Canary Shrew

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Canary Shrew
Canary shrew, photographed by Rainer Hutterer

Canary shrew, photographed by Rainer Hutterer

Systematics
Superordinate : Laurasiatheria
Order : Insect eater (Eulipotyphla)
Family : Shrews (Soricidae)
Subfamily : Crocidurinae
Genre : White-toothed shrews ( Crocidura )
Type : Canary Shrew
Scientific name
Crocidura canariensis
Hutterer , Lopez Jurado & Vogel , 1987

The Canary Shrew ( Crocidura canariensis ) is a species of shrew from the genus of the white-toothed shrew ( Crocidura ). It is endemic to the eastern Canary Islands . The species was discovered in 1985 by Rainer Hutterer near La Tiscamanita, north of Tuineje on Fuerteventura and described scientifically in 1987.

features

The Canary Shrew reaches a head-torso length of 5.4 to 7.4 cm, a tail length of 3.1 to 4.8 cm and a weight of 6 to 9.5 g. The fur is predominantly plain chocolate brown. It is dark gray-brown on the back. It's also dark at the bottom. However, the ends of the hair are whitish and make the fur appear speckled. The Canary Shrew has large ears and a long tail covered with whitish hair. The ears and legs appear lighter than the rest of the body because they are also covered with fine, white hair. In contrast to several other representatives of the white-toothed shrew, the Canary Shrew does not have enlarged front claws. The tooth formula is I 3/1 - C 1/1 - P 1/1 - M 3/3. The karyotype is (2n) = 36.

Distribution area

The Canary Shrew only lives on some of the eastern islands of the volcanic archipelago

The Canary Shrew occurs on the islands of Lanzarote , Fuerteventura , Lobos and Montaña Clara . The distribution area covers an area of ​​less than 5000 km². Fossils unearthed in the 1990s indicate that this species also existed on La Graciosa and Alegranza in the past . However, since it was never caught on either island, it is believed that it became extinct there a long time ago. Remnants of the bones of Canary Shrews discovered in owls on La Graciosa and Alegranza are most likely the result of the owls migrating between the islands.

habitat

300 year old lava in the biosphere reserve of Timanfaya in Lanzarote - a habitat of the Canarian Shrew

The habitat includes the Malpais, the barren lava fields on which there is little or no vegetation. The Canary Shrew also inhabits gardens and abandoned farmland near the lava fields, as well as rocky and sandy areas. On Montaña Clara, their occurrence is limited to a single sand dune.

Way of life

The Canary Shrew is very well adapted to the hot and dry conditions of the lava fields (called Malpais in Spanish). It uses lava tunnels that offer a small amount of protection from the weather. This enables the Canary Shrew to survive at surface temperatures of 60 degrees Celsius.

The Canary Shrew feeds mainly on insects and snails in the lava tubes, but their diet varies between the different populations. On Montaña Clara, the main diet consists of seabird carcasses, the Eastern Canary Lizard ( Gallotia atlantica ), a small lizard that weighs less than seven grams. The Canary Shrew is one of the few species of shrew that uses poison to immobilize its prey. The effect of the poison on the Eastern Canary Lizard has been studied in detail. When the Canary Shrew encounters an Eastern Canary Lizard, it attacks with a quick leap and bites the lizard's neck. This injects a neurotoxin that immobilizes the lizard very quickly and paralyzes it for 24 hours or more. The Canary Shrew is capable of consuming the entire lizard, including the legs and innards, in less than an hour. Shrews that have previously consumed food carry their prey away and hide it between the rocks to return later. This is an important strategy for surviving in an environment with uncertain resources.

The Canary Shrew's way of life is secret. She spends most of the day hidden under stones in a hollow space that has been scraped out. However, it is able to move very quickly and with great agility when disturbed. The Canary Shrew is very calm and hardly makes any sounds. The house shrew ( Crocidura russula ), on the other hand, can be heard on many occasions.

In contrast to other mammals of similar size, the Canary Shrew produces small litters made up of one to three juveniles. The gestation period is usually 32 days. Canary shrews are born naked and blind and weigh about one gram at birth. After eleven to twelve days, the young can walk and are breastfed until they are 23 days old. A Canary Shrew caught in the wild lived in human care for five years.

Persistence and Threat

On the small, uninhabited island of Montaña Clara, there are believed to be fewer than 100 specimens of the Canary Shrew

The IUCN classifies the Canary Shrew in the “endangered” category . The number of individuals and the population trend are unknown. Montaña Clara has a tiny population, believed to be less than 100 specimens. The habitat of the Canary Shrew is severely fragmented due to man-made destruction and the spread of natural barriers. The species has a very limited distribution. Rapid urbanization and the expansion of infrastructure within and in the vicinity of the distribution area led to the loss and fragmentation of suitable living space. Dehydration is also a problem. Feral domestic cats occasionally hunt the Canary Shrew. Other introduced species, such as B. Rats and mice are also present on the islands. However, it is not known if they affect Canarian shrew populations. The Canary Shrew is listed in Appendix II of the Bern Convention and in Appendix IV of the Fauna-Flora-Habitat Directive of the European Union . It occurs in several national parks on Fuerteventura, but further research is necessary to determine the environmental and nature conservation requirements.

