Rhynchocyon

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Rhynchocyon[1]
Rhynchocyon petersi one.JPG
Rhynchocyon petersi
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Macroscelidea
Family: Macroscelididae
Genus: Rhynchocyon
Peters, 1847
Type species
Rhynchocyon cirnei

Peters, 1847
Species

Rhynchocyon chrysopygus

Rhynchocyon cirnei

Rhynchocyon petersi

Rhynchocyon stuhlmanni[2]

Rhynchocyon udzungwensis

Rhynchocyon is a genus of

Macroscelididae.[1] Members of this genus are known colloquially as the checkered elephant shrews[3] or giant sengis.[4]
It contains the following five species:[5]

Ecology

The giant sengis are

ants, and centipedes, using their proboscises to dig them from the soil and its tongue to lick them up.[9] Their facial morphology limits their diets to tiny invertebrates, and unlike other members of Macroscelidea, do not supplement their diet with foods such as nuts or small fruits.[10]

They typically build ground level nests for shelter[11] requiring dry leaf litter.[12] The primary structure of a nest for R. udzungwensis, for example, consists of the excavation of a cup-like indentation in the soil, layered with leaves, and the covered with looser leaves as a roof covering.[13] They usually construct their nests at the base of trees.[13] They also use hollowed, fallen trees or trunks to retreat in shelter.[10]

They are typically active in the day (diurnal), spending their nights sheltered. Other Macroscelidea species are known to bask in the sun as a method of thermoregulation to save energy.[10] Giant sengis do not bask—and it is most likely due to their adaptation to shaded canopy forest environments.[10]

Sengis live in

estrous.[10] Mating occurs quickly and offspring grow quickly with minimal parental investment—none of which of is paternal.[10]

Each species exhibits distinct and varying coat patterns and colors. Species and subspecies found in denser forests exhibit darker coloration and patterns while open woodland species exhibit lighter, chequers. The darker species R. petersi, R. chrysopygus, and R. udzungwensis still contain

vestigial chequers, but are masked by the blended dark fur between them. This makes coat patterns an unreliable indicator of species delineation.[13]
The species are described as follows:

Taxonomy, distribution, and speciation

The genus' taxonomic status has been difficult to determine due to the very close similarities between populations. Up to ten species have been recognized, but over time they have been regrouped into four species.[2] Recently, R. cirnei, the species with the most subspecies, has had R. c. stuhlmanni separated into its own species based on updated molecular data.[2]

R. chrysopyguus, R. cirnei, and R. petersi are

mtDNA.[16]

Estimated of population size and density vary and can be difficult to determine. However, measurements of the species populations has been undertaken. R. chrysopyguus, in protected areas, is about 150 individuals per square kilometer (about 20,000 individuals); R. petersi is between 19–80 individuals per square kilometer; R. udzungwensis has an estimated 15,000–24,000 individuals. R. udzungwensis has a tiny distribution compared to the other species but resides in a protected forest.[13]

References

  1. ^ .
  2. ^ .
  3. ^ ITIS.gov
  4. . Retrieved 12 November 2021.
  5. ^ Hoffmann Michael; Rathbun Galen B.; Rovero Francesco; Perkin Andrew; Owen Nisha; Burgess Neil (2016). "The distribution of the genus Rhynchocyon in the Eastern Arc Mountains, with an emphasis on the Black-and-rufous Sengi, Rhynchocyon petersi". Afrotherian Conservation. 12: 3–8.
  6. ^ G. Rathbun. (1984). Elephant-shrews, Order Macroscelidea. In : MacDonald (ed), The Encyclopedia of Mammals. Facts on File Publications, New York: 730-735.
  7. S2CID 225142032{{citation}}: CS1 maint: multiple names: authors list (link
    )
  8. PMID 25054806{{citation}}: CS1 maint: multiple names: authors list (link
    )
  9. ^ J. Kingdon (1997), The Kingdon Field Guide to African Mammals, Academic Press, pp. 142–152
  10. ^
  11. ^ a b G. B. Rathbun (1979), "The social structure and ecology of elephant-shrews", Journal of Comparative Ethology, 20: 1–77
  12. S2CID 85816994
  13. ^
    doi:10.1111/j.1469-7998.2007.00363.x{{citation}}: CS1 maint: multiple names: authors list (link
    )
  14. ^ Corbet, G.B., Hanks, J., 1968. A revision of the elephant-shrews, family Macroscelididae. Bull. Br. Museum (Natural Hist.) Zool. 16, 45–111.
  15. ^
    PMID 24015252

External links

Sengis.org is an overview website concerning all the sengi species maintained by researcher Galen B Rathbun of the university of the California Academy of Sciences. It hosts images, videos, bibliographies, among other topics about the order Macroscelididae.