Mid-distance movements of common bottlenose dolphins in the coastal waters of Greece

Abstract

While bottlenose dolphins in Mediterranean waters often display a high degree of site fidelity, movements across distant areas can occur. Such movements have important implications in terms of population viability, particularly in basins with low bottlenose dolphin densities. We report movements of nine individuals photoidentified up to 265 km apart in western Greece. Four showed a certain degree of site fidelity to one area across several years, but were also found elsewhere, with two individuals moving between two areas. This study provides further evidence that animals appearing to be ''resident'' within a given area can temporarily leave and range widely.

Marine open cage aquaculture in the eastern Mediterranean Sea: a new trophic resource for bottlenose dolphins

“…Firstly, we sketched a grid map of 30 × 30 cells (cell size = 1 × 1 km) to represent the study area and we assigned different habitats to each cell ( (Bearzi et al 2010b). Since no dispersal rate data were available for the other organisms, we assumed a dispersal rate of 200 km yr −1 for the other top predators (e.g.…”

A Robust Design Capture-Recapture Analysis of Abundance, Survival and Temporary Emigration of Three Odontocete Species in the Gulf of Corinth, Greece

“…It is therefore important to monitor their status and abundance. Even though bottlenose dolphins are known to perform mid-distance movements to areas outside of the Gulf of Corinth [26], knowing how many individuals use this area on a regular basis is important to evaluate their conservation status and propose management actions at the local scale.…”

Occurrence of bottlenose dolphins (Tursiops truncatus) in the Río Negro Estuary, Argentina, and their mid-distance movements along the northeastern Patagonian coast

“…Results presented herein suggest accordingly that bottlenose dolphins The re-identification of several individuals in both the BSA and the RNE, approximately 200km apart, indicates that those bottlenose dolphins move along the whole northern coast of the San Matías Gulf, northeastern Patagonia, as was reported previously (Vermeulen et al, 2008). Overall, movements of coastal populations of bottlenose dolphins are known to range between shortdistances of up to 100km (Ballance, 1992;Lodi et al, 2008) and mid-distances of up to 300km (Würsig, 1978;Simões-Lopes and Fabian, 1999;Bearzi et al, 2011). Occasionally, long-distance movements of more than 500km Mate et al, 1995; or even > 1000km (Wood, 1998;Wells et al, 1999) have been recorded.…”

“…The analysis of ranging patterns of dolphins is crucial to understand several aspects of the ecology of a population (Silva et al, 2009), as dispersion is a biologically important behaviour triggered by a range of key functions such as feeding, mating and finding shelter (e.g. Bearzi et al, 2011). Generally, bottlenose dolphins living in less protected waters display extensive ranging patterns, whereas dolphins residing in protected coastal environments show a higher degree of site fidelity and residency (Wells et al, 1987), as is the case in BSA (Vermeulen and Cammareri, 2009a).…”

“…It is known that a general lack of information on the dolphin's movement patterns could bias the assessment of site fidelity and residence in certain core areas, as ranges could easily be interpreted from the perspective of the study area covered by the researchers (Bearzi et al, 2011). This could in turn insufficiently weigh the use of alternative areas.…”