Diario de bfchurch

Date: April 3rd, 2021
Time: 9:15 - 10:51
Location: Burlington Country Club
Habitat: Cleared developmental land with tree patches and water features.
Weather: Partly cloudy, 2 mph NW.
Temperature: 1 C
Species Number: 17
Total Individuals: 51

Some of the year-round species I observed were Black-capped Chickadees, Dark-eyed Juncos, To understand why birds may stay through the cold winter months, it would help to explain why others fly South in the first place. The main driving factor behind migration is food accessibility. Many birds rely on insects and seeds that are plentiful in the warmer months, but not so much in winter. To be able to provide enough food for themselves and their young, birds will fly South where food is more readily available. So, if food is less available in the winter, why are some of these birds staying? It is because there IS still plenty of food, but birds like the Black-capped Chickadee and woodpeckers are much better equipped to access it. Pileated Woodpeckers in particular have long, drill beaks that excavate trees for insects deep within. Because there is a much larger food source available to them, woodpeckers can better provide for themselves. Additionally, woodpeckers may carve out a temporary shelter in a snag for a few days to keep warm. Their ability to make a shelter virtually anywhere is another key factor that allows them to survive the winter.
There are other birds that may float between migrating and toughing out the winter. These are facultative migrators, meaning that they migrate in response to resource conditions rather than an annual point in time. If the going is good, they may stay. If the going gets rough, maybe it is better to head south. An example of these are the American Robins, which are some of the first birds to appear towards the end of winter and early spring. They tend to travel shorter distances for the winter, and this gives them access to some of the best territories when they return in the spring! Their arrival usually follows positive changes in environmental conditions like warm weather.
I am fairly certain we spotted an obligate migrant as well, an Eastern Phoebe. According to Audobon.org they leave late in the fall and arrive in early spring. Because these birds arrive so early, they get premium access to breeding grounds and food sources. The downside is that obligate migrants often don’t know what the conditions will be like when they return. This is especially true for those in Vermont, as we have wildly varying weather!

Mini-Activity: Migration distances. These rough estimates are based on the Breeding/Non-breeding territories of bird species from AllAboutBirds.org. An average point was marked on Google maps within the breeding territory and drawn to another point in the middle of the non-breeding territory. Some birds, like the Song Sparrow, are leap-frog migrators, meaning that the birds that live farther north will travel farther south than the ones that were living further south already. For cases like these, an average distance for far and short migrants was guessed at.

Black-capped Chickadees 0 km
Dark-eyed Junco 2200 km
American Robin 3000 km
American Goldfinch 1000 km
White-breasted Nuthatch 0 km
Eastern Phoebe 2000 km
Song Sparrow 2000 km
Canada Goose 3000 km

Red-winged Blackbird 1200 km
Mourning Doves 3000 km
Turkey Vulture 2000 km
Tufted Titmouse 0 km
Brown Creeper 1200 km
Mallard 1500 km
Rock Pigeon 0 km

Total 22,100 km or 13,732 mi

Date: April 17, 2021
Time: 9:00 - 10:30
Location: Centennial Woods, Burlington VT
Weather: Overcast, post-heavy rain
Habitat: Mixed deciduous and conifer forest patch near urban development

Towards the middle of Centennial Woods we came across a Winter Wren hopping among rocks and logs near the stream. I wondered why it was spending so much time on the ground, chirping and bobbing. I found on AllAboutBirds.org that Winter Wrens usually nest between ground level and twenty-three feet off that ground, and also may hop along the ground to look for food in dead logs or upturned roots. They are also more commonly found in mixed deciduous/conifer forest areas near streams. If that isn't the most apt description.

Date: 24 April 2021
Time: 10:00 - 11:30
Location: Great Hill in Acton, MA
Habitat: Small conservation land with an even mix of deciduous and coniferous trees. A small pond is located at one end of the forest where there is higher foot traffic.
Weather: Clear, blue skies and sunny. 9 mph W wind.
Temperature: 63 F
Species Count: 14

Some behaviors I noticed regarding mate selection and nesting were duetting and a sort of inter-species nest building. In my walk through the woods I heard mostly Tufted Titmice, and usually they came in pairs. I would hear a song from one side of the path, and another song pitched higher or lower immediately following from the other side. I am not sure if the difference in pitch is due to difference in sex or varies by individual, but the songs definitely seemed to be in response to one another. The other thing I noticed was a pair of American Robins that were collecting twigs off the ground, while a squirrel chomped off more sprigs from the top of the tree. This is likely not a true codependence, but a coincidence where the squirrel was able to access food and inadvertently drop nest material for the birds.
One of the coolest finds I made this weekend was of a Barred Owl hiding in its nest. It was holed up in a snag about twenty feet off the ground. I remember hearing chicks in the area last fall but was unable to see them. This owl only peeked the top of its head out of the cavity, and I could not compare its size to the mate, so I could not tell if it was the male or female. It was very cute though. Barred Owls prefer natural cavities high off the ground and tend not to alter the space much. If anything, they may add mosses, pine needles, or other minimal bedding material. This would not be terribly difficult in Great Hill because there are densely packed areas of coniferous trees, as well as swampy areas towards the pond: perfect for gathering lichens and tree sprigs. This family has been around since 2020, and I have read that Barred Owls tend to mate for life and stay in the same area if they are able. So, this couple may have little competition since the forest is on the smaller side. There is likely not much room for another family to occupy. The location of their nest is ideal as it is located near the pond, and I have read that Barred Owls like to live in matured forests with a diverse food selection including fish and frogs (of which there are many in the pond)!

Mini Activity is attached to BB submission.