Vertebrate Ecology Research Group

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Research news

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​9.1.2018: Simulated owl predation risk to voles modifies browsing effects on tree seedling growth. Predators can affect herbivores not only by direct killing... Read more | Article

​17.11.2017: Maternal hormones vs personality. Across animal taxa from insects to mammals (also humans) Individuals differ consistently in their behavior....  Read more | Article

​30.10.2017: Consistency but low heritability of nest building behaviour in blue tits ... Read more | Article

​28.9.2017: Two beaver species are found in Finland: The invasive North American and the native Eurasian beaver. Both were (re-)introduced in the 1930s... Read more | Article
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​26.9.2017: Habitat use of coexisting Microtus vole species under competition and predation risk. Both interspecific competitors and predation risk can modify the habitat use of a species. In nature ... | Read more | Article

​25.9.2017: Insect herbivory may cause changes in the visual properties of leaves and affect the camouflage of herbivores to avian predators. Insectivorous birds are able to detect herbivore-damaged trees ... Read more | Article

​22.9.2017: Effects of Insect Herbivory on Bilberry Production and Removal of Berries by Frugivores. Most of the seed dispersal is mediated by vertebrates, mainly via birds and mammals ... Read more | Article

​11.9.2017: Measures of assortative mating may be biased by environmentally-driven resemblance of partners | Read more | Article

​1.9.2017: Experimental manipulation of nest height does not support the hypothesis that birds build thicker nests for better thermoregulation of their offspring | Read article

​4.5.2017: Rabbits dig burrows. But, what goes on in these and how important is the timing for rabbit fitness ... Read more | Article

​26.4.2017: Psychologists consider personality to be a composite of many traits, what ecologists call "behavioral syndrome" arguably approximates this concept ... Read More |Article

​3.4.2017: The effects of food availability and predation risk on life-history traits and antioxidant physiology. The integration of ecology and physiology ... Read more | Article

​3.4.2017: A 23-year study on passerines in a polluted site reveals overall higher body condition,  but no temporal trends despite drastically reduced emissions | Article

​2.3.2017: Immigration is the key demographic rate driving Siberian flying squirrel population growth rates ... Read more | Open-access article

​17.2.2017: Pygmy owls choose their territory according to conspecific presence but have lower reproductive success at high densities of both conspecifics and intra-guild predators.. Read more | Article

​21.11.2016: We studied the effects of food supplementation and natural predation risk imposed by pygmy owls on the abundance and fat reserves of tit species... Read more | Article

​28.8.2016: Increased autumn rainfall disrupts trophic interactions in fragmented boreal forests. Read more | Article

15.8.2016: Golden eagles seem to provide protection for juvenile black and hazel grouse, whereas they are a threat for adult grouse | Article


15.6.2016: Developing individuals are sensitive to disturbance.  Early-life exposure to lead pollution affected vitamin A and E metabolism, which impaired growth | Article


15.6.2016: In birds, mothers give valuable resources to offspring via eggs. Investment in egg hormones vary with environmental and parental traits, and levels of different hormones are correlated | Article


​15.6.2016: Thyroid hormones from the mom: a novel mechanism for mothers to affect offspring in birds... Read more


​14.6.2016: Can mothers help to cope with climate change? Mothers altered their investment in egg hormones in response to temperature cue... Read more



​20.5.2016: All organisms age. We know that reproduction and survival often decrease as individuals age, a phenomenon called senescence, but how does personality change ...   Read more

​8.4.2016: Only four white-tailed deer were introduced in Finland in 1934 from North America. How are the deer doing today? The number of animals quickly increased .... | Read more

​16.3.2016: Egg contents are a "lunchbox" for the developing young bird. The levels of maternal hormones in the eggs depend on the food available for the mother but not on the fear induced by predators | Article


​15.3.2016: Women that show a preference for men with narcissistic facial characteristics have higher reproductive output | Article

​15.3.2016: Translocation of animals typically entails moving a small number of them with potential negative impact on genetic diversity... Read more
​12.3.2016: Male and female parents do not always have similar interests in how many young they should have: female pied flycatchers pay a cost that males do not pay when raising more chicks | Article
12.3.2016: Geolocator study shows that pied flycatchers that breed in different parts of Europe also winter in different parts of western Africa | Article

