Cycles de reproduction des microchiroptères troglophiles du nord-est du Gabon

Brosset, A.; Girons, H. Saint

doi:10.1515/mamm.1980.44.2.225

Cited by 26 publications

(40 citation statements)

References 3 publications

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“…The spatial scale of their movements remains to be determined, as does whether their movements represent true seasonal migrations, or nomadism. In any case, previous characterizations of these species as 'resident' (Fry et al, 1988;Dowsett & Dowsett-Lemaire, 1993;Christy, 1994) with fixed home ranges of 150 to 'several hundred' hectares (Brosset & Erard, 1986) are not supported by the data. A smaller species, fistulator, does not track fruit resources (at least, not on the same scale as its congeners) and does not exhibit between-site synchrony in abundance, indicating that it is relatively sedentary.…”

Section: Resource Tracking and Large-scale Movementscontrasting

confidence: 61%

Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation

Whitney

Smith

1998

Animal Conservation

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Conservation of tropical forests requires an understanding of the seasonal patterns of abundance and distribution of important seed dispersers. In the forests of Central Africa, three species of hornbills in the genus Ceratogymna (Aves: Bucerotidae) provide dispersal for over 50 species of trees and lianas, yet their ecology is poorly known. We present the first empirical evidence for resource tracking and large-scale movements by two of these species, which were previously considered resident. Hornbill numbers and fruit production were estimated over a one-year period in the Dja Reserve, Cameroon. Monthly abundances of C. atrata and C. cylindricus varied four-and 12-fold, respectively, and were predicted by community fruit availability as measured by fruitfall on a 4·3 km trail. In contrast, C. fistulator abundances varied little and were not related to fruit availability. Synchronous population fluctuations in sites 22 km distant were observed for atrata and cylindricus, but not for fistulator. Together, these results indicate that atrata and cylindricus populations track fruit resources via seasonal emigrations, while the fistulator population appears to be relatively sedentary. Comparisons of hornbill densities in primary and secondary forests suggest that they are important dispersers in both habitats, and will likely play larger roles in central African forest regeneration as more vulnerable seed dispersers are removed by hunting. If large seasonal movements of hornbills turn out to be a general phenomenon, effective management of central African forest reserves will require greater emphasis on reserve connectivity and on seasonal and spatial patterns of fruit production.1 All correspondence to: Kenneth D. Whitney Present address: Center for Population Biology, University of California, Davis, California 95616-8755, USA.evaluating the effects of disturbance on particular dispersers.Disperser populations in tropical forests are also highly affected by the availability of fruit. Fruit exhibits a high degree of spatial and temporal patchiness in most tropical forests (Fleming, Breitwisch & Whitesides, 1987;Fleming, 1992;Jordano, 1992;van Schaik, Terborgh & Wright, 1993). Periods of fruit scarcity and abundance have been related to seasonal cycles of rainfall (Foster, 1982;Fleming et al., 1987), temperature (Tutin & Fernandez, 1993), and insolation (White, 1994a), and are likely controlled by the interaction of these and a variety of other factors (van Schaik et al., 1993). Spatially, large differences in fruit availability have been recorded over distances as small as 2 km (van Schaik, 1986). Frugivores can respond to this spatiotemporal patchiness through resource tracking, with consequences for their demography, physiology, foraging movements, social organization, and mating systems (Fleming, 1992). Resource tracking via daily and/or seasonal foraging movements has been demonstrated for many frugivore taxa; recent discussions include Fleming (1992), Jordano (1992), and van Schaik et al. (1993). Flem...

