
Lindsay’s class 11 pellets – 25 mice, 1 shrew, 0 moles, 1 bird

A total of 48 pellets were dissected. Most of the pellets were the large size pellets available from Pellets, Inc. (see link below on the right). There were 4 small pellets used in Mrs. Feuerstack’s class. These small size pellets might affect the average number of prey found per pellet.

A total of 99 mice, 14 shrews, 1 mole and 6 birds were found in the pellets. That averages two and a half prey animals per pellet. If an owl produces four pellets per night how many prey animals might be eaten? How many of these would most likely be mice?

It’s interesting to note the number of birds eaten. This seems to be an unusually high number as compared to other dissection classes (look through the blog archives to see other dissection results). Perhaps the owls that produced these pellets have a particular fondness for birds. There could be several reasons for this. One might be that there was an abundance of small birds in the area that the owls hunted making it easier or more likely that they would capture birds for food. Another could be that these owls may have had a preference for birds and hunted them more successfully than the typical owl. Just like people, sometimes an animal develops a taste for certain prey. If that is the case that predator might pursue their favorite prey more so than other predators of their kind. An example of this is a kestrel I once observed. This kestrel had a fondness for snakes. It would often be seen flying to its nest box with a snake in its talons to feed its young. “Feathers in the Wind” by James J. Brett, published by the Hawk Mountain Sanctuary Association (see link below), lists insect and mice as the most favored food for Kestrels, followed by small birds and amphibians. Snakes as a food source are not even mentioned.

Ornithology at Bardonia Elementary School

Back at the end of October I visited Bardonia Elementary School in Rockland County and took 5th graders outside the school to do an autumn bird walk survey. Each student had a pair of binoculars to use and received instructions on how to use them properly, how to observe birds with the binoculars and how to identify birds by both sight and sound. Students also learned about taking field notes.

Twenty-six species of birds were identified. Six species were seen by all three classes: Blue Jay, Black-capped Chickadee, White-breasted Nuthatch, Carolina Wren, Common Grackle and House Sparrow. Many of the birds were observed just outside the 5th grade wing where a bird feeder is set up. These included House Sparrow, Black-capped Chickadee, Mourning Dove, White-throated Sparrow, Common Grackle, Blue Jay, Northern Cardinal and Tufted Titmouse. The Carolina Wren was heard by all the classes off in the woods just beyond the bird feeder area. A small stream flows through this area. This forest tangle is an ideal habitat for this wren.

The Red-bellied Woodpeckers were heard and seen in the woods to the west of the school. Both the Red-bellied Woodpecker and the Carolina Wren are species that have in the last few decades been moving northward. Some scientists think that this is due to global climate change. Both of these species are more common in the southern parts of the United States where it is warmer.

Another interesting observation was that the last class of the day was the one that observed all but one of the hawks and vultures. Hawks and vultures often use thermal updrafts to soar and glide in. The updrafts make flying easier. Updrafts build as the day wears on and the sun heats up the earth. Earlier in the day there would be less rising hot air. This is may, in part, be the reason the first two classes did not observe the hawks and vultures.

This late in the fall many of the summer residents have left, migrating for areas to the south. They have left not so much because they don’t like the cold weather, but because the cold weather makes it harder to find food. These birds eat mostly insects. The cold weather affects the numbers of insects available for the birds to find for food. Some of these birds travel as far as South America for the winter. They will be back by mid-May of next year when there will be more insects for food.

Here are the results of our survey.

Mrs. O’Hara class – 8:40 to 9:40 AM, clear skies, very few clouds, little to no wind, temperature in the upper 50’s, 15 species identified

Mourning Dove – 3
Downy Woodpecker – 1
Red-bellied Woodpecker – 2
Blue Jay – 5
Black-capped Chickadee – 3
Tufted Titmouse – 1
White-breasted Nuthatch – 1
Carolina Wren – 1
American Robin – 18
European Starling – 5
Cedar Waxwing – 3
White-throated Sparrow – 3
Red-wing Blackbird – 25
Common Grackle – 2
House Sparrow – 10


Mr. Pisano’s class – 9:50 to 10:50 AM, clear skies, very few clouds, little to no wind, temperature in the upper 50’s to lower 60’s, 14 species identified

American Kestrel – 1
Blue Jay – 9
American Crow – 13
Black-capped Chickadee – 2
Tufted Titmouse – 2
White-breasted Nuthatch – 1
Carolina Wren – 1
Northern Mockingbird – 1
Yellow-rumped Warbler – 1
White-throated Sparrow – 2
Northern Cardinal – 1
Common Grackle – 13
American Goldfinch – 11
House Sparrow – 11

Mrs. Del Valle – 11:00 to Noon, clear skies, very few clouds, little to no wind, temperature in the upper mid 60’s, 15 species identified

Black Vulture – 5
Turkey Vulture – 5
Sharp-shinned Hawk – 1
Coopers Hawk – 1
Red-tailed Hawk – 1
Mourning Dove – 2
Blue Jay – 3
American Crow – 3
Black-capped Chickadee – 2
White-breasted Nuthatch – 1
Carolina Wren – 1
Northern Cardinal – 1
Common Grackle – 9
Red-wing Blackbird – 15
House Sparrow – 15

Here is a composite list of all species seen between all three classes:

Black Vulture
Turkey Vulture
Sharp-shinned Hawk
Coopers Hawk
Red-tailed Hawk
American Kestrel
Mourning Dove
Downy Woodpecker
Red-bellied Woodpecker
Blue Jay
American Crow
Black-capped Chickadee
Tufted Titmouse
White-breasted Nuthatch
Carolina Wren
American Robin
Northern Mockingbird
European Starling
Cedar Waxwing
Yellow-rumped Warbler
White-throated Sparrow
Northern Cardinal
Red-wing Blackbird
Common Grackle
American Goldfinch
House Sparrow

Look through my blog to find other schools where I have taken students out into the field for ornithological observations. You can compare the findings of these different outings. The differences might be due to differing habitats, different locations, different times of year and different weather conditions. What differences do you find and why?