The Insectivores

 

Families:

1.     Solenodontidae—Caribbean—2 spp extant
Haitian Solenodon http://www.animalinfo.org/species/solepara.htm. Saliva toxic, introduced through a groove in the second lower incisor.
Cuban Solenodon http://www.animalinfo.org/species/solecuba.htm
Introduction of mongooses, cats, rats, dogs, probably doomed this species.  In Cuba, can buy using the Cuban Solenodon.  Perhaps extinct.

 

2.     Nesophontidae—Recent extinction in the West Indies.  Introduction of rodents, habitat destruction probably contributed.  Last known from 1930.

3.     Tenrecidae—from Madagascar and tropical Africa.  Among oldest Malagasy mammals.  10 genera, 24 species.  One subfamily, Potomogalinae (otter-shrews) is aquatic.  Size from large rat to cat.

4.     Chrysochloridae—golden moles—African, 7 genera, 18 species.

Modified claws for digging.  Shiver while asleep.  Iridescent fur with a set.

Claws held under body, rather than at side like the Talpids.


5.    

Erinaceidae—hedgehogs and gymnures—Europe, Asia, Africa.  Common animals, often kept as pets.  Similar to earliest mammals.  17 species in 7 genera.

 


Soricidae—shrews—worldwide  More than 300 species in 23 genera.  Most speciose of all the insectivore families.  Have large first incisors with secondary cusp.  A few are aquatic, a few live in deserts, but most prefer moist terrestrial habitats.

.

·       Reduced eyes

·       Incisors generally enlarged and modified (secondary cusp)

·       canines reduced

·       Unspecialized limbs (usually), no saltatory adaptations

·       cheekTeeth have sharp cusps—dilamdodont.

·       Auditory bullae and zygomatic arch lacking

 

 

Physiology—

Some shrews, including the N.A. short-tailed shrew, and Solenodon, are venemous.  Lower incisors have channel into which venom producing salivary glands empty.  Enables taking of larger prey.  Shrews bite at base of skull.

 

http://members.vienna.at/shrew/index.html for shrew info

Evolution—

Earliest eutherians probably insectivores, dentition retained.  The 3 largest Cretaceous groups of mammals are considered to be in this order.

 

 

 

 

 

6.     Talpidae—moles and desmans—primarily holarctic. Most (2/3 or so) are fossorial.  Some moles and desmans are aquatic, a few moles live on the surface.  Dilamdadont molars, but easy to tell from shrews by complete zygomatic arch, auditory bullae.  17 genera, 42 species.

 


 


 

 

 

 

Kentucky insectivores:

I.                Soricidae

A.             Sorex cinereus—masked or common shrew—only around Black Mountain

B.              Sorex longirostris—Southeastern shrew—Western half of state—easily confused with S. cinereus.  Third upper unicuspid smaller than 4th.

 

C.             Sorex fumeus—smoky shrew—rare, eastern half of state—dark grey to black (only others this color are B. b. and C. p., both of which have
short tails).


 


D.             Blarina brevicauda—N. short-tailed shrew—eastern 4/5 of the state  larger than southern, otherwise difficult to distinguish.  Work is mostly chromosomal.


 


E.              Blarina carolinensis—S. short-tailed shrew—western fifth of state—dark grey

F.              Cryptotis parva—least shrew—statewide—short tail distinguishes it from Sorex--grey

 


 


II.             Talpidae

A.             Parascalops breweri—Hairy-tailed mole—eastern fourth of state

B.              Scalopus aquaticus—eastern mole—statewide—nearly naked tail, larger than hairy-tailed

C.            
Condylura crystata—not in state—star-nosed mole—Appalachian ridge

 

Key to Kentucky insectivores:

 

Forefeet enlarged, heavily clawed for burrowing, have zygomatic arch…             Talpidae (moles)

Forefeet not modified for burrowing, no zygomatic arch                                        Soricidae (shrews)

 

 

The moles:

 

Tail heavily furred, simple nose                      Parascalops breweri

Tail mostly naked, simple nose                       Scalopus aquaticus

Nose with 22 'fingers'                                      Condylura crystata (not in KY, but Appalachian distribution)

 

The shrews:

 

1a           Tail very short, less than 1/4 of body length, generally less than 30 mm, ears not readily visible     2

1b           Tail at least 1/2 body length, ears visible                                                                                  Sorex (3)

 

2a           Usually less than 90mm, 3 unicuspids visible from side.                         Cryptotis parva

2b           Usually more than 90mm, robust, 4 unicuspids visible from side           Blarina brevicauda/carolinensis

 

3a           More than 107mm, pelage dark brown to grey                                           Sorex fumeus

3b           Length less than 107mm, chestnut brown                                                   4

 

4a           Length usually greater than 90mm, 3rd upper unicuspid not smaller than 4th         Sorex cinereus

4b           Length usuall less than 90mm, 3rd upper unicuspid smaller than 4th                       Sorex longirostris