12.3.2016: Birds fly also during the daytime when migrating across Sahara desert, reveals a new study using geolocators on four small ​passerine species | Article


11.3.2016: Prevalence of anticoagulant rodenticides in non-target predators and scavengers in Finland were studied for the first time in Finland ... Read more

​28.1.2016: "Predators may protect seedlings and grouse", says Mari Lyly. In my doctoral thesis ... Read more 


25.1.2016: The abundance and distribution of the ectoparasitic flies in the nests of pied flycatcher Ficedula hypoleuca throughout Finland | Article

​14.12.2015: Although roads are one of the major threats for moving animals, urban red squirrels do not avoid roads during dispersal... Read more | Article




29.10.2015: Experiments do not support the hypothesis that olfactory foraging cues are necessary in the attraction of birds to herbivore-damaged trees | Read more | Article


​27.10.15: Least weasels were unexpectedly found to mirror and not to avoid the activity patters of their potential avian intraguild predators | Read more | Article

​9.10.2015: Evaluating the influence of diet-related variables on breeding performance and home-range behaviour in eagle owls


7.10.2015: Researcher with long-term individual-based data generally do not support unlimited open access to data upon publication.


​5.10.2015: Raptors nests are sometimes indicators for habitats that host endangered species. White-tailed Eagle nests do not however appear to indicate wood-inhabiting fungi or vascular plant richness of the nest island | Article

2.10.2015: Do birds use social information (which they get by watching what others do) or personal information (own experience) when choosing a nest site? A study on flycatchers did not find evidence for either. It is not easy to know what birds know and think | Article

​29.9.2015: Review on the significance of hormonally-mediated maternal effects in birds using data from a well-studied flycatcher system | Article


​3.9.2015: Very fast intra-clutch response in egg mass to experimentally increased and decreased food availability suggests clear constraints by resource availability. Study also suggests a novel hormonal mechanism for maternal effects  | Article

​28.8.2015: Changes in behavior during development remain understudied. We draw attention to what is expected on the basis of theory and review the evidence for predicted patterns. The emerging picture is that behaviors are highly plastic during development  | Open access



11.6.2015: As nestlings, aggressive blue tits are not easily stressed, but this relationship disappears in adults. Using multigenerational pedigree data, we demonstrate that this change is due to genotype - age interaction | Article


9.6.2015: Studies on red squirrel movement ecology included in new book: Selonen V & Hanski IK 2015. Red Squirrels: Ecology, Conservation & Management in Europe. (Shuttleworth, C. et al., eds.) European Squirrel Initiative, Llangefni, UK.



12.5.2015: Light-level geolocators have revolutionized avian migration research, but evaluations of their impact on the life history of individuals are rare. Southern Dunlins were not adversely affected by leg-flag mounted geolocators | Article

sieppo-potretti_WV.jpg ​24.4.2015: The pied flycatcher males show systematic geographic variation in all coloration traits: they look very different from collared flycatcher males in an area of sympatry where both species occur, but more and more like them with increasing distance to the area | Article

24.4.2015: Is it good to arrive early at the breeding grounds? A study on pied flycatchers shows there is selection favoring early arrival of males, which is independent of the egg-laying date and the number of eggs laid by female | Article

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24.4.2015: Following a successful symposium on new perspectives in avian nest predation at IOC 2014 in Tokyo, the participants collaborated on a review of this topic. It focuses on recent research in the field, and identifies issues of importance for future work | Article.pdfArticle.pdf

24.4.2015: While Tengmalm’s owls in the north experience high average prey densities and low nest predation, their productivity is limited because of the wide inter-annual fluctuations in prey abundance.  Farther south owls faced higher nest predation rates but also a more stable prey base, leading to higher productivity | Article

​13.4.2015: The second assessment of climate change for the Baltic Basin provides historical and projected future impacts of climate change on the coastal and terrestrial ecosystems of the Baltic Sea basin | Book chapter  


