Käyttäjän lenarose16 päiväkirja

Date: 5/10/21
Start Time: 1:00 pm
End Time: 2:30
Location: Landry Park, Winooski VT and sorrounding neighborhoods
Habitat: residential area with scattered ornamental trees. Park is a large grassy field with playground, lined by flowering ornamental trees; has trails through a young, deciduous forest.
Weather: 63 degrees Fahrenheit, 10 mph wind, 10% cloud cover, sunny and clear

I returned to Landry Park for my last field journal. Some species were seen on the walk there through residential neighborhoods and others were seen once on the trails/in the confines of the park.

Date: 5/8/21
Start Time: 9:00
End Time: 11:00
Location: Landry Park, Winooski VT
Habitat: large grassy field with playground, lined by ornamental trees; trails through young deciduous forest.
Weather: 50 degrees Fahrenheit, 6 mph wind, 100% cloud cover, very light rain

The most bird activity was closer to 9am and it petered out closer to 11. Nobody showed up to our tour so we went on a walk on the trails and saw several Pileated Woodpeckers. At one point a Common Grackle came too close to the robin nest we were observing, and the robin chased it off, alarm calling. It's alarm calls recruited cardinals, chickadees, and tufted titmice, which flew over and also began alarm calling.

Date - 4/25/21
Start time - 9am
End time - 10:30am
Location - clearing around a cabin in Weld, Maine.
Weather (temperature, wind speed/direction, precipitation) - 48 degrees Fahrenheit, 0 mph wind, 60% cloud cover, 15% precipitation.
Habitat(s) - clearing surrounded by mixed deciduous/hardwood forest that has been regrowing from having been cleared for sheep pasture up until the 1930s. Remote location ~1 mile trail hike from a road.

Some of the behaviors related to the breeding season that I observed were singing, increased aggression, and gathering nest materials. I watched one Red-breasted Nuthatch carry a large piece of chicken down it found on the ground into a nearby maple tree, where it stashed the down in the crux of two branches, subsequently abandoning it (the down blew away in the wind). This individual seemed to be performing behaviors related to nesting but hadn't yet found a suitable nest cavity. I assume other birds' feathers and animal hair may play an important part then in nuthatches' (as well as other birds') nests; I later saw the remains of a Ruffed Grouse that had been plucked nearby (presumably by an owl), and thought those feathers might be a good source of nesting material.

Many birds were also singing, including Eastern Phoebes. Eastern Phoebes nest in the eaves of our home each year, and this pair had been seen the prior day scoping out several potential nest sites on the building. Eastern Phoebes are not cavity nesters like nuthatches, which allows them more flexibility in finding suitable nesting habitats. Eastern Phoebes nest in somewhat more open habitats than some of the other species I observed, which show a preference for denser, more coniferous forests--e.g. the Yellow-rumped Warbler, Evening Grosbeak, and Purple Finch. There was a marked difference between the birds I saw at the feeder and heard singing (i.e., staking out territorial claims) in the clearing vs. when I walked out into the woods--chickadees, jays, nuthatches, juncos, phoebes, and sparrows (Chipping and Song) dominated in the clearing, and in the denser woods I also heard Hermit Thrush, a Winter Wren, a Blue-headed Vireo, and I flushed a Ruffed Grouse. This likely reflects different nesting habitat preferences for open vs. dense habitats and deciduous vs. coniferous.

Some of these birds were just arriving and staking out territory claims. Given how early they are, I would presume that the Winter Wren, Hermit Thrush, and Blue-headed Vireo that I already heard singing this early in the season were able to stake out high-quality territories before others got to them first. These birds may be more fit, e.g. if individuals that are in better physical condition are more likely to arrive on the breeding grounds early. Maybe they were able to fly faster during migration or leave earlier due to building up sufficient fat stores more quickly.

I found the mini-activity extremely hard! Surely there must be some standard way of notating bird songs by hand... Mine was a mess, but I'd like to learn because there have been times I heard a song in the field and didn't have my phone to record it but wanted to look it up later.

