scholarly journals The diet of sperm whales (Physeter macrocephalus) in southern Australian waters

2004 ◽  
Vol 61 (8) ◽  
pp. 1313-1329 ◽  
Author(s):  
Karen Evans ◽  
Mark A. Hindell
Keyword(s):  
Species Composition ◽  
Diet Composition ◽  
Stomach Contents ◽  
Individual Variability ◽  
Physeter Macrocephalus ◽  
Foraging Success ◽  
Sperm Whales ◽  
Cephalopod Species ◽  
The Social ◽  
The Family

Abstract Stomach contents were collected from 36 sperm whales (Physeter macrocephalus) involved in two mass stranding events during February 1998 along the west coastline of Tasmania, Australia. Contents were dominated by oceanic cephalopods, with a total of 101 883 cephalopod beaks representing 48 species from 14 families of Teuthids, two species from two families of Octopods, and a single Vampyromorph species identified. Species diversity was higher in these animals than other sperm whales studied in the southern hemisphere, with samples containing an average of (±s.d.) 28.4 ± 11.1 species per sample. Diet samples were dominated by subtropical and muscular cephalopod species. Members of the family Histioteuthidae were the most important numerically, and were also important in terms of estimated reconstituted mass, although members of the Onychoteuthidae were the most dominant species in samples in terms of estimated reconstituted mass. Other families numerically important to species composition included the cranchiid, lepidoteuthid, onychoteuthid, and pholidoteuthid families, while the architeuthid, pholidoteuthid, and ommastrephid families were also important in terms of reconstituted mass. Cephalopod species composition varied with stranding site and with sex, but not with age. However, differences did not represent systemic variation with groups marked by high individual variability. Lower rostral lengths of all cephalopod species ranged from 1.3 to 40.7 mm. Calculated dorsal mantle lengths from all species ranged from 10.7 to 2640.7 mm (mean ± s.d. = 233.7 ± 215.7 mm) and estimated wet weights of cephalopod prey ranged from 2.7 to 110 233.1 g (mean ± s.d. = 828.3 ± 3073.6 g). While there were differences in the size of some cephalopod species between stranding sites and with age, this was marked by high individual variability. Differences in diet composition and prey size between sperm whales reflect individual variability in foraging success and perhaps also foraging groups related to the social structure of this species.

scholarly journals Long-term associations among male sperm whales (Physeter macrocephalus)

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244204
Author(s):  
Hayao Kobayashi ◽  
Hal Whitehead ◽  
Masao Amano
Keyword(s):  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Association Rate ◽  
Photo Identification ◽  
Male Sperm ◽  
The Social ◽  
Pelagic Habitat ◽  
Best Fitting ◽  
Social Associations

Little is known about the social structure of male sperm whales (Physeter macrocephalus) after they leave their natal units. While previous studies found no evidence for preferred associations among males, the observation of mass-strandings consisting exclusively of males, suggest that they have strong social bonds. To investigate the social associations among male sperm whales, we used half weight index of association, permutation tests and standardized lagged association rate models on a large photo-identification database collected between 2006 and 2017 in Nemuro Strait, Japan. Our results suggest that while male sperm whales are not as social as females, they do form long term associations, have preferred companionship, and forage in social proximity to each other. The best-fitting model to the standardized lagged association rate showed that associations among males last for at least 2.7 years and as most males leave the area after 2 years, associations may last for longer. Twenty dyads were observed associating over more than 2 years, for a maximum 5 years. One dyad was observed associating on 19 different days and clustered on 7 different days. Male associations may function to enhance foraging or to fend off predators. Such relationships seem to be adapted to a pelagic habitat with uncertain resource availability and predation pressure.

scholarly journals Diversity of ants and mites in the diet of the Brazilian frog Chiasmocleis leucosticta (Anura: Microhylidae)

2017 ◽  
Vol 17 (3) ◽  
Author(s):  
Mariana S. Lopes ◽  
Ricardo S. Bovendorp ◽  
Gilberto José de Moraes ◽  
Alexandre Reis Percequillo ◽  
Jaime Bertoluci
Keyword(s):  
Diet Composition ◽  
Statistical Difference ◽  
Stomach Contents ◽  
Southeastern Brazil ◽  
Pitfall Traps ◽  
Prey Category ◽  
Food Items ◽  
The Family ◽  
Family Level ◽  
Males And Females

