Blog Archive: Bird Terms

Birdorable Turkey Vulture

Bird Term: Allopreening

February 14th, 2019 in Bird Terms No comments
Allopreening Turkey Vultures

Allopreening refers to one animal preening another. While preening and grooming are usually individual actions, in some species, birds or animals will preen one another. This occurs in birds as well as other classes of animal.

We previously mentioned allopreening when discussing vultures during Vulture Week in 2015. The post Glossary of Vulture Terms explained, in part, that "allopreening refers to social grooming between multiple individuals, often performed to strengthen social bonds."

Social bonds may not be the only reason that birds preen or groom one another. Allopreening is most common in species that tend to gather in large flocks. In these species, birds in frequent close proximity to each other are more likely to transfer parasites amongst the close-knit group. Allopreening in these species helps to keep pests like ticks under control.

Allopreening between mated pairs of birds occurs more often in species where both the male and female raise their offspring together. The preening ritual may help strengthen the longer-lasting bond. In mated pairs where the birds may be separated for a long period of time, allopreening is part of a greeting ritual. For example, this type of allopreening occurs when male and female penguins are reunited after a long incubation shift where one of the mates was feeding at sea for days or weeks.

Allopreening may also help to reduce conflict or tensions among large flocks or breeding colonies of birds. The social structure of the colony plays a large part in who receives preening and how much.

Allopreening Eurasian Spoonbills
Allopreening Eurasian Spoonbills by Amy Evenstad
Allopreening Black Vultures
Allopreening Black Vultures by Judy Gallagher (CC BY 2.0)
Allopreening Arrow-marked Babblers
Allopreening Arrow-marked Babblers by Derek Keats (CC BY 2.0)
Birdorable Wild Turkey

Bird Terms: Wattles, Dewlaps, and Snoods, Oh My!

December 11th, 2018 in Bird Terms No comments
Difference between comb, wattle and dewlap

Some birds have fleshy growths hanging or protruding from the head or the neck. When these are a normal part of their anatomy, they are called caruncles.

Caruncles are often made of bare skin, though some may have a sparse covering of small feathers. They are usually bright in color, like the bright red comb of a domestic chicken.

Caruncles are thought to be ornamental in nature, found in male birds and used to attract mates, though caruncles are found in females of some species, too. Large bare patches of flapping skin may also be used to thermoregulate the bird, especially in warm climates.

Some caruncles have specific names depending on where they are found on the body.

Wild Turkey showing snood, wattle and beard by Birdorable

Comb
A comb or cockscomb is a caruncle that grows on the top of the head. Males and females of a species may both have a comb, but it is generally larger in male birds. Combs are found in domestic chickens, like the Faverolles, and related bird species.

Wattle
A wattle is a caruncle that hangs from the head or the neck. Wattles come in a set of two; when one such growth is present, it is known as a dewlap. On the Wattled Crane, the wattles hang from the upper throat and are almost fully feathered. Another wattled bird named for this distinguishing feature is the Long-wattled Umbrellabird.

Snood
A snood is a caruncle that hangs from the forehead, and can extend over the beak. These are found in both the Wild Turkey and domestic varieties. During courtship, the snood elongates and darkens in male birds.

The King Vulture has an unusual caruncle on its beak, which appears as an orange fleshy crest-like protuberance attached to the cere.

Some other species with caruncles include the Masked Lapwing (wattles), Andean Condor (comb and wattles), and the White-winged Guan (dewlap). Can you think of other bird species that have caruncles?

Compare caruncles on birds
Birdorable American Robin

Bird Term: Brood Patch

October 18th, 2018 in Bird Terms 2 comments

A brood patch is a bare area of skin that some birds develop during nesting. The bare skin is an adaptation to help with egg incuabation.

The patch of featherless skin allows the parent bird to provide extra warmth from his or her own body to the eggs in the nest, and to growing, naked, newly-hatched chicks in the first days of life.

Brood Patch on American Robin
Bird banders note brood patch on American Robin by VSPYCC (CC BY 2.0)

Both males and females can develop a brood patch, depending on the species and how incubation duty is shared. In most species, the brood patch develops as feathers are naturally shed during nesting activities. In some species, the brood patch appears through self-plucking. Ducks and geese, for instance, may line their nest with soft breast feathers, exposing the skin.

Canada Goose on Nest
Canada Goose sits on eggs in nest lined with feathers by Bradley Davis (CC BY-ND 2.0)

The location of the brood patch on the adult bird's body depends on the species. Most birds have a single bare patch of skin, while some species may develop two or even three patches.

