At the Nest: Western Kingbird Photo Essay

A half century ago, seeing a Western Kingbird in Oregon's Willamette Valley was a rare treat. Even in the drier southern reaches of that valley--around Eugene, Oregon--G.W Guillion (1951) reported encountering no more than 1-2 per year. Over recent decades, Western Kingbirds have become an increasingly common sight in this section of the Willamette Valley (Scheuering 2003). In the narrow valleys and pasturelands that reach into the foothills of the Coast Range southwest of Eugene, one can now expect to encounter a nesting pair of kingbirds every mile or so. While most clutches of Western Kingbirds fledge by the end of June (Gamble and Bergin 1996), some local adults can still be found feeding rapidly growing nestlings well into July. I encountered such a nest on 17 July and spent several minutes taking pictures and observing the comings and goings of the two adults, as well as the in-nest dynamics of the youngsters.

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Two of the three young Western Kingbirds in this nest are clearly visible in this image, while the head of the third is barely poking up behind the bird on the left. Unlike some birds, Western Kingbirds are among the species that immediately take on the appearance of adult birds as they acquire their first set of feathers (also see the image of the fledged juveniles below). Note the yellow underparts, black mask through the eye, gray throat and upper breast, and the greenish-brown wing coverts that these two birds show. (Photo taken by Dave Irons)

One of the expected things I noticed about the nestlings was an apparent pecking order. As seen in the image above, the middle bird (from my viewing angle) seemed determined to keep its head held higher than those of the other two birds. During the entirety of my visit, it had its neck craned out so that the tip of its bill would be higher than the bills of the other two birds. It kept up this behavior even during the long intervals between feedings. When one of the adults returned with food, this bird seemed particularly aggressive in its effort to get fed. From my vantage point, it was difficult to see which nestling was being fed and in what order.

According to Gamble and Bergin (1996), adult kingbirds feed just one nestling per nest visit. I suspect that bird craning its neck was getting fed with greater frequency than the other two. It appeared to be further along in in its development, both in terms of size and feather acquisition. Notice that the yellow on its underparts looks completely feathered with little exposed down. Conversely, the barely visible nestling to the left of this bird remained hunkered down in the nest and was not observed holding its head high and bill open like the others. It seemed to be a bit smaller than its siblings. Based on their feather development, these birds likely hatched about 10-13 days before this observation and this species typically fledges about 16 days after hatching (Gamble and Bergin 1996).

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Here is a slightly different angle showing the two larger nestlings with heads held high, while the third, smaller nestling is out of sight in the nest. These two birds often held their heads up even when the feeding adult was off catching insects and out of sight. (Photo taken by Dave Irons)

While the hatchlings were working things out in the nest, the adults came and went in a highly routinized manner. One adult would assume a "lookout" position on the wire about 2-3 meters from the nest, while the other adult was off capturing insects to feed the young. The lookout bird sat rather stationary, always in the same spot, only occasionally reversing its position on the wire so it would be facing the opposite direction. It remained unagitated and silent even when I was present. After several minutes of calm the lookout bird would suddenly start chattering, hovering, and frenetically hopping about on the wire and within seconds the feeding adult would come flying in to the nest. After the feeding adult filled the bills of a nestling, it would sit on the lip of the nest for a few seconds.

Satisfied that the youngsters were fed and that the feeding adult could now assume the lookout position, the lookout would leave its post and head off to hunt insects. As soon as it flew off, the feeding adult quickly moved into the same lookout position and waited quietly until the next exchange. I watched this exchange routine several times and in each case the lookout adult would commence its chattering before the other adult came into view. On one occasion I was able to spot the feeding adult almost immediately after the lookout bird started chattering and it was still over 50 meters away from the nest. Whether the lookout's chattering is a response to a visual or audio cue, I don't know, but the lookout would usually start chattering a good 5-6 seconds before the other adult arrived at the nest.

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The adult Western Kingbird above maintains a patient lookout position just a few meters from its nest as it awaits the return of its mate. About every 10 minutes it would start chattering, signaling the return of the feeding adult. After feeding the young, the feeding adult (below) lingered for a few moments on the lip of the nest and then assumed the lookout position upon the departure of the other adult. (Photos taken by Dave Irons)

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Like most young birds, these kingbird nestlings display bright yellow at the corners of their gapes and the insides of their mouths are bright orange-red (see image below). Many sources explain that the bright yellow gape mostly serves as a target of sorts for the feeding adult, particularly at low-light nest sites. Studies further suggest that the bright gape coloration may trigger the feeding instincts of the adults. Similar research also showed that if the gape color was reduced or artificially altered, birds with the brightest yellow gapes were fed more frequently (Dan Gleason pers. comm.). Other sources suggest that the intensity of the red/orange inside the mouth may be an indicator of the health of the nestling and may also affect the amount of food that the adults allocate to each nestling (Saino et al. 2003).

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Notice the yellow at the corner of gape and the bright orange inside the mouth of this young kingbird. Brightly colored gapes are found on most young birds, but the function and adult response to this bright coloration is not fully understood. (Photo taken by Dave Irons)

Among those who have experienced the combination of beauty, grace, and utter fearlessness of Western Kingbirds, this species generally ranks high on their list of favorite birds. Kenn Kaufman was so enamored with this species that he used it in the title of his book "Kingbird Highway." In chapter one he describes how this species instantly became his "favorite bird" shortly after his family moved west to Wichita, Kansas. For Kaufman, the fact that this bird had "Western" in its name signified that he must be in the West.

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Hopefully, I'll return in a few days to find a scene similar to the one captured in this image. This sibling group of juvenile Western Kingbirds was photographed earlier this month near Othello, Washington. (Photo taken by Steven Mlodinow)

If one has the good fortune to live or at least travel in western North America during the spring and summer months, this species is a common sight. Whether they are heard chattering overhead, seen perched on a fence wire, building a nest on utility pole, or teed up on big sagebrush, Western Kingbirds are a source of joy for those of us who inhabit their range. They are no longer a surprise when I find them near home, yet I'm thankful that they have become a more common part of my local avifauna.

Literature Cited:

Gamble, Lawrence R. and Timothy M. Bergin. 1996. Western Kingbird (Tyrannus verticalis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/227.

Guillion, G.W. 1951. Birds of the southern Willamette Valley, Oregon. Condor 53:129-149.

Kaufman, Kenn. 1997. Kingbird Highway. Houghton Mifflin Co. New York, NY.

Saino, Nichola, Roberto Ambrosini, Roberta Martinelli, Paola Ninni, and Anders Pape Moller. 2003. Gape Coloration Reliably Reflects Immunocompetence of Barn Swallow (Hirundo rustica) Nestlings. Behaviorial Ecology Vol 14 No. 1:16-22.

Scheuering, Rachel White. 2003. Western Kingbird. Pp. 395-397 in Birds of Oregon: A General Reference. D.B. Marshall, M.G. Hunter, and A.L. Contreras, Eds. Oregon State University Press, Corvallis, OR.


1

Dave,

Great essay. I have a simular one on Eastern Kingbirds and Red-napped sapsuckers at wildinidaho.blogspot.com. Enjoy.

Bill

2

Nice essay – here in IN we get an occasional Western kingbird, usually starting about now until Sept.

3

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