Abstract We describe here the diet of the microhylid frog Chiasmocleis leucosticta based on the stomach contents of 72 individuals (47 males and 25 females) collected in pitfall traps at the Reserva Florestal de Morro Grande, state of São Paulo, southeastern Brazil. We identified 1,981 food items distributed in 13 prey categories of arthropods, mainly ants, mites and collembolans. Formicidae was the most abundant and frequent prey category, including 16 genera from seven subfamilies, and data on ant availability in the habitat suggest that C. leucosticta selects ants actively. The second main prey category was Acari, predominantly represented by mites of the suborder Oribatida. This is the first work identifying mites to the family level in the diet of a Microhylidae. There was no statistical difference between males and females regarding diet composition.

scholarly journals Calves as social hubs: dynamics of the social network within sperm whale units

2013 ◽  
Vol 280 (1763) ◽  
pp. 20131113 ◽  
Author(s):  
Shane Gero ◽  
Jonathan Gordon ◽  
Hal Whitehead
Keyword(s):  
Social Relationships ◽  
Social Role ◽  
Group Formation ◽  
Time Lag ◽  
Group Living ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Social Unit ◽  
The Social

It is hypothesized that the primary function of permanent social relationships among female sperm whales ( Physeter macrocephalus ) is to provide allomothers for calves at the surface while mothers make foraging dives. In order to investigate how reciprocity of allocare within units of sperm whales facilitates group living, we constructed weighted social networks based on yearly matrices of associations (2005–2010) and correlated them across years, through changes in age and social role, to study changes in social relationships within seven sperm whale units. Pairs of association matrices from sequential years showed a greater positive correlation than expected by chance, but as the time lag increased, the correlation coefficients decreased. Over all units considered, calves had high values for all measured network statistics, while mothers had intermediate values for most of the measures, but high values for connectedness and affinity. Mothers showed sharp drops in strength and connectedness in the first year of their new calves' lives. These broad patterns appear to be consistent across units. Calves appeared to be significant nodes in the network of the social unit, and thus provide quantitative support for the theory in which communal care acts as the evolutionary force behind group formation in this species.

Foraging on squid: the sperm whale mid-range sonar

2007 ◽  
Vol 87 (1) ◽  
pp. 59-67 ◽  
Author(s):  
M. André ◽  
T. Johansson ◽  
E. Delory ◽  
M. van der Schaar
Keyword(s):  
Stomach Contents ◽  
Sperm Whale ◽  
Target Strength ◽  
Directional Hearing ◽  
Experimental Measurements ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Long Time ◽  
Minimum Requirements ◽  
The Subject

The sonar capabilities of the sperm whale, Physeter macrocephalus, have been the subject of speculation for a long time. While the usual clicks of this species are considered to support mid-range echolocation, no physical characteristics of the signal have clearly confirmed this assumption nor have they explained how sperm whales forage on squid. The recent data on sperm whale on-axis recordings have allowed us to simulate the propagation of a 15 kHz pulse as well as its received echoes from different targets, taking into account the reflections from the bottom and the sea surface. The analysis was performed in a controlled environment where the oceanographic parameters and the acoustic background could be modified. We also conducted experimental measurements of cephalopod target strength (TS) (Loligo vulgaris and Sepia officinalis) to further investigate and confirm the TS predictions from the geometric scattering equations. Based on the results of the computer simulations and the TS experimental measurements (TS squid=−36.3±2.5 dB), we were able to determine the minimum requirements for sperm whale sonar, i.e. range and directional hearing, to locate a single 24.5 cm long squid, considered to be (from stomach contents) the major size component of the sperm whale diet. Here, we present the development of the analysis which confirms that sperm whale usual clicks are appropriate to serve a mid-range sonar function, allowing this species to forage on individual organisms with low sound-reflectivity at ranges of several hundreds of metres.

