Diet of the Australian fur seal in Tasmania

1994 ◽  
Vol 45 (4) ◽  
pp. 653 ◽  
Author(s):  
R Gales ◽  
D Pemberton
Keyword(s):  
Inverse Relationship ◽  
Prey Species ◽  
Single Species ◽  
Adult Fish ◽  
Jack Mackerel ◽  
Fur Seal ◽  
Fish Remains ◽  
Prey Remains ◽  
Size Estimates ◽  
Prey Items

In Tasmanian waters, fish were the most prevalent prey taxa in the diet of Arctocephalus pusillus dorlferus, with cephalopods occurring less frequently. Occurrence of crustaceans and birds was negligible. Most prey remains of cephalopods were obtained from regurgitates, whereas faeces provided most fish remains. Twenty-five species of fish were identified from faecal and regurgitate samples, with redbait (Emmelichthys nitidus), jack mackerel (Trachurus declivis) and leatherjackets (Monacanthidae) constituting the main prey species. There was an inverse relationship between the occurrence of fish and that of cephalopods in the samples from Bass Strait, with fish predominating in winter and cephalopods in summer. Size estimates of prey indicated that mainly adult fish and squid were eaten. Most samples contained remains of a single species, suggesting the use of monospecific aggregations of prey items.

The ontogeny of diving behaviour in New Zealand fur seal pups (Arctocephalus forsteri)

2005 ◽  
Vol 83 (9) ◽  
pp. 1149-1161 ◽  
Author(s):  
A M.M Baylis ◽  
B Page ◽  
K Peters ◽  
R McIntosh ◽  
J Mckenzie ◽  
...  
Keyword(s):  
New Zealand ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behaviour ◽  
South American ◽  
Fur Seal ◽  
Time Periods ◽  
Prey Remains ◽  
New Zealand Fur Seal ◽  
Prey Items

This study investigated the development of diving in 21 New Zealand fur seal pups, Arctocephalus forsteri (Lesson, 1828), prior to weaning at Cape Gantheaume, Kangaroo Island. Diving behaviour was examined using time–depth recorders, which were deployed during two time periods, 5 months prior to weaning (n = 6) and 2 months prior to weaning (n = 15). Scats were also examined to assess whether fur seal pups foraged prior to weaning. The maximum dive depth attained was 44 m, while the maximum dive duration was 3.3 min. Immediately prior to weaning, fur seal pups spent a greater proportion of their time diving at night, and concomitantly several measures of diving performance also increased. In general, pups dived successively deeper (6–44 m between June and September), and the average number of dives per day, dive frequency, and vertical distance travelled increased. Prey remains were present in approximately 30% of scats and indicated that some pups were foraging as early as June (5–6 months of age, approximately 4–5 months prior to weaning). Of the scats that contained prey remains, fish (South American pilchard, Sardinops sagax (Jenyns, 1842); Australian anchovy, Engraulis australis (White, 1790); and redbait, Emmelichthys nitidus Richardson, 1845) accounted for 43% of the prey items found, crustaceans accounted for 36%, and cephalopods (Gould's squid, Nototodarus gouldi (McCoy, 1888)) accounted for 20%.

Prey harvest of the Australasian gannet (Sula serrator) in Tasmania

1993 ◽  
Vol 20 (6) ◽  
pp. 777 ◽  
Author(s):  
N Brothers ◽  
R Gales ◽  
D Pemberton
Keyword(s):  
Prey Species ◽  
Fork Length ◽  
Commercial Fishery ◽  
Target Species ◽  
Jack Mackerel ◽  
Fish Stocks ◽  
Schooling Fish ◽  
Mean Size ◽  
The Mean ◽  
Prey Items

This study investigated the diet of the Australasian gannet (Sula serrator) at Pedra Branca, an island off the south coast of Tasmania. A total of 109 regurgitations representing 394 prey items was collected from the gannets between 1986 and 1991. Pelagic schooling fish, with fork length less than 200 mm, were the most common prey items. Redbait (Emmelichthys nitidus) and jack mackerel (Trachurus declivis) were the dominant prey species, with redbait being the most numerous, contributing 72% by number and 56% by mass. The diet of the Australasian gannet was compared with the fish taken by the commercial purse seine fishery in which jack mackerel was the target species and redbait a bycatch. The mean size of commercially caught fish of both species was greater than that taken by the gannets. We suggest that there is a threshold (in the size of the fish) above which the birds cannot capture and handle the prey, effectively limiting the resource available to them. It appears that the commercial fishery and the gannets, while harvesting the same species, exploit schools of different-size fish. The potential of Australasian gannets as indicators of fish stocks is discussed.

