Browsing by Author "Cabeza, Mar"
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- Are sacred caves still safe havens for the endemic bats of Madagascar?Publication . Fernández-Llamazares, Álvaro; López-Baucells, Adrià; Rocha, Ricardo; Andriamitandrina, Santatra F. M.; Andriatafika, Zo Emmanuel; Burgas, Daniel; Temba, Eric Marcel; Torrent, Laura; Cabeza, MarDespite conservation discourses in Madagascar increasingly emphasizing the role of customary institutions for wildlife management, we know relatively little about their effectiveness. Here, we used semi-structured interviews with 54 adults in eight villages to investigate whether sacred caves and taboos offer conservation benefits for cave-dwelling bats in and around Tsimanampetsotsa National Park, south-west Madagascar. Although some caves were described as sites of spiritual significance for the local communities, most interviewees (c. 76%) did not recognize their present-day sacred status. Similarly, only 22% of the interviewees recognized taboos inhibiting bat hunting and consumption. Legal protection of bats and caves through protected areas was often more widely acknowledged than customary regulations, although up to 30% of the interviewees reported consumption of bats within their communities. Guano extraction was often tolerated in sacred caves in exchange for economic compensation. This may benefit bat conservation by creating incentives for bat protection, although extraction is often performed through destructive and exploitative practices with little benefit for local communities. In view of these results our study questions the extent to which sacred sites, taboos and protected areas offer protection for bats in Madagascar. These results support previous studies documenting the erosion of customary institutions in Madagascar, including the loss of the spiritual values underpinning sacred sites. Given that many Malagasy bats are cave-dwelling species and that most depend on the customary protection of these sites, it is important to obtain a better understanding of the complex interactions between spiritual practices, taboos and protected areas in sustaining bat diversity.
- Linking like with like: optimising connectivity between environmentally-similar habitatsPublication . Alagador, Diogo; Triviño, Maria; Cerdeira, Jorge Orestes; Braz, Raul; Cabeza, Mar; Araújo, Miguel BastosHabitat fragmentation is one of the greatest threats to biodiversity. To minimise the effect of fragmentation on biodiversity, connectivity between otherwise isolated habitats should be promoted. However, the identification of linkages favouring connectivity is not trivial. Firstly, they compete with other land uses, so they need to be cost-efficient. Secondly, linkages for one species might be barriers for others, so they should effectively account for distinct mobility requirements. Thirdly, detailed information on the auto-ecology of most of the species is lacking, so linkages need being defined based on surrogates. In order to address these challenges we develop a framework that (a) identifies environmentally-similar habitats; (b) identifies environmental barriers (i.e., regions with a very distinct environment from the areas to be linked), and; (c) determines cost-efficient linkages between environmentally-similar habitats, free from environmental barriers. The assumption is that species with similar ecological requirements occupy the same environments, so environmental similarity provides a rationale for the identification of the areas that need to be linked. A variant of the classical minimum Steiner tree problem in graphs is used to address c). We present a heuristic for this problem that is capable of handling large datasets. To illustrate the framework we identify linkages between environmentally-similar protected areas in the Iberian Peninsula. The Natura 2000 network is used as a positive ‘attractor’ of links while the human footprint is used as ‘repellent’ of links.Wecompare the outcomes of our approach with cost-efficient networks linking protected areas that disregard the effect of environmental barriers. As expected, the latter achieved a smaller area covered with linkages, but with barriers that can significantly reduce the permeability of the landscape for the dispersal of some species.
- Movement seasonality in a desert-dwelling bat revealed by miniature GPS loggersPublication . Conenna, Irene; López-Baucells, Adrià; Rocha, Ricardo; Ripperger, Simon; Cabeza, MarBackground Bats are among the most successful desert mammals. Yet, our understanding of their spatio-temporal dynamics in habitat use associated with the seasonal oscillation of resources is still limited. In this study, we have employed state-of-the-art lightweight GPS loggers to track the yellow-winged bat Lavia frons in a desert in northern Kenya to investigate how seasonality in a desert affects the a) spatial and b) temporal dimensions of movements in a low-mobility bat. Methods Bats were tracked during April–May 2017 (rainy season) and January–February 2018 (dry season) using 1-g GPS loggers. Spatial and temporal dimensions of movements were quantified, respectively, as the home range and nightly activity patterns. We tested for differences between seasons to assess responses to seasonal drought. In addition, we quantified home range overlap between neighbouring individuals to investigate whether tracking data will be in accordance with previous reports on territoriality and social monogamy in L. frons. Results We obtained data for 22 bats, 13 during the rainy and 9 during the dry season. Home ranges averaged 5.46 ± 11.04 ha and bats travelled a minimum distance of 99.69 ± 123.42 m/hour. During the dry season, home ranges were larger than in the rainy season, and bats exhibited high activity during most of the night. No apparent association with free water was identified during the dry season. The observed spatial organisation of home ranges supports previous observations that L. frons partitions the space into territories throughout the year. Conclusions Our results suggest that, in low-mobility bats, a potential way to cope with seasonally harsh conditions and resource scarcity in deserts is to cover larger areas and increase time active, suggesting lower cost-efficiency of the foraging activity. Climate change may pose additional pressures on L. frons and other low-mobility species by further reducing food abundances.
- Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscapePublication . Rocha, Ricardo; Ovaskainen, Otso; López-Baucells, Adrià; Farneda, Fábio Z.; Sampaio, Erica M.; Bobrowiec, Paulo E. D.; Cabeza, Mar; Palmeirim, Jorge M.; Meyer, Christoph F. J.Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes.
- The importance of indigenous territories for conserving bat diversity across the Amazon biomePublication . Fernandez-Llamazares, Álvaro; López-Baucells, Adriá; Velazco, Paúl; Gyawalli, Arun; Rocha, Ricardo; Terraube, Julien; Cabeza, Marrainforest for millennia. How-ever, evaluations of how much biodiversity is governed under Indigenous stewardship are scarce. Here,we integrate geospatial data of officially recognized ITs across the Amazon biogeographic boundarieswith the distribution range of >200 Amazonian bat species, to: (i) assess the potential contribution of ITsfor the conservation of this species-rich mammalian group across the Amazon; (ii) investigate which ITshost the greatest number of bat species; and (iii) analyse how threatened and Data Deficient bat speciesare distributed within the ITs of the nine Amazonian countries. Twenty-two bat species were found tohave >25% of their global distribution range within Amazonian ITs, including many forest-dependentspecies with restricted distribution ranges and a highly threatened or Data Deficient conservation status.Some particularly diverse ITs were found to harbour over half of the known Amazonian bat species, par-ticularly in transboundary areas in the North-western Amazon. At the national level, the highest numberof species with over 25% of their national Amazonian distribution within ITs was found in Peru (145), followed by Brazil (136), Colombia and Ecuador (both with 134). This study reveals the potential role of Indigenous Peoples in Amazonian bat conservation and emphasizes the contribution of their stewardship for maintaining the ecosystems in which some of the most rare and unique bat species are found
- Unveiling how herpetofauna cope with land‐use changes—Insights from forest‐cashew‐rice landscapes in West AfricaPublication . dos Reis‐Silva, Francisco; Pizzigalli, Cristian; Seck, Sambu; Cabeza, Mar; Rainho, Ana; Rocha, Ricardo; Palmeirim, Ana FilipaAgricultural induced land-use change comprises a key driver of biodiversity loss across tropical forests. Guinea-Bissau, among Afrotropical West Africa, was formerly occupied by native forest-savanna mosaics. While savannas have long given place to traditional rice agroecosystems, forests are now being transformed into cashew monocultures at unprecedented rates. The ecological impact of such rapid change is largely unknown. Here, we examined how rarefied species richness, encounters, and composition of amphibians and reptiles varied across forest remnants, cashew orchards, and rice paddies in northern Guinea-Bissau. To do so, visual encounter surveys were carried across 21 standardized sampling sites, seven in each habitat type. A total of 703 amphibian and 266 reptile encounters was recorded from nine and 14 taxa, respectively. The results show class-specific responses to habitat type. Amphibian richness was similar across habitat types, but rice paddies held more encounters and distinct composition compared to forest remnants. Reptile richness and encounters were lower in rice paddies than in forest remnants, but cashew orchards had the most encounters and a different composition compared to forest remnants. Overall, our results do not support the expected detrimental impacts of cashew expansion, which might be due to the still high heterogeneity of habitat types within the landscape. Rice paddies proved particularly important for amphibians, and for open-habitat reptiles, boosting the landscape-scale species diversity. In face of the eminent habitat conversion, maintaining heterogeneous landscapes, including the persistence of both forest remnants and rice paddies, is critical to minimize biodiversity loss in West Africa.