April 23, 2019

Field Observation 6: Reproductive ecology and evolution

On April 22, a Monday, at about 2:00 PM I walked over to Centennial Woods for my birding excursion. The weather was really nice. It was only partly cloudy with a few cool breezes here and there. The temperature fluctuated around 60 degrees Fahrenheit. I was heading to the very first entrance of Centennial which consisted of dry coniferous woods. I happened to stumble upon a bird feeder with a variety of frequent visitors. My excursion consisted of mostly walking along the trails and observing any birds I came across until roughly after 3:30 PM.
As I walked up to the bird feeder, one of the first birds I noticed was a Black-capped Chickadee. After spotting one individual, I noticed more flying back and forth from the nearby eastern hemlocks. They were very vocal and there had to be at least 10 individuals in direct proximity of the feeder. Picking out one particular individual I observed it for a couple minutes as it foraged from the feeder. I noticed that each time it picked a seed from the feed it would fly up to a branch and peck the branch with its beak. I am unsure if it was storing seeds for later or pecking the branch for other reasons. I also noticed some males in particular pick out certain perches and sing for a few minutes. I was unable to distinguish males from females so I assumed that every Chickadee that sung was a male.
After a while more birds started visiting the feeder. One of the new birds I saw was a Gold-headed finch. There was only one male in the area that let out a very low volume call. This individual perched very close to the feeder and made it his singing perch. The lone male was very calm and did not show much activity except to hop down into the feeder. That all changed when I imitated his song. When I started making a similar whistle, the male became more active, started singing much louder than before, and flew to more locations as if trying to secure more territory.
Overtime another species made its appearance. At first I had no idea what this brown, discrete robin-sized bird was. Confused of what bird I was observing I unsuccessfully tried to snap pictures. Though I was unsuccessful on capturing a photo of the brown bird, I accidentally caught a glimpse of a black bird. This black bird was much more bold and a lot easier to take a picture of. I was not entirely sure what this black bird was until it sang. Once I heard its vocalization I knew immediately it was a Brown-headed Cowbird. After making that realization, I soon noticed the male was hovering by the brown bird which I now knew was also a Brown-headed Cowbird. I did not see any mating behavior, but the male and female were very close and seemed to share the same territory. There were a couple times they both perched on the same branch and the male displayed some dominating behaviors like raising his head or looking bigger. Seeing these two together made me want to inspect the tree and surrounded area for a nest. I had no luck finding their nest if they had one but I saw a very large nest in a somewhat further away tree. No clue what made that specific nest, but I know it has to be larger than a cowbird.
After discovering the nest, I decided to continue down the trail. I did not see much on the trail, but I definitely heard a variety of calls and songs. At one point I followed the vocalizations and found myself under an eastern hemlock teamed with black-capped chickadees. Unsurprisingly, the chickadees in this area behaved the same as the ones by the feeder as they sang, foraged, and pecked the branches beneath them. After a while, I resumed my journey along the trail. I met a dead end, made my way back, noticed it was 3:30, and decided to call it a day.

Posted on April 23, 2019 03:38 by david4561 david4561 | 4 observations | 0 comments | Leave a comment

April 09, 2019

Field Observation 4: Migration

On April 8, a Monday, I decided to observe birds in and around Centennial woods . The time was 3:30 PM when I began. Chose this area because it was very accessible and I thought I would have the best chance of seeing early migrants. The weather was chilly, wet, and cloudy. Vermont’s usual weather after it rains. The temperature was somewhere in the high 30s or low 40s.
Making my way to centennial, the first birds I noticed were gulls. I suspect they were Herring Gulls, because I did not notice any rings around the bill. For a small period of time I did not see any gulls in Burlington or Winooski, but I would like to consider Herring Gulls as a year round resident. Herring Gulls are medium sized, generalists, scavengers, prefer to nest by water, have a high aspect ratio wing type, and flock most of the time. These adaptations are possibly the reasons they can stay up in Vermont and colder areas year round. They can fly long distances without expending too much energy, they can group in flocks to stay warm, they can eat a variety of food items so finding food during winter is not too difficult for them, and their feathers are well adapted for insulation.
Once I entered centennial I began hearing a variety of bird calls and songs, but I saw very few birds. One of the few birds I saw was a lone American Crow. American Crow, another year round resident, is also a scavenger and can be observed in large flocks during the winter. They appear to have feathers well-adapted for insulation and I assume the black pigmentation can help to attract and store heat. Different than gulls, crows have a slotted, high lift wing type. This allows them to take off into high elevations, but with increased thrust. Another bird I saw was a tiny songbird that seemed to be the source of most of the sounds I heard entering Centennial. To my disappointment it was a Black-capped Chickadee that was foraging high up on a pine tree. I was only disappointed, because I was hoping to see a bird I have not seen before. Black-capped Chickadee is another year round resident that is small sized, somewhat generalistic, somewhat communal, and has an elliptical wing type. During winter they are able to find food in suburbs and forest edges, they are able to fly vertically quite easily, and when temperatures drop low flock size increases allowing individuals to use other individuals for warmth.
The only migrant I came across on my bird watching excursion was a flock of American Robin. They were hanging around some staghorn sumac outside of Centennial. The robins seem to have come from the Southeast, NYC and lower, and are returning to Vermont with some continuing further North. The weather is getting warmer, ice and snow is melting, food is becoming more abundant up north as the season transitions into spring which is very accommodating for the arriving robins.

