Ornithology and Mid-winter Bird Survey at Bushkill Elementary

At the Bushkill Elementary School in Nazareth, PA, 5th grade students joined me as ornithologists doing a survey of winter birds in the school’s environmental area. Before going into the field we spent about 15 minutes inside talking about how birds are identified. Our discussion centered on how coloration, size, shape, behavior, habitat and calls or songs are used to identify birds with the use of bird field guides. The examples of field guides were A Field Guide to the Birds, Roger Tory Peterson, Field Guide to Birds of Eastern North America by David Allen Sibley, and Birds of Pennsylvania by Franklin Haas and Roger Burrows. The discussion included why ornithologist might do a bird survey. I mentioned that two bird surveys were currently in progress across the northeast, including a bald eagle survey and a waterfowl survey. Other surveys of birds are Christmas Bird Counts, Breeding Bird Atlas projects and feeder watch projects.

Some interesting observations included a Carolina Wren that flew from an evergreen into an old garage. I explained how this wren often uses garages and similar structures as shelter. We stood in front of the garage looking into the open door. I explained that sometimes to get a bird to appear ornithologist make a “spish” sound that imitates a bird warning call. This sound can entice a bird to pop up and look around to see what all the fuss is about, giving us a chance to see it. I proceeded to “spish” and the wren popped up from behind some barrels and flew up and out through an opening in the eaves.

We also had some very good looks at a couple of northern mockingbirds. One bird in particular was observed as it looked for food upon the ground. As we approached, it flew up into some wild rose bushes along a fence line, where it began to feed upon rose hips. This bird eventually flew off and joined another mockingbird in a clump of brush. We wondered if these two birds may be starting to look for a nesting site. Several crows were observed flying in pairs and searching upper branches of some of the oaks. Again we speculated that these birds were beginning to look for a place to eventually nest.

Another notable species was sharp-shinned hawk. Two were observed as they perched in trees at a great distance. The most exciting though, was an adult that flew right over the group providing most of the students a really good look at it. A fleeting glimpse of a brown creeper was seen flying in the wooded section. We searched for it in hopes of observing its distinctive feeding behavior on tree trunks. Creepers get their name because they creep up tree trunks. They never creep down. When a creeper reaches a high point it flies down to a lower point on the trunk and starts its climb up all over again. Unfortunately we did not see the creeper again.

Two species were identified by the song only. These included black-capped chickadee and house sparrow. It is likely that for both species there were several individuals present but because we did not see them we counted them as only one bird present.

The afternoon sessions seemed to produce the most numbers of birds, both days. The morning of the second day, with very little wind and sunny conditions proved to have the greatest number of birds with 9 species seen. A total of 15 bird species were seen in the two days.

The value in doing a survey like this is that it provides a glimpse of the kinds of birds that make use of the woodlot and open fields that are a part of the school’s environmental center. Over time this record might be useful in showing trend in the diversity of the kinds of birds and their numbers. These trends might then be related to changing environmental conditions. If negative trends were detected wildlife management plans might be developed to help the affected birds. This data would also be useful in land-use planning and decision making.

More information on birds, bird surveys and citizen science is available at the Cornell Laboratory of Ornithology. Click on the link to go to their website.

Our Survey Results
The birds are listed in taxonomic order.

Mrs. Dawe – 10:15 AM Thursday, Jan. 22, cloudy with strong westerly wind
Mourning Dove – 7
Blue Jay – 2
American Crow – 1
Starling – 1
Purple Finch – 1


Ms. Williams – 1:15 PM Thursday, Jan. 22, mostly sunny with no wind
Mourning Dove – 3
Downy Woodpecker – 1
American Crow – 14
Carolina Wren – 1
Starling – 12
Dark-eyed Junco – 3

Mr. Oberman – 10:15 AM Friday, Jan. 23, sunny with no wind
Sharp-shinned Hawk – 3
Blue Jay – 3
American Crow – 25
Black-capped Chickadee – 1
White-breasted Nuthatch – 1
Northern Mockingbird – 1
European Starling – 3
Dark-eyed Junco – 3
House Sparrow – 1

Mrs. Trach – 1:15 PM Friday, Jan. 23, sunny with no wind
Mourning Dove – 12
American Crow – 4
Brown Creeper - 1
American Robin – 20
Northern Mockingbird – 3
European Starling – 106

Owl Pellets and Predator Prey Relationships

Last Thursday, January 15, I visited the Jefferson Elementary School in the Schalmont CSD. I did Owl Ecology for the 5th graders. It's a fun session to do that gets students excited about science, helps illustrate scientific methods and gives the students a chance to explore and understand owls and their relationship to their prey.

There are many resources about owl pellet dissection. I suggest checking out pelletsinc. for owl pellets and teaching resources. You can click on the link to reach this great resource. Here I would like to give some thoughts on how dissecting owl pellets can lead into a discussion of predator prey relationship.

The culmination of the class is to analyze the results of the owl pellet dissection. From our investigation we know, not only what the owls ate, but also how many of each of their prey were eaten. On this day we had the following results:
Mrs. Guzewich's class - 11 pellets dissected - 19 mice, 6 shrews, 1 moles, 0 birds
Mrs. Fitzgerald's class - 10 pellets dissected - 22 mice, 4 shrews, 0 moles, 0 birds
Mrs. Walker's class - 10 pellets dissected - 23 mice, 0 shrews, 0 moles, 0 birds
Mrs. Wood's class - 11 pellets dissected - 25 mice, 8 shrews, 1 mole, 1 bird

The total number of pellets dissected was 42 with a total of 89 mice, 18 shrew, 2 moles and 1 bird. That gives an average of 2.6 prey per owl pellet for the samples investigated at Jefferson Elementary. A barn owl produces about 4 pellets a night. So in one night they might eat at least 10 animals. In one year an owl might eat over 3600 mice (mice being the most common prey - the numbers seen above can help illustrate a discussion of what the most common food for barn owls is). This large consumption of prey illustrates the concept of a balance in nature between predator and prey. Prey species reproduce in large numbers. These prey support a population of predators. As the predators increase the number of prey decreases. This smaller number of prey can not support as large a population of predators. The number of predators begin to decline. As the number of predators decreases the number of prey that survive can increase, eventually allowing for an increase in the number of predators. This balance of increasing, then decreasing then again increasing is part of the story behind population cycles of wildlife.