Hood mockingbird

Nesomimus macdonaldi

TAXONOMY

Nesomimus macdonaldi Ridgway, 1890, Hood Island (Isla Española), Galápagos Archipelago.

OTHER COMMON NAMES

French: Moqueur d'Espanola; German: Galapagos-Spottdrossel; Spanish: Sinsonte de los Galápagos.

PHYSICAL CHARACTERISTICS

11 in (28 cm). Weight not available. Generally variegated dull gray-brown above, off-white below with variable amount of darker spotting on chest. Eye yellow, bill and legs black.

DISTRIBUTION

Confined entirely to Hood Island (Española) in the Galápagos, an island measuring approximately 8 mi long and 4 mi wide (13 by 6.5 km).

HABITAT

Arid scrub; spends much time in seabird colonies.

BEHAVIOR

Totally fearless of humans. The mockingbirds of the Galápagos Islands live in groups, defending communal territories; in the Hood mockingbird the groups are larger than in the other species, at times up to 40 individuals. Groups rapidly adopt any temporary human encampment, investigating unfamiliar objects inquisitively and snapping up any offerings found therein.

FEEDING ECOLOGY AND DIET

Hood is the site of major marine mammal and seabird colonies and the Hood mockingbird, in contrast to species that live on other islands without such colonies, has developed some unique and bizarre feeding habits. The birds will eat blood

from animals' fresh wounds or eat congealed blood from the sand. Engorged ticks and skin are picked from live iguanas. The Hood mockingbird has a more powerful bill than other members of the genus, and uses this to predate the eggs of swallow-tailed gulls (Creagrus furcatus), but larger eggs of boobies and albatrosses are only attacked if already damaged. Other food items include invertebrates, vegetable matter, carrion and feces. Groups whose communal territories do not include a seabird or mammal colony have less varied diets.

REPRODUCTIVE BIOLOGY

Groups of up to 40 individuals occupy and mutually defend a group territory, intruders being intimidated by consolidated displays of aggression. In less optimal territories (e.g., those without access to colonies), group size is smaller. Little published information on nest and eggs; presumably similar to other species of the genus; the Galapagos mockingbird (N. parvulus) builds a cup-shaped nest in a shrub and lays three to four eggs which are blue-green with brown markings.

CONSERVATION STATUS

Not threatened. Within its small range, abundant and not in any obvious hazard. However, introduction of any alien predatory species such as cats would very rapidly change this situation.

SIGNIFICANCE TO HUMANS

Of very great significance with regard to evolutionary and behavioral studies. The Galápagos fauna also has a major economic impact on the finances of Ecuador by virtue of the significant influx of foreign capital from tourism and from visiting zoologists. ♦

Was this article helpful?

0 0

Post a comment