Diario de haleyferrer

Date: April 22, 2019
Time: 7:30 am - 9:00 am
Location: Intervale Trails
Habitat: Forested area that hugs a lot of edges (due to the farmland and fields in the area). The central area of the forest was completely flooded, with a couple of inches of stagnant water sitting on the forest floor.

During my bird walk this morning on the Intervale trails, I observed many different species of birds- most of which were exhibiting some sort of behavior that seemed to be related to mate/nest selection or territorial defense.
The first bird I came across was an American Robin, who was scurrying across the trail carrying a large earthworm in his bill. I assume this bird that I saw was a male who was spending his time foraging food and bringing it back to his female breeding mate. This is especially likely if the female was elsewhere building the nest, as they are the primary nest-builders. After I saw the first robin, I heard/spotted another one in a nearby tree. This individual was making a distinctive robin “yuck” call, and I presumed that she was the female of the pair communicating with the foraging male. Throughout my walk, I saw other American Robins and heard their song repeated quite frequently from different locations. These singing robins were most likely repeatedly belting out their song as a means of trying to attract a breeding mate or defending the territory which it had established for its nest.
The next bird I recorded was the Tufted Titmouse, who I heard very clearly but was unable to spot (as there was a significant amount of flooding which made the area difficult to traverse at points). I also may not have been able to spot the individual due to the nature of its nesting habits and locations. Tufted Titmice prefer to nest in tree holes and cavities, as well as artificial structures (i.e. fence posts, metal pipes). Because these nests are often very hidden and enclosed, it makes sense that I would only hear the titmouse’s call. The call that I heard very well could have been coming from a male who was defending breeding territory.
While continuing on the trail, I heard several winter wren songs coming from the same general location, and was able to spot one through my binoculars. They were singing their complex song very loudly and somewhat incessantly as I walked. This behavior seemed to be very indicative of breeding mate selection and/or territory defense. Because I heard more than one winter wren singing simultaneously, there could have been a male to male conflict in regards to territorial dispute.
I saw several black-capped chickadees throughout my walk, and they seemed to exist in pairs or small groups every time I noticed them. I was not able to locate any possible nests or cavities that were occupied by the chickadees, however I assume the areas in which I saw pairs of chickadees were somewhat close to their possible nest-site for the breeding season. Most of the chickadees I saw were only a little bit above my head level, which makes sense considering they often do not nest higher than a few meters. The nests, which are built by females, usually exist fairly deep into an excavated cavity and include a covering of natural materials, therefore they are somewhat inconspicuous when walking on a trail.
There were several three northern cardinals that I found during my walk, 2 of which were males and one which was female. One male and one female seemed to be foraging in thicket very close to the ground. The other male was found perched on a branch a couple of meters off the ground. While the male and female who were foraging did not make any noise, the perching male was singing the “cheerio cheeri-ie” song quite loudly. It seemed as though this individual was trying to find a mate or defending its territory (perhaps from the two foraging cardinals below). At one point, the foraging male cardinal took off and flew many trees down, with the female following him a few seconds later. Due to this behavior, I figured that the two individuals were, in fact, a breeding pair, and they were working on foraging nest materials or trying to find suitable nest sites.
I saw two brown-headed cowbirds together, hopping about in a mess of branches and vegetation on the forest floor. One was a male and one was a female, which can be seen in the picture I uploaded to my iNaturalist observation. The two seemed to be foraging for seeds or insects in the soil, and they never seemed to stray too far apart. The pair, which I assumed to be a breeding pair, was not making any noise (neither songs nor calls). I assume that they were so quiet because they did not have any vital territory to defend nor did they need to communicate in such close proximity. Because the Brown-headed Cowbirds lay eggs in other birds’ nests, they did not have a territory or nest site in which they had to spend energy defending.
I heard one Mourning Dove throughout my walk, who let out a strong and frequent song in the distance. I never spotted the source of the song, but it sounded as though there was only one individual. I know that Mourning Doves may nest at higher elevations than some of the other song/perching birds I observed, therefore it makes sense that I heard the call coming from a farther distance.
I saw an abundance of Song Sparrows during my walk (about 5), and heard more coming from deeper into the forest. All of the Song Sparrows which I observed seemed to be sort of jumpy and very mobile. It was hard for me to get a good look at one before it took off for another nearby branch. This behavior, to me, seemed like the individuals were looking for something- whether it be a suitable nesting site or food/resources for the breeding pair and offspring. There was one stationary male (the one that I have pictures of in my observation), who was fairly stationary and loud. He remained perched on a branch and allowed me to walk fairly close to him, as he loudly sang the entire time. Due to this behavior, I assumed that the male was defending potential territory or trying to find a suitable mate.
I saw two White-throated Sparrows during my outing- one which I assumed to be male and one female. While I was not sure about the physical distinction between male and female White-throated Sparrows at the time, their close proximity and peacefulness in each other’s company made me think that the two were not competitors. The two of them kept traveling between the ground and low twigs/branches of a nearby thicket. Because White-throated Sparrows build their nests in low elevation areas with dense vegetation, I presume that this pair was a breeding couple who was working on constructing a nest for the upcoming season.
Many birds have very specific and unique nesting characteristics which are complementary to their life history traits (i.e. diet, habitat, foraging/behavior, etc.) Out of the bird species that I observed this morning, three with some of the most distinct nesting patterns (in my opinion) were the Brown-headed Cowbird, the Winter Wren, and the American Robin. While I observed all of these bird species in the same general vicinity, their requirements and preferences for nesting are quite different. Brown-headed Cowbirds are very unlike the other species that I observed today, because they are “brood parasites”- meaning they do not build their own nest, but rather lay their eggs in the nests of other species. Female cowbirds will search for females of other bird species that are in the process of laying eggs. When she finds a host that is deemed suitable, the female cowbird will sneak into the host nest and replace one of the existing eggs with one (or more) of her own. Some popular nests in which the Brown-headed Cowbirds lay their eggs include the Red-wing Blackbirds, Ovenbirds, Yellow Warblers, Song Sparrows, etc. The types of nests which these host species occupy are not very similar, and range from nests on the forest floor to treetops. Usually, the Brown-headed Cowbird will select host nests that contain eggs with smaller volume than their own. This can result in cowbirds quickly lowering the success and wellbeing of their host individuals upon hatching. American Robins, on the other hand, build their own nests for the breeding season. Much like the female Brown-headed Cowbirds choose the host nest, female robins decide where their nests will be built. They usually choose nest sites on horizontal branches that are hidden beneath a layer of dense vegetation. Females are also in charge of building the nest, which they do from the inside out by pressing dead grass and twigs together to form a cup-shaped structure. Winter Wrens are another species of bird with nesting behaviors that I find quite interesting. Winter wrns do make their nests, however the shape and placement of these nests are different from the American Robin/ The Winter Wrens nest are more dome-shaped/globular, and offer protection on almost all sides. To obtain a maximum amount of coverage, wrens will often build nests in dead trees and cavities. Unlike the Brown-headed Cowbird and the American Robin whose nest site is scouted out and built by females, the building of Winter Wren nests is done by the males. The males will build several nests in a season before showing the nest options to a female who will choose which one to use. Nests usually exist anywhere between ground level and 20 feet above the ground.

