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Echolocation calls of bats from Madeira Island: acoustic characterization and implications for surveys

100%

Teixeira S., Jesus J.

Acta Chiropterologica

2009

tom 11

nr 1

Acoustic surveys represent a powerful tool to assess bat distribution and habitat preferences and are widely applicable to monitoring and conservation schemes. However, their correct application requires the development of robust and reliable identification procedures. Little information is available on the bats of Madeira Island (Portugal), particularly their ecological requirements, distribution and population trends, and proper guidelines for their monitoring and conservation have yet to be defined. In this study, we present the first analysis of echolocation calls from species occurring on the island to provide a tool for bat identification during acoustic surveys. Seven hundred and ninety one time-expanded recordings of search phase echolocation calls in cluttered and uncluttered habitats of the Macaronesia endemic pipistrelle Pipistrellus maderensis, Madeira Leisler’s bat Nyctalus leisleri verrucosus and grey long-eared bat Plecotus austriacus were analysed and an acoustic repertoire with their temporal and spectral features is described. Pipistrellus maderensis was easily identified based only on peak frequency while Plecotus austriacus and N. leisleri verrucosus showed frequency overlap in cluttered backgrounds. Discriminant function analysis was applied to calls of Plecotus austriacus and N. l. verrucosus resulting in a correct overall classification of 96.7% of calls, with a function based on start frequency, end frequency, duration and interpulse interval. This work provides the first description of Pipistrellus maderensis and N. 1. verrucosus echolocation calls and offers a basis for future bat surveys in order to encourage the development of locally customized conservation strategies.

Trophic habits of feral cats in the high mountain shrublands of the Macaronesian islands [NW Africa, Atlantic Ocean]

61%

Medina F. M., Oliveira P., Menezes D., Teixeira S., Garcia R., Nogales M.

Acta Theriologica

2010

tom 55

nr 3

241-250

Feral cats Felis catus Linnaeus, 1758 have contributed to the extinction of numerous native species on islands, which are clearly sources of global biodiversity. We studied the diet of this introduced predator in the Madeira and Cape Verde archipelagos, which harbour important colonies of endangered seabirds in the high mountain habitats, and compared the results with those obtained in the same habitat in the Canary Islands, Macaronesian archipelago. On Madeira, 461 prey were identified from 143 scat groups. Mammals, overall mice, constituted the basic diet appearing in 95% of cat scats. On Fogo (Cape Verde), 657 prey items were obtained from 145 scats, and mammals were also the most important prey, reaching a frequency of occurrence of 88%. Although introduced mammals were the main prey category on all Macaronesian islands, we observed variation in feral cat diet among these islands. Birds were more frequently consumed on Madeira, lizards on Tenerife (Canaries) and invertebrates on Fogo. No specific differences were observed in relation to La Palma. We suggest that the diet composition on these islands varies according to the respective availability of the different prey types.

Ograniczanie wyników

1 Acta Chiropterologica

1 Acta Theriologica

2 Teixeira S.

1 Garcia R.

1 Jesus J.

1 Medina F. M.

1 Menezes D.

1 Nogales M.

1 Oliveira P.

1 2010

1 2009

Wyniki wyszukiwania

Echolocation calls of bats from Madeira Island: acoustic characterization and implications for surveys

Trophic habits of feral cats in the high mountain shrublands of the Macaronesian islands [NW Africa, Atlantic Ocean]