A Flicker of Hope For an Endangered Flycatcher *

Environmental & Science Education, STEM, Global Change, Climate Change, Sustainability, Nature, Wildlife, Biodiversity, Earth & Space Science, Earth Systems, Geology, Nature of Science, History of Science

Ed Hessler

The natural world and the way humans live are in a running skirmish. The two most obvious of the disputes are suitable habitat - quantity and quality - and the spectre of climate change. It is an asymmetric argument since wildlife and other members of the natural world do not have a voice. They depend on us to speak favorably and persuasively for them.

The StarTribune for October 29, 2023 re-published an article from the Washington Post which alerted me to research which provides evidence for genetic adaptation in at least one bird, the willow flycatcher found in the SW United States. Cornell's All About Birds link provides descriptive material including quite a few images and also sound from their chatter.  This bird has been listed as endangered since 1995. The essay left me wanting to know more so I turned to other sources. 

The first is an story from the Wildlife Society by David Frey who begins "We usually think of evolution as taking place over eons, but researchers found that some endangered birds in California have evolved in just the past century in response to climate change."

'In what they call 'one of the few studies to document climate adaptation in a wild population,' biologists looking at the genomes of southwestern willow flycatchers in San Diego found the birds have developed adaptations to deal with wetter, more humid conditions over a matter of decades." 

Frey follows this with information about the bird, studies on birds and climate change, evolution as well as quotes from lead author, Sheela Turbeck who is now a postdoctoral fellow at Colorado State University.

The full research paper, behind a subscription paywall, was published in Ecology & Evolution. This journal has a feature titled Behind the Paper and Dr. Turbeck's essay tells us about the research and the findings. 

She calls attention to the power of well maintained museum collections. "Our recent paper takes advantage of a rare collection of historical museum specimens dating back to the late 1800s to investigate evolutionary adaptation to climate change in the southwestern willow flycatcher, a bird of conservation concern." Turbeck then describes how the research was done. Her essay includes two maps and a bar graph showing allele shifts in the birds.

This Google Classroom link from Khan Academy for AP Biology discusses the difference is between alleles and genes. It includes a video. And you can go deeper if you'd like.

Unfortunately, not also is well with this population of willow flycatchers. "Despite evidence for climate adaptation, the future is not entirely bright for willow flycatchers breeding in southern California. In fact, the number of willow flycatcher breeding territories continues to steadily decline in San Diego likely as a result of additional stressors such as habitat loss and brood parasitism (see also). Thus, continued habitat restoration efforts will be necessary to save this population from extinction. More broadly, however, this study provides a glimmer of hope for organisms faced with changing climate conditions. In particular, we show that the mixing of genetically distinct populations can increase adaptive potential and likely facilitate species responses to climate change.lowers the temperature. 

I removed two reference numbers which you may find in the original as well as see the full citations used in the preparation of this report. (my emphasis).

Turbeck's essay is short and provides a window into something of great interest to me; how scientists do research and use evidence in coming to a tentative conclusion which I repeat. "Taken together," Turbeck notes, "these findings suggest that willow flycatchers in southern California have some capacity to adapt to changing climate conditions over a century-long timescale."

*Title from essay by Dr. Sheena Turbeck