Posted on April 09, 2019 03:48 by david4561 david4561 | 3 observations | 0 comments | Leave a comment

March 25, 2019

Field Observation 3: Social Behavior and Phenology

On March 10, the first Sunday of spring break, I was in Puerto Rico. Specifically, the area around San Pablo Bayamon hospital was where I decided to observe birds. The time was 3:00 PM when I began. Chose this area because due to unforeseen circumstances I waited at the hospital for a couple hours and there just so happened to be an abundance of birds in the area. The weather was nice, warm, and sunny. The complete opposite of Vermont’s usual weather. The temperature was somewhere in the high 70's or low 80's.
For my observation I sat on a bench in front of the hospital and observed the behaviors of the birds that flew or walked in my line of sight. The most abundant species I noticed were Greater Antillean Grackles. In general, they were quite possibly the most abundant bird on the island with doves being a close second. Since they were everywhere and not very shy I chose this species to focus on.
Compared to the light brown with some streaks of white and dark brown plumage of the Zenaida Dove, the Greater Antillean Grackles has a solid black plumage with iridescence in the right lighting. The evolutionary advantage of having such dark plumage is probably to camouflage in the upper canopy. As this is a bird where when it is not in a an urban environment likes to perch up in the top understory. The Zenaida Dove I believe uses its plumage to camouflage with the ground, because despite it having the ability to fly I noticed they do a lot of foraging along the ground and usually on ground the same color as them. From an aerial view it would be difficult to pick out the doves. I assume that broad tailed hawks would prey on them given the chance and their plumage serves as a natural defense against predation.
The Greater Antillean Grackles showcased a variety of behaviors as I observed them. I witnessed foraging behavior as they flew from a nearby tree to the road in front of me to pick for any scraps or small insects. There was rainfall earlier that day, so there were some small puddles still present. Some of the grackle would fly to these puddles for a quick drink or soak. When they soaked they hopped into the puddle extending their wings somewhat, hopping out, and then shaking off to dry. When they weren’t on the road foraging, they were in the trees roosting. While in the trees, I witnessed small disputes between grackles as they fought over roosting spots. I noticed that before disputes happened one of the individuals involved would lower their head, extend their wings in a folded manner, and extend their tail feathers. I have observed them to do many things with the shape and direction of their tail feathers with or without other birds present, so I am not completely sure if it is for communication or something else. As far as what they’re trying to say if it is for communication, I think they might be communicating their mood. When they’re the most hostile or dominate they spread their tail feathers the widest. They also let out a call that sounds like a grackle, so I figure that’s how they received their name.
When I used the “psssh” method it attracted some grackles towards me. They flew over and walked around as if they were looking for something. When I stopped making a “psssh” sound they looked the most confused as if contemplating why did I come here in the first place. Based on what I saw them do when I used the “psssh” method, I believe it mimics a call to forage. When I did it the birds would generally not come directly towards me, but forage around me. I think this method works because it alerts smaller birds of local foraging opportunities. It is probably enticing because generally smaller birds make the sound, so if that sound is being made and I’m a small bird too or a slightly larger bird I can bully that bird for the food they found.

Posted on March 25, 2019 23:12 by david4561 david4561 | 2 observations | 0 comments | Leave a comment