Diet and sexual maturation of the neon flying squid Ommastrephes bartramii during autumn and spring in the Kuroshio–Oyashio transition region

2008 ◽  
Vol 88 (2) ◽  
pp. 381-389 ◽  
Author(s):  
Hikaru Watanabe ◽  
Tsunemi Kubodera ◽  
Taro Ichii ◽  
Mitsuo Sakai ◽  
Masatoshi Moku ◽  
...  
Keyword(s):  
Transition Region ◽  
Sexual Maturation ◽  
Prey Species ◽  
Feeding Strategy ◽  
Ommastrephes Bartramii ◽  
Neon Flying Squid ◽  
The Difference ◽  
Diaphus Theta ◽  
The Kuroshio ◽  
Prey Items

Diet and sexual maturation were examined in the winter–spring cohort of the neon flying squid, Ommastrephes bartramii, during its southward migration through the Kuroshio–Oyashio transition region of the western North Pacific. The main prey items are micronektonic animals and small pelagic fish, which were abundantly distributed throughout the study area. Among the prey species, O. bartramii was dependent on the Japanese anchovy Engraulis japonicus, which also migrate from the northern to southern transition region during the winter, and the micronektonic squid Watasenia scintillans throughout the study period. Other common prey items were Gonatopsis borealis, Diaphus theta, and Ceratoscopelus warmingii from October to November or December, and Tarletonbeania taylori after December. These dietary changes can be explained by the difference in the seasonal north–south migration patterns of the predator and prey species. Male sexual maturation progressed throughout the season, and most individuals were fully mature in January. In contrast, most of the females were immature throughout the study period. The feeding strategy of the squid in relation to their seasonal north to south migration and sexual maturation was discussed.

scholarly journals Predatory Behavior of Yellow Baboons

Behaviour ◽  
1976 ◽  
Vol 56 (1-2) ◽  
pp. 44-67 ◽  
Author(s):  
Glenn Hausfater
Keyword(s):  
Prey Item ◽  
Prey Species ◽  
Predatory Behavior ◽  
Primate Species ◽  
Papio Cynocephalus ◽  
Vervet Monkeys ◽  
Adult Males ◽  
Lepus Capensis ◽  
Number Of Individuals ◽  
Prey Items

Abstract1. A group of 32 yellow baboons (Papio cynocephalus) in the Masai-Amboseli National Park, Kenya, caught and ate 45 vertebrate prey items during 2519.19 hours of observation. 2. Eighty percent of the prey items were mammals and the most frequently eaten species were African hares (Lepus capensis), vervet monkeys (Cercopithecus aethiops) and neonate gazelle (Cazella granti and G. thomsoni) in that order. The details of predatory behavior for each prey species are described. 3. Rates of predation were significantly higher during the long dry season than during other months of the year, although no correlation was found between total monthly rainfall and monthly rates of predation. A lognormal model however provided a good fit to the monthly rate of predation data suggesting that the rate of predation by Amboseli baboons was affected by several factors that acted multiplicatively with respect to each other and were themselves related to rainfall or dryness. 4. A mean of 2.3 individuals fed directly from the carcass of each prey item. A mean of 3.5 individuals per prey item fed directly or indirectly, i.e., on scraps, from each carcass. In general, both the number of individuals who fed from each carcass and the duration of their feeding bouts was dependent upon the gross body size of the prey item. Adult males fed directly from the carcass of prey items for about three times more minutes than expected from their number in the group; other classes of individuals fed directly from prey carcasses for only one-fourth as many minutes as expected. In general, an adult male would be expected to feed on each category of vertebrate prey at least once per year, while individuals of all other age-sex classes would be expected to feed on most prey categories only once every two years. 5. The most frequent social behavior around prey items was agonistic bouts; no cooperation, simultaneous feeding or specific begging gestures were observed. 6. Estimates of the total number of prey killed annually by Amboseli baboons indicate that baboon predation probably has a negligible effect on prey populations other than vervet monkeys. 7. It is speculated that the need for vitamin B12 underlies baboon predatory behavior, and perhaps that of other primate species as well.

