Search results for "saalistus"

Evaluating the potential for evolutionary mismatch in Batesian mimics: A case study in the endangered smooth snake (Coronella austriaca)

2018

Many harmless organisms gain a survival advantage by mimicking venomous species. This is the case of the endangered smooth snake (Coronella austriaca), which mimics venomous vipers. Although this may protect the smooth snake against most of its natural predators, it may render them at greater risk of mortality from humans, who are more inclined to kill species, such as vipers, that they consider dangerous. This may cause an evolutionary mismatch, whereby humans may counteract the natural advantage of mimicry. We explore this possibility of evaluating the willingness of humans to kill smooth snakes versus the adder (Vipera berus), as well as their ability to discern them in the Åland Islands…

Out in the open : behavior’s effect on predation risk and thermoregulation by aposematic caterpillars

2020

Abstract Warning coloration should be under strong stabilizing selection but often displays considerable intraspecific variation. Opposing selection on color by predators and temperature is one potential explanation for this seeming paradox. Despite the importance of behavior for both predator avoidance and thermoregulation, its role in mediating selection by predators and temperature on warning coloration has received little attention. Wood tiger moth caterpillars, Arctia plantaginis, have aposematic coloration, an orange patch on the black body. The size of the orange patch varies considerably: individuals with larger patches are safer from predators, but having a small patch is beneficia…

Kilpailu vaikuttaa nieriän ravintoon

2013

Lapin nieriäkannat ovat monin paikoin taantuneet uusien kalalajien levittäytymisen seurauksena. Tuore väitöskirjatutkimus osoittaa, että nieriä voi vaihtaa ravintoaan ja elinpaikkaansa vähentääkseen kilpailua muiden kalalajien kanssa. nonPeerReviewed

Rannan halkoisjalkaisäyriäisten (Mysidacea) silakan (Clupea harengus v. membras L.) mätimuniin ja vastakuoriutuneisiin poikasiin kohdistama saalistus

2007

Social transmission in the wild can reduce predation pressure on novel prey signals

2021

Funder: Suomen Kulttuurirahasto (Finnish Cultural Foundation); doi: https://doi.org/10.13039/501100003125

Contrasting structural complexity differentiate hunting strategy in an ambush apex predator.

2021

AbstractStructural complexity is known to influence prey behaviour, mortality and population structure, but the effects on predators have received less attention. We tested whether contrasting structural complexity in two newly colonised lakes (low structural complexity lake—LSC; high structural complexity—HSC) was associated with contrasting behaviour in an aquatic apex predator, Northern pike (Esox lucius; hereafter pike) present in the lakes. Behaviour of pike was studied with whole-lake acoustic telemetry tracking, supplemented by stable isotope analysis of pike prey utilization and survey fishing data on the prey fish community. Pike displayed increased activity, space use, individual …

Social information use by predators : expanding the information ecology of prey defences

2022

Social information use is well documented across the animal kingdom, but how it influences ecological and evolutionary processes is only just beginning to be investigated. Here we evaluate how social transmission may influence species interactions and potentially change or create novel selection pressures by focusing on predator-prey interactions, one of the best studied examples of species coevolution. There is extensive research into how prey can use social information to avoid predators, but little synthesis of how social transmission among predators can influence the outcome of different stages of predation. Here we review evidence that predators use social information during 1) encount…

Indirect effects of invasive crayfish on native fish parasites

2013

Interactions between invasive and native species are often modified by parasites. One little-studied scenario is that invasive species affect parasite transmission to native hosts by altering the relative abundance of hosts needed in parasite life cycles, for example by predation on these hosts. Here we show that presence of an invasive crayfish species, Pacifastacus leniusculus, decreases the mean abundance of native parasites transmitted from snails and aquatic isopods to perch, Perca fluviatilis, in two large boreal lakes in Finland. In contrast, parasites transmitted to the fish from planktonic copepods or mussels, hosts not readily preyed on by crayfish, were not affected by crayfish p…

Crayfish predation on mussels : an experimental approach

2013

Tässä työssä tutkittiin kokeellisesti rapujen simpukoihin kohdistuvaa predaatiota. Käytetyt rapulajit olivat jokirapu Astacus astacus ja amerikkalainen tulokaslaji täplärapu Pascifastacus leniusculus. Jokirapupredaatiota tutkittiin pikkujärvisimpukalla Anodonta anatina ja täplärapupredaatiota pikkujärvisimpukalla sekä jokihelmisimpukalla Margaritifera margaritifera Kokeissa ravut laitettiin yksittäin 15 litran läpivirtausaltaisiin simpukan/simpukoiden kanssa. Täplärapu osoittautui tehokkaammaksi predaattoriksi onnistuen aukaisemaan seitsemän 42:sta Anodontasta. Jokirapu ei saanut avattua yhtään 37:stä Anodontasta. Aukaisemisen ja pehmytosien syömisen lisäksi rapujen havaittiin nakertavan si…

Interspecific interactions and premating reproductive isolation

2008

Interspecific interactions have several evolutionary consequences: for example, two species may compete, hybridize, or behave aggressively towards each other, or there may be predator–prey interactions. One consequence of these interactions is the evolution of premating reproductive isolation between the two species. The most obvious interspecific interaction, which has an effect on reproductive isolation, is the avoidance of hybridization, or, in other words, the reinforcement process. The theory of reinforcement states that when hybridization is maladaptive, selection pressure causes a divergence in female mate preference and/or in male secondary sexual characters. It is often assumed tha…