UVM Ornithology Journal Entry #4

On 8 April 2020 on my brother's farm formerly known as the Gifford Farm in Randolph Vermont I conducted a 90 minute bird walk through a mix of habitats observing 14 total species. The weather was 55 °F and partly cloudy. Wind was consistently blowing between 5-10mph but the direction was inconsistent due tot he topography within the valley. Sadly due to a broken phone I was unable to take any photographs or audio recordings during this bird walk. Over the course of this bird was I walked through a variety of habitat typed including early successional forest responding from a clear cut 5 years ago, a mature hemlock forest which had been selectively cut with an understory of raspberry bushes, A mature hardwood forest comprised of maple, ash, and beech, open pastures and fields of all exposures, and a secondary growth forest comprised of white pine, ash, paper birch, and American beech. Despite walking through all of these habitat types, the greatest concentration and variety of birds I observed was from the driveway of the farmhouse as I was getting ready to depart on the hike. One major observations I noticed within all these habitats is that the majority of observations I made were either singular male birds or pairs of birds which I find very indicative of the spring season as many species are beginning to pair up as weather warms up bringing us into their mating season.
During this bird walk I observed many migratory and non-migratory species. Mourning doves can sometimes be a migratory species, but through my observations they do not appear to migrate from both my brothers farm and my parents farm as grain provides ample high quality food for them throughout the winter, therefore these doves observed were likely resident doves. Another resident species which I observed is wild turkey. Due to their large body size, lack of ability to hold sustained flight, and generalist feeding habits wild turkeys are not a prime candidate to migrate. Being generalists they are able to forage throughout the winter, which is more beneficial to them becuase the high mortality which would stem from the amount of energy it takes to sustain flight for such a large bodied bird. Another non-migratory bird species I observed during this bird walk was the ruffed grouse. Another generalist species which is more adapted for quick maneuverability rather than long distance sustained flight therefore would not be a good candidate for migration. Ruffed grouse are generalist which usually feed off the ground while perched in apple trees and eating berries off bushed and needles off conifers. Because of this snow does not typically cover their food supply during the winter and they are able to thrive off this generalist lifestyle even as food available varies with season. The last non-migratory species of which I want to discuss is the American Crow. Even though American Crow are strong fliers they don't appear to need to undergo migration as their generalist diet allows for ample food throughout the winter. Crows are able to feed off another from nuts and seeds, to the remains of carcasses discarded by farmers or left over from predator kills. Because of this coupled with their flocking mentality they are able to have lower mortality rates as resident species than they would while undergoing migration.
Of the migratory species observed both the waterfowl species being Canada goose and mallard ducks are the most difficult to assess the distance they migrate. Both of these species often have holdover populations which can be found in this region throughout most of the year feeding in cut corn fields or in bays kept open through warm spring inlets. The northern extent to which they migrate is also difficult to predict. Some migratory birds will never reach New England while others are just passing through this region towards breeding grounds in Canada. Because of this assessing the extent to which these birds migrate is difficult. These birds migrate though because they often rely on open water and agriculture to feed which becomes a restricted resource in the winter due to cold temperatures and snow. Because of this a percentage of these populations migrate to areas with warmer weather and greater food availability, while others stay in this region to holdover on what food remains. The American Robin is another migratory species which I observe in great number in this region in the spring. Robins during the winter migrate as far south and Florida or Northern Mexico before traveling north in the spring to breed. Robin which we are seeing in Vermont likely migrate to Florida in the winter which is a total straight line distance of 1,200 miles. This multiplied by the 15 Robin's I observed is a total migration distance of 18,000 miles. I speculate the American Robin chooses to migrate back in early April because as the ground is beginning to thaw out it is at its softest which brings worms which are a big food source for robins near to the surface making for a high food availability which is important while approaching breeding season. Like the American Robin, the Red-winged blackbird is another migratory species traveling from across the US to northwest Mexico to winter. This is a total distance of 2400 miles. Like the other migratory species I observed I speculate these birds are likely arriving in early April to get the first access to food and breeding grounds as they thaw out as it both limits competition for food as well as nesting locations.

Publicado el abril 9, 2020 01:56 MAÑANA por thatchermorrison