San Cristobal mockingbird (Mimus melanotis)

Description

What’s the World’s Favourite Species?

San Cristobal mockingbird fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

San Cristobal mockingbird description

One of the first animals Darwin encountered when he arrived in the Galapagos in 1835 was the San Cristobal mockingbird ^{(3) (4)}. His subsequent discovery of two more species of mockingbird, each occupying a different island and differing subtly in appearance, provided tinder for the incendiary theory of Natural Selection ⁽³⁾. The San Cristobal mockingbird has a somewhat streaked, greyish-brown crown and upperparts, and an almost white throat, chest and belly. Prominent black lores mark the base of its relatively short downwards curving bill and black ear patches are conspicuous below its amber to reddish-brown eyes. The loud and melodious, territorial song of this species is typical of all the Galapagos mockingbirds ^{(2) (5)}.

Also known as

Chatham mockingbird.

Synonyms

Nesomimus melanotis.

Size

Length: 25 - 26 cm ⁽²⁾

Male weight: 53.2 g ⁽²⁾

Female weight: 48 g ⁽²⁾

San Cristobal mockingbird biology

In comparison with the mockingbirds occupying the other islands, the San Cristobal mockingbird is somewhat shy ⁽³⁾. Much of its time is spent foraging through leaf litter for arthropods such as grasshoppers and crickets. Fruits and berries are also taken from low vegetation, and on occasion it can be seen darting amongst the marine iguanas, picking off their ticks ^{(2) (5)}.

Unlike the other mockingbird species, the San Cristobal mockingbird is not known to breed cooperatively ^{(2) (3) (5)}. Instead the relatively large, three to five hectare territories are normally occupied by just a single pair, sometimes accompanied by another adult. Breeding takes place from January to April, with each breeding pair building a bulky twig nest, high up in the crotch of a tree, out of reach of introduced predators ^{(3) (5)}. Incubation of the two to five eggs is left to the female, but both parents share feeding duties ⁽⁵⁾.

San Cristobal mockingbird range

Endemic to San Cristobal Island in the central Galapagos ^{(2) (6)}.

San Cristobal mockingbird habitat

The San Cristobal mockingbird is found in a wide range of habitats all over the island, from mangroves and arid lowland scrub, to taller forest patches and stands of arborescent cacti. However, it does tend to avoid dense lowland forest, wet woodland, grassland and built up areas ^{(2) (5)}.

San Cristobal mockingbird status

Classified as Endangered (EN) on the IUCN Red List ⁽¹⁾.

San Cristobal mockingbird threats

The global population of the San Cristobal mockingbird, restricted to a single island, is believed to be declining as a consequence of human activities ^{(2) (6)}. The introduction of invasive plants and animals, and an increase in the size of the human population, has contributed to the loss and degradation of large areas of habitat on San Cristobal. Furthermore, feral rats and cats are thought likely to be responsible for high rates of predation on mockingbird nests, and there is a growing threat of avian parasites and diseases spreading to mockingbirds from local chicken farms ⁽²⁾.

San Cristobal mockingbird conservation

For their unique biological diversity and significance, the Galapagos Islands are designated both a National Park and a World Heritage Site ⁽²⁾. As a consequence, conservation of the islands’ native fauna and flora is a high priority. One of the priorities for the conservation of the San Cristobal mockingbird to conduct further research to identify which factors are of greatest threat to the species so that appropriate conservation action can be taken ⁽²⁾.

Find out more

For further information on the conservation of endemic flora and fauna of the Galápagos see:

• The Charles Darwin Foundation:
  www.darwinfoundation.org
• Galápagos Conservation Trust:
  www.gct.org

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org

Authentication

Authenticated (01/07/09) by Paquita Hoeck, University of Zurich.
http://www.zm.uzh.ch/zmneu/englisch/forschung_e/forscher_e.php?id=23

Glossary

Arborescent

Having the structure, growth habit or appearance of a tree.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Incubation

The act of incubating eggs, that is, keeping them warm so that development is possible.

Lores

The space between a bird’s bill and eyes.

References

1. IUCN Red List (January, 2009)
   http://www.iucnredlist.org
2. BirdLife International (January, 2009)
   http://www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=6862&m=0
3. Darwin's Mockingbirds (January, 2009)
   http://oikos.villanova.edu/Nesomimus
4. Darwin, C.R. (1845) Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world, under the Command of Capt. Fitz Roy, R.N. 2nd edition. John Murray, London. Available at:
   http://darwin-online.org.uk
5. del Hoyo, J., Elliott, A. and Sargatal, J. (2005) Handbook of the Birds of the World. Volume 10: Cuckoo-Shrikes to Thrushes. Lynx Edicions, Barcelona.
6. Charles Darwin Foundation. (2006) Charles Darwin Research Station Fact Sheet: Mockingbirds (Nesomimus spp). Charles Darwin Foundation for the Galapagos Islands (AISBL), Galapagos, Ecuador. Available at:
   http://www.darwinfoundation.org/files/species/pdf/mockingbird-en.pdf