Sperm whale
(Physeter macrocephalus)

Sperm whales occur throughout the year and are associated mainly with deep-water and canyon-associated habitats (Alves et al., 2018). Habitat suitability increases from June to November and is highest at sea-surface temperatures of around 23°C (Fernandez et al., 2021). The presence of calves and neonates indicates that Madeira is also used as a calving area (Correia-Fagundes & Romano, 2013).

Sperm whales produce powerful broadband clicks, with energy extending from <100 Hz to at least 20–32 kHz and a peak frequency often around 10 kHz (Møhl et al., 2003). Their acoustic activity is dominated by long series of regularly spaced ‘usual clicks’ during deep foraging dives, typically emitted at intervals of ~ 0.5–2 s (Miller et al., 2004). These clicks are generally interpreted as biosonar signals used in prey detection, often accelerating into much faster buzzes or creaks during prey capture (Miller et al., 2004). In contrast, shorter stereotyped click patterns, known as codas, are produced mainly during social interactions at the surface and are linked to cohesion within social groups. These consist of brief sequences of ~ 3–40 clicks, typically lasting less than 3 s (Watkins and Schevill, 1977; Weilgart and Whitehead, 1993; Rendell and Whitehead, 2003).