2012 Fall

Barred Owl Research Report

This report is a summary of the fall 2012 field research. The students compiled the information and put together the report.




by Morton
There have been very few times in my life that I have been asked to interact with squirrels. Generally, I view squirrels in the same way that the customers I sell pellet guns to view squirrels; adorable tree rats that torment the community of people who enjoy having a pecan tree or a bird feeder in their yard. Last week in Ecology class, however, I spent more time entertaining myself with squirrels than I ever thought I would. To be honest though, I’m not sure many people expect to spend two hours of their day attempting to record the eating habits of squirrels.

Armed with data sheets, two cups of acorns (of the red oak and white oak varieties), and measuring tape (to see just how far a squirrel is going to go to bury the remains of his meal), my group and I began trekking around the park in search of a squirrel willing to be a guinea pig for our experiments. It is probably necessary to mention, however, that it was rather apparent that no one in my group had any practice calling squirrels. It’s probably not unusual to lack that skill, it’s likely that most people do, but I’m sure we all wished that we were more practiced squirrel callers after the fifth squirrel ran from us instead of towards us.

We wandered around the park, searching for squirrels. It was even more discouraging for us when we found pecan trees where squirrels were abundant and none of them wanted anything to do with us despite our offerings of acorns.

After what seemed like an hour of searching but was probably only thirty minutes, we found our squirrel A. Squirrel A, hereafter dubbed ‘Buddy’ because of his amiable nature, was one greedy squirrel. He didn’t seem to care that how close we were so long as we kept throwing acorns at him. He ate them and cached them so fast that my first few recordings on his activities are hackneyed and only semi-finished. We never got a chance to accurately measure how far he went to bury his nuts and all of our recorded data are guesses. Buddy would always take the top off of whatever acorn he was given if it had one, regardless of whether or not he was going to eat it, and he never seemed to eat the whole acorn. Buddy would eat half or less of each acorn and then shove the rest of the nut in the mud. At first, Buddy was running about twenty feet away to stash his prizes, but he soon gave up that effort and ran only about five feet away to bury his leftovers. He definitely wanted to be near his new food source.

Buddy with an acorn

Buddy preparing to cache his acorn


Before we knew it, we had eight pages of notes and had spent approximately thirty minutes tossing nuts at Buddy and watching him eat, bury, or ignore them. Buddy was quite the willing test subject. As we continued feeding him, we noticed another squirrel nearby watching our efforts with Buddy. We tried to engage him, but squirrel B simply ignored us and ran away. We shrugged off the insult of squirrel B’s behavior and continued feeding Buddy, our new best friend. After about twenty minutes, which we spent happily feeding Buddy, squirrel B came back. However, squirrel B’s intentions were not quite as innocent as we had thought. Squirrel B will hereafter be known as Jack because of his….donkey-ish behavior.

Buddy eating in background while Jack is running around looking to steal buried treasure

We watched in horror as Jack attacked Buddy in the cutest display of violence I have ever seen. They hissed and fought for a few seconds, but soon they lost interest and Buddy, apparently the loser of the tiny fight, decided to move about five feet away from us to let Jack have his turn at test subject. We decided to try and feed Jack and Buddy at the same time since we needed the data and, even though we were upset that Jack had been a jerk, we still needed data and two guinea pigs are better than one. Buddy was still greedy as ever and he gobbled up the white oak acorns we tossed to him (it seems that Buddy’s favorite kind of acorn is a white oak acorn because he ate those ravenously and only nibbled on the red oaks before shoving them into the dirt).

Jack is a jerk. This is something we made known to everyone in class and I will reiterate the statement several more times before this narrative is over. Jack stood in the same place Buddy had been standing while we fed him, but Jack was not nearly as cooperative. Where Buddy was the perfect test subject, Jack was the worst. We would toss Jack an acorn, several acorns actually, and he would simply stare at us. After a few minutes (during those few minutes we were able to feed Buddy an acorn or three) Jack would grab an acorn off the ground and nibble on it for a while. Jack would rarely grab the acorn we had actually thrown to him, so we usually had no idea how to chart the type of acorn he was eating. Jack was a jerk. As we tossed acorns to him and Buddy, if became very apparent that feeding Jack was not beneficial to our records because we couldn’t chart his habits, outside of the few times he went to store his nuts. We had to guess nearly everything for Jack.

Buddy’s home

After a while Buddy, probably feeling neglected because of our efforts with Jack, left and soon after our best friend left so did we. We didn’t leave, however, before we saw Jack go to the spot where Buddy had been caching his acorns and steal one. Jack is the worst squirrel there ever was.

Vegetation Study

by Weber
To determine if an area is  suitable habitat for the Barred owl, a number of important criteria must be met. First, is there a sufficient prey population to sustain two or more owls? Second, is there suitable tree species for the owls to roost and nest? Barred Owls prefer dense tree cover and only nest in hollowed trees, thus the trees must be big enough. Third, are there an abundence of predators or competitors in the area? A large population of Great Horned Owls or the presence of other animals who use the same trees to nest or hunt the same prey would likely discourage nesting behavior for Barred Owls. Finally, is there a presence of a natural or artificial disturbence in the area that may reduce suitability? The presence of a large population of humans, a major roadway, or a number of other issues could make the area less appealing to the Barred Owl.
Last year, the Habitat Suitability Index (HSI) for Barred owls was determined for this section of the greenway trails. You can refer to the “Research Project” section for that data. We recently started an intense vegetation study of three random plots that will be used as a part of assessing this section of greenway. We will be recording various abiotic measurements (i.e. soil temp., air temp., wind velocity, relative humidity, light intensity at forest floor) throughout the fall at each of our plots to look for changes and to also measure the health of the forest. We are also measuring vegetative cover and diameter at breast height (DBH) of trees at each plot.
Other notes: We watched a raccoon feed and then cross the creek. We also observed two baby turtles “swim” down the creek. On our way back to the barn, a copperhead crossed our path.

Common vs. Rare Butterflies

The recent explosion of butterflies on the greenway trail has sparked some interest into these insects. Bill Day has done an extraordinary job documenting some species in pictures. Two particular species, the Silvery checkerspot and the Hayhurst’s scallopwing, have both been recently observed on the trails, but have different natural histories.

Silvery Checkerspot- Chlosyne nycteis
The Silvery Checkerspot butterfly is a member of the Brush-footed family (Nyphalidae). It lives mainly in wet woodlands. Adults fly from May until early September in 3 broods with gaps between broods. According to the graph below from NC data, this species has been observed most from the middle of August to the beginning of September. This data makes sense considering that you can visit the trails now and spot them by the hundreds. This would seem to indicate that food here is most abundant during this time.

Photo by Bill Day

Hayhurst’s Scallopwing- Staphylus hayhurstii
This species, which is a member of the Skipper family (Hesperidae), prefers disturbed areas like trails. Unlike the Silvery Checkerspot, this species is categorized as rare to uncommon in most of the Piedmont region. However, when they are spotted it is during July and August. You can refer to the map to see how uncommon they really are. There are really no good explanations to why they are uncommon. Their larval host plant is Lambsquarters (Chenopodium album)), which is abundant in this region. It may be that people just overlook them because of their small size (wingspan- 1.375 – 1.875 in). The adults fly from late April until early September so if you are visiting the trails, keep an eye out.

Photo by Bill Day

Bugs everywhere

August is a good time to see the tremendous diversity of insects on the greenway trails. Whether feeding, flying, or mating, they were out in force.