30.3.2015: Finnish house sparrows are shrinking! Capturing house sparrows in the same 10 localities sampled in the mid-1980s revealed that their body mass declined dramatically in 25 years, possibly caused by the same (unknown) factors responsible for this species' population decline | Article

 |26.3.2015: Analysis of 300 years of genealogical data from Finland shows that heritability and genetic correlations between lifespan, family size and ages at first and last birth were similar both before and after these vital rates changed as part of the formation of modern society. Human evolution is ongoing, both then and now  Article


​16.3.2015: The chicks of black pied flycatcher males are more likely to die in cold temperature than those of brown males. A cross-fostering experiment revealed that this is not due to the genes shared between fathers and offspring but due to differences in the performance of the fathers in different temperatures | Article



​15.2.2015: A literature review indicates that voluntary conservation of nest sites is rarely used in raptor conservation. The existing evidence however suggests that it can be a useful tool when nests are located on private lands  | Article 



​29.1.2015: The endangered Apollo butterfly disappeared during the 1900s from most of its range in Finland and Europe. A multi-year re-introduction experiment releasing larvae reared n captivity shows that the species has the potential to establish a population in what is suitable, but now empty habitat. Success rate was low, however, and confined to only a subset of islands which likely explains why Apollos have not re-colonised their former range | Article

21.1.2015: In birds, both parents often care for their offspring, but can dad also influence when and how much offspring his partner produces (and hence to care for)? Long-term tawny owl data reveals that dad indeed also "decides" when in the season a clutch is produced, but not how many eggs it contains | Article | VERG Author


​5.1.2015: Although intraguild predation has been broadly studied, quite little is still known about the predation impacts of avian top predators on mammalian mesopredators. Here, we present results based on abundance data, which suggest that killing and intimidation by golden eagles may not be a relevant cause of decrease for populations of red fox or pine marten | Open-access article


​26.12.2014: One sign of potential inbreeding depression is when more heterozygous individual have higher fitness than more homozygous ones. White-tailed deer in Finland are descendants from a population founded by only 4 individuals. In this population, heterozygosity correlated strongly with inbreeding and more heterozygous individuals attained a larger body mass | Open-access Article 



11.12.2014: Pre-industrial male humans belonging to a cohort with a male-biased sex ratio enjoy lower child mortality and higher Lifetime Reproductive Success, compared to males born in a male-biased cohort. These findings support the "culled cohort hypothesis", where long-term consequences of in utero selection for biased sex ratios are expected | Article | VERG Author 



28.11.2014: Producer–consumer models predict that consumers follow pulsed resources with a time lag. However, individuals may anticipate future resource pulses by increasing reproduction just before the pulse. Red squirrels in forests depend on spruce seed production. We found that adult population during winter peaked at the same time as the resource pulse. However, there was also a lagged response, supporting the classical view of producer–consumer models | Article | Author


​24.11.2014: Wood pigeons have been breeding regularly in Finnish cities since 1991. Colonisation of cities by wood pigeons was influenced by geographic location: larger cities and cities located closer to the sea were colonised first. The habitat use of wood pigeons changed during the urbanisation process, which is still in progress | Article | Author's page


​21.11.2014: Individual variation in breeding dispersal has important consequences, but underlying causes and fitness consequences remain poorly understood. In the Eurasian kestrel, both individual traits and environmental factors interact to shape breeding dispersal strategies. Additionally, we found sex- and -environment specific consequences of breeding dispersal in terms of reproductive success | Article | PDF | OIKOS Blog post on this paper



​10 Nov 2014: Research on the ecology of top predators has provided regular contributions to general ecology.  We propose ways to facilitate synthesis by relying on the collective contribution by all scientists in the field and will strive to consolidate and formalise top-order predation as a holistic, cohesive, cross-taxonomical field of research studying the ecology, evolution and behaviour of apex predators and their capability to exert top-down forcing on lower trophic levels | Article | PDF 



10 Nov 2014: Animals adjust their behavior in response to cues on what their conspecifics have done. We find that Eurasian kestrels lay earlier in nest-boxes where the proof of earlier successful breeding (pellets and other prey remains) were left, compared to kestrels breeding in cleaned boxes, despite the fact that the pellets increased the risk of kestrel young being parasitized. Thus, kestrels value information on where breeding was successful more than its cost | Article | PDF


