Galápagos mockingbirds () are endemic land birds whose range is limited to the Galápagos Islands, west of Ecuador in the neotropical region. Galápagos mockingbirds are found year-round on the islands of Fernandina, Genovesa, Isabela, Marchena, Pinta, Santa Cruz, and Santiago.
Members of the subspecies Mimus parvulus parvulus live on the islands of Isabela, Fernandina, Daphne, and Santa Cruz. Those in the subspecies of Mimus parvulus barrintoni live only on Santa Fe Island. Members of Mimus parvulus personatus inhabit the islands of Pinta, Marchena, Santiago, and Rábida. Subspecies members of Mimus parvulus wenmani inhabit Wolf Island. Members of Mimus parvulus hulli live on Darwin Island. Birds of the subspecies Mimus parvulus bauri inhabit only Genovesa Island. (BirdLife International, 2018; McNew, et al., 2020)
Galápagos mockingbirds are terrestrial land birds whose elevation range reaches a maximum of 1,500 meters above sea level. They are commonly found in the forests comprising of gumbo-limbo trees (Bursera graveleons), and dry shrubland with cacti succulents (Optunia megasperma), with large patches of mesquite (Prosopis julifora), and saltbush (Cryptocarpus piriformis). Specifically, on the island of Genovesa, Galápagos mockingbirds can be found in thick red mangroves (Rhizophora mangle). (BirdLife International, 2018; Cody, 2020; Curry, 1989)
Galápagos mockingbirds are endothermic and have bilateral symmetry. Both males and females are usually 25-26cm in length from their short, black beaks to their dark brown tails. Females are 6-8% smaller than males as measured by weight. Females' weight averages 51 grams while males' weight averages 56 grams. Females' and males' wingspans are 110.1mm and 118.0mm, respectively. Beak lengths are 19.6mm in females and 20.3mm in males.
Both sexes have white stripes located on their auriculars. They have yellow irises that are surrounded by blackish-brown lores. Their head color varies in black and brown, colors that continue along their dorsal side. These mockingbirds' anterior wing feathers are dark brown with white stripes and tips. White covers the posterior of their wings and the abdominal cavity which travels to the breasts and collars the nape. Juveniles have a spotted abdominal cavity.
Subspecies are recognized, and they differ in markings. Members of the subspecies Mimus parvulus personatus are larger in size and beak length. Their flanks, posterior to the wing, are a darker shade of brown. Members of the subspecies Mimus parvulus wenmani have a lighter brown shaded head. They also have larger stripes located on the anterior part of the wings. Those in the subspecies Mimus parvulus hulli have black malars and broader white caudad tips on the wings. Although those in the subspecies Mimus parvulus bauri are similar to the former Mimus parvulus hulli have more streaks on the dorsal side and flanks. Members of the subspecies Mimus parvulus barringtoni are similar to Mimus parvulus bauri but have a smaller wingspan. (Cody, 2020; Curry, 1989; Kinnaird and Grant, 1982)
Galápagos mockingbirds are polygynous. Within the groups, there is more than one breeding female. The dominant males of the group are determined by age and if they have bred with the most females. The dominant males decide whether subordinate males can mate with females in the group. Male mockingbirds stay in their natal territory for life, but females tend to join different groups if they find mates from other territories.
Galápagos mockingbirds are cooperative breeders. Parents receive help with their offspring from nonbreeders, other parents in the territory, and relatives of the parents. The helpers will provide nesting materials and protection for the nestlings. (Curry, 1988a; Curry, 1988b; Curry, 1989; Curry and Grant, 1989; Grant, 1983; Kinnaird and Grant, 1982)
Galápagos mockingbirds are seasonally-breeding, iteroparous birds that reproduce sexually and lay eggs. Nesting begins in January or February. Mating occurs only in the wet season, from January through May. Females average 2.6 clutches in one breeding season with 3 to 4 eggs per clutch. Incubation takes approximately 12 to 13 days. The fledgling period is approximately 11 to 17 days. Parents continue to feed juveniles up to five weeks after they leave the nest. Juveniles are identified by having spots on the chest and immature plumage from about four to six months of age. Females reach sexual maturity as early as eight months, while males reach sexual maturity a year after their birth. (Curry, 1988a; Curry, 1988b; Curry and Grant, 1989; Grant and Grant, 1979)
Galápagos mockingbirds lay eggs and are altricial at hatching. Mockingbirds are cooperative breeders. Helpers are subordinate males that are unable to breed, nonbreeding females, and relatives of females in the group. Helpers will defend and forage to support the nest. Mothers and helpers take turns providing resources and protection. Male parents tend to the nest less frequently than female parents. This continues until fledglings are independent. Once the juveniles are independent, they stay in the territory of their parents and become a helper. Male and female juvenile mockingbirds, nonbreeding adults, and breeding adults can be helpers. (Curry, 1988b; Curry and Grant, 1989; Grant and Grant, 1979)
Galápagos mockingbirds' longest lifespan recorded for males was eight years, while the longest lifespan recorded for females was six years. However, Curry and Grant (1989) estimated that males may live to 12.1 years and females may live to 9.0 years. They reported that the adult mortality rate is 59% for males and 50% for females.
