Käyttäjän pyramidlakejake päiväkirja

Date --- 3/7/2021
Start Time --- 11:15 AM
End Time --- 12:30 PM
Location --- Derway Island Nature Trail off North Ave, Burlington, VT 05408
Weather --- (Temperature) =25 degrees Fahrenheit, or ~ -4 degrees Celsius ... (Wind) = 10mph N ... (Precipitation) = none
Habitats --- Area of land along Winooski River bank ... river covered by ice. Lots of ice and some snow on trails, surrounded by leafless trees and branch/twig litter on the ground. Some trees cut down were seen shredded into sawdust material.

Video observation of White-breasted Nuthatch can be viewed in notes of individual bird's observation (link attached)

We're already a week into March, but winter is here to stay for just a bit longer in Burlington. Upon venturing down to Derway Island bordering the Winooski River, the paths meant for safe travels were transformed into zones of slow and ultra-tiny steps thanks to the thick layers of ice. After getting past the hazardous portion of the walkways, we proceeded toward the river, right up near the edge to look for animal prints and scat; wind was strongest over in this area, whereas deeper into the island, wind remained minimal to nonexistent. A scan of the water bodies (Lake Champlain and Winooski River) with binoculars revealed no nearby water or shore birds. Coyote, racoon, and skunk tracks were found in various areas along the river. Deeper into the island's trails, where the snow and ice were not so treacherous, two Northern Cardinal (M+F) were spotted in southward flight. Three Black-capped Chickadees were seen in scattered trees, shivering and bopping from branch to branch. A singular Tufted Titmouse was observed curiously scoping a branch or two before flying off towards the northwest. After hearing light pecking on a tree, we saw a White-breasted Nuthatch facing downward on a tree, chirping and pecking frequently. The bird seemed to have found tiny insects within the bark of the tree to sustain himself.

These birds, like any animal when outside during winter, are exposed to the winds and surrounding temperature of the harshly cold season in the northeast. However, the warm blooded avian animals have evolved to maintain high internal temperatures while residing in this area of the United States. Like humans will do when feeling chilly, birds replicate this action to generate kinetic energy, transformed into body heat. We saw the Black-capped Chickadees doing this while resting (through the binoculars) on our adventure, where I assume they were taking a quick break from searching for nutritional value. According to (https://www.audubon.org/how-do-birds-cope-cold-winter), the opposing muscle contractions performed aid in retaining significant amounts of generated heat. The Tufted Titmouse we saw, who was relatively swift inspecting branch after branch, in what I suspect was foraging and relocating upon lack of success. When we heard the White-breasted Nuthatch tapping away at the tree, we quickly located it and witnessed it face-down clinging to a tree, about 20 feet above the ground. We took the video we linked in the observation comments, then slowly approached the base of the tree. The bird didn't seem to be phased by us whatsoever, as we craned our necks upward to admire its beauty. After a series of pecks, the bird would crane his neck away from the tree to ingest the insects just captured by its bill. The specific tree it was hanging on seemed to be full of what the bird was looking for, as it communicated yonder through minute calls. At the beginning of the linked video, one can hear a faint White-breasted nuthatch murmur from afar.

Birds that stay put during the winter months might alter their diet by favoring more "insulating" foods during this period of time. For example. the passerines we saw on this excursion were probably searching for nutritious items that allow them to retain heat. I know berries are often present and littered along the ground in Derway from plucking them off branches, but we did not see any today. Nor did we see any seeds, which would also be a hot commodity during this time. When insects return from their state of dormancy once warmer weather approaches, the passerines will look to nibble on them for nutrients.

Lots of snags were observed, and many had deep cavities created by various types of woodpeckers. While all were too high to even poke with a branch, I imagine an animal, whether it be a family of birds or chipmunks or squirrels, reside in these open spaces that provide shelter. According to Coombs, Bowman and Garroway (2010), southward-facing cavities are exposed to more light in the northern hemisphere, which in nature make these shelters warmer than their northward-facing counterparts. As a result, I'd expect that the tree cavities of Derway Island would have more residents in the southward-facing than northward-facing cavities.

Citations

Coombs, A., Bowman, J., & Garroway, C. (2010, November 1). Thermal properties of tree cavities during winter in a northern hardwood forest. Retrieved March 07, 2021, from https://bioone.org/journals/Journal-of-Wildlife-Management/volume-74/issue-8/2009-560/Thermal-Properties-of-Tree-Cavities-During-Winter-in-a-Northern/10.2193/2009-560.short

Date --- 3/21/2021
Start Time --- 11:15 AM
End Time --- 12:30 PM
Location --- Water Works Park off Penny Lane, Burlington, VT 05401
Weather --- (Temperature) = 55 degrees Fahrenheit, or ~ 13 degrees Celsius ... (Wind) = 4mph S ... (Precipitation) = none. Very sunny.
Habitats --- Pier w/ many docks extending out to view Lake Champlain. The surface of the water closer to land was frozen over in geometric patterns. Closer to the A_Dog Skatepark was an old, rusted, metal framework of a building. Bare trees scattered along Island Line Trail, including a huge scrap metal piece at the water's edge.

