Nathalie Jaquet

Intra-specific variation in social organization provides valuable insights into the selective forces driving social evolution. Sperm whales are distributed globally and live far from shore, thus obtaining large sample sizes on social organization in multiple areas is logistically challenging and few comparative studies exist. In order to address ho...

Sperm whales exhibit highly structured social behavior that depends on sex, age, and possibly local ecological characteristics. We analyzed sighting data collected between 1994 and 2005 to determine the social structure of sperm whale groups in the northern Gulf of Mexico (714 good-quality photographs of 285 individual whales). Average typical grou...

The movements of female and immature sperm whales Physeter macrocephalus in the tropical Pacific Ocean and adjacent waters are described using photoidentifications over time scales of 3 d to 15 yr and the tracks of followed groups over scales of 1 to 48 h. The female/immature whales frequently made movements of less than 2000 km and occasionally ma...

For much of the past two centuries, sperm whaling has been economically very profitable, and therefore whalers and, more recently, scientists have tried to understand Sperm Whale (Physeter macrocephalus) distribution and the factors controlling it. However, due to their deep-living mode of life, their cosmopolitan distribution and our limited knowl...

Sperm whales occur worldwide and feed largely on meso- and bathypelagic squid, but little is known about the behavioral ecology of this predator and its prey. In the Gulf of California, sperm whales are thought to feed on the abundant jumbo (Humboldt) squid, an ecologically and commercially important species. In this study, we attached satellite-li...

We tried to find discriminating features for sperm whale clicks in order to distinguish between clicks from different whales, or to enable unique identification. We examined two different methods to obtain suitable characteristics. First, a model based on the Gabor function was used to describe the dominant frequencies in a click, and then the mode...

Knowledge of whale length is important to ecological studies. However, photographic techniques to measure sperm whales traditionally require high vantage points or a complicated stereo system. Furthermore, these traditional techniques require an alongside approach that often prevents individual identification. For simple and fast size measurements...

Analysis of the usual click rates of sperm whales (Physeter macrocephalus) at Kaikoura, New Zealand, confirms the potential for assessing abundance via "click counting." Usual click rates over three dive cycles each of three photographically identified whales showed that 5 min averages of usual click rate did not differ significantly within dives,...

A bstract Sperm whale movements, residency, population structure, and behavior were investigated in the Gulf of California in 1998 and 1999. Variations in sperm whale movement patterns and behavior were related to changes in prey abundance (jumbo squid, Dosidicus gigas ) determined by fishery statistics. Photo‐identification data revealed that seve...

regular clicks from single diving male sperm whales off Kaikura, New Zealand were currently investigated on the presence of dominantfrequencies in the Fourier spectrum. Notwithstanding the results of Goold and Jones (\cite{goold95}) for the clicks in our dataset the higher dominantfrequency did not clearly show up in a plot of the Fourier spectrum....

Sperm whales (Physeter macrocephalus) feed predominantly on meso- and bathypelagic cephalopods for which effective sampling methods have not been developed. The Gulf of California is one of the very few areas where sperm whales might feed on a commercially fished species of squid (jumbo squid, Dosidicus gigas), presenting a unique opportunity to in...

Sperm whales (Physeter macrocephalus) are sexually dimorphic in several respects, including size, latitudinal distribution, and social structure. Females are known to have complex social structures, including long-term bonds, but the social structures of sexually mature or maturing males have received much less attention. Using data from aggregatio...

Off Kaikoura, New Zealand, we recorded individually identified male sperm whales (Physeter macrocephalus) for entire dive cycles in order to investigate vocal behavior of individual whales and to examine possible functions of sperm whale clicks. In our study, sperm whales were almost always silent at the surface. They consistently started clicking...

Male sperm whales (Physeter macrocephalus) were the preferred target of the whaling industry between 1950 and 1985, but despite hundreds of thousands of kills, very little is known about their ecology. To partially redress this, we present data on residency, seasonal distribution, and diving behaviour of individually identified sperm whales off Kai...

Movement patterns of groups of female and immature sperm whales (Physeter macrocephalus), which were followed over periods of 0.5–2.5 days in the South Pacific, were correlated with defecation rates to investigate foraging behavior, estimate the probable size of patches of prey and the distances between them. Relationships between environ-mental me...

It has often been suggested that, given their large food requirements, sperm whale Physeter macrocephalus distributions should reflect the distribution of productive ocean environments, and it seems therefore that chlorophyll concentration might be a good indicator of sperm whale distribution. To examine the existence of such a relationship, and to...

The purpose of this study was to investigate sperm whale Physeter macrocephalus distribution in relation to underwater topography, temperature gradients and primary and secondary productivity. The influence of these factors over different spatial scales (80 to 640 nautical miles) was examined, and the importance of food resources in determining spe...

The charts of Maury (1851) and Townsend (1935) contain a considerable amoun tof information on where and in which season, 19th century Yankee whalers made their kills, especially of sperm whales Physeter macrocephalus. Measures of the total catch of sperm whales from Townsend's charts are a good and easily available source of information on the pre...

The sand goby Pomatoschistus minutus (Pallas) occurs seasonally in high densities in shallow water and intertidal sediments, preying extensively on small macroinvertebrates such as Corophium volutator (Pallas). P. Minutus densities were experimentally manipulated inside cages maintained on intertidal flats in the Ythan estuary, Aberdeenshire, U.K.,...