By Linda de Kort
One of the most distinctive birds we will see returning to valley wetlands this spring are Black-necked Stilts (Himantopus mexicanus). They will be coming from wintering grounds on the California coast and Central America. You can’t miss them. They have a striking plumage of contrasting glossy black above and snowy white below. They have a dark needle like bill and their most remarkable feature is the long red legs on which they balance. Compared to body size, the Black-necked Stilt has the longest legs of any bird, except the flamingo. In her book, Bird Feats of Montana, Deborah Richie reports that the stilts are one-quarter body and three quarters legs. That is like a 5-foot person walking on 20-foot stilts! The long legs are, of course, a great advantage to these shore birds who forage in marshes and shallow lakes. The taller the bird the deeper it can wade, the higher its vantage point and the larger and more diverse its pantry. At close range you can catch the reflection of their large bright red eyes, which contribute to their excellent vision. They generally probe and peck for their food in the soft mud with their sensitive bills searching for bugs, beetles, caddisflies, mosquito larvae and aquatic plants. You can sometimes see them gracefully sweeping their long necks through the water in pursuit of small fish, which they herd into shallow waters. Black-necked Stilts wade for their food, and will only swim or dive when under duress. Consequently these birds, which are over a foot (from tail to bill), are easily observed from shore if we keep our distance.
The young look very much like the parents but have buffy edges on their back feathers. Last June while visiting the Bear River Bird Refuge we spotted a young stilt that appeared to be in an awkward position (see photo). It seemed to be sitting with its knees bending forward. After some reflection however, we remembered that a bird’s knee is located much further up the limb, hidden underneath its feathers. The area from the ankle to the toes (actually a foot) is what we can see and what we often mistakenly interpret as the leg. So this hatchling was simply taking a rest by squatting on its bent ankles.
This little guy might have only been a day old. Fully developed young leave the nest 24 hours after hatching and are flightless for several weeks. The parents do not feed the young after they hatch; they do however fiercely defend them in their first vulnerable weeks by dive-bombing, wing flapping and high-pitched calls. Predators of adults, hatchlings and eggs include mammals (coyote, raccoons, skunks and fox) as well as other birds (hawks, owls, herons, gulls, ravens and magpies). Both parents are also very involved in nest building. While one mate stands watch, the other forms a depression about 2 inches deep by scraping into the dirt with breast and feet. The nest is then usually lined with grasses, shells, mud chips, pebbles, and bones. The normal clutch consists of 4 eggs and incubation varies from 21-30 days, depending on the temperature. On very hot days the parents have been observed going to the water and wetting belly feathers; they then return to the nest to cool the eggs. Both parents have also been seen submerging shell fragments from the hatchlings in nearby water probably to prevent attraction of predators.
The Black-necked Stilt is abundant in natural and man-made wetlands from the southern United States to the South America. They were first known to breed as far north as Canada in the late 1970’s. Sightings in the northern range are now more numerous which may be a result of global climate change as well as altered land use.
You can soon start looking for these returning migrants to our valley. Typically mating pairs arrive in small numbers in early April. Gael Bissell reported spotting one Black-necked Stilt in the Lower Valley alkaline wetlands during Fish Wildlife and Parks spring waterfowl surveys as early as the last week in March. Bob Lee reports that they have been seen at the Lost Trail Wildlife Refuge, and the Winnies have observed them in early May at the West Valley ponds.. Local ornithologist Craig Hohenberger has also seen them at Blasdel Waterfowl Production Area near Somers where they have built nests. The largest numbers observed have been on the north shore of Flathead Lake in mid-to-late April. Eggs are laid in May and hatch in June, and young begin flying in July. Parents and young are usually gone by late August. So we have a few months ahead to spot these elegant stilts along our shores and in our wetlands. They are unmistakable and unforgettable. Good luck.