Galápagos mockingbirds are motile and can fly. They do not migrate, living solely on their natal island. Galápagos mockingbirds are diurnal. Female parents and helpers contribute to building nests in cactus bushes (Opuntia) and other shrubs and certain trees such as Galápagos croton (Croton scouleri), yellow geiger (Cordia lutea), and palo santo (Bursera graveolens).
Galápagos mockingbirds are social and maintain a dominance hierarchy. The dominant male is the oldest in the group and controls the territory using flick-fights and chasing. Other mockingbirds defend this dominant bird and help the breeding pairs with foraging. Lower-ranking males and females will lower their bodies and make loud calls when approached by a dominant bird to show submissiveness. The dominant birds eat first. Submissive birds make rattling noises when begging for food. Mockingbirds produce alarm calls when predators or intruders are nearby. Mockingbirds also have a special "chirrup" call that alerts other mockingbirds to flee the area.
Galápagos mockingbirds recognize other mockingbirds by facial patterns. Hatch (1966) observed mockingbirds approaching one another and peering into their faces before attacking. Mockingbirds will also wing-flash predators by exposing their white feathers under the wings very quickly.
Mockingbirds sunbathe by bowing and fluffing their back wings. They will also lean to one side and raise the upper wing to expose the posterior side of the wing to the sun. Hatch (1966) observed the same movements of sunbathing being done with light rain showers. (Burtt, et al., 1994; Curry, 1988b; Grant and Grant, 1979; Hatch, 1966)
Home ranges and territories have not been quantified. However, territories are maintained by mockingbirds flick-fighting, i.e., flicking their tail up and down quickly. Pecking at the feet ensues if the intruders do not surrender. The intruders may often be chased out of the territory. (Burtt, et al., 1994; Curry, 1989; Grant and Grant, 1979; Hatch, 1966)
Galápagos mockingbirds communicate with one another through loud songs. They do not mimic sounds. Galápagos mockingbirds have an interspecific alarm call for predators nearby. They often use body language to communicate with each other as well. Crouching and turning away is a sign of submission from a juvenile to a parent. Another way of physically communicating to other Galápagos mockingbirds is through flick-fights or dancing. Dancing is a series of tail and wing flicks, as well as moving towards and away from an intruder. Small chirps are made from both parties as well as bystanders. Sometimes dancing would lead to pecking or chasing away the intruder.
Galápagos mockingbirds have adequate eyesight due to their ability to identify other mockingbirds by the markings on the face. They use vision to forage on the ground. Most birds have corpuscles in their tibias so they can sense vibrations while perched. This may help when locating insects in the ground. Galápagos mockingbirds sometimes use tactile receptors on the tongue to determine if something is edible. Galápagos mockingbirds can hear sounds from other mockingbirds or sounds of predators. They can recognize the behavior of other species, like the “cooperative” position that Galápagos land iguanas (Conolophus subcristatus) assume when it wants to be cleaned from dead skin and ticks. (Christian, 1980; Cody, 2020; Curry, 1986; Grant, 1983; Hatch, 1966; Wallace and Mahan, 1975)
Galápagos mockingbirds are omnivores that feed primarily on arthropods. Mockingbirds will forage for nectar from prickly pear cacti (Opuntia helleri), fruits of Galápagos lantana (Lantana peduncularis), and berries from palo santo trees (Bursera graveolens). Galápagos mockingbirds consume eggs of the red-footed boobies (Sula sula) and great frigatebirds (Frigata minor). Curry (1986) observed a mockingbird eating crickets stolen from a Galápagos centipede (Scolopendra galapagaea). He also mentioned that mockingbirds will eat feces, lizards, and carrion but did not identify the species. Galápagos mockingbirds eat leftover food from the teeth of sleeping California sea lions (Zalophus californianus). Mockingbirds will also eat ectoparasites and skin off of Galápagos land iguanas (Conolophus subcristatus) and Santa Fe land iguanas (Conolophus pallidus). If the skin picking causes bleeding, mockingbirds will drink it. Galápagos mockingbirds have been observed preying on invasive house mice (Mus musculus) as well. (Christian, 1980; Cody, 2020; Curry, 1986; Gotanda, et al., 2015; Grant and Grant, 1979; Harris, 1968)
Galápagos mockingbirds' eggs, hatchlings, and adults are preyed on by short-eared owls (Asio flammeus). Predators of eggs and hatchlings are the yellow-crowned night-herons (Nycticorax violacea) and lava herons (Butorides striatus sundevalli). Galápagos hawks (Buteo galapagoensis) also are predators.