Date - 4/18/21
Start time - 5:30pm
End time - 7pm
Location - Trail leading to Lone Rock Point in Burlington, VT
Weather (temperature, wind speed/direction, precipitation) - 58 degrees Fahrenheit, 3 mph wind, 30% cloud cover, no precipitation.
Habitat(s) - trails through young mixed deciduous forest. Walked from the wooded area surrounding Rock Point school garden/buildings to the edge of Lake Champlain.

Date - 4/4/21
Start time - 10am
End time - 11:30 am
Location - North St. and surrounding areas, Winooski
Weather (temperature, wind speed/direction, precipitation) - 52 degrees Fahrenheit, 13 mph wind, 60% cloud cover, no precipitation.
Habitat(s) - Residential/suburban area with sparse trees/little vegetation.

Year-round species I saw were Black-capped Chickadees, European Starlings, Ring-billed Gulls, Mourning Doves, Northern Cardinals, and American Crows. Foregoing migration may allow birds to avoid the risks inherent in migration (predation risk, etc.) while maintaining their own territories and also enabling them to capitalize on spring resources the moment they are available (VS. migrants, which must stake a new territory claim every season and may arrive after resources have begun to become available).

However, overwintering itself requires a number of adaptations to the cold, both behavioral and physiological/morphological, which can be costly - Black-capped Chickadees, as a case study, roost overnight in cavities to keep warm, have extra insulating down feathers, cache foods to save for later (something our overwintering corvids will also do), and have fairly generalist diets which may aid in their ability to survive in the low-resource environment. Species dependent on insects are absent from VT in the winter. Shivering, cross-current exchange and regulated hypothermia are other ways in which overwintering species cope with the cold.

The obligate migrants I saw were the Eastern Phoebe, Turkey Vulture, and Common Grackle. Common Grackles typically move further into the western and southern portions of their ranges in the U.S. during the winter, but some may stay in far southern VT, so they would be coming from no less than 100 miles away, but most likely further. Turkey Vultures in the northeast winter in the southern states usually, ~850 miles away. Eastern Phoebes migrate similar distances. That adds up to a very approximate distance of ~1,800 miles migrated total by these 3 species to get to Vermont. Arriving in early April before other migrants may allow these early migrants to stake out territory claims and get a headstart on breeding---but, as the last week or so has shown us, early spring can be very variable in terms of temperature and conditions, so it's a gamble, and enduring snowstorms may be especially challenging for some species not adapted to overwintering.

As for facultative migrants, until recently we had Pine Grosbeaks and other irruptive species in VT which had come due to low food availability in their typical, more northern ranges to eat shriveled fruits and seeds. These seem to have departed at this point, going back to their northern ranges as winter turns to spring and food becomes more available. I saw European Starlings, which I believe will either stay in their northern range here in VT year-round or migrate south to the middle states; the decision is probably based on food availability, the harshness of the winter, and maybe on dominance status, too. The environment can support fewer individuals over the winter due to lower food availability, so dominant individuals may stay while individuals in excess of the carrying capacity for that species in VT winter may be forced to migrate.

Date - 3/21/21
Start time - 4 pm
End time - 5:30 pm
Location - West Spring St. and surrounding areas, Winooski
Weather (temperature, wind speed/direction, precipitation) - 62 degrees Fahrenheit, 1 mph wind, 5% cloud cover, no precipitation.
Habitat(s) - Residential/suburban area with sparse trees/little vegetation.

I noticed a number of birds beginning to transition to summer behaviors. A pair of male Northern Cardinals in red alternate plumage were chasing eachother around , flying after each other and emitting high pitched short squeaks as they did so; it at first seemed aggressive but they did not actually attack each other, so I wonder if I was seeing the beginning of territorial behavior, which would be fitting with their circannual rhythm. I heard many Northern Cardinals singing, and overall preparing for the breeding season. A number of other clues to the coming of spring: I saw an American Crow collecting sticks, presumably for nesting materal; it cawed loudly five times, then flew off with the sticks in its bill. I saw a pair of Mourning Doves cooing at each other, perhaps a courtship behavior. And I heard an American Robin singing. Ring-billed Gulls were prominent where I am, flying around in packs of 5 or so and loudly vocalizing to indicate when a food source had been located; they used auditory cues to maintain group cohesion as they foraged together. Moving inland and foraging in groups seems to be a seasonal mini-migration and change in behavior in gulls.

