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The fourth dimension in landscape analysis: changing of heritage and ecological values in the Evora cultural landscapes

100%
Batista T., de Mascarenhas J. M., Mendes P.
Problemy Ekologii Krajobrazu
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2011
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tom 30
2

Family planning: does variation in reproductive strategies affect vulnerability to extinction in the greater spear-nosed bat Phyllostomus hastatus?

100%
Mendes P., Oprea M., Brito D.
Acta Chiropterologica
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2013
|
tom 15
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nr 2
Different reproductive strategies among populations might affect population growth rates, and a population's vulnerability to threats. Population viability analysis may help guide population management and the identification of populations more prone to decline, allowing a preventive approach to avoid population declines and extinctions. The objective of the present study was to evaluate if differences in reproductive strategy translate into differential intrinsic vulnerability among different populations of Phyllostomus hastatus. We used the software VORTEX to model the dynamics and viability of P. hastatus populations under different reproductive scenarios. We modeled a total of 12 scenarios evaluating variations in reproductive characteristics of the species (monoestry vs polyestry, harem size, and infant mortality rate). Phyllostomus hastatus populations were viable under most scenarios, except with scenarios incorporating monoestry and high pup mortality. Our results demonstrate that both reproductive strategies (monoestry and polyestry) found in P. hastatus result in viable and stable populations under natural conditions. However, polyestrous populations have higher growth rates, making them more resilient to natural and/or anthropogenic disturbances. A significant portion of the more resilient populations in South America overlap the Amazon Forest, a continuous and preserved habitat under low human pressure, which bodes well for the long-term persistence of these populations. On the other hand, the populations of the species that evolved the monoestrous reproductive strategy are located in Mesoamerica, a Biodiversity Hotspot that is under severe human impacts, particularly from habitat loss. Conservation biologists and managers must take into account intra-specific demographic differences of species when planning for their long-term persistence.
3

The system Tetrabothrius bassani (Tetrabothriidae)- Morus bassanus (Sulidae) as a bioindicator of marine heavy metal pollution

88%
Mendes P., Eira C., Vingada J., Miquel J., Torres J.
Acta Parasitologica
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2013
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tom 58
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nr 1
Helminths are known to accumulate higher amounts of certain elements than their hosts. The present study assesses the accumulation of heavy metals in Tetrabothrius bassani and in its host, the Atlantic gannet (Morus bassanus) found dead due to bycatch along the seashore in the centre of Portugal. Samples of kidney, liver and pectoral muscle of 23 infected gannets, as well as specimens of T. bassani were analysed for As, Cd, Cr, Cu, Hg, Mn, Pb, Se and Zn by ICP-MS. The evidenced lower concentrations of Cr and Pb in tissues of gannets in comparison to an earlier study performed in the same area may reveal a change in the diet of M. bassanus between both study periods. The highest bioaccumulation factor was obtained for Cd with a 12.7-times higher concentration in the cestode than in gannet muscle. Lead concentration in T. bassani was 6.9-times higher than in kidney tissue, 8.5-times higher than in muscle and 9.5-times higher than in liver of M. bassanus. The cestode/seabird system T. bassani/M. bassanus can be considered a promising bioindicator system to monitor environmental Cd and Pb pollution in marine ecosystems.
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