Systematics

Based on lower jaw measurements, it has been argued that the Canary Shrew should be treated as a subspecies of the Sicilian shrew ( Crocidura sicula ). However, there is morphological, ecological, paleontological and molecular evidence that supports the species status. The genetic distance between C. canariensis and C. sicula suggests that the two species diverged about 5 million years ago.

literature

  • O. Molina: Crocidura canariensis Hutterer, López-Jurado In: Palomo, LJ, Gisbert, J. and Blanco, JC (Eds.): Atlas y Libro Rojo de los Mamíferos Terrestres de España. Dirección General para la Biodiversidad (Spanish), 2008.
  • RD Stone: Eurasian Insectivores and Tree Shrews; An Action Plan for their Conservation. IUCN, Gland, Switzerland 1996, p. 19.
  • Rainer Hutterer: Type specimens of mammals (Mammalia) in the collections of the Zoologisches Forschungsmuseum Alexander Koenig, Bonn. In: Bonn Zoological Bulletin. Volume 59, pp. 3-27.

Individual evidence

  1. ↑ Rainer Hutterer: Type specimens of mammals (Mammalia) in the collections of the Zoological Research Museum Alexander Koenig, Bonn Bonn Zoological Bulletin. Volume 59: p. 3-27
  2. ↑ a b c Hutterer, R., Lopez-Jurado, LF, and Vogel, P. (1987) The shrews of the eastern Canary Islands: a new species (Mammalia: Soricidae) . Journal of Natural History, 216 (7): 1347-1357.
  3. ↑ a b c d e f g h i j Molina, O. (2008) Crocidura canariensis Hutterer, López Jurado In: Palomo, LJ, Gisbert, J. and Blanco, JC (eds.) Atlas y Libro Rojo de los Mamíferos Terrestres de España . Dirección General para la Biodiversidad
  4. ↑ a b Grzimek, B. (2003) Grzimek's Animal Life Encyclopedia . Second edition. Volume 13: Mammals II . Gale Group, Farmington Hills, Michigan.
  5. ↑ Nowak, RM (1991) Walker's Mammals of the World . The Johns Hopkins University Press, Baltimore and London
  6. ↑ a b c d e f Hutterer, R. 2008. Crocidura canariensis . In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.
  7. ↑ Hutterer, R. 1999. Crocidura canariensis . In: AJ Mitchell-Jones, G. Amori, W. Bogdanowicz, B. Kryštufek, PJH Reijnders, F. Spitzenberger, M. Stubbe, JBM Thissen, V. Vohralík, and J. Zima (eds.), The Atlas of European Mammals , Academic Press, London, UK.
  8. ↑ a b c d Palomo, LJ and Gisbert, J. 2002. Atlas de los mamíferos terrestres de España. Dirección General de Conservación de la Naturaleza. SECEM-SECEMU, Madrid, Spain
  9. ↑ Hutterer, R., Maddalena, T. and Molina, OM 1992. Origin and evolution of the endemic Canary Island shrews (Mammalia: Soricidae). Biological Journal of the Linnean Society 46: pp 49-58.
  10. ↑ Stone, RD 1996. Eurasian Insectivores and Tree Shrews; An Action Plan for their Conservation . IUCN, Gland, Switzerland.
  11. ↑ a b c Lopez-Jurado, LF and Mateo, JA (1996) Evidence of venom in the Canarian shrew (Crocidura canariensis), immobilizing effects on the Atlantic Lizard (Gallotia atlantica). Journal of Zoology, 239 (4): pp 394-395.
  12. ^ Sarà, M. 1996. A landmark-based morphometrics approach to the systematics of Crocidurinae. A case study on endemic shrews Crocidura sicula and C. canariensis (Soricidae, Mammalia) . In: Marcus, LF, Corti, M., Loy, A., Naylor, GJP and Slice, DE (Eds.), Advances in Morphometrics . Tuscany, Italy
  13. ↑ Michaux, J., Hutterer, R. and Lopez-Martinez, N. 1991. New fossil faunas from Fuerteventura, Canary Islands: evidence for a Pleistocene age of endemic rodents and shrews . Comptes Rendus de l'Academie des Sciences (Paris), ser. 2 312 (6): p. 801-806
  14. ↑ Vogel, P., Cosson, JF and Lopez Jurado LF 2003. Taxonomic status and origin of the shrews (Soricidae) from the Canary islands inferred from a mtDNA comparison with the European Crocidura species . Molecular Phylogenetics and Evolution 27 (2): p. 271-82.

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