Diario de gracey4

4/3/2021
Start Time: 9:20 am
End Time: 12:00 pm
Location: Missisquoi National Wildlife Refuge
Weather: 50º F, no wind/precipitation
Habitats: marsh surrounded by young deciduous forest, large open field across road

Migration is a time-consuming and energetically-costly endeavor. It is therefore understandable that many species stay in an area year-round, especially if their diet and lifestyle allow them to do so. In order for the benefits of migration to outweigh the costs, reproduction must make up for the high mortality rate experienced during migration. Mortality resulting from staying in the breeding area year-round must also be sufficiently high so that overall survival is drastically improved with migration. Many of Vermont’s non-migratory species, such as Black-capped Chickadees, Tufted Titmice, and American Crows, are generalists that can cope with the decrease in available food by being able to survive on a range of different food sources depending on availability and time of year. During their pre-basic molt, many species will also grow in additional down feathers for extra insulation during the colder winter months.
American Robins are an example of a facultative migrant than can adjust their migration in response to environmental conditions. Depending on current conditions, individuals may or may not leave Vermont for the winter. It’s possible that many of the robins encountered are returning to Vermont after wintering farther south, or travelled south from farther north to winter and are on their way back north.
A few obligate migrants are beginning to return to Vermont already. Returning relatively early, before most other migrants, may grant these species exclusive access to resources before other migrants begin to arrive. Arriving in early April also likely allows more time for breeding and rearing young, and may potentially grant some of these species the ability to raise an additional brood. However, one disadvantage to arrive this early is that weather is still somewhat unpredictable, and likely less mild than it would be had they arrived sometime in May.
For this mini activity, I calculated the distances travelled for American Kestrel, Northern Harrier, Wood Duck, Osprey, and Tree Swallow. I estimated each species’ wintering area to be around the Everglades in South Florida, near the Neuse River in North Carolina, near Willington, Georgia, near the Florida Keys, and near Jacksonville, Florida, respectively. The total distanced travelled by all five species was calculated to be around 5,566 miles.

Date: 4/17/2021
Start time: 7:20 am
End time: 10:00 am
Location: Saxon Hill Recreation Area
Weather: ~40º F, no wind or precipitation
Habitat: mixed deciduous and coniferous forest

4/23/2021
Start Time: 7:10 am
End Time: 8:55 am
Location: Saxon Hill Recreation Area
Weather: ~50º F, no wind/precipitation
Habitat: mixed deciduous and coniferous forest

Throughout this trip, the primary behavior I encountered related to mate and territory selection was singing, from a variety of different species. I also encountered two Hermit Thrushes chasing each other along one of the trails; this was maybe related to territory establishment or defense. Two of the Yellow-bellied Sapsuckers also appeared to be chasing each other, and this also may have been territory-related. I also saw an American Robin on a nest overhanging one of the trails. The majority of the species seen are likely nesting deeper in the woods, away from the trails and from potential human disturbance. Species such as American Robins or Black-capped Chickadees that build their own nests may have more flexibility in the trees that they can choose to nest in, as opposed to cavity nesters like Yellow-bellied Sapsuckers which are restricted to trees that they are physically able to excavate. Specifically where a species builds its nest, whether high in a tree or closer to the ground, will also influence where it is able to nest.
The nesting American Robin I encountered seemed to be defending a rather poor territory. The nest was on a branch directly above one of the trails, and I imagine that this site makes the nest especially vulnerable to human disturbance. I’m not exactly sure just how often that particular trail is used, however, so it’s possible that it isn’t actually used all that often and disturbance isn’t a major problem. Assuming that this territory is indeed of relatively poor quality, it would indicate that this bird is unable to establish or defend a higher-quality nesting territory.
Another species I encountered singing and likely engaging in breeding activity was the Pine Warbler. Given the composition of the surrounding forests, it’s possible that these birds are using pine needles and moss as part of their nest construction. I also encountered several people walking their dogs, so it’s possible that these birds are using dog hair in their nests for insulation. These materials would all likely be found relatively close to or on the ground.

https://drive.google.com/file/d/1Raozz4HtTJp-GEvmQscM1i2LrFtRTrAp/view?usp=sharing