Archivos de Diario para marzo 2020

06 de marzo de 2020

Bird Outing, Early Spring at UVM 2020

This observation was conducted in the woods outside the resident area of UVM's Trinity campus. The area is a dense deciduous forest, which, at the time was populated by leafless trees and conifers. There were several S.T.A.G's with cavities in them but all appeared uninhabited at the time of observation. There was still about a half inch of snow covering the majority of the ground with some areas having over 3 inches. The temperature was in the 40's at the beginning of the observation but dropped to around 30 by the end.
Throughout the 90 minute observation time, starting at 5:30 pm and ending at 7 pm, a total of around 300 American Crows were seen all flying westward. The birds would come in a steady stream with groups of about 20 flying overhead at a time. An average of 15 seconds divided each group with there being breaks for a couple minutes occasionally and other times more than 50 birds flying together. The crows were observed calling to each other where an individual in one group would give off 3-4 caws and another individual in a different group would respond with 3-4 caws as well. This pattern occurred throughout the entire observation with there being intermittent calling between individuals in the same group.
There were a group of 5 European Starlings that followed in the midst of a larger group of crows. These birds called to each other and flew much closer together than the crows. Only this small group of 5 was observed over the entire time. These birds were also heading west in the same direction as the crows and disappeared along the horizon with them as well.
In the forest itself a number of titmice were observed singing from a conifer tree. It was unable to be determined if they were individuals nesting together but after their song was first heard they did persist in the tree for the continuing duration of the observation.
None of the birds were seen eating or performing any activity besides the flight of the crows and starlings and the singing of the titmice.
S.N.A.G's are important habitats for wintering birds and those that birds that nest here over the winter as it allows these birds to have a relatively well insulated home. As there are virtually no insects at the time of observation it is most likely that birds are consuming fruits and seeds or scavenging. The crows may spend their time all together in a large open area overnight as the safety in numbers as well as the cooperation in obtaining food is beneficial in the winter months.

Anotado en marzo 06, viernes 13:33 por wfinegar wfinegar | 3 observaciones | 0 comentarios | Deja un comentario

26 de marzo de 2020

Bird Outing, Early Spring at UVM 2020

The time of observation was between 8am and 9:30am. The weather was clear in the morning but cold, later that day it snowed heavily, around 5 inches total.

Of the observed birds, the crows seemed to have the most communication and interaction between individuals. The crows were observed to be cawing and making other noises at others within the group who would respond with movements or other vocalizations. The assumption of the purpose of the vocalizations is that of assertion of belonging and communication of existence of the food they were eating. The robins, while presumably also feeding as the group was seen wandering about an open field, were not making vocalizations and instead all seemed to be operating autonomously and without respect to others. This contrasts with the crows who seemed to be working together as a group with a shared interest among all the individuals. The chickadees observed were perched in a bush and would make occasional vocalizations to one another but made no movement or change in posture.

The coats of the crow and the robin as observed differ greatly. The robins have slate grey dorsal feathering with a burnt orange underbelly and torso. The crows are completely black in contrast, with no differing markings. The slate grey may have evolved in robins to allow them to camouflage with their forest habitat where it matches the bark of trees around them. The dark coloring of the crows may have evolved to aid in heat retention or killing of bacteria by sunlight.

One of the observed robins was seen pecking at the ground and picking up dried leaves presumably in search of food. As it was early in the morning this is consistent with what one would expect from its circadian rhythm and the robins presence at the current time, that being early spring, is consistent with a migration southward during the winter and its suspected circannual rhythm.

Anotado en marzo 26, jueves 00:46 por wfinegar wfinegar | 3 observaciones | 0 comentarios | Deja un comentario