Mini Activity:
When I sat quietly in one spot in the forests surrounding the Intervale Center, I heard many different species singing/calling from all different directions. The chaos and volume of all the different competing sounds was sort of mind-blowing, and it took me awhile to discern any individual species. Once I let the symphony of bird songs sort of settle in my brain, I was able to focus in on one species at a time and try to identify them. I heard several winter wrens that seemed to be about 20 yards in front of me. I could tell that they were different individuals due to overlapping songs as well as slight differences in vocalization patterns. Almost immediately in my ear, I heard the very recognizable song of the Song Sparrow, who in actuality ended up being a lot farther than I thought based on audio alone. Across the marshy area to my right, I heard a woodpecker drumming away, however I was unable to ID it based on the drum beat alone. From very far behind me, I heard an individual making a lengthy call that comprised of crazy combinations of whistles, trills, and clicks. While I never was able to find the bird and confirm, the chaotic nature of its song seemed like me to be coming from a European Starling. There were a couple of other songs in the distance that I simply could not ID at the time, due to them blending in with the songs of other birds or me simply not recognizing them. I wrote down some notes that came from the same general location of the woodpecker drumming- which I illustrated as short of short staccato notes that are evenly spaced. Upon looking up the sound for the Downy Woodpecker, I realized that those short squeaky calls could have been coming from the same individual that I heard drumming.

