zoey_november's Journal

Date: 4/23/19
Time: 7:30-9:00AM
Location: Salmon Hole, Burlington, VT
Weather: Chilly after a few days in the mid 60s, but warming up to around 45 degrees. Sunny and clear.
Habitat: Riparian flood zone, mostly open deciduous woods alongside the Winooski River. Some dense thickets of shrubby underbrush.

As the sun warmed up the air, I noticed more and more birds vocalizing, staking out breeding territory with their spring songs. I observed two large conflict events related to breeding season and territory.

First I heard and located one Downy Woodpecker, and about 5 minutes later I heard another calling from further away. The far one came progressively nearer and began chasing the first. This lasted for a couple minutes, with the two birds flying after each other and squeaking loudly. Within a short time several other Downy Woodpeckers showed up until there were around 5 or 6 chasing each other from tree to tree. There was a lot of rapid chatter, and it was hard to tell if they were mostly chasing a single individual or if they were all chasing each other. It didn’t seem to be territory-specific, because they traveled from tree to tree over a good distance without returning to a certain area. I wondered if there were any females involved, but it was difficult to tell. It may just have been a dispute to determine hierarchical ranking between males - if so, maybe it makes sense that they weren’t defending a specific spot because by deciding who the top males are, they can then allocate territory by default.

The second major commotion I noticed came from three pairs of Canada Geese staking out nest sites on an island in the river. The island was shaped so that the highest ground was upstream, and the ground sloped downward from there until it sank back under water at the downstream end. Upstream there were a few trees and bushes, and downstream there were only cattail reeds. There was one pair of geese at an upstream nest site, one in the mid-range, and one down at the soggy end of the island. Approximately every 7-10 minutes, the downstream pair would slowly begin to swim upstream until they were close to the middle pair's site. At this point, both the middle pair and the upstream pair would start displaying, honking, and hissing, working up into a frenzy and eventually charging the downstream pair. The downstream pair retreated and each pair left the water and returned to their site.

This process repeated itself for over an hour with periodic attempts from the downstream pair to upgrade their location, each time being chased off by the upstream geese. Interestingly, the dominant pair furthest upstream also attacked the middle pair during these conflicts, although the middle pair never infringed on the upstream pair's territory. After more than half a dozen such altercations, the downstream pair gave up and flew away, probably to find a better nesting site with less aggressive neighbors. I wonder what gave the dominant geese the upper hand in this situation – were they simply the first to arrive that year, or had they claimed that spot in previous breeding seasons? Were they healthier and stronger than the other geese? Younger, or older? I was left thinking about how geese decide how much energy to invest in fighting for a spot before they try to go look somewhere else.

Comparing nesting habitats, it's clear that the geese preferred higher ground and drier nest sites with good shrubby coverage close to the water's edge. Downy Woodpeckers obviously require very different nesting conditions: they are cavity nesters, and tend to prefer sloping trunks with the entrance on the underside, presumably to protect against precipitation (according to the Cornell Lab of Ornithology). Proximity to an abundant food source is also important, just as it is for the geese - so I guess this area provides good foraging for both aquatic omnivores and insectivores. I also looked into nesting habits of the Ruby-crowned Kinglet: a bird I was lucky enough to get very close to (after my camera ran out of battery!). I learned that these tiny birds can have up to 12 eggs per nest! Similar clutch size to geese, but with very different diets and energy-expenditure ratios. Like woodpeckers, their diet includes insects and small fruits and seeds, but I believe the kinglet preys on much smaller beetles whereas woodpeckers will take larvae from their tree cavities. Kinglet nests are very thick, but made from flexible spiderwebs, fur, and plant fibers to allow the nest to expand as the young grow bigger, ranging from 2 inches to 4-6 inches deep (Cornell Lab of Ornithology).

I also tried to sit and make a sound map of all the birds I could hear during the peak of the cacophony. It was difficult, as the geese drowned out a lot of the smaller birds, but I learned that Red-winged Blackbirds tended to be close to the water's edge, as did Song Sparrows. Hermit Thrushes were further uphill, and the Ruby-crowned Kinglet occupied the area in between. I also heard a couple crows and cardinals that seemed to be coming from the opposite bank of the river. Comparing my experience in the field to the recordings I brought home, I was impressed with the brain's ability to focus in on one sound in the midst of a lot of similar noise. On recording, a lot of individuality is lost and it's much harder to pick out distinct species or individuals, as all the noise is more equalized.

