Monteiro S.,University of Minho |
Monteiro S.,University of Aberdeen |
Ferreira M.,University of Minho |
Vingada J.V.,University of Minho |
And 4 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2015
In order to improve our knowledge on the feeding ecology of long-finned pilot whales (Globicephala melas) in Northeast Atlantic waters, skin samples of 68 long-finned pilot whales stranded in Northwest Iberia (n=22) and Scotland (n=46) were analysed using stable isotopes of δ13C and δ15N. Isotopic mixing models were applied to obtain a quantitative estimate of the proportion of the main prey species in the diet of pilot whales. Stable isotope analysis revealed that 57.8-73.8% of the diet in Northwest Iberia consisted in curled octopus (Eledone cirrhosa), followed by European flying squid (Todarodes sagittatus), while in Scotland the predominant prey species was either Histioteuthis sp. or T. sagittatus, depending of the trophic enrichment factor applied. These results are generally in accordance with previous stomach content studies; however, the isotopic analysis may provide new information regarding key prey species and habitat use that could be missed or underestimated if only stomach contents analysis were used. Additionally, considering that the Atlantic Coast of Iberia was responsible for 95% of the landings of the main prey consumed by pilot whales in this area, between 2000 and 2010, these data provide trophic baseline information to be taken into account in fishery impact assessment studies and management decisions. © 2015 Elsevier B.V.
Santos M.B.,Spanish Institute of Oceanography |
Monteiro S.S.,University of Minho |
Vingada J.V.,University of Minho |
Vingada J.V.,University of Aveiro |
And 6 more authors.
Marine Mammal Science | Year: 2014
There is little previous information on feeding habits of long-finned pilot whales (Globicephala melas) in the northeast Atlantic. The present study analyzed stomach contents of pilot whales stranded in Portugal (n = 6), Galicia (northwest Spain) (n = 32), and Scotland (United Kingdom) (n = 10), from 1990 to 2011. These animals ranged from 213 to 555 cm in length (24 females, 19 males and 5 of unknown sex). The main prey identified were cephalopods of the families Octopodidae and Ommastrephidae, the former being numerically more important in Iberia (Portugal and Galicia) and the latter more important in Scotland, with Iberian whales also showing a more diverse diet. Multivariate analysis revealed evidence of geographical and seasonal variation in diet. Generalized Additive Modeling results indicated that more octopus (Eledone cirrhosa) were eaten in Iberia than in Scotland, more in the first half of the year, and more in larger whales. Numbers of ommastrephid squids in the stomach decreased over the study period and varied with season and whale length. This study confirms cephalopods as the main prey of pilot whales, as previously reported, although our results also suggest that, in the northeast Atlantic, ommastrephid squid are largely replaced as the main prey by octopods at lower latitudes. © 2013 by the Society for Marine Mammalogy.