Date: April 8, 2019
Location: Centennial Woods
Time: 1:00-2:30 pm
Weather: raining the entire time, pretty cold (low 40s), lots of cloud coverage
Habitat: Deciduous Forest

As is the case with most of my walks, I saw an abundance of Black-capped Chickadees in Centennial Woods this afternoon. Throughout my time in Vermont, I have noticed that Black-capped Chickadees have a very consistent presence throughout all of the seasons- which is why they were one of the first birds that I learned to identify. Black-capped Chickadees are largely permanent/nonmigratory residents, meaning they stay in the same general homer range throughout the entire year. There are documentations of Black-capped chickadee “irruptions” during fall months, however, in which groups may undergo irregular migration due to a factors such as habitat destruction or lack of resources. In northeastern United States, such irruptions correlate strongly with fluctuations in northern seed crops. Despite these infrequent movements, Black-capped Chickadees are permanent residents and therefore have various adaptations that allow them to survive through the fluctuating seasons of their habitat (which could be all over the country). In Vermont, the cold and long winter represent a harsh climatic environment to which chickadees have responded with several physiological and behavioral adaptations. Black-capped Chickadees undergo facultative hypothermia, for example, in which they actively decreased to a certain temperature so as to reduce heat loss and save energy. By lowering their body temperature to about 15 degrees below its normal temperature, Black-capped Chickadees can conserve a quarter of their hourly metabolic expenditure. Black-capped Chickadees also have adopted advanced spatial memory capacities which allow them to store large quantities of food for colder months in which resources may be low. They also partake in behaviors such as roosting and finding insulation during colder temperatures.

The American Robin is another permanent Vermont resident that I see quite often. This species has records of migrating slightly more than chickadees, however such movement usually entails short distances in response to food shortages, rather than temperature changes. While Robins mostly eat fruits in the winter, they switch to earthworms and insects a sa food choice in the spring. Because elevated temperatures coincides with ground thawing, it is common to see increases in American Robin numbers in early spring- however this does not necessarily indicate that they were previously migrating in a far southern location. To stay warm during winter months in Vermont, Robins often will seek shelter in dense patches of vegetation or roost with one another to share body heat. They also often are seen fluffing their feathers, which increases the amount of air next to the body and thus allows for more heat to be circulated and retained. Down feathers exist closer to their skin to trap air and insulate heat so as to keep internal organs at a safe temperature. Feathers on their underside can often fluff up to the point that they cover their legs and toes, as well. In the winter, American Robins will spend most of their day foraging and eating- which helps them to stay warm and keep caloric intake high.

White-breasted Nuthatches are also permanent residents that I have seen an abundance of this winter. Like other non migratory bird species, however, they have had irregular movements as a result of seed failure, reproductive successes, etc. White-breasted Nuthatches are able to stay in Vermont all year round by altering their dietary habits as a result of the changing seasons and available resources. While they eat insects in summer and spring months, White-breasted Nuthatches switch over to a diet of mostly nuts and seeds in colder months. Most of their circadian clocks are devoted to foraging and eating in the winter. They also have very effective ways of storing food resources and returning to them (even after months).

