Search results for "Predator-prey interactions"

Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs

2014

Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and…

Many forms of the wood tiger moth (Parasemia plantaginis) : selective heterogeneity favours polymorphic warning signals

2013

Item Response Trees: a recommended method for analyzing categorical data in behavioral studies

2015

Behavioral data are notable for presenting challenges to their statistical analysis, often due to the difficulties in measuring behavior on a quantitative scale. Instead, a range of qualitative alternative responses is recorded. These can often be understood as the outcome of a sequence of binary decisions. For example, faced by a predator, an individual may decide to flee or stay. If it stays, it may decide to freeze or display a threat and if it displays a threat, it may choose from several alternative forms of display. Here we argue that instead of being analyzed using traditional nonparametric statistics or a series of separate analyses split by response categories, this kind of data ca…

Research data supporting "Social information use about novel aposematic prey is not influenced by a predator’s previous experience with toxins"

2019

This data is from the experiment investigating social avoidance learning in wild-caught great tits, conducted at Konnevesi Research Station in Central Finland during winter 2017. Sheet 1 (���main data���) contains data from the main avoidance learning experiment, including individual attributes (sex, age, weight etc.), experimental treatments and individuals��� foraging choices in the learning trials. Sheet 2 (���preference test���) contains data from the initial preference test of the symbols that were used in the experiment, and Sheet 3 (���visibility test���) data from the initial visibility test of the same symbols.

Olfactory cues and the value of information : Voles interpret cues differently based on recent predator encounters

2018

Prey strategically respond to the risk of predation by varying their behavior while balancing the tradeoffs of food and safety. We present here an experiment that tests the way the same indirect cues of predation risk are interpreted by bank voles, Myodes glareolus, as the game changes through exposure to a caged weasel. Using optimal patch use, we asked wild-caught voles to rank the risk they perceived. We measured their response to olfactory cues in the form of weasel bedding, a sham control in the form of rabbit bedding, and an odor-free control. We repeated the interviews in a chronological order to test the change in response, i.e., the changes in the value of the information. We found…

Research data supporting "Social learning within and across predator species reduces attacks on novel aposematic prey"

2019

This data is from the experiment that investigated how wild-caught blue tits and great tits use conspecific and heterospecific information about unpalatable prey, published at the Journal of Animal Ecology (2020). The experiment was conducted at the Konnevesi Research Station from October to December 2017. Sheet 1 (“Main experiment”) contains data from the main avoidance learning experiment. Sheets 2 (“Symbol preference blue tits”) and 3 ("Symbol visibility blue tits") contain data of blue tits' symbol choices in initial preference and visibility tests.

Not just the sum of its parts : Geographic variation and nonadditive effects of pyrazines in the chemical defence of an aposematic moth

2022

Chemical defences often vary within and between populations both in quantity and quality, which is puzzling if prey survival is dependent on the strength of the defence. We investigated the within- and between-population variability in chemical defence of the wood tiger moth (Arctia plantaginis). The major components of its defences, SBMP (2-sec-butyl-3-methoxypyrazine) and IBMP (2-isobutyl-3-methoxypyrazine), are volatiles that deter bird attacks. We hypothesized that (1) variation in the chemical defences of male wood tiger moths reflects the local predation pressure; (2) observed differences in quantity and quality of defence among populations have a genetic basis; and (3) increasing con…

Colour alone matters : no predator generalization among morphs of an aposematic moth

2018

Local warning colour polymorphism, frequently observed in aposematic organisms, is evolutionarily puzzling. This is because variation in aposematic signals is expected to be selected against due to predators' difficulties associating several signals with a given unprofitable prey. One possible explanation for the existence of such variation is predator generalization, which occurs when predators learn to avoid one form and consequently avoid other sufficiently similar forms, relaxing selection for monomorphic signals. We tested this hypothesis by exposing the three different colour morphs of the aposematic wood tiger moth, Arctia plantaginis, existing in Finland to local wild-caught predato…

Multimodal Aposematic Defenses Through the Predation Sequence

2021

Aposematic organisms warn predators of their unprofitability using a combination of defenses, including visual warning signals, startling sounds, noxious odors, or aversive tastes. Using multiple lines of defense can help prey avoid predators by stimulating multiple senses and/or by acting at different stages of predation. We tested the efficacy of three lines of defense (color, smell, taste) during the predation sequence of aposematic wood tiger moths (Arctia plantaginis) using blue tit (Cyanistes caeruleus) predators. Moths with two hindwing phenotypes (genotypes: WW/Wy = white, yy = yellow) were manipulated to have defense fluid with aversive smell (methoxypyrazines), body tissues with a…

Evolution of signal diversity: predator-prey interactions and the maintenance of warning colour polymorphism in the wood tiger moth Arctia plantaginis

2017

Aposematic organisms avoid predation by advertising defences with warning signals. The theory of aposematism predicts warning signal uniformity, yet variation in warning coloration is widespread. The chemically defended wood tiger moth Arctia plantaginis shows both geographic variation and local polymorphism in warning coloration. In this thesis, I studied whether predation by local avian predators is driving the evolution of wood tiger moth warning colours. The close relatives of the wood tiger moth designated here to genus Arctia do not show similar colour polymorphism. The wood tiger moth is thus apparently under evolutionary radiation and provides a natural laboratory for observing curr…