PENDULINE TITMICE: Remizidae

PHYSICAL CHARACTERISTICS

Penduline titmice (sometimes called penduline tits) are small passerines (PASS-uh-reenz; perching songbirds) with short wings and tails, delicate heads, and straight bills. Plumage (feathers) is the same over the entire body, being dull-colored in both males and females. But the actual body color and shape differs widely among species. Upperparts range from pale grays, whites, and yellows to chestnut and olive green, and underparts range from white to yellow. Some adult species have black masks on the head and deep chestnut on the back. A few species are bright yellow or red. Tail length also varies: some are very short while others are relatively long. Their feet have four toes, all at the same level. The hind toe points backward, allowing them to firmly grip slender perches. One of the more constant features of penduline tits is the bill, which is shaped like a cone with a needle-like point, more sharply pointed than in other titmice. Penduline tits are 3.0 to 4.3 inches (7.5 to 11 centimeters) long and weigh between 0.16 and 0.44 ounces (4.6 and 12.5 grams).

GEOGRAPHIC RANGE

Penduline tits are widely found from Africa through Europe and into Asia. One species, the verdin, is located in North America, specifically in southwest United States and northern Mexico.

HABITAT

Penduline tits are found in a large range of open country habitats including deserts, large reed beds in marshes and along riverbanks, and scrublands and forests.

DIET

Penduline tits eat many invertebrates (animals without backbones), fruits, and small seeds. They grasp food with one foot while pecking at it with their bill. The birds often search in spider's nests and crevices (cracks) in trees.

BEHAVIOR AND REPRODUCTION

Penduline tits are very active and quick birds. They are usually found in pairs or in small groups for most of the year. Species that live in forests are found in the tree canopy (treetops). Because of their ability to move quickly and skillfully, penduline tits easily move through branches and the undersides of twigs and branches. They often roost in groups at night. Penduline tits that live in northern temperate (mild) climates migrate during the breeding season. Others that live in warmer climates are generally sedentary (tend not to migrate, move seasonally). The birds are fairly quiet but do sometimes give out high-pitched calls and songs that range from various notes to others that only repeat certain notes. They sometimes sound a "ti ti ti" followed by a short whistle.

During the breeding season, penduline tits are territorial, but only defend a small area just around the nest. Since the birds use only a small nesting area, other penduline tits will nest close by in a colony-type arrangement; that is where large numbers of birds nest together. The mating system is very complex. Penduline tits can be monogamous (muh-NAH-guh-mus; having one mate) or polygamous (puh-LIH-guh-mus; having more than one mate). Breeding takes place from April to July in northern temperate climates, while in African species, breeding depends on local climates (with some species breeding during the wet season and others breeding during the dry season).

The nests of penduline tits are "pendulous" (meaning that they hang loosely from a base). Nests are found in many different locations such as branches of trees and shrubs and reeds along waters. The shape of nests are usually teardrop or pear-like with a hole near the top; except for one species that builds a cup-shaped nest, which does not hang. A ledge is sometimes built near the entrance, which is fastened together for protection from its enemies. Penduline tits make nests from plant matter that is pressed flat to produce a strong outside covering. It is lined inside with soft grasses, mosses, and lichens (plants growing on rocks).

Females lay white eggs with red spots, except for the species verdin, whose eggs are bluish green. Females lay two to nine eggs. The incubation period (time it takes to sit on eggs before hatching) is between thirteen and seventeen days, and the nestling period (time necessary to take care of young birds before they can leave the nest) is about eighteen days. The caring of the chicks is performed by both parents, with some species using helpers to assist the parents.

PENDULINE TITMICE AND PEOPLE

People show little interest toward penduline tits other than admiring them for their complicated construction of nests. In the past, their nests have been used in eastern Europe as slippers for children and in Africa as purses within certain tribes.

PENDULINE TITMICE NESTS ARE PENDULOUS

Penduline titmice get their name because their nests are pendulous. Pendulous means to hang loosely, which is how their nests are constructed. Male penduline tits build elaborate bag-like nests of feathers and soft plant fibers. Nests hang suspended, usually from tree branches or off of reeds above water.

CONSERVATION STATUS

Penduline tits are not considered to be threatened. Some species, however, are declining in numbers due to increasing amounts of farming and general human development of their habitat.