The findings, published in the journal Science and Justice, could lead to wider use of fingerprinting methods in the field to more easily identify poachers in regions with high levels of ivory-related crime. Ivory has previously been considered a difficult material to obtain fingerprints from and such techniques have not been commonly used when illegally sourced ivory has been seized despite fingerprinting being one of the oldest, simplest and most cost-effective forensic tools. Ivory itself is a highly porous, ridged material and fingerprints enhanced with conventional powders have been largely ineffective as a result. This presents a significant challenge for police and forensic experts to develop the level of fingerprint detail required for an accurate identification. However in recent years, newer powder materials have emerged for fingerprinting. These are composed of smaller particles, which allow for more detail to be observed as they adhere better to smaller amounts of fingermark residue left behind. The latest study tested three types of powders on three seized elephant tusks loaned by the Metropolitan Police Service's Wildlife Unit. Those involved in the study compared two of the new powders to a more traditional powder using a variety of tests. The team found that the newer reduced-size powders were able to provide clearer, useable fingerprint detail that is vital for identifying the donor. Reduced size powders stuck more easily to remaining fingermark residues than the more traditional powders, despite the ridged and porous nature of the ivory surface. The clarity of ridge detail was found to be at its highest within seven days after the print was deposited, suggesting the method would work best in regions of the world that are closest to the sources of ivory. However, imaging and fingerprint experts were also able to lift some useable prints up to 28 days after they were deposited using the new powder. The researchers also showed its applicability to rhino ivory, hippo teeth and sperm whale teeth. Study author, Dr Leon Barron, a Senior Lecturer in Forensic Science in the Division of Analytical and Environmental Sciences at King's College London, said: 'This is the first time that fingerprinting on ivory has been thoroughly investigated and a practical solution offered. The only other study carried out over a decade ago simply showed that fingerprints were unstable and that the clarity of ridge detail was low making it difficult to make reliable identifications. Our study has shown for the first time that these newer powders could potentially be used for identifying poachers, and are especially suited to rangers working in the field.' Director of Forensic Services at the Metropolitan Police, Mr Gary Pugh OBE, said 'The concept for this work was originally devised by an imaging expert based on his experience at crime scenes. The application has been developed into a viable front line evidence recovery technique through our Strategic Alliance with King's College London. The equipment required to put this form of fingerprinting into practice is inexpensive and relatively easy to procure, making it a simple, cost-effective forensic tool to combat wildlife crime.' More information: Kelly A. Weston-Ford et al. The retrieval of fingerprint friction ridge detail from elephant ivory using reduced-scale magnetic and non-magnetic powdering materials, Science & Justice (2015). DOI: 10.1016/j.scijus.2015.10.003
Monteiro S.S.,University of Minho |
Monteiro S.S.,University of Aveiro |
Mendez-Fernandez P.,CNRS Coastal and Marine Environment Laboratory |
Mendez-Fernandez P.,University of Sao Paulo |
And 13 more authors.
Marine Ecology Progress Series | Year: 2015
Integration of ecological and genetic approaches is a particularly powerful strategy to identify natural population diversity and structure over different timescales. To investigate the potential occurrence of population differentiation in long-finned pilot whales Globicephala melas in the North Atlantic, both biogeochemical (fatty acids and stable isotopes) and genetic (mito - chondrial DNA) markers were analyzed in animals from 4 regions within the North Atlantic: the northwestern Iberian Peninsula, the United Kingdom, the Faroe Islands and the United States of America. Genetic data revealed strong regional levels of divergence, although analysis of molecular variance revealed no differentiation between the northeastern and northwestern Atlantic. Results from biogeochemical tracers supported previous dietary studies, revealing geographic and ontogenetic dietary variation in pilot whales. Fatty acids revealed ecological differentiation between all regions analyzed, while stable isotopes showed an overlap between some sampling regions. These results suggest that both ecological and genetic factors may drive the levels of pilot whale differentiation in the North Atlantic. The ecological differentiation observed may be related to the exploitation of different foraging niches (e.g. oceanic vs. coastal), which can be highly influenced by prey distributions or oceanographic phenomena. Genetic differentiation may result from historical or contemporary processes or even limited dispersal mediated through the social structure displayed by this species and potential foraging specialization. These results highlight some problems when assessing population structure across multiple markers and the ecological vs. evolutionary timescales over which differences may accumulate. Notwithstanding, the data provide preliminary information about pilot whale diversity and stocks in the North Atlantic, giving essential baseline information for conservation plans. Copyright © 2015 Inter-Research.
Lawrence J.A.,University of Pretoria |
Foggin C.M.,Wildlife Unit |
Prozesky L.,University of Pretoria
Journal of the South African Veterinary Association | Year: 2010
Three African buffalo (Syncerus caffer) that died after capture and translocation from Mutirikwe Recreational Park in southern Zimbabwe showed macroscopic and microscopic lesions of cardiomyopathy compatible with a diagnosis of gousiekte. The buffalo had had access to Pavetta schumanniana, a plant that is known to cause gousiekte. Death was attributed to cardiac failure as a result of previous consumption of the plant, exacerbated by the stress of translocation.