Date: 4/3/19
Time: 8:00–9:00AM
Location: Centennial Woods, Burlington, VT
Weather: Chilly, around 32 degrees, warming up to 37 in sunny spots
Habitat: Dense mature forest of Eastern Hemlock, edge habitat composed of deciduous trees and shrubs, and open meadow with phragmites, a creek, and Staghorn Sumac.

I observed an American Robin singing an unusual version of his song high up in a tree. It sounded like a Robin's voice and had all the right notes, but they were put together in a strange order. I visually identified it as a Robin through binoculars. I wonder if this was a juvenile undergoing the song crystallization phase, trying out his voice and practicing adult song without quite getting it right yet, or just a rare form of the song that I hadn't heard before (see recording below). American Robins overwinter in Vermont, but have only starting singing territorial songs within the past several weeks. Being generalists, it is more cost-effective for them to find food here year-round than to invest a lot of energy resources in migrating to an area where the food might not even be much more available than where they were to start out with. In the summer, they can eat insects and grubs, fruit, and seeds. In the winter they can find frozen bugs in trees, fruit like crab apples and pin cherries that cling to the branches all season, and maybe even some nuts here and there. Thriving in suburbia, they might take advantage of bird feeders or anthropogenic food. Their large bodies are well-adapted to surviving the cold, with their plump shape minimizing surface area and maximizing retention of thermal mass. Dark-eyed Juncos also stick around all winter, and have similar body shapes and diets to Robins. Juncos huddle in cavities overnight for warmth in the winter, but I wonder where Robins roost when it's very cold.

In a treetop near the Robin, I heard chatter and saw smooth sleek brown birds. They were identified by Michael MacDonald (ornithology professor at UVM) as Bohemian Waxwings, facultative migrants who are passing through Vermont on the way to their breeding territories. According to the Cornell Lab of Ornithology, Bohemian Waxwings overwinter in the middle of the US, and travel up to Northern Canada and Alaska for breeding. They appear at our latitude for just a brief period in early spring, stopping over long enough to refuel. Their photosensitivity at this time of year produces hormones triggered by increasing daylight, which allows them to match their physiology with the environment so they don't fly north too early. They were taking advantage of the abnormal abundance of crab apples in the area, which had a great reproductive year and overwhelmed the consumption needs of local species.

Using the range maps and migration information provided by All About Birds (Cornell Lab of Ornithology) I determined that the average migratory distance travelled by the birds I observed totaled up to more than 12,530 miles! To put that into perspective, that's about twice the distance from Oregon, US to Santiago, Chile! Even the distance traveled by individual birds is very impressive – some Mourning Doves and Chipping Sparrows likely traveled over 2,500 miles from Southern Mexico up to Vermont and other Northeastern states.

Date: 3/13/19
Time: 10:00-11:30AM
Location: Raven Ridge, Huntington, VT
Weather: Warm, around 30 degrees and slightly overcast. Snow is about 20 inches deep in most places.
Habitat: Around the edge of a small neighborhood and a mature forest that was logged last winter.

I observed a couple of Hairy Woodpeckers for about 40 minutes. At first, I could only tag along behind them as they flew from tree to tree. They called frequently, which helped me locate them, but they were always in different trees. One time one of them landed in a tree where the other was, and the other took off immediately, without being pursued. I don't know if they were calling to each other or not, but they were doing the sharp short 'peek' call, not the long rattle/whinny. Finally one of them settled high in a large dead White Pine, where it foraged continuously for at least 15 minutes. It then rested on a branch for about 6 minutes. Overall, during the time I observed it, it spent about 30 minutes foraging, 10 minutes traveling, and 6 minutes resting.

