Salmonberry Birds in Bellingham

See look how tiny! Photo: Rick Leche, Creative Commons

As I walk through Lake Padden during this spring month, I hear an array of bird calls and songs. Some familiar, and some unfamiliar. Lets be honest, most of them I have no clue how to even begin to identify. However, among the songs that I hear is the distinctive song of a Swainson's Thrush (Ctharus ustulatus). Their songs are very flutelike with an upward spiraling tone. This is super cool, not only because I actually know this bird and can identify it but I see one sitting on some bare branches of a Douglas Fir tree that overhangs on the trail. These sneaky birds are easy to hear, hard to spot and are only here for a short period of time. During the winter months, their little tiny bodies migrate all the way to South America.

Map by Cornell lab of Ornothology

On their journey to Mexico and South America, the Swainson's Thrush travels at night and can cover more than 100 miles in some eight hours of flying. To replenish themselves from the long journey they stop and feed during the day. This may sound like a similar story--eating all day and staying up all night? Well, these birds may have have figured out the secret to college... power naps! It turns out that Swainson's Thrush's take numerous daytime "micro naps" that only last a few seconds. They rest with one eye open and one eye closed. This rests only half of their brain, keeping the other half alert to predators. Pretty efficient for such a small bird! Though their migration patterns are pretty cool, I obviously had no observations of that while at Lake Padden. Some behavioral characteristics that I did notice were:

• Move by short hops along the branches of the tree
• Move its head and body in a very sporadic manner.
• Sings a lot of songs - on average of 7 times in one minute
• Often makes a short whistle noise in between songs
• Once perched on a branch calling or singing, it does not move its feet often (only once every 30 minutes), mostly only moves head. This is possibly to hear other other birds songs better. It seemed to 'listen' and face the way that the other bird calls and songs were coming from.

At this point you might be asking- why is your post titled "Salmonberry Birds in Bellingham?" Well, it turns out that the natural history of the Swainson's Thrush is actually very rich in this area. The Swainson's Thrush is called the Salmonberry Bird by Northwest Coastal Indians because of its frequent nesting and feeding on salmonberry plants. This name also came about about because the birds start to arrive in the Northwest from their winter in the South America around May, when the Salmonberries start to ripen.

Swainson's Thrush in Salmonberry Photo: Mike Yip

As you can tell, the Swainson's Thrush has a lot of cool things about it. However, these birds have had declining populations in some areas, even losses as great as 30%. While the decline in the population is unknown there is some speculation as to why. One hypothesis is the problems on breeding grounds like grazing, development, human activity, and invasions of nonnative plants. But also if you think about the journey that these birds make there is the significant amount of Swainson Thrush's that die from collisions with windows, radio and cell-phone towers as well as tall buildings. Imagining the journey from Bellingham to South America, you could figure how altering stopover sites could also rapidly effect an entire population. 

Now, maybe the next time you're walking though a wooded area, though you might not see the shy bird, you might be able to recognize the call or song as a Swainson's Thrush. Just from knowing its rich history, the miles its travelled, and its declining population, I encourage you to take the time to appreciate its song a little more. 

Sources:

http://www.allaboutbirds.org/guide/Swainsons_Thrush/lifehistory

http://birdnote.org/show/swainsons-thrush-power-napper

http://bna.birds.cornell.edu/bna/species/540/articles/introduction?__hstc=75100365.98088de821c1ed41971f2e810ad6d1e0.1433309574362.1433398376654.1433401961552.4&__hssc=75100365.1.1433401961552&__hsfp=493601307