Erkki Korpimäki

Erkki Korpimäki
University of Turku | UTU · Department of Biology

Professor

About

348
Publications
83,683
Reads
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19,093
Citations
Citations since 2017
46 Research Items
4668 Citations
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20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Introduction
Erkki Korpimäki currently is emeritus professor at the Section of Ecology, Department of Biology , University of Turku, Finland. He does research in Ecology and Evolutionary Biology. The current project is on population dynamics, reproductive success, dispersal and survival of avian predators in relation to habitat change (e.g. forest loss and intensification of agricultural practices) and climate change in northern ecosystems.
Additional affiliations
February 2011 - April 2011
January 1991 - present
University of Turku
Position
  • Professor
January 1986 - December 1989
University of Oulu
Position
  • Researcher

Publications

Publications (348)
Article
Full-text available
Climate change is increasing the frequency of extreme events, such as droughts or hurricanes, with substantial impacts on human and wildlife communities. Extreme events can affect individuals through two pathways: by altering the fitness of adults encountering a current extreme, and by affecting the development of individuals born during a natal ex...
Article
Full-text available
Social polygyny usually benefits males by increasing the number of offspring, whereas it is detrimental for females as they must share the resources provided by their mate. An intersexual conflict may exist in animals with obligatory bi-parental care, such as birds of prey, in which females incubate and brood, whereas males provision food for their...
Article
Full-text available
Climate change is a pervasive threat to biodiversity. While range shifts are a known consequence of climate warming contributing to regional community change, less is known about how species’ positions shift within their climatic niches. Furthermore, whether the relative importance of different climatic variables prompting such shifts varies with c...
Article
Full-text available
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 materna...
Article
Full-text available
Background: Birds act as intermediate or definitive hosts of cyst-forming coccidia parasites of the genus Sarcocystis Lankester, 1882. However, the spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species, including the Tengmalm's owl Aegolius funereus (Linnae...
Article
Full-text available
Physical condition is important for the ability to resist various parasites and diseases as well as in escaping predators thus contributing to reproductive success, over-winter survival and possible declines in wildlife populations. However, in-depth research on trends in body condition is rare because decades-long datasets are not available for a...
Preprint
Full-text available
The spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species including Tengmalm’s owl Aegolius funereus (Linnaeus, 1758). Therefore, this study is focused on the morphological and molecular description of a new Sarcocystis species found in the intestine of the...
Article
Full-text available
Food-hoarding behaviour is widespread in the animal kingdom and enables predictable access to food resources in unpredictable environments. Within-species, consistent variation among individuals in food-hoarding behaviours may indicate the existence of individual strategies, as it likely captures intrinsic differences in how individuals cope with r...
Preprint
Full-text available
Background Birds act as intermediate or definitive hosts of cyst-forming coccidia parasites of the genus Sarcocystis Lankester, 1882. However, the spectrum of species of Sarcocystis in birds and the role of the latter in the transmission of coccidia are still incomplete for many avian species including Tengmalm’s owl Aegolius funereus (Linnaeus, 17...
Article
Tree cavities are an essential requirement for reproduction and survival of secondary cavity nesters. Little is known, however, about how cavity distribution in space and time may limit their use during and outside of the breeding season. Using long-term (17 yr) data on the use of nest-boxes resembling tree cavities by individually marked Eurasian...
Article
Full-text available
Recent wildlife population declines are usually attributed to multiple sources such as global climate change and habitat loss and degradation inducing decreased food supply. However, interactive effects of fluctuations in abundance of main foods and weather conditions on population densities and reproductive success have been studied rarely. We ana...
Chapter
Full-text available
This is a review of owl and raptor food studies in Finland mainly between 1828 and 1974 which was the period covered by a new book: Ornithology in Finland and written by Esa Lehikoinen, Risto Lemmetyinen, Timo Vuorisalo & Mia Rönkä. This book has an extensive list of references from page 491 to 546. In this chapter, raptors included also shrikes an...
Article
Full-text available
Large brains in prey may select for adoption of anti-predator behavior that facilitates escape. Prey species with relatively large brains have been shown to be less likely to fall prey to predators. This results in the prediction that individuals that have been captured by predators on average should have smaller brains than sympatric conspecifics....
Article
Full-text available
It is much debated whether the direct effects of weather or biotic interactions determine species’ responses to climate change. For example, an important biotic factor for herbivores in northern ecosystems is the availability of winter food. If the food availability changes because of the changing climate, it likely has major impact on the abundanc...
Article
We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a...
Article
Full-text available
Changing climate can modify predator–prey interactions and induce declines or local extinctions of species due to reductions in food availability. Species hoarding perishable food for overwinter survival, like predators, are predicted to be particularly susceptible to increasing temperatures. We analysed the influence of autumn and winter weather,...
Article
Specialist individuals within animal populations have shown to be more efficient foragers and/or to have higher reproductive success than generalist individuals, but interspecific reproductive consequences of the degree of diet specialisation in vertebrate predators have remained unstudied. Eurasian pygmy owls (hereafter POs) have less vole‐special...
