scholarly journals Effects of sensory mode in prey discrimination and predatory behaviour of rock lizards

2020 ◽  
Vol 42 (1) ◽  
pp. 125-132
Author(s):  
Pablo Recio ◽  
Gonzalo Rodríguez-Ruiz ◽  
José Martín
Keyword(s):  
Visual Cues ◽  
Prey Species ◽  
Foraging Ecology ◽  
Sensory System ◽  
Predatory Behaviour ◽  
Sensory Mode ◽  
Rock Lizard ◽  
Prey Discrimination ◽  
Tongue Flicks ◽  
Number Of Individuals

Abstract An essential part of foraging ecology is to understand the processes of detection, recognition and discrimination of prey, as well as the sensorial modalities involved. Often, predators do not rely on a single sensory system but on multiple interacting senses. Specifically, lizards mainly use vision and vomerolfaction for prey pursuit. Here, we used an experimental approach to study how the Carpetan rock lizard, Iberolacerta cyreni, responds to different types of stimuli (chemical, visual, or both combined) from two prey species. The number of individuals approaching the prey and the number of attacks differed between treatments, however, we did not find differences in latency time, number of individuals attacking the prey or number of tongue flicks. Our results suggested that visual cues combined with chemical stimuli enhanced detection of both prey species and that prey discrimination occurred posteriorly and independently of using any or both types of stimuli.

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.

scholarly journals Dive behaviour and foraging effort of female Cape fur seals Arctocephalus pusillus pusillus

2019 ◽  
Vol 6 (10) ◽  
pp. 191369 ◽  
Author(s):  
S. P. Kirkman ◽  
D. P. Costa ◽  
A.-L. Harrison ◽  
P. G. H. Kotze ◽  
W. H. Oosthuizen ◽  
...  
Keyword(s):  
Prey Species ◽  
Foraging Ecology ◽  
Critical Role ◽  
Ecosystem Structure ◽  
Depth Range ◽  
Dive Behaviour ◽  
Top Predators ◽  
Fur Seals ◽  
Cape Fur Seal ◽  
Benthic Diving

While marine top predators can play a critical role in ecosystem structure and dynamics through their effects on prey populations, how the predators function in this role is often not well understood. In the Benguela region of southern Africa, the Cape fur seal ( Arctocephalus pusillus pusillus ) population constitutes the largest marine top predator biomass, but little is known of its foraging ecology other than its diet and some preliminary dive records. Dive information was obtained from 32 adult females instrumented with dive recorders at the Kleinsee colony (29°34.17′ S, 16°59.80′ E) in South Africa during 2006–2008. Most dives were in the depth range of epipelagic prey species (less than 50 m deep) and at night, reflecting the reliance of Cape fur seals on small, vertically migrating, schooling prey. However, most females also performed benthic dives, and benthic diving was prevalent in some individuals. Benthic diving was significantly associated with the frequency with which females exceeded their aerobic dive limit. The greater putative costs of benthic diving highlight the potential detrimental effects to Cape fur seals of well-documented changes in the availability of epipelagic prey species in the Benguela.

scholarly journals Polar bears are inefficient predators of seabird eggs

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Patrick M. Jagielski ◽  
Cody J. Dey ◽  
H. Grant Gilchrist ◽  
Evan S. Richardson ◽  
Oliver P. Love ◽  
...  
Keyword(s):  
Decision Making ◽  
Optimal Foraging ◽  
Visual Cues ◽  
Foraging Ecology ◽  
Optimal Foraging Theory ◽  
Nest Density ◽  
Polar Bears ◽  
Somateria Mollissima ◽  
Resource Density ◽  
Foraging Performance

Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears ( Ursus maritimus ) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears' foraging performance on common eider ( Somateria mollissima ) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density.

scholarly journals Characterising the foraging ecology and mercury exposure of the Nationally Critical Whenua Hou diving petrel

2021 ◽  
Author(s):  
Grace Tocker
Keyword(s):  
Breeding Season ◽  
Trophic Level ◽  
Interannual Variation ◽  
Prey Species ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Mercury Exposure ◽  
Potential Threat ◽  
Breeding Seasons ◽  
Diving Petrel

