Foraging in nature: foraging efficiency and attentiveness in caterpillars with different diet breadths

Bernays, Elizabeth A.; Singer, Michael S.; Rodrigues, Daniela

doi:10.1111/j.0307-6946.2004.00615.x

Cited by 84 publications

(68 citation statements)

References 36 publications

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“…Our ability to integrate all relevant dimensions enables a better assessment of the consequences of any changes in the environment (both biotic and abiotic) to which organisms are exposed, and determine the extent to which the behavioural repertoire displayed in response to changing conditions may be optimal. Where such methods are used in measures of foraging success they can be equated with energy expenditure to assess efficiency (Bernays et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

N-dimensional animal energetic niches clarify behavioural options in a variable marine environment

Wilson

McMahon

Quintana

et al. 2011

Journal of Experimental Biology

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SUMMARYAnimals respond to environmental variation by exhibiting a number of different behaviours and/or rates of activity, which result in corresponding variation in energy expenditure. Successful animals generally maximize efficiency or rate of energy gain through foraging. Quantification of all features that modulate energy expenditure can theoretically be modelled as an animal energetic niche or power envelope; with total power being represented by the vertical axis and n-dimensional horizontal axes representing extents of processes that affect energy expenditure. Such an energetic niche could be used to assess the energetic consequences of animals adopting particular behaviours under various environmental conditions. This value of this approach was tested by constructing a simple mechanistic energetics model based on data collected from recording devices deployed on 41 free-living Magellanic penguins (Spheniscus magellanicus), foraging from four different colonies in Argentina and consequently catching four different types of prey. Energy expenditure was calculated as a function of total distance swum underwater (horizontal axis 1) and maximum depth reached (horizontal axis 2). The resultant power envelope was invariant, irrespective of colony location, but penguins from the different colonies tended to use different areas of the envelope. The different colony solutions appeared to represent particular behavioural options for exploiting the available prey and demonstrate how penguins respond to environmental circumstance (prey distribution), the energetic consequences that this has for them, and how this affects the balance of energy acquisition through foraging and expenditure strategy.

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Section: Discussionmentioning

confidence: 99%

N-dimensional animal energetic niches clarify behavioural options in a variable marine environment

Wilson

McMahon

Quintana

et al. 2011

Journal of Experimental Biology

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“…Foraging and feeding can be hazardous, due to increased exposure to natural enemies (Bernays, 1997), and the risk of predation/parasitism accumulates with prolonged development and feeding (Moran and Hamilton, 1980;Loader and Damman, 1991;Benrey and Denno, 1997). It is widely thought that generalists are more susceptible to this kind of selective pressure than are specialists (Geitzenauer and Bernays, 1996;Oppenheim and Gould, 2002;Bernays et al, 2004). Rapid development and high protein consumption seen in HV are therefore explicable as evolved traits selected to reduce the higher predation risk experienced by this species under natural conditions.…”

Section: Compositions Of the Self-selected Dietmentioning

confidence: 99%

Nutrient regulation in relation to diet breadth: a comparison ofHeliothissister species and a hybrid

Lee

Behmer

Simpson

2006

Journal of Experimental Biology

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SUMMARY We examined the nutritional correlates of diet breadth in insect herbivores by comparing patterns of diet selection, nutrient balancing, post-ingestive utilization and development in two sister species of caterpillar and a hybrid between them. One species, Heliothis virescens (HV) has a broad host range, feeding on plants in at least 14 families. The other, Heliothis subflexa (HS), is a specialist on plants in the genus Physalis(Solanaceae). Experiments using synthetic foods showed that when the caterpillars were allowed to mix their diet, the generalist self-selected a higher-protein diet whereas the specialist ate almost equal amounts of protein and carbohydrate, which accords with differences between the two species in the nutrient content of their natural diets. When confined to nutritionally imbalanced diets, the generalist showed a propensity to over-eat high protein:carbohydrate (P:C) diets to a greater degree than did the specialist and maintained higher rates of development. The generalist did not, however,over-eat low P:C diets to the same degree as the specialist. The hybrid selected a diet composition that was indistinguishable to that of its generalist father (HV), while its response to imbalanced diets was closely similar to that of the specialist mother (HS). The generalist converted ingested nutrient to growth with lower efficiency than did the specialist and the hybrid. Our findings imply that different behavioural and physiological traits linked to nutrient regulation are under genetic control and are explicable in terms of the different life-histories, feeding ecologies and presumed levels of nutritional heterogeneity in the environments of the two insects.

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“…Other studies have treated interspecific comparisons between naturally generalist versus specialist species. These have shown specialists to be more efficient (Oppenhiem & Gould 2002), more accurate ( Janz & Nylin 1997), or both (Bernays et al 2004) in their selection and use of host plants. Two studies that compare conspecific populations exhibiting divergent degrees of specificity have similarly demonstrated the greater efficiency (Bernays & Funk 1999) and accuracy ( Janz & Nylin 1997) of more specialized forms.…”

Section: Introductionmentioning

confidence: 99%

Individual advantages to ecological specialization: insights on cognitive constraints from three conspecific taxa

Egan

Funk

2005

Proc. R. Soc. B.

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The information-processing hypothesis (IPH) posits that specialist herbivores should make hostassociated decisions more effectively than generalists and thus enjoy associated fitness advantages that may help explain the evolutionary prevalence of host-specific insects. This is because generalists must evaluate a greater diversity of host plants/cues than specialists and thus face a cognitive challenge that is predicted to constrain the efficiency and accuracy of their choices. Here, we present the first individuallevel evaluation of this hypothesis. This involved experimentally quantifying the specificity, efficiency, and accuracy of host selection, as both larvae and adults, for many individuals representing each of three 'host forms' of Neochlamisus bebbianae leaf beetles. These experiments provided several significant findings: host forms differed in larval specificity, with the more specialized host forms more efficiently and accurately selecting optimal hosts as both larvae and adults. Positive correlations between larval specificity and both efficiency and accuracy across test individuals provided the most direct evidence to date for a biological association between these variables. Our results thus provide strong and consistent support for the IPH at the level of both populations and individuals. Because individual N. bebbianae make many host-associated decisions in nature, our results suggest that cognitive constraints may play a major role in the evolutionary dynamics of ongoing ecological specialization and diversification in this species.

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Foraging in nature: foraging efficiency and attentiveness in caterpillars with different diet breadths

Cited by 84 publications

References 36 publications

N-dimensional animal energetic niches clarify behavioural options in a variable marine environment

N-dimensional animal energetic niches clarify behavioural options in a variable marine environment

Nutrient regulation in relation to diet breadth: a comparison ofHeliothissister species and a hybrid

Individual advantages to ecological specialization: insights on cognitive constraints from three conspecific taxa

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