Why Count Birds

Photo credit: Tammie Sanders

A student in Kentucky monitors a nest box. Thousands of citizen scientists are helping The Birdhouser Network to study cavity-nesting birds

Each year, tens of thousands of citizen-science participants are making important contributions to bird studies at the Cornell Lab of Ornithology and other organizations. Why? Many say that they count birds because it enriches their own lives and adds to scientific knowledge and bird conservation. Indeed, their data are helping researchers to investigate far-reaching questions such as the impacts of West Nile virus, global warming, and acid rain on birds. Here we provide an overview of several studies in progress and highlight some citizen-science findings published in leading scientific journals. We hope you'll consider joining these research efforts. Getting involved can be as simple as counting and recording the birds you see when you look out your window or take a walk.

Human Impacts

Studies in progress:
• Birds in Forested Landscapes participants are recording the presence and absence of forest-breeding birds and habitat characteristics to help show how forest fragmentation, acid rain, and recreation are affecting birds.

Why count birds?
Views from project participants...

Ralph Mahler, Napa, CA
Semiretired social worker/program director, 54
“It's just plain fun! I've come to appreciate how much the birds vary in behavior and color.”
eBird, Project FeederWatch, Great Backyard Bird Count

Laura Erickson, Duluth, MN
Producer, Journey North radio program, 51
“Birds just don't have the money or political influence to get sufficient funding to do their own research when they're in trouble, so I'm happy to volunteer my time to help them.”
Golden-winged Warbler Atlas Project

Jennifer Maxwell, Greenville, TX
Fire captain, 40
“For me, it's the best, and probably cheapest, therapy for all the stress that is encountered in life.”
The Birdhouse Network, Project FeederWatch, Christmas Bird Count

Katherine P. Murdock, Hot Springs, SD
Artist, writer, naturalist, retired teacher, 94
“I like to feel that I can help Cornell with its important projects. I've been participating in Project FeederWatch since it began 16 years ago.”

Christine Johnson, Thornton, NH
Biologist/graduate student, 25
“Using long-term data is the only way we can make effective conservation decisions.”
Project FeederWatch

Phil Kahler, Hillsboro, OR
7th –10th-grade science teacher, 40
“Classroom Feeder Watch involves my students in real-life scientific investigations. Bird watching fosters an appreciation for wildlife that cannot easily be duplicated in the classroom by other means.”

Yuliana, Ipala, Guatemala. Student, 11
“It was a great experience to work with my classmates. I am happy to learn about pigeons and tropical forest birds and understand more about nature.”
PigeonWatch

Henry Fansler, Winston-Salem, NC
Instrument calibrator and tester, 55
“Try to imagine the forest in late spring and summer without the song of the Wood Thrush. What a sad loss that would be.”
Birds in Forested Landscapes

• The Birdhouse Network is examining impacts of pesticides on the breeding success of cavity nesting birds.

Published findings:
• Using data from Birds in Forested Landscapes, the Lab of Ornithology published A Land Manager's Guide to Improving Habitat for Scarlet Tanagers and Other Forest-interior Birds in 1999.

• Acid rain has had a strong negative effect on the likelihood that Wood Thrushes attempt to breed in some regions. The data on Wood Thrushes were based on the Birds in Forested Landscapes project and the Breeding Bird Survey (Proceedings of the National Academy of Sciences, 2002, 99:11235–11240).

• Data from the British Trust for Ornithology Common Birds Census showed that increasingly intensive farming in the United Kingdom has caused declines in abundance of many birds over 19 years (Journal of Applied Ecology, 2002).

ClimateChange

Studies in progress:
• The Birdhouse Network is investigating the influence of climate on egg-laying dates and nesting success (see "How Bad Was It ?").

• Great Backyard Bird Count participants are measuring snow depth to determine how snow cover affects annual bird distributions. Preliminary results show that American Robins avoid areas with snow cover www.birdsource.org/gbbc.

• Christmas Bird Count data suggest in preliminary analyses that climate has not played a major role in large-scale shifts in bird species' ranges over the last 40 years.

Published findings:
• First evidence of large-scale impacts of rising temperatures on birds (Nature 1999, 399:423–424). Using 92,828 records spanning 57 years in the British Trust for Ornithology's Nest Record Scheme, researchers found that egg-laying date was related to temperature or rainfall for 86 percent of bird species examined in Great Britain; 37 percent showed long-term trends over time accounted for by changes in climate.

• Tree Swallows have begun laying eggs on average about 9 days earlier over the past 30 years, apparently in response to climate change. Researchers used 3,450 records from the Cornell Lab of Ornithology's North American Nest Record Card Program (1970–1992) and 5 nest record programs in Canada. (Proceedings of the Royal Society of London Series B, 1999, 266: 2487–2490).

Disease

Photp credit: Diane L. Tessaglia-Hymes

Contributing to bird studies can begin with an act as simple as filling a feeder and counting the birds

Studies in progress:
• Christmas Bird Count data are being used to assess the impact of West Nile virus on crows in the Northeast (see "West Nile File"for more information).

• Urban Bird Studies participants are providing valuable data for evaluating the effects of West Nile virus on birds, particularly crows, in urban areas where they are little studied. Year-round results can also help track what happens to crows during the summer, when West Nile virus takes its largest toll.

• Project FeederWatch will be using its extensive database to examine population trends in feeder birds, such as jays and chickadees, in regions where West Nile virus outbreaks have occurred.

• The House Finch Disease Survey is tracking the spread of House Finch eye disease and its effects on House Finch populations.

Published findings:
• Some 180 million fewer House Finches exist today than would have if they had never been exposed to the House Finch eye disease. The disease appears to be regulating the numbers of House Finches in some regions. The findings were based on data collected by participants of the House Finch Disease Survey and Audubon's Christmas BirdCount (Proceedings of the National Academy of Sciences, 2000, 97:5303–5306).

How Your Counts Count

W hether you want to know if global warming is affecting bird populations or why you didn't see many juncos at your feeder last week, finding the answers begins with counting birds and contributing your data to a citizen-science project. Keep in mind that the way that you report data can affect the usefulness of your records.

Many bird watchers use checklists to keep track of birds, marking a check next to the species they see. Checklists show which species were present or absent—data that can be useful in some studies. For example, the Lab's recent findings on the negative effects of acid rain on Wood Thrushes used a protocol that recorded habitat features and the presence or absence of thrushes. If you take the additional step of counting birds, your data become even more valuable. Count data are used in studies of bird abundance and distribution, including assessments of the impact of West Nile virus and climate change on birds.

Some citizen-science projects ask you to indicate whether you are reporting all the birds you see. If you do, your data gain an additional layer of value. In studies of bird distribution and abundance, knowing where a species is absent is as important as knowing where it is seen. Using your data on bird absences, researchers can help determine whether disappearances of birds might have been caused by local events or widespread factors such as drought.

If you keep track of birds at the same location year after year, your data can help address how bird populations change over time. A species may be rare in one year at your locale but common in another. In some cases, fluctuations like these are normal. Scientists need many years of data from the same locale to interpret long-term patterns and changes.

Each year only half of our registered citizen-science participants submit data. Some say that they didn't report their data because they didn't see anything interesting. Don't worry! Your ordinary counts are as valuable to researchers as a once-in-a-lifetime observation. Baseline data are crucial to document normal patterns of changes in bird abundance and distribution and departures from normal variation.

How to Get Involved

Join the Lab's research team! Work toward the understanding and conservation of birds by participating in our citizen-science projects. Follow this link for a list of projects and contact information.