Structures spécifiques des peuplements de rongeurs d’agro-écosystèmes et d’écosystèmes «naturels» de la Guadeloupe et de la Martinique

Abstract

The Muridae rodent community of Guadeloupe and Martinique (French West Indies) includes 3 alien species: the Ship Rat (Rattus rattus), the Norwegian Rat (Rattus norvegicus) and the House Mouse (Mus musculus). A 26,740 trap-night effort conducted under standardized sampling methods showed a strong heterogeneity of the species frequency distribution among 4 agricultural ecosystems (sugar cane, banana, cassava and watermelon) and 3 "natural" ones (tropical rain forest and islands or islets covered either totally or partially by a dry vegetation). A second step of the analysis conducted at a smaller space scale, from the surrounding ecosystems of the cultivated areas to the inside of these ones, gave the same result. The House Mouse constituted the majority of the captures in the agricultural ecosystems (56% for the total and 84% for sugar cane specifically). This species is well represented inside the cultivated area and poorly outside. The Ship Rat is well represented in the "savannah" and "thorn-scrub", and in tropical rain forest, habitats that surround sugar cane and banana fields respectively. Statistically less numerous than the others, the Norwegian Rat was nevertheless well represented in the cultivated area devoted to watermelon and cassava, and concentrated in the field margins. The build-up and the optimisation of strategies for controlling the alien rodents in tropical islands are discussed in relation to these results. The build-up of sampling strategies to evaluate epidemiological and environmental risks due to these alien rodents is also discussed. This last discussion was done in the light of a new result showing that 57% of sampled Guadeloupe House Mice hosted Leptospira interrogans on their kidneys.

Epidemiology and molecular study of Leptospira spp. in bats and rodents in the Republic of Guinea

“…In 2004, Pascal M et al showed that cultivated fields act as reservoirs for mice, whereas "savannahs" and tropical rainforests play this role with regard to the black rat; this could justify the wide variation in prevalence observed in our study by species depending on the place of capture [23].…”

“…The Kindia region had the highest number of positive samples (5), followed by N'zérékoré (4). The largest number of samples was taken from the species Rattus rattus (75), followed by Mastomus natalensis (56), S.leucogaster (32), T.thersites (23), Praomus sp. (7), N.hispida (4), Mus musculus and P. daltoni presented the same number of specimens ( 3), E.helvum and Crocidura sp.…”

“…The highest number of samples was recorded in the Pastoria district (58 samples), followed by the districts of : Samoria (52), Koliady II (49), Fommèdè (25), Féréfou II (12), Khabya (6), Dammakhania (3), Yabara (2) and Dadia (1).The highest number of positive cases was registered in Koliady II,14 positive with a percentage of 73.7%, Pastoria 4 positive with a percentage 21.1% and Féréfou II, 1 case with a percentage 5.3%. From this table, we can see that the species M. natalensis was the most frequently encountered (736) out of a total of 801 samples, followed by the species R. rattus (42) and the species P. daltoni (23).…”

Isotopic ecology and extirpation chronology of the extinct Lesser Antillean native rodent Antillomys rayi Brace et al. (2015)

“…Therefore, they have comparable metabolic turnovers and thus similar residence times regarding the integration of environmental isotopic signals (Podlesak et al, 2008;Royer et al, 2013a). Furthermore, the black rat is present in all natural environments of Guadeloupe (Delattre and Le Louarn, 1980;Pascal et al, 2004b;Goedert et al, 2020), whereas the Norwegian rat and House Mouse are more restricted to human-dominated environments (Pascal et al, 2004b). The black rat therefore appears to be the most appropriate species for building a present-day isotopic reference series for comparisons with fossil A. rayi.…”