Cuvier's Beaked Whale

Abundance and Distribution

Cuvier’s beaked whales are thought to have the most extensive range of any species of beaked whale (Jefferson et al.,1993). They are found across all oceans at all latitudes except the most polar regions, suggesting they are tolerant of a very wide temperature range. They prefer areas of deep water, far from the coastal shallows. Despite their elusiveness, they are found fairly commonly on the eastern tropical Pacific, where they are of highest abundance (Jefferson et al.,1993).

The habitat range of Ziphius, extracted from Marine mammals of the world. Jefferson et al. 1993.

The habitat range of Ziphius, extracted from Marine mammals of the world. Jefferson et al. 1993.

It is thought that worldwide there are well over 100,000 individuals, with 80,000 of these residing in the eastern tropical pacific and 15,000 around Hawai’i (Taylor et al., 2008). However, little is known how many Cuvier’s beaked whales actually are in existence as there are many difficulties associated with collecting accurate measurements of their abundance. As we have seen, they spent the majority of their time more than 50 meters below the surface of the water, and when they do breach the surface, it is usually for very brief time periods. Consequently, all data collected on the numbers observed must account for the whales that were missed before an estimate of the population as a whole can be made.

Over the course of 10 years of observations carried out by McSweeney et al. (2007) in the period between 1990 and 2006, only 35 encounters with groups of Cuvier’s beaked whale were recorded, only 12 of which were not orchestrated by locating tagged individuals. This number is almost certainly not representative of the entire population of the area. This data is probably only able to be recorded during long periods at the surface, which are infrequent especially during the day.

Acoustic recordings of the echolocation noises of beaked whales in the North Pacific found that the majority of the sites passive acoustics were obtained were dominated by the echolocation sounds of Cuvier’s beaked whale (Baumann-Pickering et al., 2014). They also found some evidence of seasonality, in that for 3 consecutive years there were a higher number of whales recorded in more southerly parts of the North Pacific.

 

Extracted from http://whaleopedia.org/

Extracted from http://whaleopedia.org/

Individual range

There is evidence that Cuvier’s beaked whales, to some extent, frequent the same areas (McSweeney et al., 2007). Large numbers of photographs were taken in order to recognize individuals within groups spotted. 49 individuals were identified and their sex determined by presence of visible teeth and linier scarring in males. 40% of these individuals were seen multiple times during the data collection period, and females seemed to return to the same area more (McSweeney et al., 2007).

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