Sperm Whale Head Research Articles

Size Distribution of Sperm Whales Acoustically Identified during Long Term Deep-Sea Monitoring in the Ionian Sea.

The sperm whale (Physeter macrocephalus) emits a typical short acoustic signal, defined as a “click”, almost continuously while diving. It is produced in different time patterns to acoustically explore the environment and communicate with conspecifics. Each emitted click has a multi-pulse structure, resulting from the production of the sound within the sperm whale’s head. A Stable Inter Pulse Interval (Stable IPI) can be identified among the pulses that compose a single click. Applying specific algorithms, the measurement of this interval provides useful information to assess the total length of the animal recorded. In January 2005, a cabled hydrophone array was deployed at a depth of 2,100 m in the Central Mediterranean Sea, 25 km offshore Catania (Ionian Sea). The acoustic antenna, named OνDE (Ocean noise Detection Experiment), was in operation until November 2006. OνDE provided real time acoustic data used to perform Passive Acoustic Monitoring (PAM) of cetacean sound emissions. In this work, an innovative approach was applied to automatically measure the Stable IPI of the clicks, performing a cepstrum analysis to the energy (square amplitude) of the signals. About 2,100 five-minute recordings were processed to study the size distribution of the sperm whales detected during the OνDE long term deep-sea acoustic monitoring. Stable IPIs were measured in the range between 2.1 ms and 6.4 ms. The equations of Gordon (1991) and of Growcott (2011) were used to convert the IPIs into measures of size. The results revealed that the sperm whales recorded were distributed in length from about 7.5 m to 14 m. The size category most represented was from 9 m to 12 m (adult females or juvenile males) and specimens longer than 14 m (old males) seemed to be absent.

Time and frequency domain characteristics of sperm whale clicks.

Regular clicks from diving sperm whales, both large bull males and smaller females, were recorded in deep oceanic water off the Azores and subsequently sampled to computer disks for digital analysis. A total of 8540 clicks were marked and analyzed. Simple temporal analysis of the interclick intervals during feeding dives revealed mean click rates for male sperm whales of 1.1713 s-1 and 1.9455 s-1 for females. Fourier analysis showed distinctive peaks in the spectra of bull male sperm whales at 400 Hz and 2 kHz which were stable over extended periods of up to 20 mins. The clicks contained higher frequency components with energy ranging up to at least 12 kHz but not concentrated at any sharply defined frequency. The clicks of smaller female sperm whales showed similar spectral peaks, shifted to 1.2 and 3 kHz, respectively, but these peaks were less pronounced than those in the male click spectra and less stable with time. Higher frequencies were also present up to at least 15 kHz. The previously reported multiple pulse structure of sperm whale clicks is confirmed, but digital filtering reveals this structure to be frequency dependent. Analysis using the short-time Fourier transform confirms the complex time-frequency structure of individual clicks. The frequencies at which the multiples emerge in male and female clicks supports the idea of air cavities in the sperm whale head acting as sound reflectors, although the magnitude of the second pulse at high frequencies suggests some form of off axis distortion. It is also possible that air cavity resonance in the head of the sperm whale may act to reinforce the high-frequency components of the click, and that such components may have superior range and resolution performance in terms of echolocation.

Holocene Vegetation and Environments of Sperm Whale Head, Victoria, Australia

The pollen and stratigraphic analysis of two coastal interdune swamps on Sperm Whale Head in the Gippsland Lakes of south-eastern Victoria provides a regional picture of vegetation and environmental changes from beyond 7200 years BP to present. Moisture availability was greatest between about 7000 and 5200 BP with continuously moist swamp conditions and the presence of tall open forest in the area. Rainfall may then have fallen slightly causing the elimination of tall open forest elements though the increasing influence of the sea on ground water salinity may also have affected the vegetation. Water levels in the depressions were higher between 5200 and 4000-3000 years ago, due perhaps to the attainment of present sea level, and lake conditions prevailed. Subsequently lakes became very shallow or intermittent, and hypersaline, while open eucalypt woodlands replaced the previously dominant Casuarina communities on dry land. A decrease in moisture availability to present-day levels is inferred, combined with an increase in fire frequency or intensity. The dry land and aquatic vegetation was further modified in recent times, due presumably to the activities of European man. The derived record from this area correlates well with others from lowland southeastern Australia and provides some valuable information on the status of present-day communities within the region.

Random combinations of acyl and alcoholic groups through overall wax esters of sperm whale head oils

1. 1. The wax esters in the head oils of the sperm whales, Physter catodon Linné, captured in the Antarctic Ocean were analyzed by GLC using a polar column. 2. 2. The saturates of C26-C32, the monoenes of C28-C36, and the dienes of C30-C38 were found as the major components. 3. 3. The compositions of the overall wax esters based both on the carbon number and degree of unsaturation were closely in agreement with those calculated from the compositions of the fatty acids and fatty alcohols assuming biochemical esterification in a random fashion.

Gas chromatographic separation of wax esters based on the degree of unsaturation

AbstractThe wax esters of sperm whale head oil have been characterized by gas‐liquid chromatography on an APOLAR 10C column according to their carbon number and number of double bonds. The novel technique permits the direct quantitative analysis of saturated and unsaturated wax esters.

Gas Chromatographic Analysis of the Wax Esters in Sperm Whale Head Oil based on the Unsaturation

A gas chromatography of the wax esters in sperm whale head oil on APOLAR 10C column has characterized them according to their carbon number and number of double bonds. The analytical results obtained by the new technique were confirmed by comparison with those obtained by GC using the nonpolar column OV-17.

Sperm whale head oil: Part I. The ester fraction

The wax esters of sperm whale head oil have been isolated and shown to range from C 25–C 38 in chain length. The total wax esters were then fractionated according to the degree of unsaturation and the observed compositions have been compared to the values calculated assuming synthesis in a random fashion.

鯨油の研究 (V) マッコウ鯨油の脂肪酸成分

Previously, we(1) reported about the chemical and physical properties of oils contained in various parts of a sperm whale body, and found noticeable differences among these oils. This time, we studied on the quantitative composition of fatty acids of sperm whale head. cavity oil. The results obtained are shown in Table 1 to Table 8. The following facts were noticeable. The amounts of saturated and unsaturated acids were nearly equal. Very large quantity of lower fatty acids (less than C14) was present.