Diario de laurenberkley

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: 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.