grady_jakobsberg's Journal

Date: 5/10/2021
Time: 11:00 am - 12:30 pm
Cloud Cover: 30%
Temperature: 58 degrees F
Wind: 2-7 mph
Precipitation: None
Habitats: Urban streets of the Old North End, deciduous forest and scrub near the Intervale, river side along the Winooski River

Date: 4/24/2021 Time: 9:00 - 10:00 am Cloud Cover: 100% Temperature: 53 degrees F Wind: 5-10 mph Precipitation: None Habitats: Urban, Suburban, Retention Pond, Deciduous Forest, Coniferous Forest We found a number of empty nests today, primarily in bushes or small trees. The one occupied nest that we found was an American Robin in the crook of a small, baren tree. Compared to many of the other nesting spots we found, this one was very exposed and didn't look like an optimal spot. This might indicate that the bird is not very fit or dominant relative to its peers. Many of the other empty nests that we found were within dense evergreen shrubs. These were all empty, but while we were snooping around one spot, a robin was singing incessantly at us - likely in an effort to defend its territory. At a different nest we found, we were able to see the difference in the material in different parts of the nest. The bottom was extremely smooth and fine - likely a combination of material choice and the effect of a bird sitting on it so constantly. The outside material was made of larger, distinct twigs and straw pieces, with some down and plastic mixed in. It was hard to tell if the nest was still in use - there was no evidence of a bird being there recently but the nest was in good shape if it was abandoned. We saw a lot of nests up higher in the crooks of tree branches that could've been squirrels' nests or abandoned squirrel nests that were reclaimed by birds. Looking from the outside, these were primarily made of leaves with some largest sticks poking out. These nests were likely constructed in fall - considering the need for easily available, dead leaves. Mini Activity- Sound Map: - Image Submitted Separately on Blackboard with the URL

Date: 4/17/2021
Time: 2:00 - 3:30 pm
Cloud Cover: 60%
Temperature: 46 degrees F
Wind: 2-7 mph
Precipitation: None
Habitats: Suburban and mixed forest

Date - April 4, 2021
Start time - 9:00 am
End time - 10:30 am
Location - University of Vermont Athletic Campus and Burlington Country Club
Weather - temp: 35 degrees F, 60% cloud cover, 2-7 mph winds
Habitat(s) - urban/suburban walking paths, some deciduous and coniferous tree groves, detention pond, and surrounding marsh

There were a good number of non-migratory birds that we encountered today, but the Black-capped Chickadee is one of the most iconic for this region. Despite being small and light, they are surprisingly hardy birds. During the winter, they stock up on seeds, fruits, and frozen insects to survive during the cold nights - usually shivering throughout the night to keep themselves warm. It is also essential that they find a good place to roost, usually small cavities in trees where they can stay insulated. They can be found in coniferous forests because the pine needles provide more shelter and insulation than barren deciduous trees. There are several reasons why BC Chickadees and other birds don't migrate. Migration is energetically expensive and high risk. BC Chickadees are generalists, so they are better able to find food during the winter than specialist insect eaters. Staying during the winter also gives them the ability to find the best roosting spots that they are so reliant on. They also tend to be at the center of mix-species flocks that stick together to drive off predators with mobbing behavior.

We saw a bunch of facultative migrants, including Canada Geese, Red-winged Blackbirds, American Robins, Song Sparrows, and Turkey Vultures. The Canada Geese were already beginning to nest, being an early migrant and early nester. We saw predominantly male Red-winged Blackbirds since they migrate before the females to set up territories. With spring just beginning in Vermont, the ground has thawed out and plants are starting to bud. We saw a few American Robin on the ground, poking around for worms, which probably wasn't possible until a couple of weeks ago. Red-winged Blackbirds were gorging themselves on the high protein tree buds. These birds are coming from tropical environments that have relatively low productivity, so springtime in Vermont provides a lot of abundant food sources. However, Vermont can still get very cold this time of year, causing the ground to refreeze and food sources to be harder to find. Many of these species, like Canada Geese and Mallards, will continue to fly north from here, but this area could very well be the stopping point for a lot of species.

