Search results for "eläinekologia"
showing 3 items of 3 documents
Cormorant predation mortality of perch (Perca fluviatilis) in coastal and archipelago areas, northern Baltic Sea
2021
Abstract Perch (Perca fluviatilis) is an important prey species of the great cormorant (Phalacrocorax carbo sinensis) in the coastal waters of the northern Baltic Sea. The annual predation mortality caused by cormorants was estimated based on the consumed numbers of perch in relation to the abundance of perch in vulnerable age groups in the sea. We used existing stock assessment data (Archipelago Sea) or a simple population model in other areas (Gulf of Finland, Bothnian Sea, and Quark), based on commercial and recreational perch catches, and estimated fishing and natural mortalities, with distributions describing our understanding about the likelihood of different values for every variable…
Effects of interspecific relationships in forested landscapes on breeding success in Eurasian treecreeper
2005
Jatkuvat vanhoihin metsiin kohdistuvat metsänhakkuut kaventavat puukiipijöiden ja kekomuurahaisten elinmahdollisuuksia. Havaitsin tämän väitöstyössäni, jonka teemoina olivat puukiipijän ja kekomuurahaisten välinen ravintokilpailu puiden rungoilla ja petojen, lähinnä kärpän, lumikon ja käpytikan vaikutus puukiipijän pesintämenestykseen pesäpönttöpopulaatiossa. Tutkimus on toteutettu Keski-Suomen metsissä Konneveden, Hankasalmen ja Laukaan kunnan alueella vuosina 1990-2003. T his study is focused on the effects of predation to the breeding success of Eurasian treecreeper and resource competition between red wood ants, Formica rufa -group and treecreepers. One of the most important factors in …
Supplementary data to: Context-dependent coloration of prey and predator decision making in contrasting light environments
2021
A big question in behavioural ecology is what drives diversity of colour signals. The dataset covers the testing of the context-dependent predator selection on prey coloration. In the first experiment, detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) was tested by manipulating stimulus luminance and chromatic context of the background. In the second experiment, the effect of two light environments on the survival of aposematic, colour polymorphic wood tiger moth (Arctia plantaginis) was tested. For detailed description of the material, methods, and results of the study, see the article.