Raptor Prey Remains

2020 ◽  
Author(s):  
Ed Drewitt
Keyword(s):  
Feeding Ecology ◽  
Prey Species ◽  
Local Level ◽  
Body Parts ◽  
Change Over Time ◽  
The Common ◽  
Prey Remains ◽  
Over Time ◽  
Prey Populations

Are you curious about the remains of an animal you have found? This compilation of the most likely found body parts of animals eaten by raptors will help you identify your discovery. Including over 100 species of bird and mammal prey of raptors such as sparrowhawks, peregrines and hen harriers, this photographic guide highlights the common feathers, fur and other body parts found at raptor nests, roosts, plucking posts and other opportunistic spots. Discovering what raptors eat is an important part of confirming their feeding ecology and how this might change over time, vary on a local level or in response to changing prey populations, as well as dispelling myths and assumptions about what certain raptor species eat. Diet studies are vital for the conservation of raptor species; the more we know about what they need for survival the more we can predict and plan long-term for the protection and survival of raptors that may be vulnerable and in decline. This is the first book to show in detail the actual parts of a bird, mammal or other animal that you are likely to find in a garden, woodland or beneath a raptor roost. As more people take an interest in raptors and watch species such as peregrines via webcams and through watch groups, there is greater opportunity for finding prey remains. This book provides the first and most important step in identifying a prey species.

scholarly journals Selective feeding by pelagic fish in the Belgian part of the North Sea

2013 ◽  
Vol 71 (4) ◽  
pp. 808-820 ◽  
Author(s):  
Karl Van Ginderdeuren ◽  
Sofie Vandendriessche ◽  
Yves Prössler ◽  
Hakimu Matola ◽  
Magda Vincx ◽  
...  
Keyword(s):  
North Sea ◽  
Prey Species ◽  
Pelagic Fish ◽  
Horse Mackerel ◽  
Calanoid Copepods ◽  
Oikopleura Dioica ◽  
The North ◽  
Fullness Index ◽  
The North Sea ◽  
Prey Items

Abstract Pelagic fish and their planktonic prey are susceptible to a changing climate, giving rise to mismatches and planktonic bottlenecks. A detailed examination of the feeding ecology of pelagic fish can provide valuable insights in the causes and consequences of these phenomena. The present study investigated the diets of both juvenile and adult herring, sprat, horse mackerel, and adult mackerel in the Belgian part of the North Sea (BPNS) in relation to the distribution of zooplankton and ambient abiotic conditions. A study sampling pelagic fish and zooplankton simultaneously every month during consecutive years, and spanning nearshore to offshore sampling locations, is unprecedented in the southern North Sea. In all, 71 prey taxa were found in 725 stomachs of fish gathered at ten stations, sampled monthly in 2009 and 2010. The proportion of fish with empty stomachs was low (11%), and the number of prey species ranged from 0 to 21 sp. per stomach. The diet of herring and sprat was dominated by calanoid copepods, but herring stomachs also contained many decapod larvae, amphipods, cumaceans, and mysids. Mackerel added sandeels to an otherwise planktivorous diet. Horse mackerel consumed both benthic and pelagic prey. The highest frequency of occurrence in the stomachs was observed for the calanoid copepods Temora longicornis (33 408 of all 55 004 prey items identified) and Centropages hamatus (5003 times found). The fullness index ranged between 0 and 20.6, and averaged highest for sprat (0.86), followed by herring (0.60), horse mackerel (0.26), and mackerel (0.24). We observed a different composition of zooplankton species and life stages in the plankton samples compared with those in the fish stomachs. More adult and female copepods were eaten than the plankton samples would suggest. Also, the calanoid copepod Acartia clausi, the most common calanoid species in the BPNS, was barely eaten, as was the case for fish eggs and larvae, and for common planktonic species known to be preyed upon elsewhere (e.g. Oikopleura dioica, Evadne nordmanni, Euterpina acutifrons). Additionally, plankton densities averaged highest in spring and at midshore (20–30 km from shore) stations, but fullness index was highest nearshore (<12 km from shore) and (apart from sprat) in summer. A significant correlation between fullness index and total density of planktonic prey species was not observed, indicating that zooplankton densities were not restrictive. Yet the fact that more than 100 plankton species occurred in the plankton samples and just two of these (T. longicornis and C. hamatus) accounted for nearly three-quarters of all ingested prey items leads us to conclude that even minor changes in the ecology or phenology of these dominant zooplankters could have profound effects on pelagic fish stocks.

