Christmas Bird Counts

by Tom Dodd

You don’t have to be an expert birder to participate in National Audubon’s Christmas Bird Counts (CBC)! Many, if not all the count compilers will gladly take a list of the birds that you are seeing at your feeder on the day of their count.

 

In 1900, Frank M. Chapman, an ornithologist, proposed a new holiday tradition that would count birds on Christmas Day rather than hunt them. There were 25 counts on that first day. Fast forward to 2021, and there are now over 2500 CBC’s in the United States, Canada, Hawaii, the Pacific Islands, the Caribbean, and Central and South America.

 

Each bird count is done within a 15-mile diameter circle with 33 count circles located in Massachusetts. Surprisingly, 72% of the Massachusetts Conservation Restrictions that are held by The Trustees are located within CBC circles. Each count has a compiler that is responsible for scheduling the count sometime between Dec 14 and Jan 5 and recording all the bird sightings that were seen on that day. 

"Each bird count is done within a 15-mile diameter circle with 33 count circles located in Massachusetts." 

Most counts are held on the same weekend day each year and have many people participating, by walking trails, looking out over lakes and ponds, recording sightings (both observed and heard) while driving, and waking for early morning listening of owls. Other people participate by sending in their important observations of birds at their bird feeders while sitting comfortably inside their house. So how many people do these counts? The Millis, MA CBC has been done every year since 1973, with nearly 50 years of bird counts! In 1985, a huge effort was made to have 500 participants, with most of those people reporting birds from their feeders. This was an astounding number of people participating that hasn’t been repeated since. Typically, there are 35 participants counting with only a handful of people sending in results from watching their feeder.

 CBC’s are a great resource for monitoring winter bird populations. The Millis, MA Count records an average of 68 bird species each year. Common birds, such as, Black-capped Chickadee, Northern Cardinal, American Crow, and Blue Jay are seen every year. However, that can’t be said for all the species recorded with some interesting trends occurring over the years. Here is a comparison of Count data of what was seen in the first 20 years (1973-1993) versus what was seen in last 20 years (2000-2020). Note that this is a quick analysis. Proper studies would consider the number of hours people were in the field or watching feeders (count hours). But, in general the trends are what is being seen.

 

Bird Species	First 20 years	Last 20 years	Status
Ruffed Grouse	Average of 18/year	6 sightings	Severe decline
Ring-necked Pheasant	Average of 23/year	Average of 3/year	Severe decline (maybe less stocking by state)
Wild Turkey	6 sightings	Average of 59/year	State reintroduction has been successful
Turkey Vulture	No sightings	Average of 4/year in last 10 years	Increasing due to less snow cover?
Bald Eagle	No sightings	Average of 2/year in last 5 years	State reintroduction has been successful
Red-bellied Woodpecker	8 sightings	Average of 23/year	Large Increase – due to warmer winters?
American Kestrel	Average of 10/year	1 sighting	Severe decline – loss of habitat?
American Crow	Average of 1566/year	Average of 419/year	Decline –West Nile Virus affected them in 2000; other causes?
Common Raven	No sightings	Average of 2-3/year in last 10 years	Increase – Reason?
Carolina Wren	Average of 3-4/year	Average of 42/year	Large Increase – due to warmer winters?
Eastern Bluebird	No sightings in first 15 years	Average of 70/year	Large Increase – due to warmer winters? Nest box availability?
American Robin	Average of 32/year	Average of 469/year	Large Increase – due to warmer winters?
Evening Grosbeak	Average of 106/year	No sightings	Severe decline – Reason?

 

For more information, you can contact https://www.audubon.org/conservation/join-christmas-bird-count.

Tom Dodd is the CR Stewardship and Data Specialist at The Trustees. He has been doing the Christmas Bird Count since 1975.