Madeira Whale Museum

Caniçal, Portugal

Madeira Whale Museum

Caniçal, Portugal
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Dinis A.,Madeira Whale Museum | Dinis A.,University of Madeira | Dinis A.,The Interdisciplinary Center | Alves F.,Madeira Whale Museum | And 9 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2017

In order to investigate social structure, 11 years of individual photo-identification data of bottlenose dolphin were analysed. We examined the type of association indices between pairs of identified individuals; the patterns of affiliation between individual dolphins and the probabilities of association between individuals over time. Between 2001 and 2012, there were 272 encounters which resulted in the identification of 501 individuals. The discovery curve resulting from the photo-identification analysis indicated an open population with regular recruitment of new individuals. All individuals were found to be associated at an association index of <0.05. A total of 291 individuals recorded from 2004 to 2012 were used to assess the temporal pattern of the social structure. The model fit to the Standardized Lagged Association Rate (SLAR) that best described the studied bottlenose dolphin population was ‘casual acquaintances’, and the analysis of associations over time showed a decreasing SLAR curve that falls until reaching the null rate, confirming random associations. The decline of the SLAR curve after ~500 days (1.4 years) suggests disassociation over that time period which can be explained by demographic events such as mortality or emigration. In an open ocean habitat like Madeira this is not unexpected, as there are neither geographic boundaries nor enclosed environments. This population presented a dynamic and fluctuating social structure, where groups change in size and composition. In future conservation efforts this population should be considered as one large community, where individuals associate, disassociate and reassociate with each other over time. Copyright © Marine Biological Association of the United Kingdom 2017

Reggente M.A.L.,University of Milan Bicocca | Reggente M.A.L.,nter Marine Research and High Education Center | Alves F.,Madeira Whale Museum | Alves F.,The Interdisciplinary Center | And 6 more authors.
Journal of Mammalogy | Year: 2016

Nurturant behavior toward dead conspecifics has been documented in several free-ranging marine and terrestrial mammals but still remains undocumented and poorly understood for most species. This study describes observations of adults carrying dead calves and juveniles in 7 odontocetes (toothed cetaceans) species and discusses the subject in mammals in general. Observations are based on 14 events from 3 oceans and constitute the 1st records for Indo-Pacific bottlenose dolphins (Tursiops aduncus), spinner dolphins (Stenella longirostris), killer whales (Orcinus orca), Australian humpback dolphins (Sousa sahulensis), and sperm whales (Physeter macrocephalus), as well as presenting additional records for Risso's dolphins (Grampus griseus) and short-finned pilot whales (Globicephala macrorhynchus). Information on how the adults supported and carried the dead conspecifics, on the gender of both adults and dead young, and on the age class of the dead young, is presented. Moreover, a comparison with terrestrial mammals, including a compilation of published literature, and a discussion on possible hypotheses to explain this particular type of behavior are given. The present study helps to corroborate that adults mourning their dead young is a common and globally widespread behavior in long-lived and highly sociable/cohesive species of mammals. © 2016 American Society of Mammalogists,

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

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.

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.

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.

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