Blog - Page 35 of 53 - Krebs Creek

Scientific Name "Cinclus mexicanus" American dippers, also known as water ouzels, are the only aquatic songbird in the Americas. That's the unique thing about them that sets them apart from all other American songbirds. To be more specific, they're aquatic because they hunt and forage underwater. These birds catch most of their food on the bottoms of rocky, fast-moving mountain streams. American Dipper Characteristics What do American dippers look like? The American dipper or water ouzel is a nondescript grey-colored bird with a stocky build. They are up to 7 inches long from beak to the end of their short tail, and their wingspan is approximately 9.1 inches "23cm". As stated, their bodies are grey, transitioning to a brown stained head. They also have white feathers on their upper eyelids, making it so that it flashes white when they blink their eyes. Their legs are proportionately long for their body size, and the skin color on their legs varies from grey to pink. Their toes are long with curved claws that help them grip the bottoms of swift-moving streams. Male American dippers are slightly heavier than females. They weigh up to 2.01 ounces "57 grams" while females weigh up to 1.80 ounces "51 grams". These birds have some other characteristics that are a little harder to spot that equip them for hunting underwater. First, they have nictitating membranes, and these are the third set of eyelids. Nictitating membranes are transparent and fit over an aquatic animal's eyes so that they can keep them open underwater and yet have them protected. Some other aquatic animals with nictitating membranes are otters, beavers, alligators, and crocodiles. In addition to nictitating membranes, American dippers have a flap in each nostril that closes when they're underwater. American dippers also have a disproportionately large uropygial gland, " also known as the preen gland," that secretes oil to keep their feathers waterproof. This helps keep them dry and warm when they're walking or swimming along the bottoms of cold water mountain streams. American Dipper Range The southern end of the American dipper range is in Panama. From there, their range extends up through central America and north America, through the western United States and Canada, and it ends at the tree line in western Canada and Alaska. There are five different recognized subspecies of American dipper. From Wikipedia, they are as follows. Cinclus mexicanus unicolor- Found in Alaska, western Canada, and the western U.S Cinclus mexicanus mexicanus- Found in the north and central portions of Mexico Cinclus mexicanus anthonyi- Found in Southeastern Mexico, southwestern Guatemala, eastern Honduras, and northwestern Nicaragua Cinclus mexicanus dickermani- Found in Southern Mexico Cinclus mexicanus ardesiacus -Found in Costa Rica and western Panama American Dipper Habitat American dippers will never be far away from swift, clear cold mountain streams. In fact, they prefer streams with steep gradients, boulders, and waterfalls. They use undercut or over-hanging banks for cover and nesting locations. Additionally, they sometimes build their nests behind waterfalls or on cliffs adjacent to mountain streams. American Dipper Behavior An excellent place to find an American dipper is on the bank of a mountain stream. Often they'll stand and rapidly bob their head up and down over the surface of the water or underneath the surface, and they sometimes do this up to 60 times per second. This is how they've earned the name "American Dipper." The cool and interesting thing about these birds is that they earn most of their living underwater. In other words, they dive, hunt, and forage underwater in fast-moving mountain streams. They will either hop from the bank into the water or dive from the air. American dippers have been documented to dive as deep as 20 feet below the water's surface. In the water, they will move either with or against the current, and they can either walk along the stream bottom or swim using their wings for propulsion. They will roll rocks on the stream bed to search for nymphs to feed on or look for small fish and water surface insects to attack from below. American dippers don't migrate in the wintertime. If the streams in their home territory completely frozen over, they might move to slightly lower elevations or to a larger river where the current keeps the channel free from ice. What Do American Dippers Eat? American dippers feed on aquatic insects such as mayflies, stoneflies, dragonflies, damselflies, water beetles, and midges. Additionally, they feed on their nymphs. They also feed on the larvae of mosquitos and small fish and fish eggs. This leads to the question, "What eats American dippers?" On at least one occasion, a large bull trout was documented to have consumed an American dipper, and this stands to reason since these birds sometimes swim around with large predatory trout and char. American Dipper Mating And Nesting Behavior The mating season for these birds occurs in mid-summer. Male American dippers compete for the attention of females with their songs. Once the female has selected her mate, the pair get started building their nest. American dipper nests are round and 8 to 10 inches in diameter. They dip their nest materials in water and weave them together. They make the outer shell of their nest out of moss. On the other hand, the inner chamber of their nest is a cup made from grass, leaves, and bark strips. In a finished nest, the mossy exterior will absorb any moisture and keep the woven grass interior dry. Source They build their nests high up above deep water to make it hard for predators to get to them from below. For example, a cliffside above a deep instream pool is a perfect site for an American dipper nest. The Raising Of Their Chicks Typically, the female will lay 3 to 5 eggs per clutch. She'll have to incubate them for 13 to 17 days. The female does all the incubation while the male provides her with food. When the young are born, they are featherless and helpless. The female will stay in the nest with them for a week or so, while they're unable to regulate their own body temperature. After that, she joins the male to help find food for them. American dipper young leave the nest 24-25 days after birth. At this time, they can already dive and swim. The male and female American dipper split up their brood and continue to care for them for up to three weeks after leaving the nest. These birds are monogamous through the remainder of that year. Some pairs stay together through the winter but generally, after the pair's brood is raised for that year, they go their separate ways.