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  • Carol Millar

North American Bluebird Society Conference

October 29, 2022

By Carol Millar

The North American Bluebird Society held a conference on Zoom. Four scientists presented their research to 64 people who attended. The president of NABS, Bernie Saunders, hosted the meeting. He said that with climate change causing the polar vortex to sink further south alternating with extreme heat causing fires and drought, the expectation is that bird populations, especially migratory birds will decrease rapidly. 

John Sauer, with the Breeding Bird Survey (BBS), studies spacial and temporal trends in bluebird populations. In 1978 there was a very cold winter out east that reduced the Eastern Bluebird population significantly, but they have mostly recovered. Mountain Bluebirds have been declining steadily. From 1970 to 2021, 1.8 million Mountain Bluebirds were lost. The Western Bluebird population, although the lowest in number of all the bluebirds is the most stable.

Tom Auer with Cornell University Laboratory of Ornithology and co-developer of eBird, discussed trends for Mountain Bluebirds from input by citizen scientists. eBird currently has close to 1 million ebirders and it is growing internationally by 20% a year. People enter data about particular bird sightings and their locations and the eBird crew take this data to discover habitat, range, abundance and trends. They have found a broad scale decline in Western North American bluebird populations. A decrease of 34% of bluebirds from 2007 to 2021. However, there has been a slight increase in British Columbia and the Canadian Prairies. One thing they have been able to determine is that exotic grasses like Cheat grass has had a detrimental impact on populations and areas of sage grass restoration has had a very strong and positive impact on bluebird populations. 

Robyn Bailey with Cornell University Laboratory of Ornithology spearheads the American Nestwatch program. The Canadian equivalent is the Birds Canada program. Again, this is based on citizen science, where anyone can input data about birds which is then analyzed to get a broad picture of nestbox bird populations. They get in 1,000 to 1,400 reports a year. Currently, they have 20,529 Mountain Bluebird nest records. One thing they determined is that birds other than Mountain Bluebirds sometimes do take over bluebird nests. House Sparrows are 1.4% responsible, but Tree Swallows are the biggest predators followed by House Wrens. Another result found was that the heat wave last year did not have an impact on Mountain Bluebird populations. Neither are they impacted by light or noise pollution. However, Western Bluebirds are impacted by noise pollution. Predator guards have been found to be useful in creating higher survival rates, with the exception of Western Bluebirds and Bewick Wrens. Questions they are exploring are: Do Mountain Bluebirds migrate earlier with earlier insect arrivals? And, do supplemental feedings of mealworms improve survival rates? 

Brooke Bateman is with Climate Watch with Audubon. Loss of biodiversity goes hand in hand with climate change. Currently, 389 bird species are on the brink of extinction. Grassland birds, such as Mountain Bluebirds, are impacted negatively, as habitat decreases. If climate change can stay below 1.5 degrees, many species can survive. A study, currently in the planning stage, will again involve citizen scientists to help monitor specific birds, including Western and Mountain Bluebirds, to see if birds are shifting their habitat in winter and summer. This study runs in 2023, from Jan. 15 – Feb. 15 and May 15 to June 15. It is thought that Mountain Bluebirds have more success in changing to new habitats, but there are fewer places they can move. 


The conference was concluded with questions and answers and a commitment by the speakers to try to find ways to share information with each other. Great to hear scientific data on what impact climate change is having on bird species. Citizen science is a great asset for these scientists and it is encouraging that their input is significant to various studies. 

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