Blog Archive: Bird Terms

Birdorable Chimney Swift

Bird Terms: Nocturnal, Diurnal, and Other Active-Time Classifications

July 26th, 2019 in Bird Terms No comments
Birdorable Eurasian Eagle-Owl

When most people think of owls, one of the facts that often comes up is that they are nocturnal. Nocturnal animals are most active during the night, sleeping by day. While most owl species are nocturnal, not all are. Adaptations found in nocturnal animals include enhanced eyesight, hearing, and sense of smell. Besides owls, other bird species known for being nocturnal include the Southern Brown Kiwi, the Kakapo, and the Common Nighthawk. Familiar nocturnal animals include bats, raccoons, and fireflies.

Diurnal animals are most active during the day, and sleep at night. For the most part, all animals first evolved to be diurnal. Nocturnal animals later evolved adaptations for being active at night in order to avoid predators and reduce competition with other species. Advanced color vision is an adaptation seen in diurnal animals. While most birds are diurnal, many species migrate at night, mostly to avoid predation. Animals known for being diurnal include most reptiles, pollinator insect species, and primates (including humans).

There are other terms to describe when animals are active:

  • Crepuscular animals are most active during twilight hours, around dawn and around dusk. Examples of crepuscular birds include the Barred Owl and Chimney Swift.
      
  • Cathemeral animals are active during spurts of time during the day and night. The activity is sporadic and occurs at irregular intervals. Cathermal animals are usually active during parts of both daytime and nighttime. Lions and some species of lemur are known for being cathermal.
Birdorable American Robin

Bird Term: Oology

May 24th, 2019 in Bird Terms 1 comment

Oology is the study of bird eggs. It also refers to the study of bird nests and breeding behavior. Oology can also refer to the hobby of egg collecting, which is illegal in many locations.

Early scientific ornithological study often involved collecting birds by shooting them to study their anatomy and plumage up close. It also involved the collection and study of their eggs. Scientists studying the difference between samples of Pergrine Falcon eggs over time were able to identify DDT usage as the cause of a decline in raptor populations in the 1960s and 1970s.

Egg collecting as a hobby remained popular as the scientific value of this type of study declined. This was extremely popular especially in the United Kingdom, though the hobby was denounced by the British Ornithologists' Union as early as 1922. Although UK laws have made the amateur hobby collection of eggs illegal since 1954, oologists continue to pursue the hobby by collecting eggs. Egg collecting is illegal in many other jurisdictions as well, including the United States.

Read more:

Bird egg illustrations
Bird egg illustrations by Biodiversity Heritage Library (CC BY 2.0)
Blue eggs in robin next
Robin nest with eggs by gardener41 (CC BY-SA 2.0)
House Finch eggs
House Finch nest with eggs by John Flannery (CC BY-SA 2.0)
Mallard nest
Mallard nest with eggs by Jeremy Halls (CC BY-SA 2.0)
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.