Oceanographic factors influencing the distribution of South American fur seal, Arctocephalus australis around the Falkland Islands before the breeding season

2009 ◽  
Vol 89 (8) ◽  
pp. 1597-1600 ◽  
Author(s):  
Vladimir Laptikhovsky
Keyword(s):  
Prey Species ◽  
Falkland Islands ◽  
South American ◽  
Important Food ◽  
Factors Influencing ◽  
South West ◽  
Fur Seals ◽  
Fur Seal ◽  
Important Food Source ◽  
Productive Zone

Distribution of fur seals Arctocephalus australis has been studied in October 2007 on the western, southern and eastern Falkland shelves during the survey of spawning grounds of the red cod, Salilota australis. Fur seals presence/absence, numbers and sex were recorded at every oceanographic station. Animals were found foraging on the shelf edge south-west of the islands, in a productive zone with quasi-stationary eddies at a periphery of upwelling. It was also the zone of maximum abundance of lobster-krill, Munida spp.—an important food source of fur seals and aggregations of both red cod and blue whiting, Micromesistius australis. No fur seals were found in waters of the relative cold and saline Falkland Current as well as in the relatively warm, fresh and oxygen-rich waters of Argentine Drift. It allows supposing that position and extension of the foraging grounds are caused by oceanographic features determining distribution of prey species.

On the Diet of the Boa Epicrates striatus on Hispaniola, with Notes on E. fordi and E. gracilis

1987 ◽  
Vol 8 (3) ◽  
pp. 251-258 ◽  
Author(s):  
José A. Ottenwalder ◽  
Robert W. Henderson ◽  
Albert Schwartz ◽  
Teresa A. Noeske-Hallin
Keyword(s):  
20Th Century ◽  
Mus Musculus ◽  
Prey Species ◽  
Rattus Rattus ◽  
Stomach Contents ◽  
Early 20Th Century ◽  
Ontogenetic Shift ◽  
Small Rodents ◽  
Prey Remains

AbstractThe stomach contents of 214 specimens of Hispaniolan Epicrates (Serpentes: Boidae) were examined for prey remains. The largest species, E. striatus, exhibits a sharp ontogenetic shift in diet: snakes < 60 cm SVL ate predominantly Anolis lizards; snakes 60-80 cm SVL took anoles and small rodents; and snakes > 80 cm SVL ate birds and rats (Rattus rattus). Epicrates fordi preyed on anoles and small rodents, and E. gracilis took only Anolis. E. striatus ate larger individuals of the same species of Anolis consumed by Hispaniolan colubrids. Before the arrival of Europeans on Hispaniola, large Epicrates striatus most likely preyed upon birds and now-extict rodents (Brotomys, Isolobodon and Plagiodontia) and insectivores (Nesophontes). The diet of E. striatus would have gradually shifted from native to introduced mammals, and by the early 20th century, when most native, non-volant mammals had become extinct on Hispaniola, the shift would have become nearly complete, with the exotics Mus musculus and Rattus rattus becoming the predominant prey species.

The diet of the Common Kestrel in the urban environment of the city of Nitra

2008 ◽  
Vol 2 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Lucia Kečkéšová ◽  
Michal Noga
Keyword(s):  
Urban Environment ◽  
House Mouse ◽  
Common Vole ◽  
Microtus Arvalis ◽  
Nesting Sites ◽  
The Common ◽  
Prey Remains ◽  
The City ◽  
Prey Items

The diet of the Common Kestrel in the urban environment of the city of Nitra The diet of the urban Common Kestrel population was studied in Nitra during 2003-2005. Totally, 671 prey items were identified by the analysis of pellets and prey remains collected under the nesting sites. Insect, mainly represented by order Coleoptera, was found to be the most abundant prey. Regarding biomass, the Common Vole (Microtus arvalis) was predominated. In comparison with other articles published, the studied sample was rather rich in the Lesser White-toothed Shrew (Crocidura suaveolens) and the House Mouse (Mus cf. musculus).

Activity Differences influencing Food Selection in the Marine Fish Pomatoschistus microps

1986 ◽  
Vol 43 (1) ◽  
pp. 223-227 ◽  
Author(s):  
Carin Magnhagen
Keyword(s):  
Prey Density ◽  
Laboratory Experiments ◽  
Prey Species ◽  
Food Selection ◽  
Reproductive Period ◽  
Food Selectivity ◽  
Encounter Rate ◽  
Low Density ◽  
Low Activity ◽  
Prey Items

Diets of female and male Pomatoschistus microps during the reproductive period (May–July) differed. Males ate less but used a wider range of prey species than did females. While males guard the eggs and therefore are tied to a nest during the breeding season, females have a higher mobility which leads to a higher prey encounter rate and hence a higher food selectivity than in males. After reproduction the differences between the sexes in food intake and diet disappeared. In laboratory experiments the fish were less active in aquaria with a high prey density than in those with a low density. A decrease in food selectivity with an increasing prey density can thus be due to a decrease in the activity of the fish. At a high prey density, P. microps may benefit from having a low activity and taking unselectively the prey items in its vicinity. The advantages could be reduced detectability by predators and decreased energy expenditure due to locomotion.

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