Mini Activity- Frequent Flyer:
Canada Goose: about 1,200 miles
Mallard: 750 miles
Red-winged Blackbird: 800 miles
Song Sparrow: 500 miles
Total: 3,250 miles - not all the migratory species but some

Date - March 21, 2021
Start time - 9:30 am
End time - 11:00 am
Location - Burlington Waterfront along the bike path
Weather - temp: 45° F, wind: 2-5 mph, precipitation: none, 0% cloud cover
Habitat(s) - sandy/rocky shoreline, urban, and some marsh

Walking up the bike path to meet the group at Echo, the first thing I noticed was a couple of Northern Cardinals calling back and forth at each other across the path. As I listened, I picked up on small differences in their calls as they went back and forth - namely differences in the length of the long "what" notes at the beginning of each call. I'm not sure what this means, but it was clear they were communicating over something. I also heard a lot of Canada Goose calls as they flew overhead in V formation in groups of 10+. I believe they honk in an attempt to keep the V formation together, which makes the long migratory flights less energetically costly for the group as a whole.

Two species that I saw a lot of today were Mallards and Ring-billed Gulls. I find it interesting that in some species like the Mallard, the plumages of males and females are dramatically different, but in other species like the Ring-billed Gulls, the plumages of males and females are practically identical. Male Mallards have a very distinct iridescent green head and females are mottled brown across their body. This sexual dimorphism is likely because the males have to attract females with their elaborate coloration - which could be explained by either the handicap principle or sexy son hypothesis. Mallards form breeding pairs in the fall and then migrate together, only parting ways after breeding season. This is something I observed today - all the Mallards I counted were in even numbers.

Ring-billed Gulls on the other hand look exactly the same for males and females. There is likely some type of coloration in the plumage that their ultraviolet-sensitive eyes can pick up on that we can't see. There are only a couple of similarities between the plumages of these two species. They both have black wing-tips which are colored with melanin to provide better structural support. They also both have featherless legs and feet, instead, they have a scaley material that provides better protection for all the uses of their feet. Countercurrent exchange allows them to maintain a warm body temperature despite a lack of insulation in their feet.

Many of the birds I saw today, mainly the ducks, gulls, and geese, were sitting in the water along a part of the shore where the surface ice was melted. Since there were a ton of them in a very shallow area, my guess is that they were simply resting during migration. This is the time of year for it (given circannual rhythms) and it was clear they weren't there to forage for food. Many of these species, such as Canada Geese, will travel with other species during migration, so it makes sense to see such a diverse group doing so. My only question is why they would be resting during the day rather than at night.

Mini Activity- Spishing:
We scared away a few Common Grackels and American Goldfinches with our spishing. While the sound can stress them out, birds are also often curious about it. Black-capped Chickadees particularly can be interested in the sound, and many other species tend to form mobbing groups around them. Small birds will flock around the sound to see if it is coming from a potential threat.

The weather today was a balmy 18 degrees with about 60% cloud cover at 9 am (we walked until 10:30 am). We left the Davis Center circle and walked down to Centennial woods, taking a short route into the woods and back over the hour and a half walk. We walked through a mix of urban environments (prior to the woods), and coniferous and deciduous forest.

The first thing we saw was a flock of about 14 Red Crossbills flying over the parking lot. They could be returning from a short nonbreeding winter season in more southern states - the main strategy that migratory birds use to survive the winter. However, I think most of the birds we saw today were year-round residents that had their own ways of handling the cold. We saw many smaller birds with their feathers fluffed up into little balls, such as the Dark-eyed Juncos who were perched in a dense shrub, likely to stay warm. Most of the birds we saw were in areas of Centennial Woods dominated by coniferous trees, whose needles provide extra insulation compared to the leafless deciduous trees. They were concentrated in large groups there - walking through we would hear the calls of 10 or more different birds who were likely staying together to work together in finding food. This highly populated area had plenty of snags and cavities - valuable resources for staying warm in the winter (more on that later). There was also evidence of squirrels pulling apart pine cones for food, which birds likely scavenge afterward because that is a food source they wouldn't otherwise be able to get at. Birds rely more heavily on fruit, seeds, and nuts during the winter because many of the insects they eat during the summer aren't around. We saw several different species, including the American Robin and Darke-eyed Junco, eating shriveled up berries that had fallen off various shrubs.

