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Wednesday, June 22, 2011

Painted Turtle Laying Eggs

While in Monroe, NY working with the Sapphire Elementary School I observed this Painted Turtle (Chrysemys picta) laying eggs. It was already well into the act when I found it on the lawn next to a Dunkin Doughnuts parking lot. I observed it digging her nest for about 15 to 20 minutes before she started laying eggs. She laid 7 eggs in about 10 minutes. I watched her burying the eggs for about 20 minutes before I had to leave.

A great reference for Painted Turtles is Thomas Tyning's book, A Guide to Amphibians and Reptiles, in the Stokes Nature Guides series.


Saturday, June 11, 2011

King Elementary Owl Pellet Study

I had a wonderful time exploring owl ecology and their prey preference with all of you 3rd grade ornithologists. Here is a review of what we found.

Mrs. Davis’s class dissected 9 pellets and found 22 mice, 1 shrew, 1 mole and 1 bird.

Mrs. Sirico’s class dissected 9 pellets and found 30 mice, 1 shrew, 0 moles and 0 birds.

Mrs. Kipp’s class dissected 8 pellets and found 25 mice, 0 shrews, 0 moles and 1 bird.

The overall results were 77 mice, 2 shrews, 1 mole and 2 birds. This would seem to contradict my hypothesis of shrews being a second favorite food over moles and birds (I always present the favored prey for owls as a hypothesis answering the question of what owl like to eat). Our results say that birds and shrews are equally favored. Remember though, we have a very small sample of 26 pellets. That number of pellets could have been produced by three or four owls in 3 or 4 nights. Do you think it is a good idea to base our decision on this small of a sample?

Look over other owl pellet dissection results here in my blog. Combining the results from other school would serve to increase our sample size and give us better data that we can use to evaluate my hypothesis that mice are the number 1 favored food, with shrews being the second most favored and moles and birds tied for third favored.


Field Ornithology at King Elementary

Well, the school year is winding down and I am trying to catch up with blogging about my school visits. I did my annual bird survey at King Elementary in Warwick on June 1. Here is what we found.

The weather was hot, not the best birding conditions, but we still found 29 species of birds. Six species were observed by all three classes. Mrs. Flynn’s class was in the field from about 9:20 to 10:00. The temperature was in the mid 80’s with slight haze in the sky and no wind. Mrs. Shoock’s class started looking for birds at about 1:00 and ended at about 1:45. The temperature was in the low 90’s with a strong breeze from the West and a hazy sky. Mrs. Boccia’s class looked for bird from about 2:20 to 3:00 The temperature was in the mid 90’s, very humid, sky with complete high altitude haze and slight breeze from the West.

Here is the total list of birds seen. I have put a letters after each species to indicate which classes observed or heard that bird.

Black Vulture (B, F, S)

Turkey Vulture (B, F, S)

Sharp-shinned Hawk (S)

Coopers Hawk (B)

Red-tailed Hawk (B)

Chimney Swift (B)

Downy Woodpecker (F)

Eastern Phoebe (F)

Eastern Kingbird (B)

Blue Jay (B, S)

American Crow (F, S)

Tree Swallow (S)

House Wren (B, S)

Eastern Bluebird (B, F, S)

Wood Thrush (F)

American Robin (B, F)

Gray Catbird (B, F, S)

European Starling (F)

Cedar Waxwing (B, F)

Yellow Warbler (B, S)

Common Yellowthroat (B)

Chipping Sparrow (B, F, S)

Song Sparrow (S)

Rose-breasted Grosbeak (F)

Red-winged Blackbird (B, F, S)

Brown-headed Cowbird (B)

Baltimore Oriole (F, S)

Purple Finch (F, S)

American Goldfinch (S)

It was exciting to see so many birds even though we were looking for birds during the hottest time of mid-day. The best time to look for birds would be early morning and I am sure if we were to survey birds around the school at that time we might get an additional 5 to 10 more species.

I think every school should establish a yearly list of birds observed or heard at their school. Additional bird studies could be conducted at school, including setting up bird feeders and conducting a feeder watch, and building, setting up and monitoring nest boxes. When students do animal reports they could be encouraged to do reports on birds that live around the school, incorporating their own observations of those birds in their reports.

Tuesday, June 07, 2011

Today I visited three 4th grade classes at Lynnwood Elementary School in Schenectady (Guilderland Central School District). We were ornithologists studying owls. As part of our class we dissected owl pellets to learn about what their preferred prey is. Here is what we found.