Article
Full-text available
Results from a 47-year study of Tengmalm's Owls Aegolius funereus in western Finland show that abundance of their main prey (Microtus and Myodes voles), and the three-year, high-amplitude fluctuations in vole populations, is fundamentally important in regulating the owl populations. A strong positive relationship emerged between breeding densities...
Presentation
Intraspecific competition, i.e. competition occurring between individuals of the same species, can affect the spatial distribution of a species and lead to costs in terms of a reduction in fitness. The amount of resources available for each individual will decrease with increasing population size, resulting in a more intense intraspecific competiti...
Article
Full-text available
Fluctuations in the abundance of main prey species might shape animal communities, by inducing numerical responses and dietary shifts in predators. Whether numerical responses and dietary shifts differ among individuals of different age and sex has so far gained little attention. These differences could affect how much predators consume main and al...
Article
Natural cavities are a critical resource for non-excavating hole-nesting birds, many of which are declining in northern Europe. In the heavily managed boreal forests in Finland, cavities may be a scarce resource, but their availability to different hole-nesters has been examined in only a few studies. We studied the abundance of suitable cavities i...
Article
Full-text available
Climatic conditions, trophic links between species and dispersal may induce spatial synchrony in population fluctuations. Spatial synchrony increases the extinction risk of populations and, thus, it is important to understand how synchrony-inducing mechanisms affect populations already threatened by habitat loss and climate change. For many species...
Article
Mothers may vary resource allocation to eggs and embryos, which may affect offspring fitness and prepare them to future environmental conditions. The effects of food availability and predation risk on reproduction have been extensively studied, yet their simultaneous impacts on reproductive investment and offspring early life conditions are still u...
Preprint
Full-text available
Animals' life-history traits vary largely along many continuums across species and several physiological parameters have been proposed as possible mediators that drive the life-history variation, such as metabolic rates, glucocorticoids, and oxidative stress. Interestingly, thyroid hormones (THs), despite closely interacting with these physiologica...
Conference Paper
Full-text available
Intraspecific competition, i.e. competition occurring between individuals of the same species, can affect the spatial distribution of a species and lead to costs in terms of a reduction in fitness. The amount of resources available for each individual will decrease with increasing population size, resulting in a more intense intraspecific competiti...
Article
Full-text available
Background: Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness paramet...
Article
Full-text available
Hoarding behaviour (storing food for a later use) has evolved to reduce starvation risk when resources are scarce. Different age and sex classes often show differences in foraging due to experience, skills or life history strategy, but such differences in hoarding under spatio-temporally varying environmental conditions have rarely been studied in...
Article
Full-text available
Natal dispersal, the one-way movement between birth site and first breeding site, is an important determinant of species gene-flow and invasion potential. While dispersing in unfamiliar habitat, individuals may adjust their movement based on possible costs and benefits of moving, termed context-dependent dispersal. The role of factors, such as popu...
Article
Full-text available
Lethal interactions can shape ecosystem structure, and consequently understanding their causes is ecologically relevant. To improve both empirical and theoretical knowledge on superpredation (i.e. predation on high‐order predators), we studied an eagle owl population, including its main prey and mesopredators, and then we crossed these results with...
Article
Full-text available
Habitat choice often entails trade-offs between food availability and predation risk. Understanding the distribution of individuals in space thus requires that both habitat characteristics and predation risk are considered simultaneously. Here, we studied the nest box use of two arboreal squirrels who share preferred habitat with their main predato...
Data
Areas of different habitat types within small and large buffers around occupied and unoccupied squirrels nest boxes. (DOCX)
Data
Yearly occupancy rates of flying and red squirrel nest boxes. (DOCX)
Article
Full-text available
Competing species and predators can alter the habitat use of animals but both factors are rarely simultaneously controlled for. We studied in experimental enclosures how closely related species, the sibling vole ( Microtus levis Miller, 1908) and the field vole ( M. agrestis L., 1761), adjust their habitat use when facing either the competing speci...
Article
Prolonged physiological stress response may lead to an excessive production of reactive oxygen species (ROS) and ultimately to oxidative stress and severe fitness costs. We investigated whether natural variation in predation risk, induced by pygmy owls (Glau-cidium passerinum), modifies the oxidative status of two free-living food-supplemented pass...
Article
Full-text available
Browsing effects of voles on plants can be mitigated by means of non-lethal predation, i.e. by subjecting voles to predator cues. Earlier studies largely focused on mammalian olfactory cues, whereas here we exposed Microtus voles to owl calls to examine whether the introduced predation risk reduces browsing on tree seedlings (silver birch, Scots pi...
Poster
Full-text available
Hoarding behaviour evolved in few small species to reduce starvation risk, especially in response to harsh winter condition or food shortage. Some species of owls, such as Eurasian pygmy owls (Glaucidium passerinum), store prey in natural cavities or in nest-boxes. Despite storing habits of pygmy owls being already documented at the population leve...
Article
Full-text available
Predator presence and shortage of food resources can alter behavior and cause chronic physiological stress, with long-term detrimental effects on the prey. Recently, it has been hypothesized that cellular damage via oxidative stress could be associated with such effects. Variation in food availability and predation risk could modify the oxidative/a...