​7 Nov 2014: The distributions, ecologies and behaviours of the three jaegers species vary across the Arctic. We propose that jaegers evolved in tundra areas where lemming-vegetation interactions generated lemming density oscillations with a mean period short enough to provide dependable breeding resources. Our hypothesis indicates that the jaeger guild could be a product of coevolution with arctic lemmings and competitive speciation | Article | VERG Author


​7 Nov 2014: Experimental manipulation of food supply can assess the extent wild birds are food limited. Our meta-analysis shows that extra food is allocated to increase immediate reproduction in most cases. They also support the view that bird species have evolved different life-history strategies to cope with environmental variability in food supply | Open Access Article | VERG Author


​6 Nov 2014: Few studies have looked at women’s preferences for men who are high and low in Dark Triad personality traits (i.e., Machiavellianism, narcissism, and psychopathy). We investigated female preference for computer manipulated Dark Triad male faces and found that women showed a low preference for the high morphs of Dark Triad in both long and short term relationships | Article


31 Oct 2014: Northern ecosystems are facing unprecedented climate modifications, threatening especially arctic species. Over 21 years, rough-legged buzzards in Finnish Lapland laid earlier because of earlier snowmelt. Their breeding success was lowered because of lower abundance of grey-sided vole (and not due to unfavorable weather). Climate change impacts specialist predators with cascading effects at the ecosystem level | Article | VERG Author


29 October 2014. Birch trees react to cues released by their neighbors: when a moth larvae starts chewing the leaves of a tree, also the neighboring trees start raising up their chemical defenses against potential herbivores| Article   


18 Sept 2014: In preindustrial northern Finland, agricultural livelihood of settled Finns was associated with higher fecundity, shorter birth spacing and lower maternal mortality compared to forager Sami. Agricultural Finns also had higher annual population growth rate than forager Sami, which was accounted by differences in age-specific fecundity but not in mortality | Article | Info in Finnish | VERG Author


5 Sept 2014: The female tawny owls of broods laid early in the season are more bold towards human observers and they also produce more offspring than females of later nests. A central question in evolutionary ecology is whether such phenomena are because individuals differ from each other or are simply driven by external factors, such as local food supply. We show that the latter explanation applies to the tawny owl boldness - laying date - fitness relationship - in contrast to what is commonly assumed in behavioral ecology | Article | VERG Author


31 July 2014. Would one additional offspring in a breeding attempt increase your lifetime reproductive success or reduce it through costs on your survival? In male Tengmalm’s owls it is doing neither, apparently because they do not change their parental effort in response to manipulations of brood size | Article



15 July 2014. The number of eggs laid generally depends on the size of the nest, indicates a large collaborative study covering >17000 nests of 21 bird species. There is, however, variation between species in the strength of the relationship | Article



21 May 2014: In the Kalahari Desert sociable weaver nests are a prominent feature in the landscape. These large nests provide a refuge to a range of organisms, including Kalahari tree skinks. They also provide a breeding site for a predator of the skink: the African pygmy falcon. Skink abundance was positively correlated with weaver nests. Skinks also frequently perched on the nest and used it as a refuge. Surprisingly, the presence of breeding pygmy falcons did not affect skink abundance | Article | VERG Author



30 April 2014: Clutch size (number of eggs) of great tits depends on nest box size while that of blue tits or flycatchers does not, shows data combined from many Palaearctic breeding populations | Article




9 April 2014: Even solitary breeding mammals may huddle in groups, e.g. in winter time, which is usually explained by benefits from thermoregulation or kin cooperation. However, this was not the case in flying squirrels. Instead, group formation seemed to be related to mating behaviour | Article  

8 April 2014: New book "Quantitative Genetics in the Wild" published including two chapters co.authored by assistant prof Jon Brommer | OUP Book


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1 April 2014: Sometimes it is good for a male to look like a female if it wants to avoid aggression from other males. But brown pied flycatcher males take it a step further: they mimic the females of another species, the collared flycatcher | Article