The diet of sperm whales ( Physeter macrocephalus Linnaeus 1758) off the Azores

1993 ◽  
Vol 339 (1287) ◽  
pp. 67-82 ◽  
Keyword(s):  
North Atlantic ◽  
Stomach Contents ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Commercial Activities ◽  
The North ◽  
The North Atlantic ◽  
Modal Mass ◽  
Neutrally Buoyant

Stomach contents from 17 sperm whales, 15 males and two females, caught during commercial activities in 1981-1984 in the Azores region were identified and measured. A total of 28 738 cephalopods and 16 fish were represented in the collections. In addition, there were tunicates in two whales and m an-m ade products in three whales. None of the stomachs were empty. Flesh was present in 94.1% and indigestible fragments alone, including mandibles (beaks) of cephalopods, were present in 5.9% of the stomachs. Twelve species of cephalopod were represented by flesh and 40 species were represented by lower beaks. The cephalopod families contributing food to the whales in this region are, in order of their contribution by estimated mass, the O ctopoteuthidae (39.8%), the Histioteuthidae (32.7%), the Architeuthidae (12.1%), the Lepidoteuthidae (4.5% ), the Ommastrephidae (3.4% ), the Pholidoteuthidae (2.1% ), the Cycloteuthidae (1.9% ), the Cranchiidae (1.7%) and eight other families each contributing less than 1 % by mass. Presence of Gonatus beaks in the stomachs show which whales have migrated southwards to the Azores just prior to capture and the presence of a large Megalocranchia species possibly shows which whales have m igrated from higher latitudes off Iceland. However, the presence of Teuthowenia maculata shows which whales came north from the West coast of Africa, just prior to capture. The modal mass of cephalopods consumed is 400-450 g which represents 0.00001 of the whales’ body mass. 77.5% of the species eaten have luminous organs and 82% of the species are neutrally buoyant. It seems likely that the sperm whale is obtaining 77% of its food by swimming through luminous shoals of slow-swimming, neutrally bouyant squids and only about 23% by chasing faster swimming, larger cephalopods. Cephalopods not previously recorded from the North Atlantic are Onychoteuthis boreali-japonicus , and Histioteuthis bonnellii corpuscula . Histioteuthis ?miranda may have been collected by the whales much further south than the Azores. Species not recorded previously in the diet of sperm whales in the North Atlantic are Ommastrephes bartrami , Gonatus steenstrupi , Histioteuthis ?miranda , H. bonnellii corpuscula , H. meleagroteuthis , Discoteuthis laciniosa , Mastigoteulhis species, Chiroteulhis species, ?Helicocranchia , Liocranchia reinhardti , and ?Liguriella .

scholarly journals Stomach contents of sperm whales Physeter macrocephalus stranded in the North Sea 1990-1996

1999 ◽  
Vol 183 ◽  
pp. 281-294 ◽  
Author(s):  
MB Santos ◽  
GJ Pierce ◽  
PR Boyle ◽  
RJ Reid ◽  
HM Ross ◽  
...  
Keyword(s):  
North Sea ◽  
Stomach Contents ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
The North ◽  
The North Sea

Social structure and mating system of sperm whales off northern Chile

2004 ◽  
Vol 82 (8) ◽  
pp. 1360-1369 ◽  
Author(s):  
Amanda K Coakes ◽  
Hal Whitehead
Keyword(s):  
Social Structure ◽  
Mating System ◽  
Relative Abundance ◽  
Northern Chile ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
The Social ◽  
Mean Size ◽  
Males And Females ◽  
The Mean

We studied the social structure and mating system of sperm whales (Physeter macrocephalus L., 1758) off northern Chile over 10 months in 2000, photographically identifying 898 individuals. The mean size of encountered groups of females with immatures was about 23 animals, while the estimated mean size of units (sets of females and immatures with permanent relationships) was 11 animals. About 4% of the population consisted of large mature males, although this varied seasonally. Groups of females and immatures, as well as large males, spent only a matter of days within the study area at a time. There was no evidence for preferred ranges for the males, for males consistently accompanying particular groups, or for males forming coalitions. Males roved between the groups of females and immatures. Both mature males and females or immatures appeared to take the initiative in maintaining or breaking close associations. These results are similar to those from studies off the Galápagos Islands, even though the habitat, nonsocial behaviour, and relative abundance of mature males were quite different in the two areas.

