Wader

Waders, also known as shorebirds, are a group of birds that belong to the order Charadriiformes. You can often see them along shorelines and mudflats. They look for food like small insects and crustaceans in the mud and sand. In Europe, they are called waders, while in North America, they are often called shorebirds.

There are about 255 different kinds of wader birds, and most of them live near wetlands or coasts. Many of these birds, especially those from Arctic and temperate regions, travel long distances during migration. Some, like the bar-tailed godwit, can fly over 13,000 kilometers non-stop from Alaska to New Zealand.

Smaller wader species are often called "sandpipers," although this name does not always mean they live near sand. The smallest wader is the least sandpiper, weighing just 15.5 grams, while the largest in length is the Far Eastern curlew, measuring about 63 centimeters.

Taxonomy

Waders used to be grouped together in one group, but scientists now know this was too simple. Recent studies show that waders are better understood as several different groups.

Traditionally, waders are split into two main groups with 16 families. The third group, Lari, sometimes includes some wader-like birds as well. These groups include many different kinds of birds such as plovers, sandpipers, and oystercatchers.

Characteristics

Shorebirds are birds that live in wet, coastal areas. They often have long legs that help them walk in shallow water, which is why they are called waders. Many of these birds like places with mud or rocks. They usually move to different places before they breed, and this helps them stay strong for long journeys.

Most shorebirds eat small creatures like insects and small animals that they find in mud or soil. They have special bills that help them feel for food hidden in the mud. Some bigger shorebirds can eat larger animals like insects and small reptiles.

Sexual dimorphism

Like many animals, shorebirds can look different depending on whether they are male or female. These differences can include size, color, and how quick they are. In some species where one male mates with many females, males and females look quite different. In other species where one male mates with one female, males are often just a bit bigger than females.

Sexual selection

One reason shorebirds develop differences between males and females is because of mate choice. Females often prefer males that have certain traits, like being bigger. Bigger males can sometimes win competitions for mates because of their size. In some species, the roles are reversed, and females are bigger and compete for males.

Natural selection

Another reason for differences in shorebirds is natural selection. This means that traits that help birds survive, like having a bigger bill to find food, become common in the group. These traits help the birds live better in their environment. Sometimes, traits that help in finding food can also make a bird more attractive to mates.