Diario de willbaxterbray

On Thursday, May 6th, I walked along the Winooski Nature Trail, in Winooski, Burlington. I walked the full loop trail starting from the parking lot by the river. The habitat covered ranged from wetland communities with tall grasses, to large open, managed grassy lawns, to alluvial forest communities with birch trees, aspen, and cottonwood. I started the walk at 4:40 pm and ended at around 5:40. Weather was sunny and clear, temperature was 62˚ F.

On Saturday, May 8th, I visited Centennial Woods in Burlington, VT. Since we did not get any visitors who wanted to walk, I spent an hour and a half waiting at the entrance and observed some birds from there. I started at 8:50 am and ended at 10:40. Weather was fairly overcast, and it rained lightly towards the end. Temperature was 54˚ F.

On Sunday, April 26th, I visited Centennial Woods in Burlington, VT. I walked the entire 2 miles starting from the runoff pond in front of the lower parking lot, and then through the far entrance in the parking lot I walked down to the beaver pond where I stood for around 5 minutes to do my sound map, then I sort of followed trails all over the place. Mainly hemlock dominated forest. I started the walk at 4:17 pm and ended it at 5:49. Weather was clouded and rainy and it was 60˚ F.

On this walk I observed a variety of mate selection related behaviors. For instance, I saw a Ruby-crowned Kinglet calling vigorously and displaying it's red crown, quickly drawing in two other kinglets. At the end of my walk I saw a male Brown-headed Cowbird singing from a prominent, bare branch of one of the tallest trees in the area, at which point one male and one female cowbird joined it. The singing male then performed a number of its high-pitched calls as well as a display where it sort of bowed down in front of the female and puffed up its feathers.

I also was happy to get great views of a Pileated Woodpecker. These birds have interesting habitat requirements for nesting, as they like to excavate large cavities, preferably in mature trees, where they build their nest. Other species may nest on the ground, or in large twig-based nest high up in trees, but many woodpeckers differ in this respect as they can nest in cavities that they are able to build. Since they primarily use their own body mechanics to make a nest, one benefit is they don't really need to gather very many nest materials. One notoriously territorial species I observed singing was a Hermit Thrush. This bird was deep in the woods out of view, but I heard its distinctive and beautiful song. I would say this particular bird was defending a prime territory, given that it was deep in the woods away from a trail where visitors may disturb it. The fact that it was defending prime territory suggests it is quite genetically fit.

I visited Shelburne Pond at 7:49 am on Sunday, April 18th. I arrived at the fishing access point and walked about a mile through the UVM trails that exist on the west side of the pond. These trails go through cedar dominated forest, as well as beech-maple dominated forest. The weather was cloudy and it rained lightly when I arrived for maybe 10 minutes. It was 46˚ F and I left after 70 minutes.

On Sunday, April 4th, I visited Colchester Pond in Colchester, VT. I walked the entire 3 miles loop around the pond, and it took me from open field habitats (where I was hoping to find a Northern Shrike but no such luck that day), into forest that cycled between cedar, beech/maple hardwood, and hemlock dominated patches, to eventually more open field habitat on the other side. I started the walk at 12:02 pm and ended it at 1:47. Weather was partly clouded and a bit windy, 47˚ F.

On this walk I was happy to see a number of spring migrants, as well as some friendly year-round residents. It's interesting to consider how these residents, such as the White-breasted Nuthatch, American Goldfinch, and Black-capped Chickadee, are adapted to all four Vermont seasons and the unique challenges each season brings. The most obvious challenge for these residents, especially in Vermont, is dealing with winters. One of the major benefits of migration is the way it grants birds the ability to avoid, to a large degree, difficult seasonal weather. Birds like chickadees and goldfinches that live year round in Vermont must be able to develop feathers capable of keeping them warm during harsh winter months, also they must rely on high metabolic rates that are capable of generating significant warmth. Another issue Vermont residents face in winter is food scarcity. I know nuthatches and chickadees in particular have learned how to collect and store food, in tree cavities and in other places. These birds must also have more strongly developed capacity for memory, as stored food is only beneficial if it can be found again.