I also observed several species in the area of a few trees at the edge of the yard near a feeder. There were about 5 Black-capped Chickadees, a White-breasted Nuthatch, a Brown Creeper, a Hairy Woodpecker, and a Tufted Titmouse. As far as I could tell, only the chickadees were making use of the feeder – the rest were foraging under bark or calling out territory. The chickadees had a ritual for approaching the feeder: first, they would fly in close to the top of a nearby tree or shrub. Then, they would hop lower down as they scouted out the scene. When they determined it was all right, they went to the feeder, and then returned to their spot in the nearby shrub to eat the seed. Then they would either return to the feeder or go back to the woods. One time, a chickadee tried to land on the feeder while another was already there, and it got chased off with a quick set of chatter and wingbeats.

I tried "pishing" for a while, with various lengths, pitches, and tones to my amateur calls. Felt pretty foolish, and didn't notice any behavioral effect in the nearby songbirds. If pishing does attract small birds, maybe it is because they think there is a small stream nearby that they can take a sip from. Some pishes also sound a bit like an alarm call that is similar across species, so maybe they are coming together to defend an individual against a perceived predator.

The Black-capped Chickadee has black, tan, and white plumage arranged in thick horizontal layers. With dark above and light beneath, it exhibits countershading that helps it blend into its surroundings. Since the little bird forages both high up and on the ground, this makes sense in terms of camouflage. The contrast of black and white on its head likely attracts potential mates. The Hairy Woodpecker is entirely black and white, except for a patch of red on the back of its head, which it can either accent or diminish depending on behavior. It's plumage is arranged in a checkered pattern of regular black and white horizontal stripes across its back. When it clings to a tree trunk or perches on a branch, it maintains an upright body posture, and blends in easily from all sides with the bark and dappled shadows. The red flair on its head can be used in communication, signaling, and courtship. Having a bright splash of color shows evolutionary fitness as it makes an animal more vulnerable to being spotted by predators. Both the Hairy Woodpecker and the Black-capped Chickadee have a pattern of black, white, black on their faces which accentuates their beaks, potentially making them look bigger, stronger, and more threatening.

Date: Feb. 28, 2019
Time: 6:30-7:45 AM
Location: Forest behind Raven Ridge, Huntington, VT
Weather: Clear and sunny, around 12 degrees, no wind. 1.5 inches of fresh powder over old snowpack, about 9 inches deep.
Habitat: New growth softwood forest consisting of birches, maples, oaks, aspen, with a dense patch of mature hemlock. Backed by a steep rocky ridge with lots of staghorn sumac, close to a tiny stream and a nearby small neighborhood with cleared fields.

Early in the morning after a cold night with fresh snow, I noticed that many birds were not yet up and about. After an hour, I heard more activity than I did around 6:30am. This is likely due to the way that small birds conserve energy overnight by lowering their body temperature and metabolism. Once the sun comes up, ambient temperature begins to rise, making it easier for birds to move around with less energy expenditure going towards body heat.

I heard Black-capped Chickadees singing their territorial fee-bee songs once the air got warmer. I wonder if some of these individuals had just emerged from a nightly torpor. Up on the rocky ridge, I found several nooks and crannies in the ledge where I think some of them passed the night. In a few crevices, I found some scuff marks where the rock was worn, and a little plumulaceous feather along with a bit of defecation.

I was unable to visually observe any chickadees due to the dense hemlock canopy, but if I had seen them, I expect they would have been plump and puffed up against the cold instead of sleek and thin like they are in the summer. The Cornell Lab of Ornithology tells me their diet is mostly seeds and fruit in the winter, whereas in the summer their diet switches to 80% insects. With the songs coming from the Eastern Hemlock stand, I wonder if they were eating hemlock cones or picking hibernating bugs out from under the folds of bark. Chickadees only eat their food where they feel safe under cover, so they often carry their food to a hidden spot to eat it. When it's cold, it would benefit them to find a food source that also provides cover to minimize handling time and maximize profitability in terms of energy expenditure, so maybe that's why they were in the Eastern Hemlocks.

Over the course of my walk, I found 5 dead snags. 4 were about a foot in diameter, and varied in height from around 10-15 feet tall. These snags were deciduous, and had cavities the size of quarters or golf balls. I rapped on the trunks and pressed my ear against them, but heard and saw nothing. The last snag I saw was from a massive White Pine that was likely a pasture tree at one point (there is barbed wire in the area). The trunk was about three feet in diameter, with lots of short stumps of branches still attached. The trunk broke off about 12 feet up, and I don't know if it was hollow or solid inside. I didn't find any cavities in this one, maybe because the wood was much harder and not yet very decomposed.