<p>With seabird species in decline globally, significant research has gone into characterising their key prey species and foraging areas that need protection. Knowledge on the diet of a species has important implications for the development of conservation programmes. The sand dune system on Whenua Hou is home to the endemic Whenua Hou diving petrel (Pelecanoides whenuahouensis; hereafter WHDP) and a population of common diving petrels (Pelecanoides urinatrix; hereafter CDP). The WHDP is considered ‘Nationally Critical’ due to its small population size (~200 individuals) and restricted breeding range (0.018 km2) on Whenua Hou. The foraging ecology of the WHDP is relatively unknown, as is its exposure to sources of marine pollution. This thesis aimed to characterise the foraging ecology of the WHDP, the potential interspecific competition with the sympatric CDPs, the prey present in the diets of each species, and their resulting exposure to mercury from the environment. In chapter 2, I used stable isotope analysis to infer the trophic dynamics of the WHDP. By sampling and analysing both blood and feathers, I was able to investigate potential differences in WHDP foraging ecology between the breeding and non-breeding seasons. I found a difference between the foraging ecology of male and female WHDPs, with results indicating females forage further out to sea than males and on prey of lower trophic value. I found that WHDPs forage an entire trophic level higher during the breeding season than the non-breeding season. As my sampling effort spanned three consecutive breeding seasons (2017-2019), I was able to detect interannual variation in the foraging ecology of WHDPs. The results revealed that WHDPs foraged at a higher trophic level during the breeding season of 2018 compared to that of 2017 or 2019. By characterising the isotopic niches of both the WHDPs and CDPs over the three years, I was able to demonstrate a degree of trophic segregation between the two species during the breeding season. In chapter 3, I designed and went through the initial development stages for a novel multiplex-PCR assay to identify the prey species present in the diets of WHDPs and CDPs. The obstacles faced in the development of this protocol highlighted the suitability of DNA metabarcoding as an alternative method. In chapter 4, I analysed the mercury concentration in the same blood and feather samples used for stable isotope analysis. I demonstrated that male WHDPs had higher concentrations of mercury in their tissues than females, correlating with their foraging at a higher trophic level. The interannual variation in mercury concentration did not correlate with the trophic variation of WHDPs among years, indicating that the environmental fluctuations in mercury levels had a stronger effect on mercury exposure than diet. WHDP tissues consistently had higher concentrations of mercury than CDPs, correlating with their isotopic niche segregation and highlighting a potential threat to individual survival and reproductive success in WHDPs. Overall, my results describe patterns in the foraging ecology of the WHDP, as well as highlighting the potential threat from mercury exposure. This research can be used as a baseline for future investigations into the key prey species for the endangered WHDP and the impacts mercury exposure may be having on the population growth of this species. </p>

Sensory Components of Behavioral Isolation Between Zimbabwe and Cosmopolitan Drosophila Melanogaster

2010 ◽  
Vol 56 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Daina Ma ◽  
Dean P. Smith ◽  
Zhichao Zheng ◽  
Pawel Michalak
Keyword(s):  
Drosophila Melanogaster ◽  
Visual Cues ◽  
Sensory System ◽  
Central Africa ◽  
Mate Recognition ◽  
Sensory Cues ◽  
Incipient Speciation ◽  
Choice Preference ◽  
Behavioral Isolation ◽  
Males And Females

Successful reproduction requires males and females from the same species to recognize and prefer each other over individuals of other species. Mate recognition is mediated through the sensory systems, and one way speciation can occur is through behavioral isolation via sensory cues.Drosophila melanogasterfemales from central Africa (the "Zimbabwe" morph) prefer to mate with Zimbabwe males over males from otherDrosophilastrains ("Cosmopolitan" strains). Cosmopolitan females typically show little or no preference towards Cosmopolitan males. We hypothesize that alterations in one or more cues detected by the sensory system underlie the mating preferences of Zimbabwe females. Here, we investigate the relative contributions of three sensory factors (olfaction, vision, and hearing) to female mating preference using a number of Zimbabwe strains. Our findings suggest that auditory and visual cues are the most critical to this mate choice preference phenomenon. These results elucidate plausible mechanisms underlying incipient speciation inDrosophila.

scholarly journals Visual and Chemical Prey Cues as Complementary Predator Attractants in a Tropical Stream Fish Assemblage

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Chris K. Elvidge ◽  
Grant E. Brown
Keyword(s):  
Visual Cues ◽  
Foraging Behaviour ◽  
Chemical Cues ◽  
Prey Species ◽  
Public Information ◽  
Foraging Strategies ◽  
Predator Species ◽  
Foraging Modes ◽  
Relative Attractiveness ◽  
Ambush Predators

To date, little attention has been devoted to possible complementary effects of multiple forms of public information similar information on the foraging behaviour of predators. In order to examine how predators may incorporate multiple information sources, we conducted a series of predator attraction trials in the Lower Aripo River, Trinidad. Four combinations of visual (present or absent) and chemical cues (present or absent) from each of two prey species were presented. The occurrences of three locally abundant predatory species present within a 1 m radius of cue introduction sites were recorded. The relative attractiveness of cue type to each predator was directly related to their primary foraging modes, with visual ambush predators demonstrating an attraction to visual cues, benthivores to chemical cues, and active social foragers demonstrating complementary responses to paired cues. Predator species-pair counts were greatest in response to cues from the more abundant prey species, indicating that individuals may adopt riskier foraging strategies when presented with more familiar prey cues. These differences in predator attraction patterns demonstrate complementary effects of multiple sensory cues on the short-term habitat use and foraging behaviour of predators under fully natural conditions.