31 March 2014: A Genotype-Age interaction is the fingerprint of evolved senescence. Now found for the first time in a plant Current Biology Dispatch

31 March 2014: House sparrows, like most vertebrates, show dramatic differences in size between populations. We demonstrate that Finnish house sparrow differentiation in size (especially of the bill) likely has an adaptive basis and adheres to the latitudinal gradient of larger birds in the north, as discovered by Bergmann | Article

20 March​ 2014: Blue tit females that defend themselves aggressively are passive when they defend offspring, but this relationship is opposite in males. Males and females differentially value themselves versus their young possibly because of the different reproductive roles they have | Article

5 March 2014: Meta-analysis shows that correlated behaviors are likely to form an evolutionary constraint. But how can you test whether a behavioral  syndrome in your study species is a significant constrant on evolution? Article

4 March 2014: Great tits are more eager to cover their eggs when the pied flycatcher is around. They seem to be hiding information about their clutch size from the competitor that could use the information by settling close | More

 VERG links


 VERG News


27.11.2017: PhD student Pauliina Järvinen awarded two year funding by BGG Doctoral Program

27.10.2017: Barbara Class defends PhD thesis on animal personality

26.10.2017: VERG organises Symposium on animal personality

30.9.2017: Erkki Korpimäki gives plenary lecture at World Owl Conference in Evora, Portugal

20.9.2017: Jenni Poutanen interviewed by YLE on white-tailed deer project

9.9.2017: Tuuli-Marjaana Koski defends PhD thesis on tri-trophic interactions with Julia Koricheva (UK) as opponent

19.8.2017: Erkki Korpimäki gives plenary lecture at European Ornithologists Union Conference in Turku, Finland

18-21.7: Suvi Ruuskanen invited speaker in workshop 'Early-environment effects' Bern, CH.

15.5.2017: Societas pro Fauna et Flora Fennica awards 4 months grant to Tom Sarraude's PhD project

10.5.2017: Emil Aaltonen foundation awards 10 months grant to Pauliina Järvinen's
PhD project

25.4.2017: Turun Yliopistosäätiö awards 6 months grant to Pauliina Järvinen PhD project

20-31.3.2017: Jon Brommer and Barbara Class visit Netherlands Institute of Ecology (NL)

1.3.2017: Suvi Ruuskanen gives invited lecture in Glasgow

Antoine Stier awarded 3-year post-doc position in the Turku Collegium for Science and Medicine to work with Suvi Ruuskanen

1.1.2017: Suvi Ruuskanen appointed editor-in-chief for Ornis Fennica journal

24.1.2017: Erkki Korpimäki gives invited lecture at Charles University in Prague, Czech Republic

30.11.2016: Giulia Masoero awarded a 4-yr and Jenni Poutanen a 3-yr funding period for their PhD projects!
13.10.2016: Jenni Poutanen receives funding from Wihurin Säätiö for PhD project

7.10.2016. Pauliina Järvistö defends her PhD thesis. The opponent is Alexandre Roulin.
12-13.9.2016: Jon Brommer chairs  Swedish Research Council panel in Ecology, Evolution and Systematics

1.9.2016: Bin-Yan Hsu joins VERG as post-doc with Suvi Ruuskanen

4.7.2016: Suvi Ruuskanen in Ph.D. opponent committee at University of Groningen

7.6.2016: Toni Laaksonen is awarded the Panda prize by WWF Suomi for work on white-tailed eagle

3.6.2016: Mari Lyly awarded best poster prize in XVI Nordic Congress of Wildlife Research

17.5.2016: Elina Koivisto receives 7 months grant from Finnish Cultural Foundation

28.4.2016: Suvi Ruuskanen awarded CIMO grant for PhD student Tom Serraude

8.4.2016: Tom Sarraude joins VERG as a PhD student

10.3.2016: TUKES report co-authored by Elina Koivisto on accumulation of rodenticides published
2.2.2016: Pauliina Järvinen joins VERG as a PhD student

29.1.2016: Mari Lyly defends PhD thesis at 12 o'clock, with opponent RA Ims

14-17.10.2015: Jon Brommer invited to workshop on "Generalising Pace of Life Syndrome" in Hannover

6.10.2015: VERG seminar cruise. Group members present short overview of their ongoing work

5.10.2015: Toni Laaksonen gives public popular lecture on white-tailed eagle in Salo

28.9-2.10.2015: Jon Brommer invited guest at workshop "Life history Evolution", GroningenNL

7-8.9.2015: Jon Brommer Ecology panel member for Swedish Research Council

11.-12.6.2015 Toni Laaksonen attends a PhD defense committee and a seminar in Lund.