Mrs. Janssen’s class dissected 10 pellets which contained the bones of 30 mice, 7 shrews, 1 mole and 2 birds.

Mrs. Follonsbee’s with several students from Mr. Miller’s class dissected 13 pellets which contained the bones of 38 mice, 1 shrew, 0 moles and 0 birds.

Mrs. Romano’s class with several students from Mr. Miller’s class dissected 14 pellets which contained the bones of 43 mice, 1 shrew, 0 moles and 0 birds.

A total of 37 pellets were dissected revealing the remains of 111 mice, 9 shrews, 1 mole and 2 birds. As a way of illustrating what a hypothesis is I told them that I had researched what Barn Owls eat and had hypothesized that their most favored food was rodents, such as mice. Shrews were a second favored prey and moles and birds were tied for third. Our findings would seem to support this hypothesis.

In our wrap up discussion I mentioned that there seemed to be a larger than usual number of prey per owl pellet. I speculated that this might be due to the large number of smaller mice found in the pellets. We could see this size difference when comparing skulls, jaw and hip bones. We wondered whether this might reflect the fact that at this time of year there might be many more rodent nests which the owls might find by listening to the squeaks of the young, hence the finding of smaller sized bones of young mice. An owl eating 4 or 5 small young mice might get as full as an owl eating 2 or 3 full grown mice. If we compare the average number of prey animals per pellet to the findings of pellets at a different time of the year we might find evidence supporting this.

The average number of animals per pellet with the Lynnwood students was 3.3 animals per pellet.

We can compare this to the findings from four 4th grade classes at Leptondale Elementary School in Wallkill (see previous post). These were pellets were collected approximately one month earlier. At Leptondale there were 40 pellets dissected. These contained the bones of 122 mice, 3 shrews, 1 mole and 2 birds. This gives an average of 3.2 prey per pellet. That is not much different than the average found at Lynnwood, perhaps we need to look at owl pellets found even earlier in the year.

Let’s look at pellets collected in mid-winter. I visited the Nazareth Intermediate School in Nazareth, PA in January (see previous post in the blog archive). Working with 14 4th grade classes we dissected 168 pellets and found 335 mice, 45 shrews, 20 moles and 6 birds for an average of 2.42 prey per pellet. If we look at what Lynnwood students found in March of 2010 there were 111 mice, 5 shrew, 1 mole and 0 birds in 41 pellets for an average of 2.9 prey per pellet.

There does indeed seem to be a difference in the number of prey eaten per pellet at different times of the year. It also seems that there might be a difference in the number of shrew and moles taken at different times of the year. Look over other owl pellets studies that I have done with other schools at different times of the year in my blog archives.

Leptondale Elementary School Owl Pellet Dissection

Ah, spring has run away on me and I am late in getting some of my school visits recorded here on my blog. One of my favorite environmental education activities is owl pellet investigations. It's an incredibly exciting way to learn about owl behavior and there predator-prey relationships.

In May I had my annual visit at the Leptondale Elementary School in Wallkill, NY. The 4th grades do my Owl Ecology session. The culmination of the class is the dissection of owl pellets to learn about what owl eat. Here are the results for all four 4th grade owl pellet dissections.

Mrs. Psilopoulos’ class dissected 9 pellets and found 28 mice, 2 shrew, 0 moles and 1 bird.

Mr. Zupan’s class dissected 11 pellets and found 35 mice, 0 shrew, 1 mole and 0 birds.

Mrs. Danneman’s class dissected 10 pellets and found 25 mice, 1 shrew, 0 moles and 0 birds.

Mrs. Davis’ and Mrs. Gunderson’s class dissected 10 pellets and found 34 mice, 0 shrews, 0 moles and 1 bird.

The totals for all four classes were 122 mice, 3 shrews, 1 mole and 2 birds found in 40 pellets. That is an average of 3.2 prey per pellet. This average is a little higher than what I often find at other times. What do you think might have caused this higher average?

More food for thought. If an owl produces two pellets a night, how many mice would an owl consume in a year? By eating this many mice do you think the owl helps farmers and orchard growers?

Clearly mice are the most favored prey. With the data we collected it is not clear that shrews are much more favored than moles and birds. More pellets should be dissected to see if there really is a difference. You can order more pellets for yourself (see the link to Pellets,Inc. at left), dissect them and add that data to our findings, or you can look over other reports in my blog from other schools for more data. As a mater of fact, you can look to see what Leptondale students found in past years by looking through the blog archives. My blog is www.schoolyardnaturalist.blogspot.com.

Take some time to wander in the woods and find pellets from owl in your backyard!