Feeding Ecology of the Tasmanian Spotted Skink, Niveoscincus Ocellatus (Squamata: Scincidae)

1996 ◽  
Vol 44 (2) ◽  
pp. 205 ◽  
Author(s):  
E Wapstra ◽  
R Swain
Keyword(s):  
Feeding Ecology ◽  
Foraging Behaviour ◽  
Additional Data ◽  
Prey Size ◽  
Feeding Activity ◽  
Foraging Strategy ◽  
Dietary Composition ◽  
Stomach Fullness ◽  
Terrestrial Arthropods ◽  
Ambush Predation

The feeding ecology of the spotted skink, Niveoscincus ocellatus, was examined over a 6-month period, from October to March, with additional data from one sample in midwinter. The investigation considered feeding activity, dietary composition and foraging strategy. Feeding activity,measured by stomach fullness, was unrelated to age, sex or reproductive status and showed little variation during the warmer months; in winter feeding was greatly reduced. N. ocellatus exhibits flexible foraging behaviour; a wide variety of terrestrial arthropods is taken opportunistically in accordance with a wide ranging foraging strategy. However, the consistent occurrence of cryptic and hidden prey indicates that active search foraging is also utilised. No evidence for ambush predation was found and, unlike many other small skinks, few arboreal or aerial prey are included in the diet, even though the habitat is rock scree and woodland where such prey abound. No evidence for any in a specific partitioning of diet based on kind or size of prey was obtained although a slight, but significant, correlation exists between maximum prey size and lizard size.

Foraging behaviour of the endangered Australian skink (Liopholis slateri)

2014 ◽  
Vol 62 (6) ◽  
pp. 477 ◽  
Author(s):  
Megan A. McKinney ◽  
Christine A. Schlesinger ◽  
Chris R. Pavey
Keyword(s):  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Field Of View ◽  
Wide Field ◽  
Buffel Grass ◽  
Wide Field Of View ◽  
Burrow Entrance ◽  
Central Australia ◽  
Ambush Predation ◽  
Straight Ahead

The foraging behaviour of the endangered Australian skink (Liopholis slateri) was investigated through detailed observation of a subpopulation of lizards during seven months of sampling. Slater’s skinks primarily exhibited ambush predation, darting from burrow entrances to distances of up to 4 m with a success rate of ~70%. The direction of darting was often straight ahead and almost always in an 180° arc in front of the burrow entrance. Juveniles foraged more frequently and further from burrows than adults. Ants were the most common prey item taken and juveniles targeted small ants as prey more often than adults and often moved further to capture these prey. The spread of introduced buffel grass (Cenchrus ciliaris) in central Australia in recent decades is a possible contributing factor to the decline of L. slateri. A wide field of view appears to be critical for the success of the sit-and-wait foraging strategy employed by the skinks and additional research is required to determine whether further encroachment of buffel grass around burrow systems will impede visibility and directly affect foraging behaviour of these skinks.

scholarly journals Variations of Salminus hilarii diet (Ostariophysi, Characidae): seasonal and ontogenetic effects

2015 ◽  
Vol 75 (3) ◽  
pp. 574-580
Author(s):  
GA Villares Junior ◽  
R Goitein
Keyword(s):  
Prey Size ◽  
Pearson Correlation ◽  
Feeding Activity ◽  
Stomach Contents ◽  
Food Composition ◽  
Spearman Correlation ◽  
Statistical Comparison ◽  
Significant Difference ◽  
Ontogenetic Effects ◽  
Size And Morphology

AbstractThis study described the variations seasonal and ontogenetic of Salminus hilarii diet. Samples were collected in the Sorocaba River, São Paulo, Brazil, one of the few rivers where individuals of the species still occur in a higher frequency. The preys consumed were analyzed by Importance Alimentary Index (AIi). To determine similarities between year seasons, the AIi data were analyzed by the Morisita-Horn index and reduced in cluster analysis, along with a statistical comparison made by one-way ANOSIM test (5%). The feeding activity was analyzed according to the stomach repletion index and compared among the year seasons using non parametric variance analysis Kruskal-Wallis test (5%). Comparison of prey consumed between immature and adult individuals was made by Spearman correlation (5%). A Pearson correlation (5%) was applied between the standard length of the fish and prey consumed, as well as between the mouth and prey heights. The analyzes of stomach contents showed that the diet of this species was exclusively piscivorous, with significant difference of prey consumption during the period, the same happening among adult and immature individuals. It was observed that these fishes use to swallow their prey whole and that significant correlations between size of predator and prey size can be observed. There is also correlation between the mouth height and the maximum prey depth. Salminus hilarii feeds on the available prey, and the species food composition and feeding activity depends on prey`s abundance, their size and morphology, as do the water temperatures.