One particular facultative migrant I was excited to see on this walk was the Yellow-bellied Sapsucker. According to their "All About Birds" page, these birds winter in the Southeastern United States to Eastern Mexico all the way down through parts of Central America. Some birds do breed in Vermont, so it's possible that the individual I saw will be sticking around, but sapsucker range does extend up through Northeastern Canada as well as up through Central Canada and into Northwestern Canada and even a small segment of Eastern Alaska. Sapsuckers mainly eat sap from trees, which is a food source that I would imagine is pretty constant across its range, so I don't think food availability is the primary factor driving its migratory route. I would imagine climate or certain breeding habitat requirements play much more of a role. The Southeastern US and Mexico is likely getting very hot these days, which is an environmental change that could be the trigger of the sapsucker's migratory journey.

Mini Activity:
The total distance travelled from wintering site to Colchester Pond by the 6 spring migrants I observed today, is a whopping 7500 miles! I got this number from estimating on Google Maps the migration routes according to each bird's "All About Birds" range map.
Here are my estimates for each individual species:
Great Egret: 2000 miles
Turkey Vulture: 1200 miles
Yellow-bellied Sapsucker: 3000 miles
Eastern Phoebe: 1700 miles
Song Sparrow: 1400 miles

On Sunday, March 21st, I visited Wheeler Nature Park in South Burlington, VT. From the parking lot, I walked down through the open field area and into cedar dominated forest. At this point I decided to turn right and walk up the hill through more cedars. Then I followed the trail as it looped around and took me back down into the lower cedar forest and eventually into the more open, beech and maple dominant forest. I followed the trail out of this forest patch and into the lower part of the open field area until I reached a small bridge over a stream, at which point I sat for about ten minutes. Then I followed the trail back through the forest yonder from whence I came, and lo and behold I ended up back at the parking lot. I started the walk at 3:29 pm and ended it at 5:53 pm. It was a beautifully clear and sunny afternoon, 63˚ F, very little wind.

Wheeler Park was rich with bird song, and I had plenty of opportunities to observe how birds use their calls and songs to interact in different ways. One particularly interesting interaction was between a pair of chickadees I saw that seemed to be gathering nest materials. They were fairly close to each other, and even though they were hard at work stripping bits of moss and twigs from the cedars they were in, they still called to each other regularly, and occasionally calls from one bird would draw the other bird closer. Another call/song related observation I made was that towards the end of my walk, as the sunlight light grew dimmer, I heard more birdsong. I imagine this has to do with the circadian rhythm of birds, and the fact that their behavior over the course of the day is linked with this rhythm, and largely triggered by their perception of light through their pineal gland. The change in light seems to trigger a behavioral change in this case.

On this walk I saw birds with a wide range of plumage, and in particular I thought the differences between the bright, showy colors of the Blue Jay, and the muted, inconspicuous grays and browns of the Common Redpoll were particularly interesting. It seems to me that these differences are a good example of prioritizing camouflage vs reproduction. The stunning, bright, blue tones of the Blue Jay are great for attracting mates, while the cryptic brown streaking displayed by the redpolls I saw are ideal for blending in with the wintery vegetation they tend to inhabit.

When I experimented with "spishing" on yesterday's walk, I was met with a range of reactions. I noticed that when I spished a lone chickadee that I heard calling from deep within a thicket, the bird immediately stopped calling, and as far as I could tell did not move any closer to me. When I spished at a pair of chickadees, who happened to be near a group of juncos and redpolls, a single redpoll began calling and flew up from the ground to a higher branch that was closer to me. This individual's response seemed to trigger a chain reaction in other nearby birds, as shortly after the redpoll's response, several juncos and redpolls flew up from their hiding spots to check me out, and finally the chickadees began calling and flying near me as well. I know that spishing is meant to mimic the alarm calls that songbirds like wrens, chickadees and titmice use to signal to other birds that a potential predator is present in the area. Maybe when a lone bird hears an alarm call, their typical response is to hide or flee, while birds in a larger group may have to confidence to investigate and even harass the potential predator until it leaves the area.