The last species I observed on this cold and rainy day was a house sparrow, which existed closer to the edge of Centennial woods near the apartments and buildings. House Sparrows are pretty sedentary, and usually don’t move more than a few kilometers during their lifetime. Young birds may be seen migrating somewhat longer distances in the winter time (usually from high to low elevations). House sparrows are skilled at seeking out shelter in dense vegetation or cavities/holes so as to protect themselves from harsh elements in different seasons. They also show behavioral adaptations to cold weather by huddling as well as tucking their head and feet into their feathers.

All of these birds are able to forego the migration process due to physiological and behavioral adaptations that allow them to survive the various seasons in Vermont (or wherever their respective homeland is). The exact reason for this may be that making efforts to remain in one spot is more energy efficient than spending an extended period of time flying to a less harsh climate. Also, the permanency of populations of these species most likely helps to alleviate widespread conflict over resources and ecological instability- as these birds tend to stay in their home ranges and thus maintain some sort of consistency with each other as well as their surroundings.

While the cold, rainy weather this afternoon limited the amount of bird species that I was able to observe (all of which were nonmigratory), there are several spring migrant species that are beginning to show up in the Burlington area-- exciting! There are many spring migrants that have come to VT for their breeding season (or will be very soon), including warblers, Hermit thrushes, Red-winged Blackbirds, and Scarlet Tanagers. Scarlet Tanagers, which are one of my favorites, are long distance migrators who will not typically arrive in Vermont until a little later in the season. They migrate to South America for the wintering season (usually leaving by mid/late-summer) and return back to their breeding grounds by May. Scarlet Tanagers make this long trip across the Gulf twice a year, usually traveling at night. A major incentive for species to migrate southward during the wintering season is to maintain a sustainable amount of food and resources. Scarlet Tanagers, for example, migrate to South America so that they are able to eat fruit and insects- something that would not be available had they stayed in Vermont throughout the winter. While their food source down south is suitable in the winter, they return back north for breeding season due to more optimal nest locations/opportunities. Scarlet Tanagers prefer to breed in mature deciduous forests, and build nests in oak, pine, and beech trees (among others), which are abundant in Northern areas.

While the Scarlet Tanager will not arrive until late April or early/mid May, there are many birds that are already beginning to arrive. Advantages of arriving to their breeding grounds early include being able to claim a territory and nesting spot before other competitors arrive. However, there are many instances in which birds may arrive early for breeding season and then experience an unexpected freeze. In this case, it is quite possible for ill-equipped birds to not survive the harsh conditions.

Mini Activity

Migratory distances of my observed birds (max):

Black-capped Chickadees
2 miles
Usually stays in the same vicinity during wintering and breeding seasons, however irruptive movement gives their species a 2 mile (ish) average for migration

American Robin
100 miles
The amount that a Robin migrates depends on the individual as well as the available resources. Some Robins will not migrate at all and remain in their Northern habitat, while some may fly a fairly large distance southward to access food resources (insects and fruits)

House Sparrow
No migration
Sources say that the House Sparrow maintains a pretty consistent home range all year.

White-breasted Nuthatch
1 mile
Not a lot of movement, sometimes groups or individuals will undergo irruptive migration; but usually not too far

Total
The birds that I observed have the potential to have migrated over 100 miles collectively over the past couple of months, however they are largely nonmigratory birds so that number may be high (depending on the individuals)

Time: 12:00-1:30
Date: March 25, 2019
Location: Centennial Woods
Weather: Sunny, clear skies, 40 degrees
Habitat: Deciduous forest, trail running through, river and swampy areas create break in dense vegetation

note: my phone suddenly stopped working about halfway through the bird walk, so I recorded species by hand and tried to describe their relative location in the woods

Because my phone stopped working pretty prematurely on this bird walk, I was not able to record the exact location of every single individual I saw. However, I used that malfunction as an excuse to really slow down and spend more time observing how the various species of birds interact (rather than trying to record as many as possible on the app). When I took the time analyze the different sounds and behaviors of different birds, I was able to recognize some communication patterns across certain species.

