Birdsongs to wake up to in the early morning

Migration Ends – Nesting Begins


It’s been so warm at night that I have left my bedroom’s sliding door open. As a result, I’ve been awakened at about 5:00 a.m. by singing birds (and wide-awake cats who think they need to be fed). Three of my favorite summer birds have now arrived and are starting to sing.

Olive-sided Flycatcher, doing what flycatchers do
Olive-sided Flycatcher, doing what flycatchers do

The first is a local Olive-sided Flycatcher. He’s been singing his song, which sounds exactly like “Quick! Three Beers” from the top of the fir tree. He continues his song all day, off and on, but I didn’t realize he was a dawn singer as well. Both sexes look the same – uniform gray, with a whitish chest. 

Swainson's Thrush
Swainson's Thrush

My second dawn bird species were Swainson’s Thrushes. They have been calling with their characteristic whistled note, transcribed as “Whit!” But this morning, for the first time, I heard the male’s song, an eerie ascending upward flute-like spiral of notes. You don’t have to get up at dawn to hear this song; if your window is open, you can hear them and then drift back to sleep. And, fortunately, they also like to sing in the evening. Again, both sexes look alike in this species.

Black-headed Grosbeak - male
Black-headed Grosbeak - male

My third “favorite spring migrant” is the Black-headed Grosbeak. The notes of his song are vaguely robin-like but stay in a narrow range and can continue burbling along for a minute or more. The male is brightly colored, with an orange body, black head and wings and bold white markings on the wings. The female is much duller colored, but both sexes have large, thick bills.

The Miracle of Migration

There are numerous amazing features of birds’ lives and biology, but none is more amazing than migration. For example, many small North American breeding birds fly non-stop across the Gulf of Mexico twice a year. Audubon News recently reported on that one of the common avian migration paths takes them to southern Lake Michigan and past the tall skyscrapers of Chicago.

Some number of migrants slam into skyscraper windows, falling to the pavement below. And, for years, their remains have been gathered for research and preservation (called the window-strike collection).  One researcher became interested in the gut microbiome of the fallen migrants, focusing on thrushes like the Swainson’s Thrush.

“Microbiome” refers to the entire collection of microbial organisms that live inside a larger organism, including each of us. These microbiota include bacteria, fungi, viruses, and the like that help us digest food and maintain robust life. Each of us – and each bird – includes within it an entire ecosystem of non-human or non-bird cells. One estimate suggests that in humans, the cells of these microbiota outnumber our own cells.

The window-strike study had one remarkable insight: the microbiota of spring migrants and fall migrants were very different. Mammal microbiomes, including our own, are stable over time. In us, new species do not come and go throughout the year. But the microbiome of these birds radically changed with changes to the birds’ diets.  So, it seems that one of the birds’ required adaptations to long-distance migration is multiple annual changes to gut microbiome.  

This made me imagine birds stopping at their favorite yogurt shop along their migration routes for probiotic upgrades. And, as it turns out, this is what they do. The seasonal changes of food sources create radical shifts in a bird’s microbiome. In terms of their insides, they are what they eat. And these changes, as much as stored fat and the like, contribute to successful long-distance migration.

Bird migration biology

The biology of migration was the focus of another research article, which concluded that. some bird species fly 100 hours non-stop between their Canadian breeding territory and their South American wintering grounds. How do they manage that?

Since researchers cannot actually follow migrating birds, they placed ready-to-migrate birds in a wind tunnel and monitored biological changes over their flight time. The results were surprising. It seems that migrating birds initially depend primarily on protein, meaning diminished muscle mass, to fuel their long-distance flights. Only after a portion of the available protein is utilized does the migrating bird turn to its stored fat. This was an entirely unexpected finding and suggests that we have much to learn about bird migration.

Another question, of course, is how migrating birds manage to stay awake during the long migrations. The research didn’t fully answer this question, but did document that one of the study subjects, a Blackpoll Warbler, managed to stay awake and fly for 28 continuous hours, presumably outlasting multiple shifts of research observers.

George Walter is environmental program manager at the Nisqually Indian Tribe’s natural resources department; he also has a 40+ year interest in bird watching. He may be reached at

Photos for this column are provided by Liam Hutcheson, a 15-year-old Olympia area birder and avid photographer.


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  • Terrilovesanimals

    Thank you! I love seeing them come to my yard and actually start trusting me. Happened because I throw out walnuts to my squirrels every day. Then the birds come :) I love it! Nice article!!

    Sunday, June 11, 2023 Report this