Temporal and geographic variation in the social structure of female sperm whales

1992 ◽  
Vol 70 (11) ◽  
pp. 2145-2149 ◽  
Author(s):  
Hal Whitehead ◽  
Benjamin Kahn
Keyword(s):  
Social Structure ◽  
Galapagos Islands ◽  
General Area ◽  
Physeter Macrocephalus ◽  
Galápagos Islands ◽  
Sperm Whales ◽  
The Social ◽  
Seychelles Islands ◽  
Mean Size ◽  
Geographic Differences

The social structure of female sperm whales (Physeter macrocephalus) was examined from data collected during studies of identified individuals off the Galápagos Islands in 1985, 1987, and 1989, off the Seychelles Islands in 1990, and off mainland Ecuador in 1991. Three levels of social organization were examined in the Galápagos Islands studies. "Units," permanent associations between individuals, showed no significant deviation from a mean size of 13 individuals. "Groups," temporary associations between units lasting a few days, had a mean size of 24 individuals. Group size was lower in 1987 (an "El Niño" year) than in 1985 or 1989, but this difference was not statistically significant. "Aggregations" of groups in the same general area lasting periods of hours were significantly larger in 1985 (mean of 77 individuals) than in 1987 (mean of 47 individuals). There are significant differences between areas in aggregation sizes but not in group sizes. Groups appear to aggregate frequently off the Galápagos Islands, occasionally off mainland Ecuador, and very rarely off the Seychelles Islands. These temporal and geographic differences in sizes of groups and aggregations in sperm whales are probably caused by variations in the distribution and abundance of their food, but responses to recent exploitation may also be a factor.

Stomach contents of a sperm whale (Physeter macrocephalus) stranded in Italy (Ligurian Sea, north-western Mediterranean)

2013 ◽  
Vol 94 (6) ◽  
pp. 1087-1091 ◽  
Author(s):  
Fulvio Garibaldi ◽  
Michela Podestà
Keyword(s):  
Stomach Contents ◽  
Sperm Whale ◽  
Western Mediterranean ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Western Basin ◽  
Ligurian Sea ◽  
Beak Size ◽  
Species Specific ◽  
Available Information

The stomach contents of a male sperm whale, Physeter macrocephalus, stranded on Forte dei Marmi beach (Italy, Ligurian Sea) were examined. Food items consisted exclusively of cephalopod hard parts: 233 upper and 291 lower beaks and one fish eye lens. The majority of the identified cephalopod beaks belonged to Histioteuthis bonnellii, but a few beaks of Galiteuthis armata and Octopoteuthis sp. were also found. A new beak size–cephalopod size regression was created for H. bonnellii with specimens caught in the study area. Reconstructed prey weight for the species was much higher when applying this new regression instead of Clarke's, highlighting the need for area- and species-specific regressions for dietary studies. Our analysis represents the second report on the stomach contents of sperm whales from the Mediterranean and the first available information for the Western basin.

Stomach contents of cetaceans stranded in the Canary Islands 1996–2006

2009 ◽  
Vol 89 (5) ◽  
pp. 873-883 ◽  
Author(s):  
R. Fernández ◽  
M.B. Santos ◽  
M. Carrillo ◽  
M. Tejedor ◽  
G.J. Pierce
Keyword(s):  
Canary Islands ◽  
Stomach Contents ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Jaw Bones ◽  
Deep Diving ◽  
Fish Remains ◽  
Demersal Species ◽  
Belone Belone

Stomach contents were analysed from 23 cetaceans, including individuals of 12 species from the families Delphinidae, Physeteridae, Kogiidae and Ziphiidae, stranded between 1996 and 2006 in the Canary Islands. Cephalopod mandibles(beaks)were found in 21 stomachs and fish remains(otoliths and jaw bones)appeared in 4 stomachs. Two stomachs contained only eye lenses. Cephalopods eaten by dolphins were mainly from the families Ommastrephidae, Sepiidae and Enoploteuthidae, whereas whales had mainly taken specimens of the oceanic squid families Histiotheutidae and Cranchiidae. Fish remains included a pelagic species(i.e. garfish,Belone belone)in dolphin stomachs and bathypelagic(i.e. black scabbard fish,Aphanopus carbo, lantern fish,Lampadena luminosa)and demersal species(Lophiussp.)in a pygmy sperm whale(Kogia breviceps)stomach. Most of the prey species identified are not of commercial interest but one of the sperm whales(Physeter macrocephalus)contained a fishing hook among the stomach contents. Five(22%)of the cetaceans examined had also plastic debris in their stomachs, with big plastic items being taken by deep diving teuthophagous whales.

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