Katja Rönkä

Katja Rönkä
University of Helsinki | HY · Department of Biological and Environmental Sciences

PhD (Ecology and evolutionary biology)

About

15
Publications
7,253
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206
Citations
Introduction
After a PhD in predator-prey interactions -- that is warningly coloured moths under selection by avian predators, I have developed growing interest in bird behaviour. My current research in a host-parasite system with reed warblers and cuckoos deals with questions of range expansion, coevolution and social information use by the hosts, and involves a wide range of techniques from genomics to behavioral experiments in the field and predictive species distribution modelling.

Publications

Publications (15)
Article
Full-text available
The reed warbler (Acrocephalus scirpaceus) is a long-distance migrant passerine with a wide distribution across Eurasia. This species has fascinated researchers for decades, especially its role as host of a brood parasite, and its capacity for rapid phenotypic change in the face of climate change. Currently, it is expanding its range northwards in...
Article
Full-text available
Hosts of brood parasitic cuckoos often employ mobbing attacks to defend their nests and, when mobbing is costly, hosts are predicted to adjust their mobbing to match parasitism risk. While evidence exists for fine-tuned plasticity, it remains unclear why mobbing does not track larger seasonal changes in parasitism risk. Here we test a possible expl...
Preprint
Full-text available
The reed warbler ( Acrocephalus scirpaceus ) is a long-distance migrant passerine with a wide distribution across Eurasia. This species has fascinated researchers for decades, especially its role as host of a brood parasite, and its capacity for rapid phenotypic change in the face of climate change. Currently, it is expanding its range northwards i...
Article
Full-text available
Warning signals are predicted to develop signal monomorphism via positive frequency‐dependent selection (+FDS) albeit many aposematic systems exhibit signal polymorphism. To understand this mismatch, we conducted a large‐scale predation experiment in four countries, among which the frequencies of hindwing warning coloration of the aposematic moth,...
Preprint
Full-text available
Warning signals are predicted to develop signal monomorphism via positive frequency-dependent selection (+FDS) albeit many aposematic systems exhibit signal polymorphism. To understand this mismatch, we conducted a large-scale predation experiment in four locations, among which the frequencies of hindwing warning coloration of aposematic Arctia pla...
Data
Table S1. Examples of warning‐colour variation described in existing literature.
Article
Full-text available
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency‐dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in...
Article
Full-text available
Chemically defended animals often display conspicuous color patterns that predators learn to associate with their unprofitability and subsequently avoid. Such animals (i.e., aposematic), deter predators by stimulating their visual and chemical sensory channels. Hence, aposematism is considered to be "multimodal." The evolution of warning signals (a...
Article
Full-text available
Multiple-model mimicry, whereby different morphs of an aposematic species each resemble another defended species sharing the costs of predator education, has been proposed as a mechanism allowing colour polymorphisms in aposematic species. Male wood tiger moths, Arctia plantaginis (Linnaeus, 1758), are chemically defended and polymorphic (yellow, w...
Article
Full-text available
Multiple-model mimicry, whereby different morphs of an aposematic species each resemble another defended species sharing the costs of predator education, has been proposed as a mechanism allowing colour polymorphisms in aposematic species. Male wood tiger moths, Arctia plantaginis (Linnaeus, 1758), are chemically defended and polymorphic (yellow, w...
Article
Full-text available
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 pred...
Article
Full-text available
Despite being popular among amateur and professional lepidopterologists and posing great opportunities for evolutionary research, the phylogenetic relationships of tiger moths (Erebidae: Arctiinae) are not well resolved. Here we provide the first phylogenetic hypothesis for the subtribe Arctiina with the basic aim of clarifying the phylogenetic pos...
Data
Full-text available
The Zip file at [http://datadryad.org/resource/doi:10.5061/dryad.j54vv] contains capture-recapture data and habitat classification maps of the three false heath fritillary populations in Finland that were studied in Fabritius et al. (2015). The capture-recapture data contains information on the daily search effort (i.e. areas visited on each day) a...
Article
Full-text available
Background Species movement responses to landscape structures have been studied using a variety of methods, but movement research is still in need of simple methods that help predicting and comparing movements across structurally different landscapes. We demonstrate how habitat-specific movement models can be used to disentangle causes of different...

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Projects

Projects (3)
Archived project
Henna Fabritius' PhD thesis project (in the Centre of Excellence in Metapopulation Biology / LUOVA Doctoral Programme) focused on the challenges of conservation planning (in ecological modelling, reserve selection and conservation policy administration) that are related to maintaining a suitable disturbance level and a specific successional stage for conservation purposes. The project included four fieldwork components related to the study species, the false heath fritillary (Melitaea diamina): (1) a species and habitat distribution survey, (2) a mark-recapture study, (3) a retrospective vegetation study of temporal habitat change, and (4) a conservation consultancy project that reached 100+ meadow landowners.
Project
This project investigates multiple selection forces that aposematic and colour polymorphic wood tiger moth face in the wild. This system helps us to understand how predation by birds, diseases, sexual selection and thermoregulation shape phenotypes of individuals.
Project
PhD in the Centre of Excellence in Biological Interactions in University of Jyväskylä, under the excellent supervision of prof. Johanna Mappes, Bibiana Rojas and prof. Niklas Wahlberg