Fun Fact: Bird banders use the presence of a brood patch to determine if a bird is currently nesting. The presence of a brood patch can also help to sex or age the bird. The patch on most birds is not immediately visible on the bird's body; banders gently blow air on the belly to separate the surrounding feathers to see if a patch is present.

Birdorable Sandhill Crane

Crane Week Bird Term: Precocial

March 30th, 2018 in Bird Terms, Cranes 2 comments
Baby Sandhill Crane with parent

We're celebrating cranes on the Birdorable blog this week! Today we'd like to share a bird term that relates to cranes and other birds. Let's learn about what it means to be precocial!

The term precocial comes from the Latin praecocia, which refers to "places where fruits ripen early." A precocial species is one in which the newly hatched or born young are relatively mature. In birds, this means the baby is usually covered in downy feathers and is able to walk and even feed itself within a short time of hatching. This adaptation is found in most ground-nesting birds as a strategy to evade predators when the nest offers little shelter.

Cranes have precocial young, as do many other birds, including ducks and geese, chickens, and rails. Malleefowl chicks can even already fly within a day of hatching. There are some mammals born precocial, like the Hartebeest, whose calves can stand and walk within hours of being born.

On the other end of the development spectrum are altricial babies. In birds, this usually means at the time of hatching the chick is naked (without feathers), has its eyes shut, and is completely helpless and dependent on its parents for care all of its needs.

Two other terms related to precocial and altricial are nidifugous and nidicolous. Nidifugous species leave the nest site shortly after hatching; all nidifugous species are precocial but not all precocial species are nidifugous. Precocial birds that remain in the nest for a period are called nidicolous.

Birdorable Heermann's Gull

Gull Week Bird Term: Kleptoparasite

February 23rd, 2018 in Bird Terms, Gulls 1 comment

We're celebrating gulls on the blog this week! Today we'd like to share a bird term that relates to some species of gulls. Let's find out about kleptoparasitism!

Seagull chasing juvenile pacific gull
Photo by Jade Craven (CC BY 2.0)

Kleptoparasitism is just what it sounds like - parasitism by theft (klepto-). It basically refers to one animal stealing food from another. Before we go on, it should be made clear that gulls are not the only species that engage in this behavior. They aren't even the only birds that do so.

gulls stealing food
Photo by John Haslam (CC BY 2.0)

Why would one animal steal food from another? In some cases, the thief takes prey items that it would not be able to capture on its own. Sometimes the kleptoparasite steals food opportunistically, or to save the time and effort of obtaining prey. Kleptoparasitism can also refer to the theft of non-food items, like when Chinstrap Penguins steal nest material from other penguins to use in their own nest.

Birds in the seabird family Skua are known for their kleptoparasitic behavior. Some species of skua obtain a significant percentage of their food using this method, stealing prey caught by other seabirds.

Frigatebirds are known for this behavior as well, giving them the appropriate nickname "pirate of the sea".

Gulls can be both perpetrators and victims of kleptoparasitism. Heermann's Gulls and Laughing Gulls are known to steal fish from Brown Pelicans, snatching anything that escapes from the pelican's bill as it surfaces from a hunt. Gulls may chase others of their own species in order to steal freshly caught prey or found food items.

stealing a meal
Photo by Mike Sutton (CC BY 2.0)

Chasing down deep diving fish hunters is a way for non-diving gulls to obtain food not otherwise available.

Stealing from the Mallard
Photo by Micolo J (CC BY 2.0)

Gulls have also been known to steal food from humans! Has this ever happened to you?

Donut thief
Photo by Funk Dooby (CC BY-SA 2.0)
Birdorable Cedar Waxwing

Bird Term: Crop

November 22nd, 2017 in Bird Terms No comments

The crop is a part of an animal's anatomy connected to the digestive system. It is used to store food before digestion. It is common in birds but also found in some species of snails and earthworms, and was present in some dinosaur species.

Cedar waxwing on Seedskadee National Wildlife Refuge
Cedar Waxwing with bulging crop by USFWS Mountain-Prairie

In birds, the crop is an expandable pouch found at the throat and often visible externally, especially when full of food. Not all species of bird have a crop. In pigeons and doves it is used to store food but also to produce a substance known as crop milk to feed their young.

Golden Eagle on Seedskadee NWR
Golden Eagle with full crop by USFWS Mountain-Prairie

Scavenging species like vultures and condors will often feed until they are completely full, and then fill their crop for later digestion. The crop gives the birds a chance to store food for later digestion which is advantageous when it is unknown when the bird will be able to feed again.

Other raptor species, like hawks, eagles, and ospreys, have a crop, but owls do not.

Birds that regurgitate food to their young use the crop to soften the food items before giving it to their chicks.

baby Red-shouldered Hawk
Baby Red-shouldered Hawk with full crop by Amy Evenstad