Sunday, November 20, 2022

Viewing Dippers

A very interesting bird found near fast moving streams is the American Dipper. Just like the two named constellations in the sky, the Dipper is easy to recognize. I saw my first one last year in a stream outside Capital Reef National Park. This September, while hiking with family along the Crooked River Trail in the Boise National Forest, North of Idaho City, we saw several. They are a relatively plain looking gray bird, but what they lack in color, they make up for in personality. 

American Dipper preparing to enter the water

Just after we began our hike, we heard a loud melodious song and was wondering what it was. As much as we searched, we could not see a bird, even though it kept singing. The Merlin app identified it as an American Dipper. According to the Cornell Lab's All About Birds website, their loud bouts of singing can last up to ten minutes. We kept walking and continued to keep our eyes peeled as a couple we passed coming in the opposite direction said that they had seen several on their walk. It wasn't long before we heard them chirping and then saw several, either flying over the water, or hopping between rocks and logs. We watched in amazement as they continuously entered the freezing cold water in search of food.

Dipper submerged in the water

Their diet consists mainly of aquatic insects which they will catch underwater, along the surface, or will pick off from rocks and tree limbs. They are very adept at clinging to wet rocks and branches and won't lose their balance. It is interesting to observe them as they dive or walk straight into the current. If you are close enough and the water is clear, you can seem them walk along the riverbed with their wings open as they search for food. They can stay submerged for up to 15 seconds, closing a nasal flap to prevent water inhalation.

 

American Dipper exiting the water

Dippers nest along river banks, under trees or in crevices of rock walls. Some nests may be in locations where they are continuously being sprayed by water, but this is not always the case. An informative paper written by Henry Hann in 1950 about Dippers that were observed in 1947 and 1948 in Colorado can be found online here: https://sora.unm.edu/sites/default/files/journals/condor/v052n02/p0049-p0062.pdf. One interesting observation Hann made was that shortly after the young leave the nest, the adult will removing its lining. The reason for this is unknown, but one theory is that it may better preserve the nest structure for reuse in subsequent seasons.  

This is one bird which you could literally sit and watch for hours and it was the perfect bird to see on the last day of my sister and brother-in-law's visit from Michigan, as they will not be found east of the Rockies. I am happy that they are common in Idaho, and although they are typically found in the mountains they can be seen at lower elevations, particularly in the winter, including the Boise area.   

Resources:

The Condor, Volume 52 no. 2, March-April 1950

National Wildlife Federation/Educ-Guide/Birds/American-Dipper 

The Cornell Lab-All About Birds 

 Audubon Guide to North American Birds