Variation in the diet of the Lataste's viper Vipera latastei in the Iberian Peninsula: seasonal, sexual and size-related effects

2007 ◽  
Vol 57 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Juan Pleguezuelos ◽  
José Brito ◽  
Soumia Fahd ◽  
Xavier Santos ◽  
Gustavo Llorente ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Conservation Management ◽  
Prey Availability ◽  
Feeding Activity ◽  
Prey Type ◽  
Ontogenetic Shift ◽  
Ecological Data ◽  
Opposite Pattern ◽  
Iberian Range ◽  
Ambush Predation

AbstractSeveral life-history traits may increase vulnerability of species to extinction. Among snakes, ambush predation and dietary specialisation are factors that increase this vulnerability. European viper species, genus Vipera, display such traits and are categorised as endangered in several parts of its range. For their conservation management, a deeper knowledge of their ecology and habitat use is highly relevant. One of the species with less ecological data is the Lataste's viper Vipera latastei, a species which lives in the Iberian Peninsula and northwestern Africa. Here, we describe its diet based on the analysis of gut content of 435 museum specimens plus nine bibliographic data from the entire Iberian range. The species showed seasonal and ontogenetic shift in diet but no sexual variations. Feeding activity (percentage of vipers with prey) was low in accordance with its ambush predation tactics, being lower in spring than in summer and autumn. Prey spectrum included two main (reptiles and small mammals), and three sporadic, types of prey (arthropods, amphibians and birds). The consumption of reptiles and mammals was seasonal; the former decreased in occurrence from spring to autumn, whereas the latter showed an opposite pattern. There was an ontogenetic shift in the diet: juveniles fed mainly on reptiles and arthropods, whereas adult vipers progressively substitute this prey with insectivores, and the largest vipers primarily foraged on rodents and birds. Our results suggest that the seasonal variation in prey type was related to prey availability, whereas the ontogenetic shift was linked to gape limitation. The apparently wide prey spectrum of V. latastei must therefore be examined, taking into account that there are seasonal and ontogenetic dietary variations as well as geographic differences, the latter probably driven by climatic contrasts into the Iberian Peninsula. This new data of the endangered Iberian V. latastei can aid the effective conservation management of this species.

scholarly journals Foraging strategy of a carnivorous-insectivorous raptor species based on prey size, capturability and nutritional components

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan A. Fargallo ◽  
Juan Navarro-López ◽  
Patricia Palma-Granados ◽  
Rosa M. Nieto
Keyword(s):  
Prey Size ◽  
Foraging Strategy ◽  
Nutritional Components

scholarly journals Feeding Ecology of Greater Snow Goose Goslings in Mesic Tundra on Bylot Island, Nunavut, Canada

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 361-376 ◽  
Author(s):  
Benoît Audet ◽  
Gilles Gauthier ◽  
Esther LÉVESQUE
Keyword(s):  
Phenolic Compounds ◽  
Feeding Ecology ◽  
Nutritional Quality ◽  
Feeding Activity ◽  
Food Selection ◽  
Neutral Detergent Fiber ◽  
Total Phenolic ◽  
Snow Goose ◽  
Greater Snow Goose ◽  
Bylot Island