12.6. 2015 : Erkki Korpimäki acts as first opponent for PhD thesis of Jennifer Stien at Tromso, Norway

17.5.2015: Mari Lyly receives 6 months personal funding from the Finnish Cultural Foundation

12.5.2015: Jon Brommer receives project funding from the Finnish Academy for "Evolutionary Quantitative Genetics of personality"

24.4.2015: Tytti Turkia receives continued (2nd year) funding from Emil Aaltonen Foundation

23.4.2015: Suvi Ruuskanen awarded 5-year Academy Researcher position
23.4.2015: Suvi Ruuskanen obtains 12 months grant from Emil Aaltonen  Säätiö for ecological epigenetics
20.4.2015: Suvi Ruuskanen obtains 6 months grant from TY Säätiö for work on ecological epigenetics
16.4.2015: Suvi Ruuskanen gives invited seminar at University of Neuchatel, Switzerland
9.4.2015: Kees Schreven from Groningen start ERASMUS internship for 5 months
26.3.2015 Suvi Ruuskanen and Pälvi Salo got post doc funding from the UTU strength area Ecological interactions and ecological genetics.
26.3.2015: Julien Terraube's paper on diet specialisation in raptors awarded runner up for 2015 Watson Raptor Science Prize
16-18.3 2015: Jakub Szymkowiak visits to discuss social information in wood warbler habitat selection
12.3.2015: Erkki Korpimäki gives invited lecture at the Department of Biology, University of Oulu
12.3.2015: Toni Laaksonen gives an invited talk in minisymposium on avian habitat selection and population dynamics in Helsinki.
9.3 - 12.3.2015: Robin Abbey-Lee (Seewiesen, Germany) visits VERG to discuss "predation and behavior"
24.2.2015: Erkki Korpimäki acts as axternal examiner of the PhD thesis of Alexandra Basso and gives seminar at Bern, Switzerland
19.2.2015: Erkki Korpimäki gives invited seminar at Konnevesi Research Station
10.-11.2. 2015:Toni Laaksonen gives a plenary  talk and several other VERG members present talks and posters at the Oikos Finland meeting for ecologists and evolutionary biologists in Joensuu.
15.1.2015: Seminar in honour of Esa Lehikoinen who recently retired (in Finnish)
18.12.2014: Toni Laaksonen presents invited seminar in Vienna
16.12.2014: Lise Ruffino ends succesful post-doc at VERG  for new challenges in Aberdeen (Scotland)
10-16.12.2014: Rui Lourenço (U of Evora, Portugal) on one week vist to VERG
9.12.2014: KONE Foundation awards 100 000 € to Samuli Helle for work on evolutionary ecology of Finnish Sami people
8.12.2014: Post-doc Chaminda Pradeep Ratnayake leaves VERG to tackle new challenges in research on public information use, at Australian National University - Canberra
26.11.2014: Chiara Morosinotto gives invited seminar at Institute of Ecology and Evolutionary Biology, Bern, Switzerland
18.11.2014: Riikka Alakoski obtained funding from Nessling Foundation for PhD project on beavers
24.9.2014:Ph.D. student Alejandro (Alex) Cantarero from CSIC-National Museum of Natural Science, Madrid, Spain) on two months visit to work on flycatchers with Toni Laaksonen 
16-19.9.2014: Jon Brommer invited to inter-disciplinary workshop on behavioural development at ZiF (Bielefeld, Germany)
12-14.9.2014:  Samuli Helle invited speaker in the Nordic Evolutionary Psychology Meeting (Lammi, Finland)
3.4.2014: VERG Ph.D. student Pauliina Järvisto awarded for best presentation in AURA symposium