Know Thine Enemy: Predator Identity Influences the Response of Western Banded Geckos (Coleonyx variegatus) to Chemosensory Cues

Abstract Circular patterns, or eyespots, are common anti-predator features in a variety of animals. Two defensive functions have been documented: large eyespots may intimidate predators, whereas smaller marginal eyespots may divert attacks. However, a given eyespot potentially serves both functions, possibly depending on the predator’s size and/or experience. Naïve predators are potentially more likely to misdirect their attacks towards eyespots; alternatively, their typically smaller size would make them more intimidated by the same eyespots. Here we test how juvenile and sub-adult naïve chickens respond to a single eyespot on a butterfly’s wing. We presented the birds with dead wall brown butterflies, Lasiommata megera, that had their apical eyespot visible or painted over. We assessed the birds’ responses’ by (i) scoring their intimidation reaction, (ii) whether they uttered alarm calls and, (iii) if they attacked the butterfly and where they targeted their attacks. Results show that both age categories received higher intimidation scores when offered a butterfly with a visible eyespot. Juveniles were more intimidated by the butterfly than the sub-adults: they received higher intimidation scores and were more prone to utter alarm calls. Moreover, only sub-adults attacked and did so by preferentially attacking the butterfly’s anterior. We demonstrate an intimidating effect of the type of eyespot that has previously been shown only to divert attacks. We suggest that one and the same eyespot may serve two functions relative to different predators; however, further experiments are needed to disentangle the role of predator identity and its link to size, ontogeny and experience.

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No evidence of selection by predators on tadpole boldness

Behaviour ◽

10.1163/1568539x-00003121 ◽

2014 ◽

Vol 151 (1) ◽

pp. 23-45 ◽

Cited By ~ 11

Author(s):

Bradley E. Carlson ◽

Tracy Langkilde

Keyword(s):

Behavioral Ecology ◽

Empirical Studies ◽

Phenotypic Traits ◽

Lithobates Sylvaticus ◽

Research Attention ◽

Behavioral Traits ◽

Risk Of Predation ◽

The Subject ◽

Predator Identity ◽

Risk Reducing

Animals typically exhibit adaptive behaviors that reduce their risk of predation. The term ‘boldness’ describes individual variation in the propensity to exhibit risk-reducing behavior and is the subject of much research attention. Predators should select against boldness, and this has been supported by empirical studies and behavioral ecology theory. We tested whether a standardized assay of three boldness-associated behaviors in wood frog (Lithobates sylvaticus) tadpoles predicted survival when faced with a predator. Tadpole behavior was assayed in an open field and then tadpoles were placed, in pairs, in an enclosure with a predator (newt or larval dragonfly). Survival did not depend on differences in measured boldness, and this result held when we accounted for interactions between different boldness behaviors and between behavior and size or predator identity. The absence of selection by predators against bolder tadpoles is counterintuitive and inconsistent with our understanding of the behavioral ecology of these animals. Two possible explanations are offered for this result. First, selection against boldness may be minimized by other phenotypic traits, such as escape ability. Alternatively, the potential lack of consistency between standardized boldness assays and natural encounters with predators may limit our capacity to study the evolution of boldness, cautioning against this approach. These results highlight the complexities of the relationships between behavioral traits and fitness and the challenges associated with their study.

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Contribution of Predator Identity to the Suppression of Herbivores by a Diverse Predator Assemblage

Environmental Entomology ◽

10.1603/en13179 ◽

2014 ◽

Vol 43 (3) ◽

pp. 569-576 ◽

Cited By ~ 16

Author(s):

Elizabeth Y. Long ◽

Deborah L. Finke

Keyword(s):

Predator Identity

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Mixed assemblages of drilling predators and the problem of identity in the fossil record: A case study using the muricid gastropod Ecphora

Paleobiology ◽

10.1017/pab.2015.32 ◽

2015 ◽

Vol 41 (4) ◽

pp. 680-696 ◽

Cited By ~ 10

Author(s):

Michelle M. Casey ◽

Úna C. Farrell ◽

Gregory P. Dietl ◽

David J. Veilleux

Keyword(s):

Prey Size ◽

The United States ◽

Atlantic Coastal Plain ◽

Borehole Diameter ◽

Predator Prey ◽

Infaunal Bivalve ◽

Predator Identity ◽

Atlantic Coastal ◽

Muricid Gastropods

AbstractDrillholes made by naticid and muricid gastropods are frequently used in evolutionary and ecological studies because they provide direct, preservable evidence of predation. The muricid Ecphora is common in many Neogene Atlantic Coastal Plain assemblages in the United States, but is frequently ignored in studies of naticid predation. We used a combination of Pliocene fossil, modern beach, and experimentally derived samples to evaluate the hypothesis that Ecphora was an important source of drillholes in infaunal bivalve prey shared with naticids. We focused on the large, thick-shelled venerid, Mercenaria, which is commonly drilled by naticids today. Laboratory experiments, modern beach samples, and the published literature confirm that naticids preferentially drill near the umbo (significant clumping of holes), show a significant correlation between prey size and predator size (estimated by outer borehole diameter), and prefer Mercenaria <50 mm antero-posterior width when other prey are present. Fossil samples containing Ecphora (with or without other large muricids) show no drillhole site stereotypy (no significant clumping, greater variability in placement), no significant predator: prey size correlation, drilled prey shells larger than the largest modern naticids could produce in an experimental setting, and drillholes larger in diameter than those estimated for the largest Pliocene naticids, thus supporting our hypothesis. Substantial overlap in the placement of holes drilled by naticids and muricids, however, made identifying predators from drillhole position problematic. The lack of overlapping ranges of prey shell thickness between fossil and other samples precluded the use of drillhole morphology to establish predator identity (e.g., ratio of inner borehole diameter to outer borehole diameter, drillhole angle). Whereas the difficulty in determining predator identity from drillholes limits the types of analyses that can be reliably performed in mixed-predator assemblages, recognizing Ecphora as a prominent drilling predator creates the opportunity to investigate previously unrecognized questions.

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