Ring-billed gulls have predominantly white plumage, perhaps making it more difficult for prey to spot them when looking up from below while the birds are hunting. Comparing them to another species with little sexual dimorphism, American Crows have all black plumage with some iridescence. The iridescence may be sexually selected, and I wonder if the black plumage is an adaptation for reducing parasite loads on the feathers and keeping cool by having the feathers heated up, diverting heat from the skin and creating an environment inhospitable to parasites. This may be especially important for scavengers like ravens.

My spishing attempts were not super successful! I located one Black-capped Chickadee, who was responsive and came to lower branches to investigate, but other birds did not seem interested. Perhaps spishing sounds like the scolding/threat alert calls of some birds, and birds are inclined to investigate, or maybe it just piques their curiosity. It seems to most effectively attract small bird species that would be inclined to mob a predator together, which would make sense.

Date - 3/6/21
Start time - 9 am
End time - 10:30 am
Location - UVM Campus and Centennial Forest
Weather (temperature, wind speed/direction, precipitation) - 16 degrees Fahrenheit, 10 mph wind, ~80% cloud cover, no precipitation.
Habitat(s) - Residential area with occasional pine and crabapple trees; Mixed deciduous and evergreen natural area with a brook running through.

We walked from Aiken down into Centennial Woods. Birds were only present sparsely in open habitats on campus, and were most usually seen foraging in denser vegetation, which could potentially be a behavioral strategy by which they can be sheltered from the cold by vegetation and retain body heat. Birds seen outside of the woods were most often seen foraging on fruits from ornamental crabapples or seeds from pinecones; for birds wintering in the northern woods, insects are absent and fruits and seeds must be the primary food source. The barred owl and juncos in particular seemed to associate with dense evergreen areas. Many of our sightings were part of a single mixed-species flock, including two species of nuthatch, brown creepers, and chickadees. Mixed-species flocks are likely a behavioral adaptation to winter conditions, allowing birds to forage efficiently and pool knowledge of food resources, avoiding energy waste associated with searching alone. Some signs of spring could be seen: Black-capped Chickadees have begun singing, and crows when seen were foraging singly rather than as parts of large groups.

I observed a number of snags, usually in areas where birds were also abundant; for example on the periphery between a residential area with crabapple trees and Centennial Woods. One cavity hole had droppings in the opening, indicating that it was in use by birds. Nothing appeared when the snag was rapped on. Snags shelter birds from the cold and are primarily used overnight by small northern wintering species, including Black-capped Chickadees and woodpeckers. Many of the holes in the snags had limited space inside for a bird to roost; deeper cavities were more rare.

Today we walked from outside Aiken on central campus down to redstone campus, then looping back through athletic campus before returning to Aiken. The habitat throughout was residential, with scattered trees including crabapples, maples, and ornamental species. UVM campus gives way to suburban sprawl and downtown Burlington. The weather was overcast, a wet snow was coming down, and it was 30 degrees Fahrenheit.

We had the opportunity to view birds with very different flight patterns. Ring-billed Gulls have wings with high aspect ratios, and the individual we spotted was seen gliding on its long wings and occasionally flapping, aiding in its ID from a distance. High aspect ratio wings are useful for birds adapted to soaring across open habitats for long distances (e.g. bodies of water), as their long wing shape minimizes the need for energetically expensive flapping. By contrast, we also saw American Robins and an American Crow, both of which had elliptical-shaped wings. Their wing shape necessitates frequent flapping (vs. the gliding motion of high aspect ratio wings), and perhaps is useful for frequently landing and taking off (but not flying long distances continuously) as birds seeking scattered food resources must do. The flight of American Robins superficially resembles that of the Common Redpolls we saw in that they will tuck their wings and dip downwards between wing beats.

The undulating flight pattern of finches is highly diagnostic of the group; we used their distinctive flight pattern in tandem with calls to identify several small flocks flying far overhead as Common Redpolls. Undulating flight creates an up-and-down pattern as the birds alternate flapping with tucking the wings and free falling. Woodpeckers, I noticed, also exhibit this flight pattern. It's unclear to me how this flight pattern relates to the ecology of the birds--perhaps it combines the maneuverability of flapping flight with the energetic savings of gliding?