Snags are very important for Black-capped Chickadees because their cavities provide insulated spaces for the tiny birds to spend the night. Without them, chickadees would likely freeze during the winter. Tree cavities are also important for chickadees in the summer, because they build their nests and raise their young inside them. Tree cavities provide year-round protection from predators and the elements for Black-capped Chickadees.

Date: Feb. 09, 2019
Time: 15:15-16:45
Location: City Center Park, South Burlington, VT
Weather: Clear and sunny, around 18 degrees. Hardpack snow with large patches of solid ice where the area flooded during the recent thaw.
Habitat: Edge of small frozen marsh and sparse forest. Trees include mature White Pine with younger Paper Birch, aspen, maples, and oaks comprising the canopy. A very sparse understory has some hemlocks and cultivated conifers, but is mostly wide open.

When I stepped away from the Healthy Living parking lot and into the woods, the first thing I came upon was a homeless person's camp and a lot of trash. A bit further, I found an older, long-abandoned camp – a mossy mattress peeking through the snow, a mangled children's bike stuffed under a bush, a dilapidated tent twisted under the ice and snow, and plastic containers littered everywhere. I paused when I heard my first bird of the day – a Nuthatch, though whether Red- or White-breasted I could not tell. I strained to hear whether it sounded more like a yank or a yink, but as of now I lack the experience to differentiate. A bit beyond the second campsite was a recently cleared lot, the chipped wood of the former forest so fresh that I caught its scent even on this cold winter's day. I turned towards the frozen marsh, and ventured away from the most blatant signs of humanity.

The marsh was covered in ice over 2 inches thick, save for a small open channel. After leaping across to the other side, I found myself in denser forest, but I had not escaped mankind by any means. I found myself on a path worn by many dog-walkers and their pets, and came upon a small bench. Here I sat and acclimated myself to the area, noticing that the constant hum of nearby traffic was frequently punctuated by beeps and honks and the mechanical clang of a dumpster. After a while, I began to hear smaller sounds: the characteristic song of the Black-capped Chickadee, coming from at least three different locations close by. I tried to pinpoint them and find them with my binoculars, but was unsuccessful.

I walked to another spot and heard an American Crow, looking up in time to find it flapping steadily over the treetops, heading approximately North-East. Then I heard a short, steady, repetitive call that I couldn't identify. It sounded like a cross between a cat meowing and a baby crying. I walked towards it and paused, hearing it again. I got closer and closer, pausing to listen every few steps. Finally I was so close, I could tell exactly which tree it was in. A bit of movement caught my eye, and I looked straight into the face of... an Eastern Gray Squirrel. My momentary rush of excitement fled as I realized what an incredibly novice birder I am, and that I have no idea how to go about birding. For all my eagerness, I had mistaken the call of a squirrel for a bird.

After a while of unfruitful sitting and listening, I decided to visit the neighborhood nearby. I thought maybe some houses would have bird feeders out. As soon as I stepped out of the woods and onto the street, I was able to observe many more birds. A few more American Crows flew overhead, I saw a couple Black-capped Chickadees in a tree, and I heard a Northern Cardinal calling from someone's backyard. Straining my ears for birdcalls, I became more sensitive to my auditory surroundings and heard the small drips of runoff falling down a nearby storm drain.

I was outside during the late afternoon, which perhaps isn't the best time to go birding. I've heard that birds are more active during the beginning and end of the day, so maybe next time I will try to go out in the morning. As I was unable to visually observe more than one species of bird as it was flying, I watched some videos when I got back home. I compared the flight patterns of American Crows to Black-capped Chickadees, and found that the American Crow needs to flap its wings steadily and somewhat quickly in order to keep its large body aloft, whereas the Black-capped Chickadee has a ballistic flight pattern, with a series of 2-3 wing beats and then a glide with its wings folded in tight to its body. This might help it maneuver through tight spaces, come in for a landing in dense shrubbery, or glide up to a tree cavity and land precisely in the right position. Crows are larger and wouldn't fit in the dense shrubs anyway, so maybe they don't need this kind of precision in their flying abilities.