serikali ya mapinduzi zanzibar care tanzania and department

Rodents (Muridae)
At least three types of rats occur in Pemba all of them introduced species. These
include White - bellied house mouse (Mus musculus gentilis), Brown or Common rat
(Rattus norvegicus) and Black or House rat (Rattus rattus) (Moreau and Pakenham,
1941; Pakenham, 1984). Archeological evidence and past records and studies do not
indicate presence of other rat species in Pemba. Of the three species Rattus rattus is
the most common and abundant rodent in Ngezi forest. It is found in all habitats and
featured more than any other trapped species. There was no sighting or report on the
other two species.
Our sampling yielded only a single species of rodent, Rattus rattus, the Black Rat.
This species is known world wide as a pest of human dwellings, as a destroyer of
fresh and stored food and food products. Rodents and their relationships with people
are increasingly receiving more attention than has been the case in the past (Singleton
et al., 2003). They are important as reservoirs of several diseases, including plague.
On Pemba, however, Rattus rattus is known not only as a pest of dwellings, but it was
in addition trapped in all habitats sampled, including relatively dense forest, in Ngezi
forest reserve. In most forest reserves on the mainland, even in those surrounded by
villages and cultivation, R. rattus is only found at the edge of forest near human
settlements and other native rodent species are known to occur inside forest. In
coastal forests as well as those of the Eastern Arc, usually several species of rodents
are present (Msuya et al. 2004, Burgess et al. 2000, Stanley et al. 1998). Even on
Zanzibar the nearest island to Pemba, at least five species of native rodents are present
(Nahonyo et al. 2002).
On some islands in the Western Indian Ocean region, more extensive studies have
been conducted on the Black Rat in relation to its control, effects on human health,
and on the native endemic species of rodents on those islands. Such is the case on
Madagascar, which also has an endemic rodent fauna (Duplantier & Rakotondravony
1999) and the granitic islands of the Seychelles, which like Pemba, appear to have no
native rodents, but do have both Rattus rattus and Rattus norvegicus; the only other
terrestrial mammals found there are bats (Hill et al. 2003).
Rattus rattus as pest
When reviewing the literature, what is surprising is that there appears to have been
little attention paid to the ecological role of Rattus rattus on Pemba. This species is
recognized as a major pest of man and his crops, but we found no published
references to its abundance, breeding or effects on agriculture and humans on Pemba.
There are numerous studies conducted in many countries on the negative effects of the
Black Rat (as well as other Rattus species) on oil palm plantations and this species is
also known to be a pest of coconuts on Mafia and SongoSongo Islands (K. M.
Howell, pers. observ.; C. A. Msuya, pers. observ. 2005). In addition, studies have
indicated the negative effects of the introduced Black Rat on native fauna, including
birds (Hill et al. 2003).
Rattus rattus as vector of diseases
The Black Rat is widely recognized not only as involved in the transmission of plague
(through the plague bacillus, Yersinia pestis) but also potentially in the transmission
of murine typhus, relapsing fever, leishmaniasis, leptospirosis and many undescribed
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