Article
Ilkka Hanski may be best known for his work on insect and metapopulation dynamics, but he also contributed significantly to small mammal research. In the early 1980s he became interested in shrew dynamics, energetics, and of course, shrew metapopulations. He aimed at understanding the population biological consequences of body size in different shr...
Article
The spatial distribution of predators is affected by intra- and interspecific interactions within the predator guild. Studying these interactions under fluctuating food availability, while taking habitat characteristics into account, offers a quasi-experimental set up to determine the relative impact of con- and heterospecifics on reproductive succ...
Article
Full-text available
Previous studies on intraguild predation have mainly focused on within-class assemblages, even though avian top predators may also influence mammalian mesopredator prey. By using nation-wide long-term data from Finland, northern Europe, we examined the impacts of golden eagles (Aquila chrysaetos) together with red foxes (Vulpes vulpes) and pine mar...
Article
Food availability and predation risk can have drastic impacts on animal behaviour and populations.The trade-off between foraging and predator avoidance is crucial for animal survival and will strongly affect individual body mass, since large fat reserves are beneficial to reduce starvation but may increase predation risk. Two-factor experiments, si...
Article
Full-text available
Mothers may affect the future success of their offspring by varying allocation to eggs and embryos. Allocation may be adaptive based on the environmental conditions perceived during early breeding. We investigated the effects of food supplementation and predation risk on yolk hormone transfer in the pied flycatcher Ficedula hypoleuca. In a food sup...
Article
Full-text available
We studied the responses of red squirrels, Sciurus vulgaris, to food supplementation and avian predation risk during two winters in Finland, when the level of natural food production, spruce seeds, varied markedly. We performed an open experiment with 6 replicates in the landscape where squirrel signs were counted near a feeding station and/or acti...
Article
Full-text available
The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban...
Data
Figure S1. Intensity of urbanisation according to (A) classification by scientists. Box plots show medians, quartiles, 5‐ and 95‐percentiles, and extreme values, and (B) CORINE land cover code (red = discontinuous urban, purple = industrial or commercial units, pink = green urban sites, brown = arable land and rice field, orange = agriculture lands...
Data
Figure S2. Distribution of study plots across Europe, North Africa and the Middle East.
Data
Table S1. Summary data for study plots. See Material and methods for definitions. Table S2. Correlation matrix of explanatory variables. Table S3. Mixed linear model investigating laying date in four passerines species (CF: Collared Flycatcher, GT: Great tit and PF: Pied Flycatcher) as a function of habitat characteristics (intensity of urbanisat...
Data
Figure S3. Box plots of latitude of study plots in four passerine birds in Europe, North Africa and the Middle East.
Article
Full-text available
There is a pressing need to understand how changing climate interacts with land-use change to affect predator-prey interactions in fragmented landscapes. This is particularly true in boreal ecosystems facing fast climate change and intensification in forestry practices. Here, we investigated the relative influence of autumn climate and habitat qual...
Article
Full-text available
The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban...
Article
Full-text available
The importance of weather in relation to food resources, in determining reproduction, remains poorly understood for mammals, particularly for species that do not depend on food resources limited by spring weather conditions. We studied the effects that weather and food supply had on timing of spring reproduction and observed litter size in 2 squirr...
Technical Report
Full-text available
The EU NON-NATIVE SPECIES RISK ANALYSIS – RISK ASSESSMENT TEMPLATE for Neovison vison was made as an argument to introduce this species on the EU Invasive Alien Species list. The first Union list of 37 plant and animal species was introduced in August 2016 and another 12 were added in August 2017. However, this accounts for just 3% of all IAS belie...
Article
Full-text available
The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes toward...
Article
Full-text available
Competition, habitat structure and predation risk may alter mobility and activity of animals. In particular, small predators need to weigh the positive and negative impacts of the presence of competing larger predator species. Other predators present a risk but may also enhance the predation efficiency of smaller predators if avoiding one predator...
Article
Full-text available
The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes toward...
Article
Full-text available
Diet composition is linked to reproductive performance directly or indirectly by other life-history traits, including home range behaviour. The relationships between prey abundance, diet and individual fitness have often been explored. However, these relationships are complex and difficult to disentangle, especially in vertebrate top predators. Her...
Article
Spatial variation in the strength of trophic cascades in arctic tundra has been related to flows of subsidies across ecosystem boundaries. Here, we ask whether the input of marine subsidies in tundra systems would cause spatial variation in the strength of rodent-plant interactions between coastal areas, where predators have access to marine-derive...
Article
Full-text available
In altricial birds, the nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mo...
Article
Environmental variation across space and time can strongly influence life-history strategies in vertebrates. It has been shown that the reproductive success of birds of prey is closely related to food availability. However, relatively little is known about intraspecific differences in reproductive success of birds in relation to varying ecological...
Article
Full-text available
Top predators may induce extensive cascading effects on lower trophic levels, for example through intraguild predation (IGP). The impacts of both mammalian and avian top predators on species of the same class have been extensively studied, but the effects of the latter upon mammalian mesopredators are not yet as well known. We examined the impact o...