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Article
Open AccessUsing change trajectories to study the impacts of multi-annual habitat loss on fledgling production in an old forest specialist bird
The loss and subdivision of habitat into smaller and more spatially isolated units due to human actions has been shown to adversely affect species worldwide. We examined how changes in old forest cover during ...
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Article
Carotenoid Composition of Invertebrates Consumed by Two Insectivorous Bird Species
Dietary carotenoids are important pigments, antioxidants, and immune-stimulants for birds. Despite recent interest in carotenoids in bird ecology, we know surprisingly little about the carotenoid content of in...
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Article
Open AccessIsland selection on mammalian life-histories: genetic differentiation in offspring size
Since Darwin's pioneering work, evolutionary changes in isolated island populations of vertebrates have continued to provide the strongest evidence for the theory of natural selection. Besides macro-evolutiona...
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Article
Survival of male Tengmalm’s owls increases with cover of old forest in their territory
The loss and fragmentation of forest habitats have been considered to pose a worldwide threat to the viability of forest-dwelling animals, especially to species that occupy old forests. We investigated whether...
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Article
Forest clearing and sex ratio in forest-dwelling wood ant Formica aquilonia
Sex ratios of ants have been shown to vary with food resource levels in several studies, but it is not known whether forest clear-cutting has any effect on sex ratio of aphid-tending forest-dwelling ants. We i...
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Article
Competitive interactions among raptors in boreal forests
We examined inter-specific interactions among goshawks (Accipiter gentilis), common buzzards (Buteo buteo) and honey buzzards (Pernis apivorus) in western Finland in 1983–1996. Because goshawks are among the larg...
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Article
Individual variation in immune function in the ant Formica exsecta; effects of the nest, body size and sex
It has been generally thought that sex differences in the immune system are the result of the differing life history strategies of the sexes, although the available data are not entirely consistent with the hy...
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Article
Hatching asynchrony and brood reduction in Tengmalm's owl Aegolius funereus: the role of temporal and spatial variation in food abundance
Hatching asynchrony is the consequence of birds initiating incubation before clutch completion. It has been suggested that variation in hatching asynchrony in owls is extensive, and therefore they should be e...
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Article
Survival of male Tengmalm's owls under temporally varying food conditions
We analysed whether annual survival of male Tengmalm's owls in western Finland varies according to changes in the abundance of their main prey, Microtus voles. Our analyses were based on capture-recapture data o...
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Article
Prey depletion by the foraging of the Eurasian treecreeper, Certhia familiaris, on tree-trunk arthropods
We examined to what extent breeding insectivorous treecreepers, Certhia familiaris, affect the abundance and the mean size of their prey population on the surface of tree trunks. In order to determine foraging pr...
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Article
Experimental increase of predation risk induces breeding dispersal of Tengmalm's owl
Nest predation and its avoidance are critical components of an individual's fitness and play an important role in life history evolution. Almost all studies on this topic have been observational, and thus have...
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Article
Why do territorial male Tengmalm's owls fail to obtain a mate?
Non-breeding may occur because non-breeders are immature or somehow physiologically incapable of breeding, or because of a lack of resources (e.g. food resources, mating partners) needed to breed. There is, h...
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Article
Blood parasites and nest defense behaviour of Tengmalm's owls
Infectious diseases are expected to negatively influence essential life history traits of an individual, because investment in immunological response occurs at the expense of reduced investment in other funct...
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Article
Low heritability in morphological characters of Tengmalm's owls: The role of cyclic food and laying date?
In parent—offspring regressions, high heritability estimates of characters may simply be due to common environment: the resemblance between the living conditions of parents and their offspring in species showi...
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Article
Contrasting phenotypic correlations in food provision of male Tengmalm's owls (Aegolius funereus) in a temporally heterogenous environment
We examined the food provision rate of male Tengmalm's owls,Aegolius funereus, during one 3 year vole cycle consisting of consecutive low, increase and peake vole years. The data were collected in the midnestling...
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Article
Environmental, parental and adaptive variation in egg size of Tengmalm's owls under fluctuating food conditions
We studied egg size variation of Tengmalm's owls in western Finland during 1981–1990. The owls fed on voles whose population fluctuated in a predictable manner: low (1981, 1984, 1987, 1990), increase (1982, 19...
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Article
Does feeding effort of Tengmalm's owls reflect offspring survival prospects in cyclic food conditions?
In an environment fluctuating in a predicatable manner with wide among-year variation in offspring mortality, fitness is largely influenced by the timing of reproductive investment. In vole-eating nocturnal Te...
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Article
Delayed maturation in plumage colour: Evidence for the female-mimicry hypothesis in the kestrel
In many sexually dichromatic species, young males have female-like plumage during their first potential breeding year. The female-mimicry hypothesis (FMH) supposes that by possessing female-like plumage young ...
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Article
Fluctuating food supply affects the clutch size of Tengmalm's owl independent of laying date
In western Finland, yearly median laying dates of Tengmalm's owls varied from 14 March to 27 April during 1973–1989 and were negatively correlated with the winter densities of voles. Yearly mean clutch sizes v...
