Search results for "populaatiot"

Identifying territories using presence-only citizen science data : An application to the Finnish wolf population

2022

Citizens, community groups and local institutions participate in voluntary biological monitoring of population status and trends by providing species data e.g. for regulations and conservation. Sophisticated statistical methods are required to unlock the potential of such data in the assessment of wildlife populations. We develop a statistical modelling framework for identifying territories based on presence-only citizen science data. The framework can be used to jointly estimate the number of active animal territories and their locations in time. Our approach is based on a data generating model which consists of a dynamic submodel for the appearance/removal of territories and an observatio…

Lotic life stages of the European river lamprey (Lampetra fluviatilis) : anthropogenic detriment and rehabilitation

2015

Chimpanzees surviving in a fragmented high‐altitude forest landscape of the Congolese Albertine Rift

2021

This paper documents a community of eastern chimpanzees (Pan troglodytes schweinfurthii Giglioli, 1872) inhabiting three relict forest fragments situated on the Lake Albert escarpment, down the Ituri highlands, of eastern Democratic Republic of the Congo (DRC). The area explored had a combined forested surface of ±18.15 km2 in 2017, shrinking by 1.2% per year between 2010 and 2015. Between 2015 and 2017, we found 160 chimpanzee nests along 37.6 km of pilot walks, some up to 2,000 m altitude. Another 123 nests logged along 6.7 km transects led to an estimate of chimpanzee density of 4.62 weaned individuals per square kilometer of forest habitat. Camera‐trap images and direct observations rev…

Fitness and viability of small populations : the effects of genetic drift, inbreeding, and interpopulation hybridization

2012

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…

Studies of the life history of a parasite : a basis for effective population management

2005

Kalatäit ovat pintaloisia, jotka imevät kaloista verta. Ne liikkuvat kalan pinnalla ja vaurioittavat ihon pintaa. Ihovauriot ja niistä johtuvat bakteeri- ja sienitaudit heikentävät kalojen arvoa ja voivat johtaa kasvun hidastumiseen ja kalan kuolemaan. Kalatäiden torjunta kalanviljelylaitoksissa on ollut vaikeaa ja tehotonta, koska niiden ekologiaa ja elinvaiheita ei ole tunnettu, kertoo Teija Hakalahti. Hakalahti tutki Argulus coregoni -kalatäin ekologiaa ja käyttäytymistä loisen elinkierron eri vaiheissa, joita ovat munat, munista kuoriutuvat vapaana elävät nuoruusvaiheet ja kalassa aikuistuvat loiset. In this thesis, the life history traits of the ectoparasite Argulus coregoni were exami…

Comparison of migratory and resident populations of brown trout reveals candidate genes for migration tendency

2018

Candidate genes associated with migration have been identified in multiple taxa: including salmonids, many of whom perform migrations requiring a series of physiological changes associated with the freshwater–saltwater transition. We screened over 5,500 SNPs for signatures of selection related to migratory behavior of brown trout Salmo trutta by focusing on ten differentially migrating freshwater populations from two watersheds (the Koutajoki and the Oulujoki). We found eight outlier SNPs potentially associated with migratory versus resident life history using multiple (≥3) outlier detection approaches. Comparison of three migratory versus resident population pairs in the Koutajoki watershe…

Dynaaminen populaatiomalli Suomen valkohäntäkauriille : sovelluskohteena Pöytyän riistanhoitoyhdistys

2012

Valkohäntäkauris (Odocoileus virginianus) on Yhdysvalloista Suomeen tuotu vieraslaji. Kauriiden ja autojen yhteentörmäykset ovat lisääntyneet kauriiden määrän kasvaessa. Kolareiden ja muiden kauriista aiheutuvien haittojen vähentämiseksi kannan kokoa säädellään metsästämällä. Vuosittaisten metsästyslupien määrä päätetään kannan koon arvioiden perusteella. Tässä työssä esitellään uusi tapa arvioida Suomen valkohäntäkauriiden kantaa. Vuosittain metsästettyjen valkohäntäkauriiden lukumäärät tunnetaan metsästäjien ilmoitusten perusteella. Lisäksi metsästäjät antavat oman arvionsa metsästysalueensa metsästyksen jälkeisestä kauriiden kannasta. Tässä tutkielmassa kuvataan näitä tietoja hyödyntävä …