FJ5 MIGRATION
FJ5 MIGRATION
Date: March 23, 2021
Observation Period: (1)1:00 p.m. – 1:35 p.m. (35 minutes) (2) 2:15 p.m. - 3:00 p.m. (45 minutes)
Location: Harvest Lane, Williston, VT
Weather: 67 degrees F, Sunny, Wind- 12 mph
Habitat: Retail building with adjacent open field, shrubbery and stand of Norway spruce trees behind buildings.
Date: March 24, 2021
Observation Period: 1:10 p.m. - 1:45 p.m. 35 minutes
Location: Gardener's Supply, Williston, VT
Weather: 42 degrees F., Cloudy, Wind-8 mph N.
Habitat: Retail establishment with landscaped grounds including several ponds.
Migration is part of a bird's survival and breeding behavior, but whether or not a bird migrates depends on whether or not it has evolved and adapted to withstand severe winter conditions or whether it has been entrained to react to changes in day length that lead to migration. If resident birds have an adequate food supply and have evolved physiologically to regulate their body temperatures to conserve energy, they will forego the hazards of migration. Migration could expose a bird to risks such as severe weather conditions, predation, mortality by hunters, lack of food, or accidental incidents like a building strike. Resident birds can remain all year as they are able to adapt their food intake to availability during varying seasons. Black-capped Chickadees and House Sparrows can also regulate their body temperature to survive the cold winters and utilize behaviors such as changing plumage (feather positions and molting into thicker plumage), finding microclimates, flocking together and adjusting exposure of extremities. American Crows roost communally at night for warmth and safety from predators. By remaining in place, resident birds can defend their territory and have a location where they are ready to breed rather than moving between breeding and nonbreeding grounds.
There is much variation in migration however, and birds may travel a short distance, a medium distance or a long distance. Obligate migrants may travel either a short distance or long distance, but in general, obligate migrants are long distance migrants that leave their breeding grounds in the northern United States and Canada for wintering grounds in the southern United States and Central or South America. I observed a pair of obligate Ring-necked Duck migrants, on March 24, 2021. If an obligate migrant is here in March, it must adapt to any adverse weather conditions and unpredictable food sources. The pond where these ducks were had been iced over just a few days prior to their arrival. They only stopped to feed and rest for a few days. However, by getting an early start on the journey to their breeding grounds, they will have less competition and more options in establishing a breeding territory.
I saw several facultative migrants during these outings such as Song Sparrow, Red-winged Blackbird, Common Grackle, American Robin, Red-tailed Hawk, Canada Goose and the irruptive species, Red Crossbill. It's interesting to note that in the Macaulay library at Cornell, Red Crossbills are the most recorded bird with over 11,280 recordings. The Red Crossbill breeds at any time of the year, but they don't always breed in the same place from year to year, and, it is difficult for researchers to access sites in the vast boreal forest. The Finch Research Network is now funding tracking studies for the Red Crossbills to better understand their nomadic movement. Ten types based on flight call and bill shape have been identified in North America. It appears that Type 10, the “Eastern” Sitka Spruce Crossbill is the one most observed here. This winter Red Crossbills were forced to move to survive because only one conifer species in their Northeast range produced an adequate cone crop. They venture further south in the winter when there is a shortage of cone crops in the north. I observed them here in two different locations feeding on the seeds of Norway spruce cones and preening.
Frequent Flyer:
Total Miles: Facultative Migrants – 2,927 miles
Obligate Migrants: 621 miles Total: 3,548
Species List: (1) 3-23-2021
2 European Starlings-442 miles
1 American Robin-0
3 Red Crossbills-717 miles
1 Song Sparrow-442 miles
2 Ring-billed Gull-0
2 Red-tailed Hawks-0
Species List: (2) 3-23-2021
2 Song Sparrows
3 Ring-billed Gulls
1 American Crow-0
1 Red-tailed Hawk-0
9 Red Crossbills
Species List: 3-24-2021
2 Canada Geese-442 miles
2 Ring-billed Gulls
1 Mourning Dove-0
2 Ring-necked Ducks-621 miles
1 American Crow
1 American Robin
2 Red-winged Blackbirds-442 miles
7 Common Grackles-442 miles
Marilyn Ramenofsky, Thomas P. Hahn, in Encyclopedia of Animal Behavior (Second Edition), 2019 A Nomadic Facultative Migrant: Red Crossbill
Red Crossbill - an overview | ScienceDirect Topics
Keeping Track of These Boreal Nomads Is Notoriously Difficult | Audubon
Winter Finch Forecast Update: The Nomads – FINCH RESEARCH NETWORK (finchnetwork.org)
Crossbills here, there, and everywhere – FINCH RESEARCH NETWORK (finchnetwork.org)
The Red Crossbill Enigma | Vermont Center for Ecostudies (vtecostudies.org)
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