March 09, 2019

Field Observation 2: Physiology

On March 3, a Sunday, at about 3:30 PM I left my apartment to head over to Salmon Hole for my birding excursion. The weather was really nice that day. It was only partly cloudy with no chilling winds. The temperature fluctuated around 30 degrees fahrenheit. I was heading to Salmon Hole which consisted of woods, a coastal area, and a river. The area I intended on focusing on was the coastal area, because it bordered both the wooded area and the river. My excursion consisted of mostly walking along the Winooski river and observing any birds I came across until roughly after 5 PM.
Right as I walked towards the wooded entrance of Salmon Hole, I saw an American Crow perched up in a deciduous tree. I observed it calling for a while, stretching its neck and folding its wings in a peculiar manner. Just as I came in range to snap a picture it flew off towards the river and then across. After that I entered the wooded part of Salmon Hole. There was not any distinctive signs of birds that I came across, however I stumbled on the tracks of possibly a martin or mink. Right as I exit the woods, I witness some type of waterfowl fly just above the water’s surface. The bird looked ducklike, had white, black, and brown plumage, a black bill, and dark head feathers that matched the bill. Later I tried searching for the specific species on Merlin, but I am still unsure on what it could’ve been. It possibly could have been either a male Common Goldeneye, a male American Wigeon, a male Northern Pintail.
As I wandered around the now icy river side, I noticed some snags and nice tree hollows. I decided to pick up a stick and check them out. Had no luck finding any birds doing this, but I definitely heard birds as I walked around the area. One distinctive call that I could make out came from a Black-capped Chickadee. Though throughout the excursion I did not see any of the chickadees I heard. I noticed that the areas I heard the most chatter were areas with snags and shrubs still bearing berries. My hypothesis is that the song birds in the area frequent these shrubs for foraging and retreat into the snags when they are ready to rest or when a threat approaches.
For a while I went around harassing the snags in the area with my stick. I only stopped when I was approached by the pitbull of two girls who were also birding in the area. It was kind of unfortunate that the pitbull was there, because it scared off the mallards I saw swimming and wading in the river. Continuing my walk along the trail I saw a Downy Woodpecker scaling a pine tree and foraging for what I assume are grubs hidden beneath the tree bark. I was not able to get a clear picture of the bird due to how fast it was scaling the tree, but I tried my best.
At the end of my excursion around 4:45 going on 5 PM is when I saw the most birds. At this time it seemed all the crows in the area were returning from somewhere and for as long I was there, there was at least one crow in the sky. As that happened, I was able to get closer to the Mallards that had previously been scared off by the Pitbull and also the mystery waterfowl I observed when I started. I also witnessed a woodpecker I believe to be the same individual I saw before fly into a snag I had previously checked. Since I saw it return there and not come out for a while, I decided to leave it as that and end my birding excursion for the day.

Posted on March 09, 2019 04:57 by david4561 david4561 | 0 comments | Leave a comment

February 21, 2019

Field Observation 1: ID and Flight Physiology

Friday, February 15, at 6 am I left my apartment in Winooski to go birding. I decided to spend the 90 minutes in the area around Winooski Falls and Salmon Hole. The weather was not bad, it was not too cold or too windy. Skies were cloudy and it snowed sometime after 7 am. The habitat I observed was mostly disturbed open areas, where no matter where you were you could still hear noise from the roads. There were some areas more secluded, but I did not spend time there. Coniferous trees such as white pine and eastern hemlock made up most of the vegetation in the area.
My bird watching experience began with hanging around the platform by Champlain mills that over looks the Winooski river. Spent roughly 30 minutes in this area and didn’t see much birds reside in the area. The birds that I did see, would fly over me and perch on top of the nearby buildings. Surprisingly did not see any gulls, which I usually see in the area at other times in the year. I guess they have officially migrated. I think I saw about a dozen or so American Crows fly by me while I camped out. Some smaller brown songbirds hastily flew by as well.
After about 30 minutes I made my way towards Salmon Hole. However, instead of going to Salmon Hole I decided to head onto Colchester avenue in the direction of trinity campus. I chose to camp around the cemetery to continue bird watching. I spent most of the remaining time around there and the bridge over the Winooski River. Again, for the most part all I saw were American Crows. By this time, I decided to use American Crows as my diagnostic species.
The flight pattern of the crows was simple. They would fly in a relatively level elevation, maybe dipping an inch or so, flap at two to three beats per second, and glide for two seconds or longer after flapping anywhere from one to five times. Now the other bird I chose to compare American Crows to, was a small brown bird that I did not recognize. This bird had a much faster paced, erratic flight pattern. It would flap continuously, barely ever gliding, and would sink and rise as it flew. It also did not fly in a straight line, it spiraled towards where ever it was going. The crows had broader, lengthier wings compared to the unidentified bird. The crows looked like they had a high lift, slotted wing type. The smaller bird was harder to tell due to its speed, but I would assume it was wing type aimed at increasing thrust like elliptical or high speed.
The habitat niche of the crows seems to be variable. I would see them hanging around trees and heavily forested areas, but also see them hanging around building tops, and road sides. Overall, they seem to prefer habitat where they can perch high up and examine the ground for any possible food sources they can scavenge. On the other hand, the habitat niche of the smaller brown bird seems a little more specific. From what I observed, the bird seemed to prefer open areas with less tree density where it could quickly fly from point a to point b with limited obstacles. The bird also did not fly as high as the crows and would mostly fly towards smaller trees. Once it started snowing, I decided to head back. Before I left, I wanted to get closer to the brown bird to make out its call. What I heard was cheeps and I want to assume that means the brown bird was a house sparrow. After getting back and looking up on the web for basic information on house sparrows, I think it is safe to assume the brown bird was a house sparrow. That concludes my first observation.

Posted on February 21, 2019 00:00 by david4561 david4561 | 0 comments | Leave a comment