Journal Entry 4/8
Today, I went on a little birding excursion from 11:30am-12:30pm near my home in southern New Hampshire. It was a cloudy, quiet and cool day of 46˚ Fahrenheit.
Of the species I observed, the year round species were 20 black-capped chickadees, and 3 white-breasted nuthatches. They may chose to forgo migration because they still have food such as seeds or nuts around that can sustain them through the winter. It also maybe more productive for these birds to save their energy for foraging, caring for young and defending their territories in the winter. These birds may have physiological advantages over migrant birds such as a molt that allows them to grow another layer of down feathers to keep warm during the winter. The behavioral adaptations of non migrant birds that I observed were having dominant and bold personalities that helped them go outside their comfort zones in search of resources, and the ability to work with other bird species when foraging.
Short and long migrating species I observed were the 4 red-breasted nuthatches, 6 mourning doves, 1 American goldfinch and either a warbling vireo or a ruby-crowned kinglet (I am not quite sure). American Goldfinches, mourning doves and red-breasted nuthatches do not always migrate south and may stay year round in the north if their food supply is secure and the temperature does not drop too low. Warbling vireos migrate from the southern U.S. and Mexico to the Northern U.S. and along the Canadian border to their breeding grounds over a 2000 mile + journey. A reason warbling vireos migrate south for the winter is because their food sources are berries and insects, which are not as abundant in the north during winter. They return to the North to breed during the spring and summer months because the area is optimal territory for nesting and foraging, there is dense vegetation and abundant resources. If the bird I saw was not a warbling vireo and in fact a ruby-crowned kinglet, then my town in New Hampshire is most likely a pit stop before returning to their breeding grounds farther north to Canada (a 1200 mile + journey), since it is uncommon for this species to breed in southern New Hampshire. These birds migrate because they do not have the adaptations nor the diet to withstand northern winters. Often migrant birds have diets that consist of fruits and insects, which become scarce in winter, and they are not as competitive as the year round birds. In order for migration to be effective, the species survival must offset their mortality. The same logic applies for birds that do not migrate. Some of these migrant birds may find early April in New Hampshire to be a challenge, since there is little food like insects and fruits yet around and the temperature here still being quite cold.
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