Search results for "linnut"

Matkailun linnustovaikutukset Länsi-Lapissa

2008

Scientific Reports

2020

.-- Halimubieke, Naerhulan et al.

Asymmetries in reproductive anatomy : insights from promiscuous songbirds

2019

Directional asymmetry in gonad size is commonly observed in vertebrates and is particularly pronounced in birds, where the left testis is frequently larger than the right. The adaptive significance of directional asymmetry in testis size is poorly understood, and whether it extends beyond the testes (i.e. side-correspondent asymmetry along the reproductive tract) has rarely been considered. Using the Maluridae, a songbird family exhibiting variation in levels of sperm competition and directional testis asymmetry, yet similar in ecology and life history, we investigated the relative roles of side-correspondence and sperm competition on male reproductive tract asymmetry at both inter- and int…

The Ghost of the Hawk: Top Predator Shaping Bird Communities in Space and Time

2021

Despite the wide recognition that strongly interacting species can influence distributions of other species, species interactions are often disregarded when assessing or projecting biodiversity distributions. In particular, it remains largely uncharted the extent to which the disappearance of a keystone species cast repercussions in the species composition of future communities. We tested whether an avian top predator can exert both positive and negative effects on spatial distribution of other species, and if these effects persist even after the predator disappeared. We acquired bird count data at different distances from occupied and non-occupied nests of Northern goshawks Accipiter genti…

Assessment of the impacts of an oil spill on the populations of common guillemot (Uria aalge) and long-tailed duck (Clangula hyemalis) - an expert kn…

2012

The amount of operated oil transports continues to increase in the Gulf of Finland and in the case of an accident hazardous amounts of oil may be spilled into the sea. The oil accident may be harmful for the common guillemot and long-tailed duck populations. In this study expert knowledge regarding the behaviour and population dynamics of common guillemot and long-tailed duck in the Gulf of Finland was used to build a model to assess the impacts of an oil spill on the mortality and population size of these species. The Bayesian networks were used in the modelling. Based on the results the breeding colony of guillemots in Aspskär may survive in the consequence of recolonization. In conclusio…

Linking species interactions with phylogenetic and functional distance in European bird assemblages at broad spatial scales

2017

Aim: Understanding the relative contribution of different species interactions in shaping community assembly has been a pivotal aim in community ecology. Biotic interactions are acknowledged to be important at local scales, although their signal is assumed to weaken over longer distances. We examine the relationship between positive, neutral and negative pairwise bird abundance distributions and the phylogenetic and functional distance between these pairs after first controlling for habitat associations. Location: France and Finland. Time period: 1984 to 2011 (Finland), 2001 to 2012 (France). Major Taxa studied: Birds. Methods: We used results from French and Finnish land bird monitoring pr…

Effects of density, species interactions, and environmental stochasticity on the dynamics of British bird communities

2022

Our knowledge of the factors affecting species abundances is mainly based on time-series analyses of a few well-studied species at single or few localities, but we know little about whether results from such analyses can be extrapolated to the community level. We apply a joint species distribution model to long-term time-series data on British bird communities to examine the relative contribution of intra- and interspecific density dependence at different spatial scales, as well as the influence of environmental stochasticity, to spatiotemporal interspecific variation in abundance. Intraspecific density dependence has the major structuring effect on these bird communities. In addition, envi…

Domain‐specific neural networks improve automated bird sound recognition already with small amount of local data

2022

1. An automatic bird sound recognition system is a useful tool for collecting data of different bird species for ecological analysis. Together with autonomous recording units (ARUs), such a system provides a possibility to collect bird observations on a scale that no human observer could ever match. During the last decades, progress has been made in the field of automatic bird sound recognition, but recognizing bird species from untargeted soundscape recordings remains a challenge. 2. In this article, we demonstrate the workflow for building a global identification model and adjusting it to perform well on the data of autonomous recorders from a specific region. We show how data augmentatio…

Invasive catfish in northern Italy and their impacts on waterbirds

2022

Predatory fish have occasionally been observed preying on birds, sometimes repeatedly, but few studies were able to unravel the overall significance of avian prey in fish diet and the predation impacts on bird populations. We used a control/impact study setup, using a Nature Reserve in northern Italy and a nearby control area, to determine: 1) the contribution of waterbirds to wels catfish diet in the Reserve, 2) the population density of wels catfish in the Reserve and control area and 3) the potential impacts of waterbird depredation by wels catfish on waterbird population trends. Our stable isotope Bayesian mixing model indicated that birds contributed 12.2% (5–27.9%, 50% confidence inte…

Co‐occurrence patterns in a steppe bird community: insights into the role of dominance and competition

2023

Spatial co-occurrence patterns are determined by environmental factors, such as food availability or habitat characteristics and by biotic associations. When resources are limited, competition which implies a dominant hierarchy can shape species assemblage. Here, we study space and time co-occurrence of steppe passerines during the breeding season in a natural steppe habitat, its modulation by environmental filtering, potential biotic interactions and random processes. We applied the joint species distribution model of hierarchical modelling of species community (HMSC) to data on species presence–absence and environmental, temporal and spatial covariates acquired from seven plots in a natur…