FJ3 - Field Observation: Ecological Physiology

On February 24, 2020, I began my field assignment at approximately 2:30 pm to 4:00 pm. The temperature was 52˚F and the weather was very clear and sunny. I began my walk across Centennial Field to get to an entrance at Centennial Woods. The habitat consisted of a field, dirt roads, some small homes, no snags, not many trees, and telephone poles. Because this was a public area and had a field, there were no snags. I did not spot any birds when walking to the entrance.

Entering Centennial Woods, the habitat changed to Northern White Cedars, Maples, and a few Eastern White Pines. There was a Blue Spruce and a line of Northern White cedars boarding properties of yards nearby. I found a Juvenile American Goldfinch (or non-breeding male), a female Northern Cardinal, and 2 Dark-eyed Juncos calling in the Northern White Cedars. I knew the Northern Cardinal was a female rather than a male because there was significantly less red in the plumage. The beak and wings were red and the body was brown. The American Goldfinch did not have distinct bright yellow plumage but instead was mostly brown. However, I noticed the black and white wing with two wing bars and a yellow head. These features made it difficult to determine whether the American Goldfinch was a non-breeding male or immature. I also spotted many Black-capped Chickadees, approximately four. They were flying around more frequently within the same area most likely having the bird feeder as a food source. I saw 2 Black-capped Chickadees fly to nearby bushes, to the Northern White Cedars and they were even in the maples above me. I realized there were many birds in the area because there was a bird feeder which 2 Black-capped Chickadees were feeding/eating from. Later on, 1 Black-capped Chickadee was hopping along the branches and twigs hanging upside down to get under the branches to glean food from the surface of the branch. This is a method to help them find potential insects in the bark. Their diet in the winter consists of seeds and fruit. This diet changes mainly by increasing their intake in caterpillars, spiders, etc. All of these species were in a mixed flock which is why I found them all together. Black-capped Chickadees utilize aspects of evolution and ecology to survive the season by acting as the nucleus of mixed flocks. Being in a mixed flock can help travel together, share resources, and be alerted when predators are around. Since insects are limited in the winter, there are fewer birds acting territorial. They all found the shared resource of a bird feeder. Another aspect of evolution is going into hypothermia at night. Many species will need to lower their body temperature at night and go into hypothermia in order to survive the cold night conditions. The American Goldfinch, Northern Cardinal, Dark-eyed Juncos, Black-capped Chickadees could sleep overnight in the Northern White Cedars high in the branches to avoid predators.

At one point, I made the “phishing” call and may have gotten the Black-capped Chickadees curious. Eventually, the flock ended up moving elsewhere but was very curious for a long period of time. I saw a Tufted Titmouse making the distinct “peter-peter-peter” song which eventually was more distant the more I was moving around. As all of this was happening, I heard 2 American Crows fly overhead. After all of the birds moving somewhere else, I moved deeper into Centennial Woods. There were no snags that I saw in that particular area.

As I walked into Centennial Woods, I entered a predominately dominant Eastern White Pine stand. Throughout my walk, I noticed the heights of all the snags were significantly larger than the height of the cavity size. The cavity size would only be a few inches long and the snags were tens of feet tall. The cavity size appeared to be a small circle - in proportion to a small songbird. I checked the cavities to see if anyone was home and I did not find any species. There was a negative correlation between the abundance of snags/cavities and bird abundance. I saw approximately 10 snags and no birds. Going at dusk, there might have been a positive correlation as I probably would have seen more birds.

Snags are important because they provide shelter for many species to nest in cavities or for feeding in the standing deadwood. Species likely to utilize snags for nests are woodpeckers (Pileated, Downy, Hairy) and sapsuckers. They create holes and build nests for their young. Woodpecker holes can be used for other birds like Black-capped Chickadees, White-breasted Nuthatches, Great Horned Owls, and many more. This can help birds that may have difficulty trying to make these holes on their own. They can use those holes to sleep overnight which helps protect them from predators. The storage of food in these cavities isn’t exclusive to birds, but squirrels commonly use them as well. Insects and fungi, which live on and in the snag make a good food source for wildlife. The top of snags is good excellent lookout points for wildlife to look out for their prey. Some species which take advantage of the hunting perches are Red-tailed Hawks and Great Horned Owls. I was unsuccessful in trying to find many species of wildlife. I looped around in a circle and exited out the entrance where I came from.

I passed Centennial Field again. Eight Rock Pigeons sitting on a telephone pole line. They were producing body heat from the sun by puffing up their feathers in order to conserve body heat in between their feathers. The more trapped air, the warmer the pigeon will be. The birds were budgeting their time by resting, sleeping, and preening themselves. Being up high can help make them less vulnerable to predators. I did not see any snags the second time around. Since going through Centennial Field and Centennial Woods took about an hour, I spent my last 30 minutes at Trinity Woods.

I walked behind the tennis courts to be directly next to Trinity Woods. The area I was in was mainly Eastern White Pine, Staghorn Sumac, Maples and Oaks. I immediately noticed 4 Black-capped Chickadees flying from tree to tree around us before quickly flying away. There was a Tufted Titmouse who was joined by two other Tufted Titmouses. When I tried to walk a little closer to get a picture, they flew a little away. The Tufted Titmouse landed on the ground to inspect a hole for the presence of food.

After I heard pecking, I looked through my binoculars to see a male Hairy Woodpecker. I could tell the woodpecker was male because of the red on its head. It was a Hairy Woodpecker because the bill was about the size of its head. The Hairy Woodpecker was eating/hunting for different insects like beetles, ants, and caterpillars when pecking on the limb of a tree. The Hairy Woodpecker could sleep overnight in the cavity of a snag. It is likely that there were snags deeper in the woods, instead of the outskirts. The woodpecker will likely move in deeper in the woods in order to find a snag. There was also a White-Breasted Nuthatch. They will eat seeds in the Winter, but eat mostly insects and spiders in the Summer. Since I was on the outer edge of Trinity Woods, I did not see any snags near me in the 30 minutes I was there. The total amount of birds I saw throughout my whole excursion was 30 birds.

Posted on February 29, 2020 06:52 PM by arcurley