Penduline Titmice: Remizidae

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. ∎