AbstractAlthough mesic tundra is a habitat commonly used by arctic-nesting geese, their feeding ecology in this habitat is little known compared to wetlands. Our objectives were to determine the diet and food selection of Greater Snow Goose (Chen caerulescens atlantica) goslings in relation to the nutritional quality of plants growing in mesic tundra habitats on Bylot Island, Nunavut, Canada. We used two different but complementary approaches: examination of esophageal contents of sacrificed wild goslings, and direct observation of the feeding activity of captive, human-imprinted goslings. The latter method was innovative and provided a reliable description of the diet, with results comparable to those obtained from wild goslings. Although mesic habitats have a more diverse floristic composition than wetlands and sparse graminoid cover, Gramineae were preferentially selected and dominated the diet (~50%). The rest of the diet consisted mainly of members of the Juncaceae, Polygonaceae, and Leguminosae families. The diet of very young goslings was diverse, but as they aged and gained efficiency, they concentrated on a few taxa. Goslings ate mostly leaves (~80%), but flowers (~20%) were also important. Food selection was influenced by nitrogen and total phenolic compounds content of plants, but the ratio of phenolic compounds to nitrogen in plant organs was most determinative of food choice. Neutral detergent fiber content of plants did not influence plant selection. Both plant nutritional quality and availability determined gosling diet across different mesic habitats and growing goslings appeared to maximize their intake of metabolizable proteins.

scholarly journals Cuttlefish show flexible and future-dependent foraging cognition

2020 ◽  
Vol 16 (2) ◽  
pp. 20190743 ◽  
Author(s):  
Pauline Billard ◽  
Alexandra K. Schnell ◽  
Nicola S. Clayton ◽  
Christelle Jozet-Alves
Keyword(s):  
Food Availability ◽  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
The Other ◽  
Foraging Activity ◽  
Experimental Conditions

Some animals optimize their foraging activity by learning and memorizing food availability, in terms of quantity and quality, and adapt their feeding behaviour accordingly. Here, we investigated whether cuttlefish flexibly adapt their foraging behaviour according to the availability of their preferred prey. In Experiment 1, cuttlefish switched from a selective to an opportunistic foraging strategy (or vice versa ) when the availability of their preferred prey at night was predictable versus unpredictable. In Experiment 2, cuttlefish exhibited day-to-day foraging flexibility, in response to experiencing changes in the proximate future (i.e. preferred prey available on alternate nights). In Experiment 1, the number of crabs eaten during the day decreased when shrimp (i.e. preferred food) were predictably available at night, while the consumption of crabs during the day was maintained when shrimp availability was unpredictable. Cuttlefish quickly shifted from one strategy to the other, when experimental conditions were reversed. In Experiment 2, cuttlefish only reduced their consumption of crabs during the daytime when shrimps were predictably available the following night. Their daytime foraging behaviour appeared dependent on shrimps' future availability. Overall, cuttlefish can adopt dynamic and flexible foraging behaviours including selective, opportunistic and future-dependent strategies, in response to changing foraging conditions.

Intertidal foraging by gentoo penguins in a macroalgal raft

2020 ◽  
Vol 32 (1) ◽  
pp. 43-44
Author(s):  
James B. McClintock ◽  
Charles D. Amsler ◽  
Margaret O. Amsler ◽  
William R. Fraser
Keyword(s):  
Environmental Change ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Marion Island ◽  
Pygoscelis Papua ◽  
General Consensus ◽  
Foraging Tactics ◽  
Pygoscelid Penguins ◽  
Foraging Tactic

Foraging strategies in gentoo penguins (Pygoscelis papua) have been well studied (e.g. Croxall et al. 1988, Robinson & Hindell 1996, Lescroël et al. 2004, Takahashi et al. 2008, Xavier et al. 2017). The general consensus is this largest member of the three pygoscelid penguins displays both nearshore benthic and pelagic foraging tactics to consume combinations of crustaceans and fish. In a recent study, Carpenter-Kling et al. (2017) reported that gentoos at sub-Antarctic Marion Island displayed a novel foraging strategy that consisted of alternating typical lengthy foraging trips with much shorter nearshore afternoon trips. They suggest the latter foraging behaviour may be a response to suboptimal feeding conditions caused by local environmental change. This novel discovery reinforces the fact that, despite considerable study, not all foraging tactics in penguins have been documented. In this paper, we describe what we believe to be, yet another undocumented foraging tactic employed by gentoos.