Spring is finally here! I was excited to get down to Water Works Park, where Ciara, Erin and I sat on the benches farther out on the water; we faced northward into the wind to observe what we initially saw, the Ring-billed Gulls. Some circled overhead, while others remained by the shore's scrap metal masterpiece. After a few minutes, some paired up in the water, while others flew by the shore or remained farther out and afloat on the lake, possibly foraging or just chilling. One pair of Canada Geese were observed in southeastward flight, and a flock of about 15 were spotted to our right, flying northward over Burlington. After trekking up by the rusty metal structure, we observed some of the Red-winged Blackbirds and the Common Grackles, along with their unique calls which I love hearing in the northeast springtime. We also saw some more Ring-billed Gulls sitting on the vertical posts along the shoreline, essentially sunbathing; in retrospect I was foolish for not taking any pictures (I tend not to look at my phone while out looking for the "birbs"), I made sure to capture some audio of two Ring-billed Gulls chatting, one on the edge of a building overlooking the pier and the other below on the wall separating water and land.

As I observed the gulls for the first few minutes, I gradually began to notice that the birds communicate not only through their vocal calls, but through their flight as well, or movement or lack thereof. Often times these two communication methods were correlated; reflecting back on the two sunbathing gulls, they were motionless of course, but also silent, enjoying their sunny Sunday. The birds over by the scrap metal sat afloat on the water nearby and squawked increasingly with violation of individual space. Their responses ranged from holding their ground (often alongside another bird) to initiating direct flight at the instigating bird and squawking in louder, distinct vocalizations. When flying over the water, quieter, more infrequent vocalizations were associated with cruising, whereas more frequent, louder and higher pitched vocalizations were associated with faster flight. I believe the gulls were not necessarily communicating about food, but perhaps about territorial and/or mate disputes. I think about how the birds by the scrap metal were in pairs of twos, as were the blackbirds and geese. Eventually, a couple of gull pairs lined up along the water, as the one excluded gull circled to find a partner of his own I assume. Even the gulls far out on the water had an instigator of their own, and the bathing gulls on the posts were present in a pair. These excluded birds were probably saying they were missing out, or expressing frustration.

When comparing the plumages of the Ring-billed Gulls and the Canada Goose, I first notice a lot of light feathers on the gull and a lack of these light feathers on the geese. The white feathers are observed on the gulls' head, neck, breast, underlying flight, and tail feathers; when viewing their chest directly, it can sometimes look like a cloud. These feathers, along with their light gray wing feathers with black wing tips, all look smooth, which can be attributed to their water-resistant nature. The lightness and fluffiness in a majority of their feathers could possibly reflect the need to minimally dry the feathers; with thick feathers that go in and out of the water, the color of white doesn't absorb any light wavelengths, therefore allowing direct evaporation of water (this is what I suspect, but I'll research more into this). The Canada Goose, on the other hand, can be described as a rather large bird with a black head and long black neck, a white chinstrap and varying shades of brown along the wings and a very light cream or white color along the breast and belly of the bird. I interpret this coloration as camoflage for their environment, considering their habitats around varying bodies of water (lakes, river, ponds, marshes, etc.) and sources of grain.

I decided to keep my eye on one specific Grackle; it was the first one I spotted, located fairly close, yet still high up on the metal framework. It was ID'ed by the iridescent violet head/bib and dark feathers elsewhere. When it flew between the northward trees and the metal structure, I kept a steady hand with the binoculars and observed it meeting up with other birds, what I presume to be other Grackle and maybe the pair of Red-winged Blackbirds. Foraging attempts along with communication with these other avian members of Burlington could explain this behavior, as nothing seemed to transpire meal-wise for these birds during our visit. A sunny morning, but not great food-wise for any one of the avian species it seemed.

This wasn't during my pier excursion, but during a walk later that day down North Street and Elmwood Avenue, I spotted an American Goldfinch and a House Sparrow bopping around together in a bare tree at eye level. I capitalized on this opportunity to spish, where I so desperately wish I had birdseed! The two birds bopped closer towards me for a second, then gradually away from me, elevating into the trees. They did not seem phased, but rather they had better things to expend their energy on; after all, I was/did not have a source of food. I imagine this sound, or pattern of sounds, is intriguing to birds because it can sound like a flock of birds when done correctly. I can't hear that when I produce the sound myself, but rather when someone else produces it. However, they might have been driven off due to the identification of a neutral presence. I approached slowly from about 20 feet away, began lightly spishing at about 15, and slowly proceeded until I was about 2-3 feet from the wee lads. I stopped spishing, then continued at a light volume, producing different pitches in the process. This was when they bopped closer, then further away. Perhaps the birds hear different pitches of the spishing as a food source, like insects, which could reflect attraction to the auditory source and also support the theory of disinterest following identification of a non-food source, non-threatening individual.