PubMed | Paris-Sorbonne University, Instituto Aqualie, BioGemme Laboratory, CNR Marine Science Institute and 6 more.
Type: Journal Article | Journal: Royal Society open science | Year: 2017
Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of transiting (consistent/directional) versus localized (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry<200m and in adjacent areas), females showed localized behaviour in deep waters (19120m) and at large distances (140.6km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll-
PubMed | University Estadual Of Santa Cruz, Instituto Aqualie and Grande Rio University
Type: Journal Article | Journal: PloS one | Year: 2016
The western South Atlantic (WSA) humpback whale population inhabits the coast of Brazil during the breeding and calving season in winter and spring. This population was depleted to near extinction by whaling in the mid-twentieth century. Despite recent signs of recovery, increasing coastal and offshore development pose potential threats to these animals. Therefore, continuous monitoring is needed to assess population status and support conservation strategies. The aim of this work was to present ship-based line-transect estimates of abundance for humpback whales in their WSA breeding ground and to investigate potential changes in population size. Two cruises surveyed the coast of Brazil during August-September in 2008 and 2012. The area surveyed in 2008 corresponded to the currently recognized population breeding area; effort in 2012 was limited due to unfavorable weather conditions. WSA humpback whale population size in 2008 was estimated at 16,410 (CV = 0.228, 95% CI = 10,563-25,495) animals. In order to compare abundance between 2008 and 2012, estimates for the area between Salvador and Cabo Frio, which were consistently covered in the two years, were computed at 15,332 (CV = 0.243, 95% CI = 9,595-24,500) and 19,429 (CV = 0.101, 95% CI = 15,958-23,654) whales, respectively. The difference in the two estimates represents an increase of 26.7% in whale numbers in a 4-year period. The estimated abundance for 2008 is considered the most robust for the WSA humpback whale population because the ship survey conducted in that year minimized bias from various sources. Results presented here indicate that in 2008, the WSA humpback whale population was at least around 60% of its estimated pre-modern whaling abundance and that it may recover to its pre-exploitation size sooner than previously estimated.
Garrigue C.,British Petroleum |
Garrigue C.,South Pacific Whale Research Consortium |
Zerbini A.N.,National Oceanic and Atmospheric Administration |
Zerbini A.N.,Instituto Aqualie |
And 5 more authors.
Journal of Mammalogy | Year: 2010
Knowledge of the local and migratory movements of humpback whales (Megaptera novaeangliae) from New Caledonia is very limited. To investigate this topic, we attached satellite-monitored tags to 12 whales off southern New Caledonia. Tag longevity ranged from 1 to 52 days (X̄ 22.5 days). Tagged whales generally moved to the south or southeast, with several spending time in a previously unknown seamount habitat named Antigonia before resuming movement, generally toward Norfolk Island or New Zealand. However, 1 female with a calf traveled the entire length of the western coast of New Caledonia (∼450 km) and then west in the direction of the Chesterfield Reefs, a 19th century American ("Yankee") whaling ground. None of the New Caledonia whales traveled to or toward eastern Australia, which is broadly consistent with the low rate of interchange observed from photo-identification comparisons between these 2 areas. The connections between New Caledonia and New Zealand, together with the relatively low numbers of whales seen in these places generally, support the idea that whales from these 2 areas constitute a single population that remains small and unrecovered. © 2010 American Society of Mammalogists.
Horton T.W.,Geological science |
Holdaway R.N.,Geological science |
Holdaway R.N.,University of Canterbury |
Holdaway R.N.,Palaecol Research Ltd |
And 10 more authors.
Biology Letters | Year: 2011
Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 18 precision, despite the effects of variable seasurface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored. © 2011 The Royal Society.
Pinto de Sa Alves L.C.,State University of Rio de Janeiro |
Pinto de Sa Alves L.C.,Instituto Aqualie |
Andriolo A.,Instituto Aqualie |
Andriolo A.,Federal University of Juiz de fora |
And 2 more authors.
Acta Ethologica | Year: 2013
Aggression is often utilised in intraspecific competition to establish and maintain dominance hierarchies in social mammals. Here, we determine if aggressiveness in conditioned botos (Inia geoffrensis) during interactions with humans under provisioning is influenced by the presence or absence of food rewards and if provisioning leads to the establishment of a dominance hierarchy among these generally solitary animals. Mean values of bites among the botos for sessions in which food rewards were delivered were significantly higher than sessions in which no food reward was delivered. No significant difference exists between the mean number of bites per individual during feeding sessions, but the mean number of bites increased significantly with time when animals were not fed. Supplant behaviours were used as a non-harming alternative to bites. The botos' provisioning is a case of instrumental conditioning, in which the conditioned botos expect to receive food from tourists, increasing competition among the animals when they are not fed. The provisioned botos exhibited an almost linear dominance hierarchy. Bites and supplant behaviours were used more frequently by dominant botos to prevent subordinates from obtaining food provisions. Interactions brought about by provisioning are likely to be harmful to the botos and potentially dangerous to humans. © 2012 Springer-Verlag and ISPA.
Barbieri F.,University of the Rio dos Sinos Valley |
Machado R.,University of the Rio dos Sinos Valley |
Zappes C.A.,State University of Norte Fluminense |
Zappes C.A.,Instituto Aqualie |
And 2 more authors.
