David Kikuchi

Oregon State University | OSU · Department of Integrative Biology

Prey seldom rely on a single type of antipredator defence, often using multiple defences to avoid predation. In many cases, selection in different contexts may favour the evolution of multiple defences in a prey. However, a prey may use multiple defences to protect itself during a single predator encounter. Such "defence portfolios" that defend pre...

Undefended or weakly defended prey species can evolve to resemble better-defended prey (models) in a potentially parasitic relationship called Batesian mimicry. However, some highly defended prey have lethal defenses that might prevent predators from learning to avoid them, which raises questions as to how and why warning signals evolve in these sp...

We investigate the social transmission of innovations between predators. We focus on two classic predator-prey models. We assume that innovations increase predator attack rates or conversion efficiencies or that innovations reduce predator mortality or handling time. We find that a common outcome is the destabilization of the system. Destabilizing...

Individual behavioral variation is common, yet often we do not know how it is maintained. A potential explanation is that some behaviors must be acquired rather than genetically inherited. We investigate the social transmission of behavioral innovations, which can be key for the success of predator species, especially in contexts where environmenta...

Understanding Batesian mimicry is a classic problem in evolutionary biology. In Batesian mimicry, a defended species (the model) is mimicked by an undefended species (the mimic). Prior theories have emphasized the role of predator behavior and learning as well as evolution in model-mimic complexes but have not examined the role of population dynami...

Animals exhibit extensive intraspecific variation in behaviour. Causes of such variation are less well understood. Here, we ask when competition leads to the maintenance of multiple behavioural strategies. We model variability using the timing of bird migration as an example. Birds often vary in when they return from non-breeding grounds to establi...

Warning signals are a striking example of natural selection present in almost every ecological community – from Nordic meadows to tropical rainforests, defended prey species and their mimics ward off potential predators before they attack. Yet despite the wide distribution of warning signals, they are relatively scarce as a proportion of the total...

Mimicry is common in interspecies interactions, yet conditions maintaining Batesian mimicry have been primarily tested in predator–prey interactions. In pollination mutualisms, floral mimetic signals thought to dupe animals into pollinating unrewarding flowers are widespread (greater than 32 plant families). Yet whether animals learn to both correc...

Müllerian mimicry is a classic example of adaptation, yet Müller’s original theory does not account for the diversity often observed in mimicry rings. Here, we aimed to assess how well classical Müllerian mimicry can account for the color polymorphism found in chemically defended Oreina leaf beetles by using field data and laboratory assays of pred...

Mimicry is the phenotypic resemblance of one organism to another because the resemblance is favored by selection from a signal receiver who perceives the resemblance. We would expect mimics to resemble their models closely, yet the widespread existence of imperfect mimics confounds this expectation, and has led to a profusion of possible explanatio...

Batesian mimics-benign species that receive protection from predation by resembling a dangerous species-often occur with multiple model species. Here, we examine whether geographical variation in the number of local models generates geographical variation in mimic-model resemblance. In areas with multiple models, selection might be relaxed or even...

Warning signals displayed by defended prey are mimicked by both mutualistic (Müllerian) and parasitic (Batesian) species. Yet mimicry is often imperfect: why does selection not improve mimicry? Predators create selection on warning signals, so predator psychology is crucial to understanding mimicry. We conducted experiments where humans acted as pr...

Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes ( Micrurus ) and their mimics, o...

Imperfect mimicry presents a paradox of incomplete adaptation – intuitively, closer resemblance should improve performance. Receiver psychology can often explain why mimetic signals do not always evolve to match those of their models. Here, we explored the influence of a pervasive and powerful cognitive bias where associative learning depends upon...

Explaining variation in the abundance of species remains a challenge in ecology. We sought to explain variation in abundance of Neotropical forest birds using a dataset of population densities of 596 species. We tested a priori hypotheses for the roles of species traits, environmental factors, and species interactions. Specifically, we focused on f...

Reciprocal selection on harmless Batesian mimics and their defended models has long been hypothesized to spawn coevolutionary arms races. Mimics are thought continuously to experience selection to resemble their models better. Models are thought continuously to experience 'chase-away' selection for phenotypes that let them escape from these 'parasi...

Anthropogenic climate change is a significant global driver of species distribution change. Although many species have undergone range expansion at their poleward limits, data on several taxonomic groups are still lacking. A common method for studying range shifts is using species distribution models to evaluate current, and predict future, distrib...

Recent species locality data (from 2000-2015) used to test current and future species distribution models Species locality data complied from the following sources: ASU, Arizona State University; gbif, http://www.gbif.org; HerpNet, from http://www.herpnet.org (which has since been folded into http://www.vertnet.org); idigbio, http://www.idigbio.org...

Response curves from each environmental layer used in the current climate modeling for the Full model

Metadata for species locality data

Locality records of coral snakes collected between 1950–2000 All species locality data used in the current Maxent models. Data source codes are as follows: ASU, Arizona State University; gbif, www.gbif.org; HerpNet, http://www.herpnet.org (now http://www.vertnet.org); idigbio, http://www.idigbio.org; MISS, Mississippi Museum of Natural History; NCM...

