Icterid

Icterids are a diverse family of small to medium-sized birds. They are often called New World blackbirds. This family includes 108 different species. These species are organized into 30 different genera.

Many icterids have black feathers. These feathers are often brightened by yellow, orange, or red. The name icterid comes from the Greek word for jaundiced. This refers to the bright yellow colors many species show.

These birds have very specialized ways of feeding. One unusual trait is a process called gaping. In gaping, the skull is built for strength. The bird can open its bill very wide. It does not just open it passively. Instead, it uses force to create a gap.

This allows them to reach hidden food. For example, oropendolas and caciques use gaping to open fruit skins. They use long bills to reach the soft insides. Other icterids have different tools. Cowbirds and bobolinks have short, stubby bills for crushing seeds. The Jamaican blackbird uses its bill to pry into tree bark.

Icterids show extreme variety in their physical traits. They display significant sexual dimorphism. This means males and females look very different. Often, males are larger and more colorful than females. In this family, size differences are uniquely extreme. For example, a male great-tailed grackle is 60% heavier than its female.

The size range is also massive. The smallest is the orchard oriole. Its female averages only 15 cm in length. The largest is the Amazonian oropendola. The male can reach a much larger size and weight. This variation is greater than almost any other passerine family.

These birds live in many different environments. Most icterid species live in the tropics. However, many also live in temperate regions. You can find them in swamps, forests, and savannas.

Some species are migratory. Birds that nest in Canada or the United States move south. They often fly to Mexico or Central America. The highest density of breeding species is in Colombia and southern Mexico. Some species live in large groups. They are colonial nesters. Some colonies can have up to 100,000 birds.

Scientists have worked to understand how these birds are related. The family was first introduced in 1825. An Irish zoologist named Nicholas Vigors named them. He originally placed them in the starling family.

Modern science uses different methods. In 2014, Alexis Powell used molecular phylogenetic studies. This means looking at gene sequences to find relationships. In 2019, Carl Oliveros and his team performed a similar analysis. They found that Icteridae is a sister to the Icteriidae family. The Icteriidae family contains only one species, the yellow-breasted chat. Together, they are related to New World warblers.

Some icterids have complex social behaviors. Cowbirds practice brood parasitism. This is when a female lays her eggs in another species' nest. This is similar to how cuckoos behave. Other species can be difficult for humans. Red-winged blackbirds are considered agricultural pests. In the United States, they can damage crops like rice. In 1994, it cost $30 per acre to control them in California.

Not all species are doing well. Some are threatened with extinction. The Jamaican blackbird and St Lucia oriole face habitat loss. The tricolored blackbird of California is also threatened. This is due to lost habitats and destroyed nests.

Icterids connect to many different parts of nature. Their feeding habits fill specific niches. The Jamaican blackbird fills a role usually held by woodcreepers. Their nesting styles also vary greatly. Some species build pendulous, woven nests. These nests hang down from branches. This variety shows how successful the family has been. They have adapted to almost every type of habitat in the New World. From the smallest oriole to the large oropendola, they are a major part of the bird world.