Today, March 8, 2021, I went for a little walk around Centennial Woods Natural Area, Burlington, VT. I walked around the main loop starting from the lower parking lot entrance and took a left at the fork towards the hemlock forest by the stream. Then, after following the loop all the way around and out through the beech dominant forest at the other end and took the same left at the start but this time instead of following the trail to the hemlock forest on the right, I went left over the little bridge and eventually left from the higher entrance by the police station. I started the walk at 1:12 and ended at 2:34. Beautiful sunny clear day, very little wind, 30˚ Fahrenheit.

Even though it's still fairly cold, spring seems to be just starting, and in general birds seem to be more active, moving around much more and calling or singing often. I saw quite a few woodpeckers today, and many of them were actively drumming. I imagine it is possible that the drumming is a good way to produce body heat and keep warm. I didn't see any woodpeckers actually eating insects during their drumming, so it's possible they were mainly using the behavior as a mating display as opposed to a foraging mechanism. Most birds I observed did not spend much time resting, and instead were either actively feeding or flying from branch to branch.

I counted 15 different snags on my walk, although I'm sure there were more around. Several of them had large, rectangular cavities that are indicative of Pileated Woodpecker activity. Others had smaller Downy or Hairy Woodpecker cavities. It definitely seems like the bigger the snag, the larger the cavities would be. A few snags in particular were almost more hole than tree; I was surprised they were still standing. I did try knocking on a few of them, but was not lucky enough to have any wildlife poke their heads out. To be honest, in all my years of knocking on snags I've never had anything more exciting than a little red squirrel respond. Snags are clearly an important part of the ecosystem, as many cavity nesting species such as small owls and squirrels rely on them for a place to sleep at night.

Today, February 21st 2021, I visited Saint Michael's College Natural Area, in Essex Junction, VT. I walked along the main trail from the entrance, through the oak and beech dominated hardwood forest along the Winooski River, up the ridge to the open field area, and then down the subsequent ridge through a patch of hardwood forest with younger trees overall, into a larger, open field habitat below the ridge. I walked around the perimeter of that field towards the composting area, at which point the trail took me through a forest patch dominated by cedars and other conifers, before finally reconnecting with the first section of the trail at the initial field. I started this walk at 11:23 am and returned to my car at 1:08 pm. The sky was sunny and close to cloudless. It was 27˚ F, E/SE winds of 5 mph.

On this walk, I was very happy to see a wide variety of species. A highlight was watching a flock of around forty Common Redpolls eating seeds in the lower field. I spent quite a while studying their behavior, and I noticed they're very small birds that, while feeding, typically fly short distances between bushels of grass with quick, fluttery wingbeats. They then perch, stripping seeds from grass stalks, chirping at regular intervals. When the flock becomes agitated, most if not all birds in the group will fly in tandem up to higher branches in a nearby tree, huddled fairly close, I assume in order to get a better vantage point to view potential danger below.

They were quite different from the group of American Robins I saw feeding by the higher field closer to the entrance. These birds were 3-4 times the size of the redpolls and had significantly longer wings and a longer bill. The robins fly with quick, strong wingbeats that are more spread out compared to the "fluttery" wingbeats of the redpoll. This difference might suggest that in general birds with longer wings take longer intervals between wingbeats than birds with smaller wings. The robins I saw were flipping leaves over on the ground using their long-ish beaks presumably to look for insects? I was a little confused by this behavior because I can't imagine it's late enough in the year for live worms to be crawling around under the snow, and I normally see robins focusing on berries during this time of year. It's possible that flight pattern and wing shape has something to do with their habitat niche, but I think it's more likely to be the difference in what foods they've evolved to be better suited to eating. The redpolls are small enough to hang on to the grass stalks and have beaks that are stubby enough to crush seeds, while robins would likely struggle with both of those things due to the largeness of their beaks and bodies.

I was quite happy with the amount of species I saw today, but I do think I could have seen a few more if I had arrived earlier in the day when songbirds tend to be more active with their vocalizations and movement.