Arquivos de periódicos de março 2019

09 de março de 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 09 de março de 2019, 04:57 AM by david4561 david4561 | 0 comentários | Deixar um comentário

25 de março de 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 25 de março de 2019, 11:12 PM by david4561 david4561 | 2 observações | 0 comentários | Deixar um comentário

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