Ornithology Journal 2
Eli Tierney
• Date – 2/19/23
• Time: 3:00pm- 4:00pm
• Location – Centennial woods
• Weather – In the 20s, strong winds. Light snow flurries.
• Habitat(s) –Birches, hemlock, and white pine along trails, in a small valley off the trail with downed trees and ferns. Along creekbeds and other water bodies.
Species Observed List:
• Nuthatch (specific species unknown (2+ individuals)
• Pileated woodpecker (1 individual)
• House Sparrow (2+ individuals)
• American Crow (3+ individuals)
• Blacked-capped chickadee (5+ individuals)
Note: Many observations were made using sound identification and fast glimpses in flight. So, I am unsure of the exact amount of individuals of each were fully observed.
Journal 2
On my trek, I observed black-capped chickadees who seemed to be very adept at surviving the winter. I observed a few individuals fluffing their feathers, making them look bigger than normal. This puffing up of their feathers is used as insulation, helping to keep themselves warm. Birds' main focus in the cold winters is on finding enough food and keeping warm. During the night chickadees will find small spaces to shelter in such as tree cavities, holes, or crevices. During the night they will burn off fat to keep up with temperature regulation as it gets colder. As the morning dawns they will have to forage for food to build up the fat once again to stay warm the next night and the cycle will continue.
To find food easier in winter chickadees will form foraging flocks. Individuals in the group will search through their own part of a larger area, turning over everything they can. Once one finds food the others flock over to join in, using each other to learn where more abundant food may be. In the winter chickadee’s diet lacks small invertebrates that will be surviving winter by not being out in the open. Their winter diet relies more heavily on seeds, insect pupa and eggs, spiders, and small insects. Chickadees may also make more use of human-supplied food from feeders.
I also observed crows starting to fly in large groups across the sky. This is part of how crows keep themselves warm in winter. When it gets cold, crows start grouping together at night in roosts made up of as many crows as can fit. This allows for individuals to keep warmer as they can share body heat and burn off less energy keeping warm at night. Being in a large group also serves as protection from predators, so less energy will be spent on vigilance per individual. They will also use the same roosts year to year as they are located around areas where food is more abundant. These roosts also serve as information-sharing hubs, letting others know what places are ideal for foraging for the least energy.
When crows depart they will begin foraging using any more information they have gained. Winter diets consist of grain, seeds, fruits, carcasses, and garbage. Crows' typical diet incorporates more small animals, small birds, eggs, reptiles, and earthworms, but these types of prey are less abundant in cold weather. Roadkill and the leftovers of larger predators serve as great sources of wintertime meat for crows. Human garbage is another good source that may be more heavily relied on in winter as it is plentiful in urban areas especially where crows may roost.
Snags are a great place to conserve body heat overnight. As previously mentioned chickadees use them as they give protection from harsh winds, cold precipitation, and night predators. Other small bird species often use snag cavities for the same reason, but larger birds such as owls may use them as hiding spaces to spook prey and rest during the day. Small mammals such as squirrels, raccoons, and chipmunks can also use these spaces to build cozy hiding spaces and food caching stations. These trees, although dead provide life for many species long after they die.
תגובות
הוספת תגובה