Museums that contributed locality data for coral snakes, either directly via the curator, or through the gbif (www.gbif.org), vertnet (http://www.vertnet.org), or idigbio (www.idigbio.org) databases

All environmental layers used in the current climate modeling shown for the study area Bioclimatic variables came from WorldClim ( http://www.worldclim.org/) and soil type from the Harmonized World Soil Database ( http://www.arcgis.com/home/item.html?id=1d16ed2a0aa24ab39e5ee6c491965883). Temperature is expressed in degrees Celsius multiplied by 10,...

In the cloud forests of the central range of the Colombian Andes, we discovered a species of katydid (Orthoptera: Tettigoniidae) that imitates mosses to an uncanny degree and is exceedingly difficult to detect. The camouflage exhibited by this particular katydid seems quite specific. We discuss the evolutionary consequences of this sort of speciali...

When should multiple traits on Batesian mimics be selected to resemble corresponding traits on model species? Here, we explore two possibilities. First, features of equal salience to predators may be used to categorize prey, selecting for multicomponent mimicry. Second, if different predators use single yet different traits to categorize prey, mult...

Understanding the factors that determine population densities is critical for conserving viable populations of threatened species. Half of the 50 species in the family Cracidae have experienced population declines. We conducted a literature review to explore the relations of population densities of cracids with body size, habitat, season, and hunti...

An elegant study by Kazemi et al. (2014, Current Biology, 24, 965-969) found that blue tits, Cyanistes caeruleus, that had been trained to distinguish between rewarding and nonrewarding prey subsequently avoided novel prey that had the same colour (but not the same shape or pattern) as the nonrewarding prey. Their work suggested that certain high-s...

Predators must use the appearance of their prey to decide whether it is likely to be defended. Most theory assumes that predators have completed learning about prey appearance, yet we do not understand how predators learn which aspects of appearance to use for classifying prey. If sampling prey can be risky, predators might forgo opportunities to l...

Signal detection theory (SDT) has been invoked to help explain why imperfect mimics of particularly unprofitable or abundant models might experience no further selection to improve their mimicry. However, most tests of SDT have focused on single dimensions of mimetic phenotypes, or used multivariate techniques to compress many dimensions of phenoty...

We evaluated whether Batesian mimicry promotes early-stage reproductive isolation. Many Batesian mimics occur not only in sympatry with their model (as expected), but also in allopatry. As a consequence of local adaptation within both sympatry (where mimetic traits are favored) and allopatry (where non-mimetic traits are favored), divergent, predat...

Mimicry, where one species resembles another species because of the selective benefits of sharing a common signal, is especially common in snakes. Snakes might be particularly prone to evolving mimicry if all species share some of the same proximate mechanisms that can be used to produce aposematic/mimetic signals. We evaluated this possibility by...

Coral snakes and their mimics often have brightly colored banded patterns, generally associated with warning colora- tion or mimicry. However, such color patterns have also been hypothesized to aid snakes in escaping predators through a “flicker-fusion” effect. According to this hypothesis, banded color patterns confuse potential predators when a s...

Mimicry--when one organism (the mimic) evolves a phenotypic resemblance to another (the model) due to selective benefits--is widely used to illustrate natural selection's power to generate adaptations. However, many putative mimics resemble their models imprecisely, and such imperfect mimicry represents a specific challenge to mimicry theory and a...

Batesian mimics are harmless prey species that resemble dangerous ones (models), and thus receive protection from predators. How such adaptive resemblances evolve is a classical problem in evolutionary biology. Mimicry is typically thought to be difficult to evolve, especially if the model and mimic produce the convergent phenotype through differen...

Mimicry is widely used to exemplify natural selection's power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Müllerian mimicry complexes. Here, we consider...

Some species evolve to resemble another species so as to protect themselves from predation, but this mimicry is often imprecise. An analysis of hoverflies suggests why imperfect imitation persists in the face of natural selection. See Letter p.461

Batesian mimicry is often imprecise. An underexplored explanation for imperfect mimicry is that predators might not be able to use all dimensions of prey phenotype to distinguish mimics from models and thus permit imperfect mimicry to persist. We conducted a field experiment to test whether or not predators can distinguish deadly coral snakes (Micr...

In Batesian mimicry, a harmless species (the 'mimic') resembles a dangerous species (the 'model') and is thus protected from predators. It is often assumed that the mimetic phenotype evolves from a cryptic phenotype, but it is unclear how a population can transition through intermediate phenotypes; such intermediates may receive neither the benefit...

Terrestrial insectivorous birds in a cloud-forest on the north-western slope of the Peruvian Andes were described in terms of species richness, abundance, density, territory size and biomass. Abundance, density and territory size were also characterized for several understorey insectivores. The three terrestrial insectivore species, all in the genu...