Ocean and Coastal Management | Year: 2012
The Neotropical otter (Lontra longicaudis) is an aquatic carnivore that interacts with fisheries activities and competes with fisherman for resources. Information about the biology and conservation issues of a species can be obtained from traditional ecological knowledge collected from the communities that share the same resources. In this sense, the objective of this study was to describe conflicts between the otters and two fishing communities (Imbé and Tramandaí) in the Tramandaí Lagoon (29°57'S; 50°11'W), in southern Brazil. We conducted 36 interviews that represented 72% of the local fishermen that use gillnets in the lagoon. All fishermen reported that otters interfered with fishing activities, by feeding on fish in the gillnets, and 75% of those interviewed reported gear damage. Fifty percent of the fishermen reported that observed the otters used the lagoon daily. Many fishermen (41.6%) also reported that the amount of damage attributed to the otters was considered " small" , but the depredation was reported as occurring daily (55.5%). Fishermen from Imbé have a more negative perception of the interaction with otters, probably because they usually fish near to the area most frequently used by otters. This amplifies the magnitude of the conflict and damage. In order to minimize the depredation of fish by otters directly on the gillnets, we suggested some measures to fishery management, as well as additional studies about the potential prey overlap between the Neotropical otter and the fishery. © 2012 Elsevier Ltd.
PubMed | Instituto Aqualie, IRD Montpellier, CNR Marine Science Institute and National Oceanic and Atmospheric Administration
Type: Journal Article | Journal: Royal Society open science | Year: 2015
The humpback whale population of New Caledonia appears to display a novel migratory pattern characterized by multiple directions, long migratory paths and frequent pauses over seamounts and other shallow geographical features. Using satellite-monitored radio tags, we tracked 34 whales for between 5 and 110 days, travelling between 270 and 8540km on their southward migration from a breeding ground in southern New Caledonia. Mean migration speed was 3.532.22kmh(-1), while movements within the breeding ground averaged 2.011.63kmh(-1). The tag data demonstrate that seamounts play an important role as offshore habitats for this species. Whales displayed an intensive use of oceanic seamounts both in the breeding season and on migration. Seamounts probably serve multiple and important roles as breeding locations, resting areas, navigational landmarks or even supplemental feeding grounds for this species, which can be viewed as a transient component of the seamount communities. Satellite telemetry suggests that seamounts represent an overlooked cryptic habitat for the species. The frequent use by humpback whales of such remote locations has important implications for conservation and management.
Zerbini A.N.,National Oceanic and Atmospheric Administration |
Zerbini A.N.,Instituto Aqualie |
Clapham P.J.,National Oceanic and Atmospheric Administration |
Wade P.R.,National Oceanic and Atmospheric Administration
Marine Biology | Year: 2010
The rate of growth of any population is a quantity of interest in conservation and management and is constrained by biological factors. In this study, recent data on life-history parameters influencing rates of population growth in humpback whales, including survival, age at first parturition and calving rate are reviewed. Monte Carlo simulations are used to compute a distribution of rates of increase (ROIs) taking into account uncertainty in biological parameter estimates. Two approaches for computing juvenile survival are proposed, which taken into account along with other life-history data, resulted in the following estimates of the rate of population growth: Approach A: mean of 7.3%/year (95% CI = 3.5-10.5%/year) and Approach B: mean of 8.6%/year (95% CI = 5.0-11. 4%/year). It is proposed that the upper 99% quantile of the resulting distribution of the ROI for Approach B (11.8%/year) be established as the maximum plausible ROI for humpback whales and be used in population assessment of the species. Possible sources of positive and negative biases in the present estimates are presented and include measurement error in estimation of life-history parameters, changes in the environment within the period these quantities are measured, density dependence or other natural factors. However, it is difficult to evaluate potential biases without additional data. The methods presented in this study can be applied to other species for which life-history parameters are available and are useful in assessing plausibility in the estimation of population growth rates from time series of abundance estimates. © 2010 Springer-Verlag.
Rodrigo H.O.,Federal Rural University of Rio de Janeiro |
Especie M.A.,Federal Rural University of Rio de Janeiro |
Lodi L.,Instituto Aqualie |
Simao S.M.,Federal Rural University of Rio de Janeiro
Zoologia | Year: 2013
Parental care is any form of parental behavior that increases offspring fitness. To the authors' knowledge, this study is the first to analyze the intensity of parental care in the Guiana dolphin, Sotalia guianensis (van Bénéden, 1864). The objectives of this study are as follows: 1) to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro; 2) to investigate the influence of behavioral state and group size on the degree of parental care; and 3) to evaluate the differences between the intensity of parental care provided to calves and juveniles. Our results indicate that the intensity of parental care is high in S. guianensis and that care is more intense in larger groups. It is possible that these differences serve to maximize hydrodynamic gains and to minimize risks. Our results suggest that parental care is more intense during travel. A possible reason for this greater intensity is that the feeding dynamics show a more random pattern than other behavioral states. Moreover, the results indicate that calves receive more intense care than juveniles. These results suggest that parent-offspring conflict is possible in the study population. © 2013 Sociedade Brasileira de Zoologia.
Lodi L.,Instituto Aqualie |
Farias-Junior S.,Projeto Golfinhos
Pan-American Journal of Aquatic Sciences | Year: 2011
This note reports eleven new sightings of a previously identified male killer whale (Orcinus orca) between Mongaguá, São Paulo State and Saquarema, Rio de Janeiro State, between 1999 and 2010. These observations suggest the existence of site fidelity within these areas.