Influence of visual cues on localization of acoustic sound sources in old adults

2012 ◽  
Vol 25 (0) ◽  
pp. 23
Author(s):  
Claudia Freigang ◽  
Marc Stoehr ◽  
Kristina Schmiedchen ◽  
Jan Bennemann ◽  
Rudolf Rübsamen
Keyword(s):  
Older Adults ◽  
Visual Stimulus ◽  
Visual Cues ◽  
Spatial Information ◽  
Free Field ◽  
Sensory System ◽  
Visual Cue ◽  
Localization Accuracy ◽  
Old Adults ◽  
Age Related

Localization accuracy of stationary acoustic objects is reduced as people grow older. While it is known that this reduction can be caused by many age-related declines in the peripheral sensory system, at central cortical levels as well as in cognitive processes, it is not known how much localization performance is influenced by concurrent congruent and/or incongruent spatial information from a different sensory system, e.g., vision. In the present study we examined localization accuracy of young and old adults to acoustic stimuli that were presented simultaneously to a visual stimulus that was either spatially congruent or spatially disparate (by ±5°/±10°/±15°) in acoustic free field. The acoustic reference position was presented at frontal (9°), para-frontal (30°), and lateral (64°) positions. To infer how strongly the visual cue interacted with the auditory stimulus a unification task was examined. Here, acoustic and visual stimulus combinations were the same as in the localization task. Participants were instructed to indicate whenever both visual and acoustic information matched in terms of their spatial position. Localization accuracy was not influenced by the visual cue in young adults, but the influence of the visual distractor was strong in old adults, i.e., visual bias was strong. These observations were supported by the unification task where old adults had increased perception of congruent audio–visual directions at all reference positions and even at very large disparities (e.g., ±15°). Conclusively, concurrent information from different sensory systems highly influences auditory localization accuracy in older adults, supporting the notion that multisensory integration is enhanced in older adults.

Contrasting variations in the diet of the Andean fox Lycalopex culpaeus Molina, 1782 on geographical and environmental scales in the Atacama Desert

Mammalia ◽  
2019 ◽  
Vol 83 (5) ◽  
pp. 439-446
Author(s):  
Felipe S. Carevic ◽  
Erico R. Carmona ◽  
Francisco Cartes ◽  
Felipe Taucare
Keyword(s):  
South America ◽  
Prey Species ◽  
Atacama Desert ◽  
Current Data ◽  
Dietary Breadth ◽  
History Of ◽  
Study Sites ◽  
Number Of Individuals ◽  
Andean Fox ◽  
Main Food Item

Abstract We determined the seasonal diet of the Andean fox Lycalopex culpaeus in three habitats in the Atacama Desert, northern Chile, by analyzing their scat contents. We estimated the biomass and the number of individuals of each prey species consumed and compared our results with those of other studies on Lycalopex foxes in Chile and South America. In general, the L. culpaeus diet was characterized by a generalist behavior and higher dietary breadth than those in other ecosystems. In contrast with the other biomes of southern Chile and South America, insects represented the most frequent prey species in the present study and the main food item, comprising more than 50% of all prey at the three study sites; however, in terms of biomass, rodent and reptile prey showed the highest percentage from summer to winter. Significant differences were found between the biomass consumed among sites. Likewise, we found a relationship between the niche breadth of the diet and the primary productivity of the sites. Statistically significant differences in prey items consumed were noted across seasons and sites located at different altitudes, which reflected an opportunistic response to the availability of prey. Our report contributes to current data about the natural history of L. culpaeus in hyper-arid habitats.

scholarly journals Predation on Artificial Nests of Northern Bobwhites, Colinus virginianus, by Mammalian Mesopredators: Does the Problem-Individual Paradigm Fit?

2006 ◽  
Vol 120 (4) ◽  
pp. 452 ◽  
Author(s):  
J. B. Jennings ◽  
M. L. Kennedy ◽  
A. E. Houston ◽  
B. D. Carver
Keyword(s):  
Prey Species ◽  
Colinus Virginianus ◽  
Management Strategies ◽  
Sampling Period ◽  
Northern Bobwhite ◽  
Didelphis Virginiana ◽  
Artificial Nests ◽  
Northern Bobwhites ◽  
Number Of Individuals ◽  
Striped Skunks

Using mark/recapture procedures, predation on artificial nests of Northern Bobwhites (Colinus virginianus) by mammalian mesopredators (Raccoons, Procyon lotor; Virginia Opossums, Didelphis virginiana; and Striped Skunks, Mephitis mephitis) was assessed in relation to the “problem-individual” paradigm. The paradigm, which is untested among mammalian mesopredators, predicts that most predation on a prey species is by a small number of individuals repeatedly involved. By examining number of captures and recaptures on artificial nests during non-nesting and nesting periods in 2000-2003, predation within and among species were gauged. Results varied by species, sampling period, and year; however, predation was by a small percentage of individuals and only within the population of Striped Skunks were individuals (2 of 49) captured on an artificial nest more than once. Raccoons, Virginia Opossums, and Striped Skunks were responsible for 10, 2, and 12% of the loss of all nests available to predators, respectively. Based on low occurrences of individuals repeatedly involved in predation on nests, the problem-individual paradigm was unsubstantiated. Although Raccoons, Virginia Opossums, and Striped Skunks (as individual predators) had only moderate impact on the population of Northern Bobwhites, they had a much greater impact collectively (preying upon 24% of all nests available). To maximize Northern Bobwhite success, the most productive management is probably best directed toward a vertebrate guild that includes mammalian, avian, and reptilian predators, and management strategies that use multiple techniques.

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