Black-capped Chickadees were by far the most abundant species that I observed during my walk, and I was constantly hearing both their songs and calls as I traversed the forest. I noticed that when I heard a Black-capped Chickadee call (i.e. the “chicka-dee-dee-dee”) in one location, it was often followed by a different individual making the same call. I figured that this occurred due to the fact that a call signals some sort of danger or alarm, therefore it makes sense for other nearby individuals to respond and vocalize their recognition of said stimulus. The sing-songy “here petey” sound, on the other hand, seemed to be more randomly dispersed and less frequent. This is perhaps due to the fact that males are often the ones to sing for purposes of attracting mates, therefore it may not be as much as a call-and-response type of vocalization. In terms of visual behavior, the clusters of Black-capped Chickadees that I observed would often jump around the branches of a specific tree (perhaps foraging for food) and would often jump towards each other before spreading apart again. This type of behavioral interaction could perhaps indicate some sort of communication regarding the presence of a food source, or could be some sort of communication between a breeding pair (male and female).

Another species that I observed to be (potentially) communicating during my walk was the White-breasted Nuthatch. Much like the chickadees, I heard several nuthatch calls that came from individuals in different locations. The most common nuthatch sounds I heard were the “wha wha wha wha” songs as well as the raspy and more abrupt “yank” calls. I heard the song less frequently throughout the my walk, however I did hear it on multiple occasions in which it was carried out for an extended period of time. From what I know about White-breasted Nuthatches, their songs are used to find suitable mates for the upcoming breeding season (beginning in April, usually), therefore hearing this infrequent song makes sense. The “yank” calls were somewhat more frequent, and I presumed to have more of a two-way communicative purpose. During this time of year, monogamous pairs of White-breasted Nuthatches are most likely building their nests as well as foraging for food, therefore the “yank” or “yink” sounds that I heard were most likely signaling to each other a certain source of food or perhaps protecting the nest.

I saw a couple of American Robins during my walk, and heard several “cuck” calls as well as songs (“cheerio-cheeri-ie”). When I observed the robins, I heard these different sounds given in the same time period by the same individual(s). For this reason, I assume that both the song and call may work together to form similar purposes. For example, both the song and the call could be used as a signal of defending territory from potential trespassers, therefore it makes sense to hear them both in the same vocalization.

There were several species that I could not observe interactions for due to their more independent presence and lack of interaction with other birds of their kind. These birds include Pileated Woodpecker, American Crow, and Mourning Dove. I heard and observed all three of these species, however I only saw one individual of each throughout my walk. The American Crow was flying overhead above the forest, and gave out a few “caws”- which I assume was made to communicate with nearby crows that I did not see (because the call is fairly loud). The Mourning Dove that I observed was singing its beautiful “ooo-OOOH,- ooh-ooh-ooh” song from atop a very high perch. I presume this was a lonesome male that was singing this song for the purpose of finding a mate. The pileated woodpecker did not make any audible calls, however was drumming on a tree for an extended period of time- therefore I could not make out any specific type of communication/interaction.

During my walk, I spent time looking at the plumages of the Black-capped Chickadee and the Pileated Woodpecker, as I was able to get a pretty constant view of both of them. They are similar in that the main bodies of both of these birds have black and white feathered areas that are very contrasted and take on quite distinguishable patterns. They both have stark black and white stripes that begin on their head and may extend downward onto their body. One of the main differences between these birds’ feathers is obviously the bright red crest that exists atop the head of the Pileated Woodpecker. While this crest does not seem very practical for the purpose of blending into surroundings or keeping a low profile, it is heavily used in courtship displayed and as mechanisms of attracting mates. Evolutionary, it makes sense that more successful woodpeckers are those with brighter and larger crests that are more effective at attracting a breeding partner. Because the Black-capped Chickadee does not have any sort of vibrant distinguishing feature (nor any huge visual differences between males and females) it makes sense that these birds rely on other behaviors for courtship (i.e. buffing feathers or singing their song).