Dispersal patterns of large-seeded plants and the foraging behaviour of a frugivorous bat

2020 ◽  
Vol 36 (3) ◽  
pp. 94-100
Author(s):  
David Villalobos-Chaves ◽  
Felipe P. L. Melo ◽  
Bernal Rodríguez-Herrera
Keyword(s):  
Plant Species ◽  
Foraging Behaviour ◽  
Feeding Activity ◽  
Dry Forest ◽  
Dispersal Patterns ◽  
Selective Pressures ◽  
Night Feeding ◽  
Mutualistic Interactions ◽  
Neotropical Dry Forest

AbstractMutualistic interactions are biologically important, diverse and poorly understood. Comprehending these interactions and the effectiveness of the mutualistic partners has been the central focus of ecological and evolutionary studies, as this task requires disentangling the pieces of mutualism under study. Here, we tested the hypothesis that feeding activity of Artibeus phaeotis influences density, diversity and distance effects of the seed rain of large-seeded plant species in a Neotropical dry forest of Costa Rica. We predicted that bats’ activity increases density and diversity metrics on dispersing sites and that bats behave as short-distance dispersers. Our data revealed that, by dispersing hundreds of seeds within their small foraging areas and mostly close to fruiting trees, the feeding activity of A. phaeotis increases the density and richness of seeds underneath night feeding roosts. The functional role of A. phaeotis as disperser may vary among plant species, as we also detected that some seeds are more dispersed than others. Further inquiries to elucidate mutualistic interactions between frugivorous bats and large-seeded plant species should focus on understanding demographic and fitness outcomes, as strong selective pressures may be shaping morphological and behavioural traits of both plants and animals, ultimately influencing the survival of each partner.

Feeding habits of the velvet belly lanternshark Etmopterus spinax (Chondrichthyes: Etmopteridae) off the Algarve, southern Portugal

2006 ◽  
Vol 86 (4) ◽  
pp. 835-841 ◽  
Author(s):  
João Neiva ◽  
Rui Coelho ◽  
Karim Erzini
Keyword(s):  
Deep Water ◽  
Foraging Behaviour ◽  
Prey Size ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Prey Composition ◽  
Southern Portugal ◽  
Meganyctiphanes Norvegica ◽  
Diet Shifts

Etmopterus spinax is one of the most abundant predators of the upper continental slope off the Algarve (southern Portugal), where it is captured in large quantities in deep-water fisheries. The feeding habits of E. spinax off the Algarve were investigated through the analysis of stomach contents of 376 individuals. Prey composition was described and maturity, sex and size related variations in the diet analysed. The overall diet of E. spinax suggested a fairly generalized benthopelagic foraging behaviour primarily tuned to pelagic macroplankton/microneckton, teleost fish and cephalopods. Sex and maturity related differences in the diet were not significant. Two main ontogenic diet shifts were observed at about 17 and 28 cm total length. Small and medium sized immature sharks had a diet dominated by eurybathic crustaceans, chiefly Meganyctiphanes norvegica and Pasiphaea sivado. Larger individuals consumed more teleosts and cephalopods, in part associated with scavenging as a new feeding strategy. With increasing shark size the diet diversified both in terms of resources exploited and prey size.

Frequency-dependent prey selection by larvae of Toxorhynchites splendens (Diptera: Culicidae)

1996 ◽  
Vol 86 (6) ◽  
pp. 633-639 ◽  
Author(s):  
D. Dominic Amalraj ◽  
P. K. Das
Keyword(s):  
Aedes Aegypti ◽  
Foraging Behaviour ◽  
Anopheles Stephensi ◽  
Prey Size ◽  
Prey Selection ◽  
Fourth Instar ◽  
Frequency Dependent ◽  
Size Selection ◽  
The Stability

AbstractThe foraging behaviour of frequency-dependent prey selection by larval instars of Toxorhynchites splendens (Wiedemann) was studied in the laboratory. Prey size selection (second vs fourth instars of Aedes aegypti Linnaeus or Anopheles stephensi Liston) by third and fourth instar predators was frequency-dependent. However, in the case of second instar predators, prey size selection was not frequency-dependent and the predator preferred second instar to fourth instar prey. When offered second instars of Aedes aegypti and Anopheles stephensi the preference for one species over the other was frequency-dependent in all the three predator instars. The role of frequency-dependent prey selection in the stability of prey—predator interaction at low equilibrium levels is discussed.

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