April 2nd, 2018

On April 2nd, I went on a walk down by the waterfront of Lake Champlain. I went on the walk after my Ornithology class at around 11 am. It was between 45 and 50 degrees and the sun was shining. I heard a lot of different birds like Black-capped Chickadee's, Northern Cardinals, Blue Jays, Tufted Titmice, Woodpeckers, and Nuthatches. I also heard some birds that I couldn't figure out what they were. These birds were in a thicket of trees and were hidden. I only got a picture of one bird but I couldn't really tell what it was. The recording titled Northern Cardinal is from that thicket and you can hear multiple different bird calls and songs during the recording.

All the birds I heard on my walk are year-round residents. Birds like Blue Jays, Black-capped Chickadees, Ravens, Tufted Titmice and many more decide to stay rather than migrate. They might forego migration due to the fact that it is so energetically expensive. They have a better chance of survival and use less energy staying where they are. Since we live in an area that gets pretty cold, they have to be able to survive in the sub-zero weather. These birds have a high reproductive rate but they also have a high mortality rate. To keep warm they will shiver, huddle, fluff out their feathers, go into torpor, etc. Black-capped Chickadees specifically go into facultative hypothermia which helps to conserve heat. They also have ways to cool off during the high temperatures during the summer.

The facultative migrants are coming from the south and stopping by on their way north. Facultative migrants typically move short distances and are flexible with the timing of migration. Since these birds are flexible, they notice when it starts to get warmer/colder and the skies start to clear and they migrate then. We have had a few warmer weeks in March before the snow storms and that might have given these facultative migrants a false sense of the weather. This caused them to move back up north before actual springtime. Obligate migrants are hardwired to migrate at the same time every single year, regardless of warmer or colder weather. Advantages are that they are coming at the beginning of spring and are expecting warm weather with easy access to food. An advantage is that they are most likely coming after the facultative species meaning that they have less competition for food. A disadvantage is in cases like this week, when it snows in April and once again food becomes scarce. The snow along with the cold weather makes it harder to find food and survive for these species that are not used to it.

Mini Activity: Every bird that I saw and heard was a bird that is a year-round resident. Thus they do not migrate and stay in the area.

Publicado el 06 de abril de 2018 a las 11:42 PM por sdurant