Meghan Murphy-Shelburne Bay Park (3/2/19)- Field Notes

This week’s birding excursion took place at Shelburne Bay Park on Sunday, March 2nd. Two other people were present, one of whom was Kayley Dillon, a friend in this class. Our observations will be the same, but all additional work was completed independently. The excursion began at 10:05am, and there was very little wind, quite an overcast sky, and a light snow at start of hike that quickly stopped. The temperature ranged between 30-40°F. The first portion of the hike was made up of mixed forest, consisting of shagbark hickory, bitternut hickory, ironwood, Eastern white pine, Northern white-cedar (usually dead), and possibly American elm. We heard and eventually saw a Black-capped chickadee at the entrance, and heard American Crows calling. After walking for about five or ten minutes, we heard a White-breasted Nuthatch and attempted to pursue it for about fifteen minutes, eventually attempting to attract its attention by pishing. It eventually flew overhead and landed deeper in the forest across the trail, out of sight. We saw an American Crow fly overhead, and pishing brought in three Black-capped Chickadees. We were able to hear the call of a Brown Creeper, though we could not see it.

Further hiking brought us to an area in which one side of trail was bordered by trees and opened into a field with grazing cows, and the other side still contained dense forest. We heard a Tufted Titmouse but did not see it. We saw five birds in a tree in the field who were flushed across the trail by a large flock of about 75 European Starlings, who took over the tree. The five birds who were flushed landed close to the trail edge, and we were able to confirm that they were Eastern Bluebirds. Seven Black-capped Chickadees were also on the trail edge, perching low in bushes, and a few foraged along the ground.

We continued along the trail, and this eventually brought us back into dense forest that contained shrubbier species such as elderberry and common buckthorn. We were able to hear an American Robin, a Northern Cardinal, and several Black-capped Chickadees, though we did not see them. We eventually saw two Black-capped Chickadees near the end of the trail flying in their undulating fashion overhead and landing in a tree. We reached the end of the trail and concluded our excursion at about 12:05pm. Despite numerous woodpecker sign in the form of tree cavities, we only heard potential tapping on three different occasions, and we did not see any of the birds. We were also surprised that there were no signs of Blue Jays at any point. One possible reason for this was that we embarked later in the morning and came across several people and their dogs, so it is possible that this disturbance drove many of the birds to regions of the forest that were away from the main trail.

Winter Ecology
Most of the smaller birds like the Black-capped Chickadees were very puffy, fluffing out their feathers to retain body heat. We saw multiple Black-capped Chickadees foraging among bushes in the second part of the trail, likely looking for small seeds and possibly coming across an occasional small insect. In summer or spring, Black-capped Chickadees would be foraging primarily for small insects. Insects would be more active in the warmer weather and provide protein and energy for the birds. The fact that we failed to see certain species that we expected to see such as woodpeckers and Blue Jays could mean that these species were budgeting their time by resting. Overnight, species on this property most likely take advantage of the numerous tree cavities. Tapping on several of these trees produced no mammalian wildlife sightings, meaning that many of these cavities are unoccupied by mammals and are available for birds to spend the night in.

Snag Mini Activity
There was one small snag near the entrance with no cavities, and another small, thin snag that contained about 15 small round and oval cavities. About ten minutes into the trail, there was another small snag that contained no cavities. A medium sized Eastern white pine (EWP) snag contained two large, rectangular cavities and an additional tall, wide EWP snag contained seven large circular holes. A tall EWP snag had large circular and oval holes. We knocked, but no wildlife came to investigate. We came across a short snag with lots of circular cavities before finding a large Northern white-cedar (NWC) snag with no cavities. This was followed by a tall snag with very few small, circular cavities. A short snag with a big rectangular cavity and smaller, circular ones contained no wildlife when we knocked.

A tall snag with two large, rectangular cavities contained only cobwebs and no spiders large enough that felt it necessary to investigate after we knocked. A large NWC snag with one large, rectangular cavity followed this one. We came across a medium sized, very rotted snag that was covered in huge cavities. A tall, thin snag with very few circular cavities followed. The next was tall with large cavities near the base, and smaller cavities in middle. We knocked, but it produced no wildlife. The final snag was large with shallow circular and rectangular cavities, and it was very rotted. Despite coming across many dead Northern white-cedars, only two had cavities. We theorized that the stringy bark made it difficult to drill into, or perhaps this tree species did not attract palatable prey.

Although none of our disturbances produced any wildlife sightings, snags still provide an important source of shelter for birds, mammals, and invertebrates. In the case of birds like Eastern Bluebirds and Black-capped Chickadees and mammals such as Pine Martens and Gray Squirrels, snags with cavities can provide a warm place to spend the night or overwinter, and some species utilize these cavities to raise young. The abundance of grubs that can be found in the rotting wood provides an important food source for animals such as Pileated Woodpeckers. Snags can also provide nesting sites for birds such as Osprey, and perching sites for numerous species such as hawks.

Publicado el 07 de marzo de 2019 a las 09:24 PM por meghanmurphy