Diario de laurenberkley

Time: 10:00 am
Date: 5/1/18
Location: Overlook Park, Burlington, VT
Weather: Warm, rainy
Habitat: Developed

Time: 9:30 am
Date: 4/26/18
Location: North Beach, Burlington, VT
Weather: Chilly, sunny
Habitat: Riparian

The Rock Pigeons I observed seemed to be exclusively foraging rather than exhibiting mate selection, nest selection, or territory selection. However, the Downy Woodpecker I observed was surely exhibiting the latter behaviors. The individual was drumming on trees to, I assume, announce its territory and attract a mate as this is prime breeding season for Downy Woodpeckers.

As I understand it, Rock Pigeons prefer to nest on ledges, so they may nest on some of the rocky ledges that border Lake Champlain near North Beach. The Downy Woodpeckers prefer to make their nest cavities in dead wood about 5-50 feet off the ground, so they would most likely nest in the woods surrounding Lake Champlain.

Habitat requirements differ greatly from species to species due to available food, shelter, space and mates suited to that species in the area. The Downy Woodpecker was perhaps defending its territory with all its loud, consistent drumming. I would say it is defending a poor territory compared to other members of its species because, as aforementioned, woodpeckers prefer dead wood and I did not observe a lot of dead wood around. That may indicate that this bird does not have very high fitness.

The Rock Pigeon may make its nest out of small twigs or stems that it would acquire from leaf litter in the woods around North Beach.

My drawing for the mini activity showed two "x" marks where i heard Downy Woodpeckers, and trailing dots of the same size to show the drumming I was hearing.

Time: 5:30 pm
Date: 4/20/18
Location: Winooski River, Winooski, VT
Weather: Chilly, sunny
Habitat: Riparian

Time: 8:15 am
Date: 4/2/18
Location: Centennial Woods, Burlington, VT
Weather: Cold, partially cloudy
Habitat: Forest

Black-capped Chickadees are primarily a non-migratory species. I would attribute their winter survival to high insulation and high activity. These birds have a half-inch coat of feathers to keep them warm and continue to forage throughout the colder months of the year. The American Crow is also primarily non-migratory species. They stay warm during winter nights by gathering in large communal roosts.

Turkey Vultures are more migratory in the west than they are in the east, but the individual I observed could be recently returning from Central and South America where these birds most often spend the winter. It most likely returned because the weather has recently gotten warmer in Vermont, rather than more food becoming available because Turkey Vultures are generalists. Some American Robins are also migratory. American Robins migrate in response to food more so than to temperature. As the ground thaws in the spring, they eat earthworms and insects. This American Robin most likely returned to Burlington now because the ground has thawed and its preferred food is available.

Mini Activity- Frequent Flyer: I estimated that the migratory species I observed travelled about 5,000 miles.

Time: 2:35 pm
Date: March 25, 2018
Location: Centennial Woods, Burlington, VT
Weather: Cold, sunny
Habitat: Forest

I observed a group of five Black-capped Chickadees in Centennial Woods this afternoon. They were communicating with eachother very little, although every once and a while one would "seet" a bit at another. Perhaps this was just to check in and say hello. When I stepped closer, each bird hopped back and gave frantic a "dee dee dee" call. It was as if they were setting off an alarm, saying "back off!" When I did back off, they seemed to calm down and go about their business.

I only saw Black-capped Chickadees on this particular bird walk. Their plumage, pigmented by melanin, provides very good camouflage in the understory where they stayed for the duration of my visit. This is a clear evolutionary advantage against predators looking down at the understory from above.

All of the Chickadees I observed seemed to be foraging. One bird in particular was hopping from one small tree to another, landing perfectly and grasping the stem each time, while it scanned the ground for food. This fits into the circannual rhythm of Chickadees in that it is the muddy season in Vermont. The wet ground probably makes it easier to eat insects that live underground and these individuals were taking advantage of it.

Mini Activity: I "pished" at the group of Chickadees but nothing happened. They seemed to be ignoring me until I stepped closer. I'm not sure why this would work for other birders. Perhaps it mimics the sound of an insect that the birds would want to eat, or birds are just naturally curious creatures. Nevertheless, it did not work for me and I had a much harder time getting a photo for it.

Time: 4:30 pm
Date: March 14, 2018
Location: Island Isabela, Galápagos Islands, Ecuador
Weather: Hot, humid
Habitat: Ranges from mangrove forest to arid

I spent my spring break traveling in the Galápagos Islands. The Galápagos Islands (and most of mainland Ecuador) have little to no seasonality, rather tumultuous microclimates. Therefore the "winter" there looks much different than it does here in Vermont, but the birds that live there certainly have many adaptations for the unique environments they live in.

One commonality was many of the birds were considerably large (e.g. Brown Pelicans, Frigatebirds). I would attribute this to the generally hot and humid climate. These birds can have a lower surface-area-to-volume ratio than birds in colder climates because they don't need to retain as much heat. Perhaps some of the seabirds have counter-current exchange in their feet to cope with the cold ocean water.

Most of the birds I observed were either feeding or looking for food. For example, every time I observed a Striated Heron it was extremely focused on the water looking for fish to eat. I think this is because predation on birds on the Galápagos is relatively low, so birds don't have to worry about being preyed on and can worry more about eating.

The herons I observed as well as the Brown Pelicans, Frigatebirds, and Blue-footed Boobies were mostly hunting for fish. Most of the other birds were eating vegetation. The American Flamingo was particularly interesting to watch feed as it drags its curved beak along the waterbed then uses its lamellae to filter food out.

As aforementioned, there are no distinct seasons on the Galápagos. However, the area is significantly affected by El Niño and La Niña events which in turn impacts what birds eat. During El Niño, booby nests can become submerged by rising sea levels and chicks have died of starvation because parents were unable to find food.

Different species of birds overnighted in many different areas. Mangroves are prevalent on the Galápagos which were often taken advantage of by many birds. They could often be seen peppered with sleeping Brown Pelicans at night. Many of the finches nested in cacti.

Mini Activity- Snags provide important wildlife habitat for birds, small mammals, amphibians, and much more. Some examples of northeastern species that rely on snags would be Raccoons, Wood Ducks, and Red Squirrels. I did not observe any snags in the Galápagos. Most of the forests are mangroves and outside of those there are cacti. While there were no holes in the cacti, several finches were nesting on them.

Time: 12:53 pm
Date: February 9, 2018
Location: Winooski River
Weather: Cold, cloudy
Habitat: Riparian

While birding along the Winooski River I observed a Canada Goose in flight. It displayed strong, deep wing beats and moved in a forward, direct motion. I also observed a Mallard in flight. This bird displayed similar strong wing beats, but they beat their wings faster and more often and the flight pattern was swifter. Both species seem to have slotted wings with a high aspect ratio. I believe that the flight patterns for these species must be energetically expensive yet well suited for the long-distance migrations they make.

The two species also have similar habitat niches. I observed a Canada Goose take flight from the water and it took a long run across the water in order to reach the speed necessary for take off. I believe this was necessary to its high wing loading. When the Mallard duck took off from the water it did not have to run but it did flap its wings furiously in order to achieve lift. This was most likely due to its smaller body size relative to its wings. Overall, the wings for Canada Geese and Mallard Ducks seem tailored to taking off and landing in water, and long migrations.

The only other species I saw was a European Starling. I did hear some other songbird activity but I was unable to identify the calls. I would attribute this to the time of day. It was 1 pm when I ventured out and birds are usually more active during the morning or evening. It was also extremely cold which may have affected bird activity. I would love to return to this beautiful area to bird earlier or later in the day when there is better weather.