In terms of behavior of the birds which I observed, I found the Black-capped Chickadee and the American Robin to have interesting behaviors (which were fairly distinct from each other). Every time I saw a Black-capped Chickadee it was moving about- usually hopping on branches or taking quite flights around a tree. The birds were usually faced inward to the tree, suggesting that they were moving about in order to forage for food from the surface of the various branches or trunk. The dynamic nature of the chickadees suggests that their circadian rhythm is one that heavily surrounds foraging and eating throughout time spent awake.

The American Robin(s) that I observed, on the other hand, which much more composed and stationary than the chickadees. They were found on a tree towards the edge of a dense patch of vegetation, in a spot in which sunlight was directly hitting them. While they would give out a call/song, they did not seem to move too much. This could be because their circadian rhythm does not require them to be foraging/eating for a large part of their day, but rather it is more energy-efficient and preferred for them to be resting upon a perch and sunbathing.

“Pishing” Activity

There are many reasons why “pishing” can be used to attract or signal small birds. Although the “pshh” sound does not necessarily mimic the song of small perching birds, the raspy and abrupt nature of this sound can be very similar to some of their calls. Many small birds, such as the Black-capped Chickadee and the Tufted Titmouse, give shorter raspier calls that are used to signal alarm or distress, usually in the presence of some sort of predator. When hearing this call, small birds often will flock together to either chase away or find safety from a predator. Thus, if a similar call is made by a human, small birds may be enticed to flock towards this sound. Another reason why small birds may be attracted to this sound is perhaps the soft and raspy “pshh” sound is similar to the sounds and pitches created by potential prey, specifically smaller insects. Of course, there is also the possibility that the specific “pish” sound that is created by humans does not quite mimic any sound that the small birds are accustomed to hearing. In this case, it seems quite possible that the sound could attract birds out of their mere curiosity of this foreign sound.

Date: March 6, 2019
Time: 2:00 - 3:45 pm
Location: Shelburne Bay
Weather: The weather on this bird walk was fairly cold, with temperatures dropping to about 10-12 degrees. There was a light snow falling for the majority of the time, with fairly consistent cloud coverage (blocking the sun).
Habitat: I walked through the forested area in Shelburne that is adjacent to the bay. While I started out traversing the trails, a lot of my exploring was done off of the path.

The species that I observed during my bird walk utilize various evolutionary and ecological tactics in order to stay warm and survive the Vermont winter season. Although I did not necessarily observe these behaviors and processes directly during my time at Shelburne Bay, there is an ample amount of research and studies that provides insight into these birds’ winter lifestyles.

