The influence of density on frequency-dependent food selection: a comparison of four experiments with wild birds

Weale, Michael E.; Whitwell, Diana; Raison, Helen E.; Raymond, Deborah L.; Allen, J. A.

doi:10.1007/s004420000399

Cited by 22 publications

(32 citation statements)

References 30 publications

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“…For example, at extremely high density or when prey is aggregated, the direction of frequency-dependent predation may be reversed-rare morphs suffer heavier predation (e.g. Willis et al, 1980;Horsley et al, 1979;Greenwood, 1985; but see also Greenwood et al, 1989;Weale et al, 2000).…”

Section: Criticisms and Considerations For Future Researchmentioning

confidence: 98%

Perceptual Processes and the Maintenance of Polymorphism Through Frequency-dependent Predation

2005

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One of the key challenges of both ecology and evolutionary biology is to understand the mechanisms that maintain diversity. Negative frequency-dependent selection is a powerful mechanism for maintaining variation in the population as well as species diversity in the community. There are a number of studies showing that this type of selection, where individuals of a rare type (i.e. a rare morph or a rare species) experience higher survival than those of more common type(s). However, it is still not clear how frequency-dependent selection operates. Search image formation has been invoked as a possible, proximate explanation. Although the conceptual link between search image and frequency-dependent predation is often assumed in ecological and evolutionary studies, a review of the literature reveals a paucity of evidence demonstrating the occurrence of both in a natural predator-prey system. Advances in the field of psychology strongly support the existence of search image, yet these findings are not fully recognized in the realm of ecology and evolutionary biology, in part, we feel because of confusion and inconsistencies in terminology. Here we try to simplify the language, clarify the advances in the study of frequency-dependent predation and search image, and suggest avenues for future research. We feel that the investigations of both proximate (perceptual mechanisms) and ultimate (pattern of predation) processes are necessary to fully understand the importance of individual behavioural processes for mediating evolutionary and ecological diversity.

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Section: Criticisms and Considerations For Future Researchmentioning

confidence: 98%

Perceptual Processes and the Maintenance of Polymorphism Through Frequency-dependent Predation

2005

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“…When the exponent is larger than 1, the predator exhibits prey switching. When the exponent is smaller than 1, the predator is said to exhibit negative prey switching, because it consumes disproportionately less of the more available prey (24)(25)(26).…”

Section: Introductionmentioning

confidence: 99%

A generalized functional response for predators that switch between multiple prey species

Leeuwen

Brännström

Jansen

et al. 2013

Journal of Theoretical Biology

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ABSTRACT. We develop a theory for the food intake of a predator that can switch between multiple prey species. The theory addresses empirical observations of prey switching and is based on the behavioural assumption that a predator tends to continue feeding on prey that are similar to the prey it has consumed last, in terms of, e.g., their morphology, defences, location, habitat choice, or behaviour. From a predator's dietary history and the assumed similarity relationship among prey species, we derive a general closed-form multi-species functional response for describing predators switching between multiple prey species. Our theory includes the Holling type II functional response as a special case and makes consistent predictions when populations of equivalent prey are aggregated or split. An analysis of the derived functional response enables us to highlight the following five main findings.(1) Prey switching leads to an approximate power-law relationship between ratios of prey abundance and prey intake, consistent with experimental data. (2) In agreement with empirical observations, the theory predicts an upper limit of 2 for the exponent of such power laws. (3) Our theory predicts deviations from power-law switching at very low and very high prey-abundance ratios. (4) The theory can predict the diet composition of a predator feeding on multiple prey species from diet observations for predators feeding only on pairs of prey species. (5) Predators foraging on more prey species will show less pronounced prey switching than predators foraging on fewer prey species, thus providing a natural explanation for the known difficulties of observing prey switching in the field.

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“…Rare morphs have an advantage in systems where predators form a search image and prey more heavily on the most common morph (Allen, 1988;Weale et al, 2000;Shigemiya, 2004). Rare male morphs may have an advantage under sexual selection, as in the side-blotched lizard Uta stansburiana, where each of the three male throat colour morphs has highest reproductive success when at low frequency (Sinervo & Lively, 1996).…”

Section: Introductionmentioning

confidence: 99%

Phenotypic and genetic variation in emergence and development time of a trimorphic damselfly

Abbott¹,

Svensson²

2005

J Evolution Biol

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Although colour polymorphisms in adult organisms of many taxa are often adaptive in the context of sexual selection or predation, genetic correlations between colour and other phenotypic traits expressed early in ontogeny could also play an important role in polymorphic systems. We studied phenotypic and genetic variation in development time among female colour morphs in the polymorphic damselfly Ischnura elegans in the field and by raising larvae in a common laboratory environment. In the field, the three different female morphs emerged at different times. Among laboratory-raised families, we found evidence of a significant correlation between maternal morph and larval development time in both sexes. This suggests that the phenotypic correlation between morph and emergence time in the field has a parallel in a genetic correlation between maternal colour and offspring development time. Maternal colour morph frequencies could thus potentially change as correlated responses to selection on larval emergence dates. The similar genetic correlation in male offspring suggests that sex-limitation in this system is incomplete, which may lead to an ontogenetic sexual conflict between selection for early male emergence (protandry) and emergence times associated with maternal morph.

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The influence of density on frequency-dependent food selection: a comparison of four experiments with wild birds

Cited by 22 publications

References 30 publications

Perceptual Processes and the Maintenance of Polymorphism Through Frequency-dependent Predation

Perceptual Processes and the Maintenance of Polymorphism Through Frequency-dependent Predation

A generalized functional response for predators that switch between multiple prey species

Phenotypic and genetic variation in emergence and development time of a trimorphic damselfly

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