Galápagos mockingbirds will emit alarm calls to alert others of nearby predators. Galápagos mockingbirds have been known to wing-flash predators, exposing their posterior white wing feathers very quickly in the direction of predators. The function of the wing-flashing is unclear. (Burtt, et al., 1994; Curry and Grant, 1989; Vitousek, et al., 2007)
Galápagos mockingbirds are insectivores but can be omnivorous, mostly eating insects and seeds. In extreme cases, they eat smaller vertebrates and drink blood. They are prey to some owls and hawks.
Galápagos mockingbirds have a mutualistic relationship with Santa Fe land iguanas (Conolophus pallidus) and Galápagos land iguanas (Conolophus subscristatus). Mockingbirds remove ticks and loose skin while the iguanas sit still. The ticks and loose skin are a food source. They will also remove leftover food items from the teeth of California sea lions (Zalophus californianus).
Galápagos mockingbirds are hosts to ectoparasitic nest flies (Philornis downsi). Nest flies will live in mockingbirds' nests and feed on nestlings and brooding females. McQuistion (1990) found oocysts of an internal parasite, apicomplexans (Polysporella genovesae), present in the fecal matter of the mockingbirds. (Burtt, et al., 1994; Christian, 1980; Cody, 2020; Curry, 1986; Curry and Grant, 1989; Harris, 1968; McNew, et al., 2020; McQuistion, 1990; Vitousek, et al., 2007)
Galápagos mockingbirds are one of the many bird species contributing to the ecotourism on the Galápagos Islands. Around 12,000 tourists visit the Galápagos Islands every year mainly to see the natural beauty of the islands and all of their unique species. Another positive impact is mockingbirds' influence on research and education, as they breed cooperatively and have unique food habits. Galápagos mockingbirds help out in pest control on some of the islands. They have been observed eating invasive house mice (Mus musculus), which were introduced by humans in the 1940s. (de Groot, 1983; Gotanda, et al., 2015; Grant, 1983; Grant and Grant, 1979)
There are no known adverse economic effects of Galápagos mockingbirds on humans.
Galápagos mockingbirds are listed as a species of "Least Concern" on the IUCN Red List. They have no special status on US Migratory Bird Act, the US Federal List, CITES, and the State of Michigan List.
A threat that the Galápagos mockingbirds face is tourism. Tourists bring pathogens, litter, and invasive species that harm the environment and mockingbirds directly. Regulations aim to avoid introducing new diseases and species to the islands. Some islands have designated areas called Intensive Visitor Zones, which allow only 90 people on the shore at a time. Extensive Visitor Zones only allow 12 people at a time. Tourists must walk on marked trails. Since the introduction of domestic birds by humans, Galápagos mockingbirds are affected by avian pox.
The Galápagos Islands are a National Park, which grants Galápagos mockingbirds and all native wildlife protection. Laws and regulations are strictly enforced to reduce pests and minimize harm by tourists. (BirdLife International, 2018; de Groot, 1983; Gillespie and Clague, 2009; Thiel, et al., 2005; Vargas, 1987)
Jenna Blanchette (author), Radford University, Sierra Felty (editor), Radford University, Bianca Plowman (editor), Radford University, Karen Powers (editor), Radford University, Victoria Raulerson (editor), Radford University, Christopher Wozniak (editor), Radford University, Genevieve Barnett (editor), Colorado State University.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
flesh of dead animals.
uses smells or other chemicals to communicate
the nearshore aquatic habitats near a coast, or shoreline.
helpers provide assistance in raising young that are not their own
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
An animal that eats mainly insects or spiders.
animals that live only on an island or set of islands.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
parental care is carried out by males
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
having more than one female as a mate at one time
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
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