Foam Lake Birding No. 116

FOAM LAKE BIRDING

No. 116

Whenever I think of transient birds my mind usually recalls the various sparrows such as the White Throated, White Crowned, Harris and Lincolns that occur regularly in our backyards and are presently here. However, there are many other transients, waders for example, that never visit our yards but are quite common in rural areas.

This spring I happened to see several different waders and from that group decided to feature the Lesser Yellowlegs. The Lesser Yellowlegs is a smaller version, a twin as it were, of its close relative the Greater Yellowlegs that was covered in Article No. 22. Just about everything that was said about the Greater can also be said about the Lesser.

So, what are the field marks that can be used to tell them apart? In mixed flocks the size difference is very noticeable and can be used with confidence. If the birds are not in mixed flocks, there are two differences that are not too subtle and can be used to determine which is which. First, the distress call of the Lesser, when scared up, is a rather gentle two note yew yew; the distress call of the Greater is a much more pronounced three note dill dill dill. Second, if the birds are silent, bill length can be used with good reliability in much the same manner as is used to distinguish the Downy from the Hairy Woodpecker. (See Article No. 27). The bill of the Lesser is finer, straighter and shorter than the heavier, slightly up- curved and much longer bill of the Greater. The bill length of the Lesser is just slightly greater than the distance from the base of its bill to the back of its head; The bill length of the Greater is almost twice as great as the distance from the base of its bill to the back of its head.

This week's photo was taken this spring near a widely flooded Waldsea Lake just north of Humboldt. The birds in this instance were easy to identify because they were accompanied by the much larger Willet (not in the picture) which is approximately the same size as the Greater Yellowlegs. In the colour photo the yellow legs really stand out immediately identifying it as one of the two species of Yellowlegs.

Foam Lake Birding No. 22

FOAM LAKE BIRDING
No. 22
Even though fall brings a certain feeling of sadness because of the imminent arrival of winter, it is a good time for birding. This is the time of year to observe birds that nest in the high Arctic in the summer, such as the White Crowned Sparrow, and spend several weeks here before continuing on farther south. One such group of birds is the sandpipers. Sandpipers are relatively small, long legged and long billed wading birds that spend most of their time feeding along the edges of standing bodies of water. There are a number of species that occur locally, at one time or another, during the year.
One of these sandpipers, the Greater Yellowlegs, is this week’s featured bird. Although it migrates through here in the spring, its stopover is quite short. In addition, there are quite a few other sandpipers in the spring, and as a result, Yellowlegs are easily overlooked. In the fall when most waders stop over at larger bodies of water or fly directly to their wintering grounds, the few that do remain are relatively easy to identify. The Yellowlegs is one such species.
The Yellowlegs are easily separated from other small brown wading birds by two distinguishing characteristics. First, the Yellowlegs have yellow legs (naturally). A word of caution is needed here. When feeding in mud, the legs get dirty and may appear dark. (The picture of the Junco in the 19th article showed dark legs even though it was stated that they are pink. The Junco had been feeding on the ground after a rain.) Second, when the Yellowlegs take flight, the tail, though slightly barred, appears to be pure white. The back and wings are grayish brown; the breast and belly are whitish; the head and neck are brownish grey. Like some other sandpipers, they teeter from time to time when standing. Males and females are the same.
Again, to make things more complicated, there are two Yellowlegs – the Greater and Lesser. Other than size, these two slender waders are pretty well identical. There are differences, but they are so subtle that only an experienced birder can use them for identification. The Greater is Robin-sized; the Lesser is the size of a large sparrow. In mixed flocks, which occur commonly, they can be easily separated; in separate flocks it is much more difficult. Thankfully, there actually is one easy way to tell them apart – their vocalizations. When flushed, both birds usually make clear and repeated distress calls. The Greater makes a forceful, shrill and rapid three note dill, dill, dill; the Lesser makes a one or two note more subdued yew, yew. It should be pointed out that applying English words to describe a bird’s sound is somewhat subjective. Different people hear different things. For example, what sounds like dill, dill, dill to one person can sound like dear, dear, dear to another! For many years, ornithologists have tried to eliminate this problem in a variety of ways, some of which (such as musical notes and sonograms), only a music teacher could appreciate. In the end, we reverted back to what we had. It has problems, but it is the best system to date.
Yellowlegs occur in small flocks, perhaps family groups that prefer shallow water. As a result, they can be seen almost anywhere there is some water with muddy shore lines – the muddier the better. The birds shown in this article were feeding in Milligan Creek. The photo was taken off the concrete bridge on highway 310 just west of town.