دريجة ألبية
العمر
Dunlins typically live from 21 years and 7 months to 36 years, although the maximum recorded lifespan is 28 years and 10 months, with a theoretical lifespan ranging from 5 years to 31 years. The embryo develops inside an egg and does not feed itself. A dunlin chick hatches covered in down, quickly leaves the nest, and follows its parents; this stage lasts from 1 day to 1 month. The species reaches sexual maturity from 1 month and 3 weeks to 2 years and 2 months. A chick’s eyes open at birth. An adult bird is capable of reproduction, migrates long distances, and possesses a full set of feathers, with the adult stage lasting from 1 to 9 years.
نمط ظاهري
The dunlin has a short bill for finding small prey, and the young have this feature as well; down feathers retain the body heat of the young in the cold tundra. Adult dunlins possess a long, slightly curved bill that helps them extract worms and crustaceans from mud, and they also have short legs enabling them to walk on soft mud and tundra soil. In summer, the species’ plumage features a black spot on the belly and a reddish-brown back, while in winter, the plumage is grey above and white below.
علم وظائف الأعضاء
Dunlins measure in body length from 17 to 22 centimeters; their mass ranges from 40.1 to 48.1 grams, and their wingspan is 36 centimeters. During the embryo stage, the young have a body mass from 16 to 21 grams and a body length from 3.2 to 3.8 centimeters. The fledgling stage sees a body mass from 15 to 35 grams and a body length from 9 to 14 centimeters. Adult dunlins possess a body mass from 40 to 55 grams, and a body length from 17 to 20 centimeters.
الموطن
Dunlins inhabit river estuaries where rivers meet the sea, moderate mixed forests with warm summers and many oak, birch, and maple trees, flooded meadows with abundant grass, shallow coastal waters where crabs reside, and taiga characterized by cold winters and coniferous trees such as spruce and pine. The species’ landscape preferences include freshwater bodies like lakes and ponds, marshes and swamps, marine environments, coastal waters, and terrestrial areas. Dunlins are found in climates with cool summers averaging 15 to 20 degrees Celsius, very hot summers exceeding 25 to 30 degrees Celsius, consistently wet conditions with frequent rain, climates with abundant rainfall and cool summers accompanied by snowfall in winter, and winters with significant snow cover and cold temperatures. The species’ elevation range extends up to 400 meters above sea level.
مأوى
Dunlins are found on dry tundra areas among grass and moss. The species builds or uses a nest structure for laying eggs and raising young. The nest is constructed from moss and grass.
الجغرافيا
Dunlins are found within the Nearctic and Palearctic biogeographical realms, as well as freshwater and marine environments. The species occupies ecosystems including the Taklamakan Desert, Celtic broadleaf forests, broadleaf forests of Western Europe, Euxino-Colchian broadleaf forests, Caledonian coniferous forests, and coniferous forests of the Ziliang Mountains.
التغذية
Dunlins consume small animals found on muddy shores and in tundra; the species forages by pecking at prey from the surface or extracting it from the upper layer of mud. Their diet includes worms, crustaceans, mollusks, insect larvae, and amphipods. The food acquisition strategy involves searching for and obtaining food, with a daily food requirement ranging from 15 grams to 35 grams. Among the items consumed are beetles, butterflies, diptera (true flies), hymenoptera (ants, bees, wasps), bedbugs, orthoptera (grasshoppers, crickets), dragonflies, mayflies, stoneflies, calanids, cyclops, and euphausiids.
تكاثر
The dunlin embryo develops for 3 weeks, and the female builds a simple nest on the ground where she lays four eggs. The clutch size is 3 to 4, and both parents incubate the eggs and protect the young. The species reaches maturity at an age of 1 to 2 years, and the female produces 3 to 4 broods with a reproductive interval of 1 year. A brood consists of 3 to 4 young, and the parents care for them after hatching.