During my walk, I saw a really large abundance of American Robins (at least ten were gathered in the first few trees upon entering the forest), which allowed me to undertake thorough observations and think a lot about their winter behaviors. I noticed that some of the stationary robins that were perched upon a branch seemed very large from where I was standing, at least relatively to the robins that I see in other times of the year. Upon investigating this observation after my bird walk, I found out that robins often will fluff their feathers to help retain body heat. I found that fluffing up feathers increases the air next to the body and thus offers more protection from the cold. The composition of the Robin’s feathers also plays an important role in their winter survival, as they have a dense layer of down feathers close to the skin, which trap air and act as an excellent insulator. They have other layers which exist on top of this down feather coat, which further helps in separating the cold external air from the body heat that is being produced. During my time at Shelburne Bay, I witnessed two different robins eating small morsels of food (they looked to be some sort of berries). Consuming calories definitely assists in keeping the birds warm as it increases fat buildup as well as causes a rise in body temperature. While the other robins were not seen to be eating any food, they did seem to be moving around quite a bit- even when I was standing still and hidden. The robins kept sporadically flying between various trees, often moving as a group. Perhaps this movement was a foraging tactic, or maybe the intermittent movement helped them keep their body temperatures elevated. American Robins, like many other birds, also rely on each other for heat through roosting and cuddling. In very cold temperatures, Robins can stay close together to share body heat as well as seek protection from other weather factors (ie. snow, wind). While I did not see a lot of direct contact between the Robins that I observed, I did notice that there was a very large group of them which stayed in very close proximity the entire time I observed them- a behavior which I don’t often see when I observe a robin or robins.
During my time at Shelburne, I also saw a single Barred Owl perched on a tree very close to the edge of the forest. As I approached the owl, I noticed that I was able to get extremely close without him moving or fidgeting. As he stared me down from atop his branch, I wondered how owls are able to stay warm during the winter season- especially considering they are such independent birds. Much like Robins, I figure, Owls have a very particular feather composition that allows them to insulate their body heat effectively. Barred Owls, along with other members of the Strigiformes order, have a fluffy layer of feathers that extends all the way down to their legs and toes. They also have thick pads on their feet, which allow their extremities to remain warm during low temperatures. Due to the lack of wind that was present during the time at which I observed the owl, he was able to stand upon a tree branch that was relatively exposed to the conditions that traveled across the nearby field. I assume, however, that if wind and precipitation were especially strong, the owl would have seeked shelter behind an on-ground object or a denser, more internally-located tree.
Even though I did not directly observe or notice such behaviors, I know that there are other tactics which these birds most likely partake in to stay warm during the winter. The countercurrent exchange between birds’ body and legs, for example, allows for birds to deliver heated blood to their internal organs, and reduce blood flow to extremities without risking frostbite. Birds can also tuck their legs/feet into their feathers to shield bare skin from the cold. Many birds also have physiological responses to cold, such as shivering, entering a state of facultative hypothermia/torpor, etc. These types of physiological responses help birds to control metabolic rate and generate body heat strategically. Birds often enter a state of torpor or hypothermia at night, for example, as a method of conserving energy for an extended period of time. This involves reducing metabolism and shutting down certain systems so that less energy is required to maintain a proper amount of heat.
Because the Shelburne Bay park is such a densely forested area, I saw an abundance of snags that were distributed throughout my entire walk. By the time I was only a few minutes in, I had already counted well above ten snags/dead trees. I came across various types of dead trees, all of which could definitely be potential habitats to birds and other wildlife. Where the trail opens up right at the edge of the forest, there are several small dead trees that lay across the ground and form a jumbled mess of branches and brush. When I first spotted this scene, there were at least six American Robins that were seeking shelter in there. As I continued to walk, I found numerous snags that were standing up right. Most of these types of snags that I observed had various holes and cavities in them, either being naturally formed or formed from wildlife/birds. I noticed that the taller snags often times had several holes distributed up the length of the tree trunk at varying elevations. This, I assume, could be due to the same species of birds seeking different shelters or areas to forage for food. I also noticed that the thicker snags had larger holes that appeared to be more suitable to fit a bird or creature that is greater in volume. I knocked on a couple of these trees to see if any organism poked its head out, but I did not find any sign of life when I did this. Although I did not see any birds physically in the snags/cavities, these structures are very vital aspects of many birds’ lifestyles. Birds, and other small animals, can use snags for nests, foraging, roosting, and perching. Because of the dead/hollow nature of the trunk and branches, snags are excellent resources for birds to excavate and create fairly intricate forms of shelter. Snags also are home to many sources of food that are consumed by birds, including insects. Perhaps I would have seen more activity around the snags and cavities if I visited the area at a time in which birds were awakening or settling down for the night (dawn or dusk), which I will keep in mind for my next outing.

