Journal archives for March 2019

March 08, 2019

Field Observation 2: Ecological Physiology

On March 3rd at 11:30 a.m., I examined the bird species present at Oakledge Park for 90 minutes. The weather was slightly cool (about 36 degrees), but sunny, which made it feel much warmer, and a light breeze. The slightly warmer weather and the presence of water nearby could have influenced more bird species to be present than at other sites. I walked through several trails in the wooded areas of the park, stopping continuously to note the various bird species. During that time interval, I saw a Northern Cardinal and a Herring Gull. Two Black-capped Chickadees were observed, one by sound and one by sight.
The Black-capped Chickadee seen was in the underbrush of a tree, seemingly rustling his feathers, which could be a mechanism for the bird to keep warm. The bird was most likely resting to save its energy for foraging, since Chickadees practice foraging less during the colder seasons. The other Chickadee observed by sound was heard shortly after the first was spotted, where we heard the classic chicka-dee-dee-dee call. It is difficult to know for sure, but I assumed the second Chickadee was signaling to the other that there is food nearby, since Chickadees commonly forage in flocks. During the night when temperatures get too cold for Chickadees, the birds most likely induce facultative hypothermia, in which their body temperature drops and they exhibit little movement.
After about 20 minutes of walking and observing, a Northern Cardinal was seen about halfway up a Pine tree, making short flights from branch to branch. It was moving slightly up and down and hoping from branch to branch of a handful of trees. The Cardinal was most likely putting more energy into foraging because of the slightly warmer temperature. While observing the Northern Cardinal, a dead snag was seen nearby, but no cavities were spotted. The snag was somewhat small, an estimated 10 feet, which might explain why no cavities were present, since animals would need a larger area to make their home.
While walking close to the water, a Herring Gull was seen gliding overhead, which I could identify by the high aspect wing shape. It is unsurprising that a Gull was seen near a body of water, because this species usually nests near coasts. I am still not completely positive that it is a Herring Gull, because of the very similar shape and color of the Ring-billed Gull, and at a distance, it was hard to spot a ring around the bill. During the walk, six snags were seen in total, and more were present in the deeply wooded areas vs. on the outskirts. Of these snags, four cavities were seen on the larger trees, with each cavity correlating to a larger size of the tree. Although no animals made the cavities their home, I did see a few insects exiting when tapped on. Snags are important habitat to natural wildlife that provide protection to vulnerable species, like insects and squirrels, in harsh winter conditions.

Posted on March 08, 2019 17:01 by mkerner mkerner | 4 observations | 0 comments | Leave a comment

March 25, 2019

Field Observation 3: Social Behavior and Phenology

On March 11th at 3 p.m., I observed the bird species present at the Gateway National Recreation Area in Sandy Hook, New Jersey. The weather was very warm (about 54° F) with light cloud coverage and strong winds. Sandy Hook is a national park on the coast of the Jersey shoreline, so many gulls were seen. The first species I came across was the Canada Goose, where I saw a flock of them occupying a grassy area at the entrance of the park. Multiple flocks of Herring Gulls were seen throughout my time there, and a Turkey Vulture was spotted flying overhead.
The flock of geese was seen near a road, most likely because this species has evolved to live near human-altered landscapes. The individuals seemed to be calling to each other with the classic goose “honk.” This could be to signal a food source to one another or to find their mates. The individuals were walking slightly, but not moving very far from one another. This could be due to the fact that this species is monogamous and mates for life, so the geese kept each other in close company. A few minutes later, a Turkey Vulture was spotted flying overhead, identified by its dark plumage and large wingspan. This individual was most likely scavenging for food, possibly to bring back to its young.
I continued walking along the water and during that time, many flocks of Herring Gulls were seen. Although there were many flocks seen, at least a few in each flock exhibited a “keow” call, which signifies personal identification of individuals. This indicates that these individuals could be signaling to each other to find certain individuals, possibly mates. Some of the birds seemed to be showing lots of movement, flying short lengths along the coast, but they mainly stayed in a flock. This could be due to the fact that it may be easier to find prey in such an open, sandy area. As with Canada Geese, it is clear that this species likes to stick with other individuals of the same species because of the benefits of group living.
Every individual seen was fairly active, most likely because it was a sunny afternoon, which relates to the circadian rhythm of each individual. The amount of activity and foraging would most likely be different if it was late at night, when most individuals rest. The plumage of a Herring Gull is very light, which could be advantageous because of the habitat they occupy. These birds are normally seen by a coast, and in my case, they were all seen on the sandy shore of the beach. This lighter plumage blends in more with the light sand color, as opposed to the Canada Goose. The Turkey Vulture’s dark plumage stands out, but there is no evolutionary disadvantage since this species has very few natural predators. In regards to the “pishing” activity, there were no small flocks of foraging birds seen during the time interval, possibly because of the location.

Posted on March 25, 2019 01:41 by mkerner mkerner | 3 observations | 0 comments | Leave a comment

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