One of the most interesting things we saw today was a Barred Owl swooping away in the canopy. We didn't get a great look at it, but a small murder of American Crows followed soon after, squeaking loudly at it to move it away. I could imagine that some smaller birds are more at risk of predation during the winter from larger raptors and birds of prey because the lack of foliage leaves them more vulnerable and many of the other food sources have migrated south. That is why mobbing the predators in the way the American Crows did to the Barred Owl is an important way to fend off predators.

Mini-Activity: Snag Watch
Over the course of the walk, I saw about 15 different dead trees with cavities. They were in various states of quality - some trees were very rotted and the cavities looked to be unoccupied and falling apart. Other trees, particularly white pine, still had bark and the cavities looked to have been made more recently, evidenced by cleaner wood around the cavity entrance. Some of them had blong shapes, showing they were made by Pileated Woodpeckers. In the area we walked through that had a lot of birds, we heard a number of different species that likely used some of the surrounding cavities, including Black-capped Chickadees, White and Red-breasted Nuthatches, Tufted Titmice, and the Barred Owl. Since most of these birds aren't capable of making their own cavities, there is aggressive competition for the best sites. We didn't see any birds going in or out of cavities, but I would bet given the limited nature of them as a resource, most of the cavities I saw were occupied (except for the ones on overly rotted trees). In the winter, they're primary use is roosting to stay warm and protected at night, but during the breeding season they're main purpose is for nesting.

Date - Februrary 20, 2021
Start time - 9:00 am
End time - 10:30 am
Location - UVM Campus, Burlington VT
Weather (temperature, wind speed/direction, precipitation) - temp: 20° F, wind: 5-10 mph NW, precipitation: none, 70% cloud cover
Habitat(s) - An urban/suburban environment with some deciduous tree cover and a bit of coniferous forest at Redstone Woods.

The first birds we saw in flight were 3 Common Ravens flying over the Redstone woods. Compared to the American Crows we say, the Ravens had long wings with a relatively high aspect ratio and long, separated primary feathers. They're probably better adapted for high, soaring flight whereas the Crows are more adapted to maneuverable flight in wooded areas given their more elliptically shaped wings. I could see that the Crows had to do more flapping during flight than the Ravens, showing the different adaptations of wing shape.

We observed the interesting flight patterns of other birds, such as the American Robin which uses its smaller elliptical wings by flapping a bunch, ascending several feet, and then dropping back down before flapping again. This up and down motion looks arduous and they don't seem as adapted to higher soaring flight, but this makes sense given their tendency for staying in the ground in search of worms and berries. The last bird's flight that I'll mention is that of the House Sparrow. They too have small, elliptical wings, which they use to dart around between shrubs and bushes. They seem very explosive and able to move rapidly, but less capable of higher, extended flight. They fly like the Robin, but a smaller, quicker version. One of the reasons House Sparrows may be so comfortable and social around humans is that their quickness makes them less fearful of predation risks.

During our walk, we found a few other interesting birds. We saw a Pileated Woodpecker hammering away high up in a pine tree. There were some elongated holes in the surrounding trees, evidence that Pileated Woodpeckers had been to the Redstone Woods before. We also found one tree on Robinson Parkway that had a bunch of different songbirds, including a Northern Cardinal, Black-capped Chickadee, Red-breasted Nuthatch, White-breasted Nuthatch, Tufted Titmouse, and House Finch. I'm not sure what attracted them to that tree, but I bet there are several bird feeders on that block that they are interested in. They all seemed pretty active too, going in and out of the tree in surrounding bushes.