Field Journal 6 - Migration

For my birding trip I went to the Cheslin Nature Preserve in Embreeville, Pennsylvania. The skies were very clear and it was a warm day in the mid-60s on Monday, April 6. I was out from about 5:30-7:20 to see the birds at dusk. I saw a lot of very interesting birds and heard more that I couldn’t even begin to identify.
Some of the highlights were hearing a Brown Thrasher singing a mimicking call from the top of a tree and counting 8 Ruby-Crowned Kinglets bouncing between a few Eastern red cedars. The Thrasher was singing the entire time I was at the preserve, it was in the same tree that I passed on my way in as I was leaving. There were also many year-round and short distance migrating species; including three different types of woodpeckers and one of my favorite birds, an Eastern Towhee. On such a warm spring day, it was clear that the birds were enjoying the weather and the season as much as I was!
Some of the year-round species that I saw while out on my birding trip were the Northern Cardinal, American Robin, Mourning Dove, Downy, Wood Pecker, Northern Flicker, and Pileated Woodpecker. For the first three species listed, they are generalists and have very adaptable diets, therefore, not requiring them to migrate where their preferred food source is. On the other hand, the woodpeckers have very specific food sources (despite Northern Flickers being more variable) that are present year-round.
The facultative migrant I chose to look into is the Hermit Thrush. It is leaving the its wintering grounds for the Northern United States and Canada very soon, here in Pennsylvania we lie at the northern edge of its wintering range. Their migration is marked by a change in their diets. In the winter, they rely mainly on fruit with some insects, but, as the seasons change and the northern insects begin to breed and hatch, the Hermit Thrush takes advantage of this and migrates. It has an extensive range all the way across North America and from Guatemala to Alaska. The only obligate migrate that I came across was the American Goldfinch. This bird is a partial facultative with some tendency to stay more Northern during the breeding season where the seed crops are very plentiful. In total, the migrants that I saw on my birding trip flew 4,032 miles just to see me!

Publicado el 09 de abril de 2020 a las 02:37 AM por lukebeeson