VERDIN (Auriparus flaviceps): SPECIES ACCOUNT

Physical characteristics: Tiny, rounded short-tailed verdins have a dull yellow head and throat; chestnut shoulder patch; dark gray upperparts, and light gray underparts. They have stout but sharply pointed black bills and strong legs. Males and females look alike. Adults are 4 to 4.5 inches (10 to 11 centimeters) long and weigh between 0.21 and 0.29 ounces (6.0 to 8.2 grams).

Geographic range: Verdin are found in the southwestern United States and Mexico. It is the only species within the family Remizidae that lives in the New World (within the Americas).

Habitat: Verdins prefer arid lowland and hilly scrub desert that contains scattered thorny bushes and cacti (KAK-tie or KAK-tee); they especially like mesquite and creosote bushes.

Diet: Verdins eat invertebrates (such as insects and their larvae and eggs, and spiders), seeds, and fruits such as wild berries. Much of their water is obtained through the eating of fruits and insects. They actively forage for food among twigs, leaves, and buds, sometimes hanging upside down while clinging to twigs and leaves.

Behavior and reproduction: Verdins are usually found in singles or pairs, and in family groups after the breeding season. They do not migrate, being more solitary than other penduline tits. During the winter, they may join other species of birds while foraging. Verdins are very active, flittering about and constantly flicking their tails up. Songs of verdins consist of a gloomy-sounding, three-note series of "tswee-swee, tswee", with the second note higher. Their call is a high-pitched "tseewf" or a lower-pitched "tee-too-too" or "tee-too-tee-tee."

Verdins breed from March to June. They are monogamous and solitary nesters. Nests, which are unique from other penduline tits, are made in the shape of a sphere (ball-like), and constructed by adding several layers of thorny and non-thorny twigs, finally lining the inside with softer materials (such as leaves, grasses, feathers, plant down, and spider's silk). The finished nest is around 8 inches (20 centimeters) in diameter, and may consist of as many as two thousand twigs. Nests are usually near the end of a low limb, or in the fork of a bush or tree, and normally from 2 to 20 feet (0.6 to 6.1 meters) above the ground. Nests are also built 10 or more miles (16 or more kilometers) away from water sources. Males may build several nests within a territory, with the female selecting one of them, which may be then used for several years. The thick walls protect them from the hot desert sun and the cold desert nights. Nests built early in the breeding season have side entrances facing away from cool winds to conserve heat, while those built toward the end of the breeding season face the cooling wind during hot weather.

Females lay a clutch (number of eggs hatched together) of between two and four bluish green eggs (sometimes with reddish brown speckles). Young are brownish gray in coloring, and lack the yellow head and chestnut shoulder patch of adults. The incubation period is fourteen to seventeen days, with the fledging period (time necessary for chicks to grow feathers in order to fly) being from seventeen to nineteen days. Females may have up to two broods (young birds that are born and raised together) a year.

Verdins and people: Verdins have no special significance to humans.

Conservation status: Verdins are not threatened; they are common and increasing in numbers within their habitat. ∎

FOR MORE INFORMATION

Books:

Alsop, Fred J. III. Birds of North America. New York: DK, 2001.

del Hoyo, Josep, Andrew Elliott, Jordi Sargatal, Jose Cabot, et al., eds. Handbook of the Birds of the World. Barcelona: Lynx Edicions, 1992.

Dickinson, Edward C., ed. The Howard and Moore Complete Checklist of the Birds of the World, 3rd ed. Princeton, NJ and Oxford, U.K.: Princeton University Press, 2003.

Field Guide to the Birds of North America, 4th ed. Washington, DC: National Geographic Society, 2002.

Forshaw, Joseph, ed. Encyclopedia of Birds, 2nd ed. San Diego, CA: Academic Press, 1998.

Harrison, Colin James Oliver. Birds of the World. London and New York: Dorling Kindersley, 1993.

Kaufman, Kenn, et al. Birds of North America. New York: Houghton Mifflin, 2000.

Perrins, Christopher M., and Alex L. A. Middleton, eds. The Encyclopedia of Birds. New York: Facts on File, 1985.

Sibley, David. The Sibley Guide to Birds. New York: Alfred A. Knopf, 2000.

Stattersfield, Allison J., and David R. Capper, eds. Threatened Birds of the World: The Official Source for Birds on the IUCN Red List. Cambridge, U.K.: BirdLife International, 2000.

Terres, John K. The Audubon Society Encyclopedia of North American Birds. New York: Knopf, 1980.