Search results for "linnut"
showing 10 items of 49 documents
Poliittinen siivekäs : lintujen konkreettisuus suomalaisessa 1970-luvun ympäristörunoudessa
2010
Suomalaisen luontorunouden maisema on aina ollut linnuista rikas. Siivekkäitä ihaillaan runoudessa usein etäällä lentävinä, tai lintu paljastuu jonkun inhimillisen tunteen tai toiveen vertauskuvaksi. 1970-luvulla suomalaisen runouden lintukuvauksessa tapahtui muutos. Linnut tulivat lukijan lähelle kouriintuntuvasti mutta silti eläimellisen vierautensa säilyttäen. Ne alkoivat myös kärsiä ympäristöongelmista todellisten lintujen tavoin. Poliittinen siivekäs on ekokriittisiä ja posthumanistisia teorioita yhdistävä tutkimus lintujen konkretisoitumisesta, siitä miten linnuista alettiin kirjoittaa lintuina. Suomalaisten runoilijoiden ympäristötietoista linturunoutta suhteutetaan runoutemme tradit…
Bayesian semiparametric long memory models for discretized event data
2020
We introduce a new class of semiparametric latent variable models for long memory discretized event data. The proposed methodology is motivated by a study of bird vocalizations in the Amazon rain forest; the timings of vocalizations exhibit self-similarity and long range dependence. This rules out Poisson process based models where the rate function itself is not long range dependent. The proposed class of FRActional Probit (FRAP) models is based on thresholding, a latent process. This latent process is modeled by a smooth Gaussian process and a fractional Brownian motion by assuming an additive structure. We develop a Bayesian approach to inference using Markov chain Monte Carlo and show g…
Do large‐scale associations in birds imply biotic interactions or environmental filtering?
2023
Aim There has been a wide interest in the effect of biotic interactions on species' occurrences and abundances at large spatial scales, coupled with a vast development of the statistical methods to study them. Still, evidence for whether the effects of within-trophic-level biotic interactions (e.g. competition and heterospecific attraction) are discernible beyond local scales remains inconsistent. Here, we present a novel hypothesis-testing framework based on joint dynamic species distribution models and functional trait similarity to dissect between environmental filtering and biotic interactions. Location France and Finland. Taxon Birds. Methods We estimated species-to-species association…
Species distributions models may predict accurately future distributions but poorly how distributions change: A critical perspective on model validat…
2023
Aim: Species distribution models (SDMs) are widely used to make predictions on how species distributions may change as a response to climatic change. To assess the reliability of those predictions, they need to be critically validated with respect to what they are used for. While ecologists are typically interested in how and where distributions will change, we argue that SDMs have seldom been evaluated in terms of their capacity to predict such change. Instead, typical retrospective validation methods estimate model's ability to predict to only one static time in future. Here, we apply two validation methods, one that predicts and evaluates a static pattern, while the other measures change…
Mechanisms of population declines in boreal forest grouse
2007
Gilbert Ludwig tutki väitöskirjassaan, miksi kanalinnut ovat vähentyneet talousmetsissä. Suomen metsäkanalintukannat ovat vähentyneet merkittävästi viimeisen 40 vuoden ajan. Pesiin ja poikasiin kohdistuvaa saalistusta on pidetty tärkeimpänä syynä kanalintukantojen laskuun. Hakkuiden ja nuorten metsien osuuden lisääntymisen on katsottu lisänneen myyräkantoja ja niitä syöviä petoja, kuten kettuja, lisäten näin myös kanalintujen pesiin ja poikasiin kohdistuvaa saalistusta. Vuosikymmenten aikana laskenut poikastuotto on keskeisessä roolissa kanalintukantojen laskussa. - Ainakaan teerellä vuotuinen aikuiskuolleisuus ei ole lainkaan lisääntynyt. Hengissäsäilyminen on päinvastoin jopa parantunut, …
No evidence for associations between brood size, gut microbiome diversity and survival in great tit (Parus major) nestlings
2022
Abstract Background The gut microbiome forms at an early stage, yet data on the environmental factors influencing the development of wild avian microbiomes is limited. As the gut microbiome is a vital part of organismal health, it is important to understand how it may connect to host performance. The early studies with wild gut microbiome have shown that the rearing environment may be of importance in gut microbiome formation, yet the results vary across taxa, and the effects of specific environmental factors have not been characterized. Here, wild great tit (Parus major) broods were manipulated to either reduce or enlarge the original brood soon after hatching. We investigated if brood siz…
Data and code for manuscript: Increasing human environmental footprint does not lead to biotic homogenization of forest bird communities in northern …
2023
R-code and data for replicating statistical analyses used in the study: Increasing human environmental footprint does not lead to biotic homogenization of forest bird communities in northern USA. This study examined how forest loss and increased human domination in the state of Minnesota in the USA were associated with diversity of forest birds using bird count data.
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 …
Maternally‐transferred thyroid hormones and life‐history variation in birds
2022
1. In vertebrates, thyroid hormones (THs) play an important role in the regulation of growth, development, metabolism, photoperiodic responses and migration. Maternally transferred THs are important for normal early-phase embryonic development when embryos are not able to produce endogenous THs. Previous studies have shown that variation in maternal THs within the physiological range can influence offspring phenotype. 2. Given the essential functions of maternal THs in development and metabolism, THs may be a mediator of life-history variation across species. 3. We tested the hypothesis that differences in life histories are associated with differences in maternal TH transfer across species…
Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird
2023
An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life-history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (Mb) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed ‘common ga…