Date: 2/19/19
Location: Delta Park, Colchester
Time: 8:25 am
Weather: Sunny (no cloud coverage), cold (<10 degrees), little to no winds
Habitat: Forest (deciduous) broken up by wide walkway, continues on both sides of the lake

For my bird walk this morning, I went to Delta Park (Colchester, VT) at around 6:40 am. The sun was rising just as I began to make my way along the greenway, and birds slowly began to increase in visibility, audio, and frequency as the morning drew on. The most frequent species occurrence that I heard and saw was the Black-capped Chickadee, with several individuals scattered throughout the walk. I also saw several Downy Woodpeckers, with the drumming sound of their beaks being a consistent presence for the majority of my two hours spent outside. Other birds that I noticed included the Tufted Titmouse and the White-breasted Nuthatch. While I did hear an abundance of bird songs/calls in the distance throughout my walk, I did not record these species so as to avoid classification error and maintain location precision (as I will explain later).

Throughout my walk at Delta Park, I was very attentive to the movement of various birds, and analyzed how/why they may have the flight patterns that they do. Because I saw an abundance of Black-capped Chickadees, I was able to observe several individuals of this species in flight. Most of the flying that I could observe was only for very short distances (ie. between branches or trees), so I did not have the chance to encounter longer flight patterns. I found that the Chickadees had extremely rapid wing beats that remained strong and consistent until the individual reached their destination (no gliding was observed). Because of the nature of the Chickadee’s average flight routes, it seems as though their wings are more conducive to provide a large amount of thrust in very small increments. When the Chickadee flies, I can vaguely make out the outline of individual feathers, giving the impression that they have an “elliptical wing” type. Their wings are also fairly wide and not very long, which gives them a low-aspect ratio, with which they are able to create short, aggressive wing flaps which allow them to achieve maximum thrust. Because they need to be flapping wings steadily in order to move through the air, they seem to have a high amount of agility that allows them to quickly move through confined spaces (i.e. between leaves and branches).

Another bird whose flight pattern I observed was the American Robin. I only saw one American Robin during my bird walk, however I was able to watch it fly a fairly long distance between several trees. Unlike the Black-capped Chickadee, the American Robin’s flight pattern seemed to be more directional and less energy-intensive. The flight of the individual American Robin consisted of steady wing beats in a fairly rapid succession, however there were intermittent periods of gliding between these flaps. When the bird did flap its wings, the beat appeared to be much slower (and much more discernible) than that of the Black-capped Chickadee. While the Robin’s wing shape seems to be similar in shape to that of the Chickadee’s it is much longer and therefore has a higher aspect ratio. This characteristic of their wings and flight pattern could perhaps be beneficial for their foraging behaviors, as they eat many insects and worms. The longer feathers can allow them to get more lift from their primary feathers, and more easily glide/hover the ground if needed.

While these two birds have flight patterns that are fairly distinguishable from each other, I had a difficult time recognizing the differences between some of the other species that I was able to recognize in flight. I found that I could identify the smaller-sized birds (i.e. Tufted Titmouse, White-breasted Nuthatch, and the Black-capped Chickadee) when they were stationary on a branch, however when they flew overhead it was hard for me to make them out, especially if I did not get a chance to look at them before they took flight. Because I did not see a large abundance of birds, I did not have the chance to really study these different flight patterns and discern their differences through repetitive observations (which I hopefully will be able to do in bird walks to come).

In terms of being able to see more birds during my future excursions, I think I will go somewhere that does not entail too much habitat fragmentation from walkways or roads. While Delta Park is very forested and is home to many bird species, it is really only able to be explored via a wide bridge/walkway that cuts through the wooded area (especially in the winter). During my walk, I heard many (possible) bird species that I could not visually locate because they were far off the path and not able to be reached. Such birds included what sounded like a Brown Creeper and a House Sparrow closer to the developed houses next to the trail. Because I was not sure if merely hearing a species was enough justification to record it on the app, I chose not to enter these individuals into iNaturalist. I purposely went to Delta Park very early (just as the sun was rising), because I figured this time frame would allow me to see more birds. I found that as the sun rose higher and the morning drew on, more birds seemed to make themselves more heard/seen; compared to the very early morning in which I had to look very hard for distant birds. Perhaps next time I can try going a little later in the morning, or try to go in the afternoon/dusk so as to see if a different variety of birds would be out at that time.