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Section: Resource Tracking and Large-scale Movementscontrasting

confidence: 61%

Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation

Whitney

Smith

1998

Animal Conservation

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“…Forbes-Watson (1975) mentions an observation of this species by C. Erard in Gabon, and on the basis of this Louette (1981) suggested that it could occur in Cameroon. Erard himself does not mention the observation in two subsequent works (Brosset andErard 1986, Erard 1990), so it is assumed here that the record was not confirmed and that the species is indeed an Upper Guinea forest endemic.…”

Section: Nimba Flycatcher Vulnerablementioning

confidence: 86%

The status and conservation of threatened birds in the Upper Guinea forest

Allport

1991

Bird Conservation International

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SummaryThere are twenty-one endemic and near-endemic forest birds in the Upper Guinea forest of West Africa. Less than 80,000 km 2 of their habitat remains and this is being rapidly degraded and fragmented. Eight threatened and two near-threatened birds were identified by Collar and Stuart (1985) in this region based on the scant information then available. More recent surveys confirm the threatened status of all these birds, but two species, Melaenornis annamarulae and Malimbus ballmanni, should now be considered Vulnerable having previously been placed in the Indeterminate category. Phyllastrephus leucolepis, described since the production of the Red Data Book, is only found in the forest of east Liberia and must be considered Endangered. Records suggest that all three species are restricted to the western part of the Upper Guinea forest. There are two forest areas which are of the highest priority for the conservation of these and the other endemic birds: (i) south-east Liberia/south-west Ivory Coast; (ii) south-east Sierra Leone/northwest Liberia.Ceratogymnasubcylindricus and Phyllastrephus baumanni are recommended for inclusion in the Near-threatened category.Vingt-et-une especes forestieres d'oiseaux endemiques ou quasiment endemiques vivent dans la foret de Haute-Guinee en Afrique de l'Ouest. A l'epoque actuelle leur habitat, qui fut deja reduit a moins de 80,000 km 2 , continue d'etre rapidement degrade et fragmente. Collar et Stuart (1985) identifierent huit especes menacees plus deux especes probablement menacees pour la region, base sur le peu d'information disponible a l'epoque. Des investigations plus recentes confirment le statut de toutes ces especes sauf deux, Melaenornis annamarulae et Malimbus ballmanni, qui furent insuffisamment connus, doivent maintenant etre considered vulnerables. Phyllastrephus leucolepis ne fut decrit pour la science qu'apres la production du livre rouge et ne se trouve uniquement dans la foret du Liberia oriental, et doit done etre considere comme en danger. Des observations suggerent que toutes ces especes soient limitees a la partie occidentale de la foret de HauteGuinee. Deux regions forestieres se revelent d'etre de la plus haute priorite pour la sauvegarde de ces especes et des autres oiseaux endemiques: (i) le sud-est du Liberia/sudouest de la Cote-d'Ivoire et (ii) le sud-est du Sierra Leone/nord-ouest du Liberia. Nous recommandons d'inclure Ceratogymna subcylindricus et Phyllastrephus baumanni dans la categorie probablement menace.

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“…It has been recorded in CAR (Carroll 1988, Keith et al 1992). An inhabitant of both primary and secondary forest, it often joins mixed-species flocks (Brosset and Erard 1986, T.B.S. unpubl.…”

Section: Resultsmentioning

confidence: 99%

“…An inhabitant of lowland dense thickets, rainforest, riverine and transitional montane forest, it commonly follows ant columns (Brosset and Erard 1986).…”

Section: Resultsmentioning

confidence: 99%

A preliminary survey of birds from the Lac Lobeke Reserve, south-eastern Cameroon

Smith

Rasmussen

Whitney

et al. 1996

Bird Conservation International

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SummaryThe rainforest avifauna of south-eastern Cameroon is poorly known. In one of the first surveys of birds from this region, we report on bird species netted and observed in the Lac Lobeke Reserve. We document 11 minor range extensions, including that of the extremely rare Zenker's Honeyguide Melignomon zenkeri. The abundance of several rare species of birds and mammals in the area, in addition to low human densities and relative inaccessibility, should make the Lac Lobeke region a priority in conservation efforts. Currently, large logging operations and the commercial exploitation of wildlife threaten the fauna of the region.

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Cycles de reproduction des microchiroptères troglophiles du nord-est du Gabon

Cited by 26 publications

References 3 publications

Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation

Habitat use and resource tracking by African Ceratogymna hornbills: implications for seed dispersal and forest conservation

The status and conservation of threatened birds in the Upper Guinea forest

A preliminary survey of birds from the Lac Lobeke Reserve, south-eastern Cameroon

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