Behavioural Changes

One of the reactions of animals to external pressures is behavioural changes. Long-term monitoring of resident populations of cetaceans allowed us to determine general distribution of animals, and more importantly their potential change over time. More immediate behavioural changes will be analysed with individual movements.


General distribution

Distribution and density of cetaceans will be derived from Species Density Models using statistical models to correlate cetacean sightings with environmental covariates. In Madeira, distribution maps for bottlenose dolphins and short-finned pilot whales will be updated, based on the last 15 years of data gathered by the MWM (Freitas et al. 2014). Although cetacean distribution models are also available for the Azores (Tobeña et al. 2016), they lack information on species density. Thus for the Azores, new models of sperm whale distribution will be developed based on data spanning 20 years from an ongoing fisheries observer program (Azorean Fisheries Observer Programme - POPA).

Overlapping distribution maps of resident species with human threats will be created. Human threats will be incorporated as covariates to model the general distribution or resident species and check how those threats could be affecting their distribution.

Finally, to understand long-term habitat use in Madeira we will use static passive acoustic monitoring. This consists of deploying a fixed hydrophone within a specific area and letting it record for one year. Then, the sound recorded will be analysed to detect the presence of dolphins, through their vocalisation, during day and night time within and outside WW areas.

Individual movement

The three target species have different ecological characteristics and consequently different distribution. Therefore different methodologies will be used to look at their individual movement and use of the different areas.

In Madeira, short-finned pilot whales will be studied attaching Time-Depth-Recorder (TDR) with suction cups on the animals that will record the diving depth, coupled with fastloc GPS which records the geographical position of the animal. This will inform us on how they use different areas, i.e., foraging, resting/socialising or travelling. Furthermore, information from photo-identification data and associated GPS position will be analysed for short-finned pilot whales and bottlenose dolphins. This will inform us on individual movement and specific use of WW area and the WW exclusion zone. The proportion of the population exposed to WW activities will be estimated from individuals, photo-identified on at least two separate occasions, observed inside and/or outside the WW area.

In the Azores, a detailed study of individual movements of sperm whales will be carried out using both satellite telemetry equipment and photo-identification.