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Caniçal, Portugal

Alves F.,Madeira Whale Museum | Alves F.,University of Madeira | Alves F.,The Interdisciplinary Center | Dinis A.,Madeira Whale Museum | And 10 more authors.
Marine Mammal Science | Year: 2015

Estimates of population parameters for the short-finned pilot whale, Globicephala macrorhynchus, are scarce in literature, contributing to an International Union for Conservation of Nature (IUCN) status of Data Deficient. In this study, photo-identification data collected over 7 yr from Madeira were used to estimate for the first time survivorship, capture probability, and abundance in this species using mark-recapture methodology. The Cormack-Jolly-Seber model estimated that the adult island-associated (i.e., resident and regular visitor) whales had a constant survival rate of 0.960 (95% CI: 0.853-0.990) and an annual capture probability varying between 0.372 (CI: 0.178-0.619) and 0.843 (CI: 0.619-0.947). A parameterization of the Jolly-Seber model estimated that 140 island-associated whales (CI: 131-151) used the area throughout the course of the study. Based on a closed population model, the most precise (lower CV) annual estimate of the total number of pilot whales using the southern and eastern waters of Madeira (~900 km2) in a 3 mo period covering summer/autumn was 334 animals (CI: 260-437). No trend was observed. Despite including biases, the approach used in this study provided plausible estimates of population parameters, which can contribute to the regional conservation strategies. © 2014 Society for Marine Mammalogy. Source


Alves F.,Madeira Whale Museum | Alves F.,University of Madeira | Alves F.,The Interdisciplinary Center | Querouil S.,Montpellier University | And 11 more authors.
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2013

Pilot whales Globicephala spp. are known to display a hierarchical social pattern, but longitudinal data to infer population structure of short-finned pilot whales Globicephala macrorhynchus are rare. Using data collected between 2003-2011 in the oceanic archipelago of Madeira, the grouping structure of short-finned pilot whales was studied using photo-identification methods and mtDNA sequences and microsatellite markers to test the hypotheses that (1) there is at least one pelagic and one or more island-associated communities, and (2) groups are made of related individuals, with a matrilineal social structure. Pilot whales demonstrated a large degree of variability in site fidelity, including residents (up to 14-year interval), regular visitors and transients. The social and temporal analyses revealed a well-differentiated society with long-lasting relationships (of years). The genetic analyses suggested that individuals of the three residency patterns may not be genetically isolated, and that small groups are made up of related individuals, suggesting some degree of social philopatry, while large groups are probably temporary associations of smaller groups. It is proposed that the pilot whales encountered in Madeira belong to a single population encompassing several clans, possibly three clans of island-associated whales and others of transients, each containing two to three matrilineal pods, each with a mean of 15 individuals (SD=9, range: 4-29). We suggest that the clans interact for mating purposes when they meet. For management decisions, it is considered that the island-associated whales should not be regarded as demographically independent populations, but instead as stable social entities to be included in governmental management plans and requiring periodic evaluation of their status. The high proportion of marked individuals and low rate of mark change encourages further research in this species. © 2013 John Wiley & Sons, Ltd. Source


Dinis A.,Madeira Whale Museum | Dinis A.,University of Madeira | Dinis A.,The Interdisciplinary Center | Alves F.,Madeira Whale Museum | And 9 more authors.
African Journal of Marine Science | Year: 2016

The bottlenose dolphin Tursiops truncatus is one of the most frequently sighted cetacean species in the Madeira Archipelago (North-East Atlantic); however, little is known about its population ecology in these waters. Photo-identification undertaken during systematic, non-systematic and opportunistic surveys conducted between 2001 and 2012 was used to assess group dynamics, site fidelity, residency and movement patterns of bottlenose dolphins in the archipelago. Three different patterns of residency were assigned, based on individual sighting histories. Group size ranged between 2 and 90 individuals (median 12), with no significant monthly difference in group size. All resident dolphins formed a core, complex network with migrant and transient dolphins. In contrast, satellite clusters were formed exclusively by transient individuals. The lagged identification rate (LIR) model indicated that a dolphin remained in the area for an average of 90 days, whereas the average time an individual spent outside the study area was approximately 313 days. The Madeira Archipelago appears to be only a section of a much larger home range for this population, with the dolphins exhibiting three different patterns of occurrence that associate with each other. The information gained about this poorly studied population contributes to the overall knowledge of bottlenose dolphins in insular oceanic habitats. © 2016 NISC (Pty) Ltd Source


Alves F.,Madeira Whale Museum | Alves F.,The Interdisciplinary Center | Nicolau C.,Madeira Whale Museum | Dinis A.,Madeira Whale Museum | And 5 more authors.
Acta Ethologica | Year: 2015

This study adds the Atlantic spotted dolphin Stenella frontalis to the list of species displaying nurturant behavior as a response to perinatal mortality. It is based on two in situ behavioral observations off Madeira Island (Portugal) (but with only one continuing uninterrupted). Additionally, postmortem exams were carried out on four fresh neonate carcasses, two from the previous events and two from distinct events where carcasses were found floating with no individuals in the vicinity. The in situ observations show that adult Atlantic spotted dolphins try to support their dead calves at surface, either involving a single individual (presumably the mother) or several individuals. The highly fresh condition of the carcasses suggests that the adults abandon them after a short period of time (hours). The postmortem exams suggest that the four neonates died from natural causes, and not from anthropogenic causes, predation, or other intra- or interspecific behavioral interaction as described in some cetacean populations. Accurate lengths at birth are also provided, which are scarce in literature for this species. © 2014, Springer-Verlag Berlin Heidelberg and ISPA. Source

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