The end of the line

By Anna 4.2.2010 – 1:35 in Random picks
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Overfishing and depletion of fish stocks is a worldwide problem. The documentary movie The end of the line provides a comprehensive insight into the conflicting interests associated to global fisheries: economics, politics, history, tradition, welfare of individuals, profits of industry. Not surprisingly, among these aspects conservational values and scientific recommendations often gain less attention. The movie focuses on Atlantic cod and Bluefin tuna fisheries as two very illustrative cases.

As an interesting contrast to the inefficient attempts to control fishing through political means, the movie highlights how publicity, media and consumers’ awareness can affect the market: restaurants and supermarkets are adopting their own ‘sustainable policies’ and avoiding to sell species at risk. This phenomenon was recently discussed also in New Scientists, but with the focus being on potential problems related to such industry-driven sustainability policies (Beware of ‘bluewash’: which fish should you buy?).

Undoubtedly, the lack of general consensus of what is sustainable fishing can lead to problems but, given the inefficiency of politics in regulating fisheries, it is intriguing to see if the demand-supply dynamics of consumers and industry might in the end be more successful. Time will show.

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Genetic diversity & finite samples

By Juha 29.1.2010 – 7:00 in Journal club
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Obtaining adequate sample sizes for population genetic studies from wild populations can sometimes be painstakingly difficult. Take for instance the heroic fishing effort of 15114 (trap)hours in over 200 ponds which yielded less than twenty nine-spined sticklebacks. With such small sample sizes, estimates of genetic variability are easily biased.

In a recent paper, Bashalkhanov et al introduce a simple regression based method to estimate genetic variability for small samples. The method is based on simple non-linear model for which the parameters can be estimated from empirical data (e.g. from a population with largest sample size in the data). They validate their method with simulations and show that it is robust and outperforms other model based methods.

To me, this looks as an important paper. If I have got it correct, this paper outlines a much better way of getting proper estimates of allelic diversity than nowadays commonly used rarefactioning. I wish this had been around before the Shikano et al. paper* went into press.

Bashalkhanov S, Pandey M & Rajora OP (2009) A simple method for estimating genetic diversity in large populations from finite sample sizes. BMC Genetics 2009, 10:84 doi:10.1186/1471-2156-10-84

*Shikano T., Y. Shimada, G. Herczeg & J. Merilä. History vs. habitat type: explaining the genetic structure of European nine-spined stickleback (Pungitius pungitius) populations. Molecular Ecology, in press.

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Evolving sticklebacks – from genes to phenotypes

By Juha 28.1.2010 – 9:39 in Random picks
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_Laatikkokuva

Finally something interesting in Helsinki: a minisymposium to be held at Auditorium 1041 (Biocenter 2) February 4th (12.30-16.00).

Speakers include Prof. Michael Bell (Stony Brook Univ, USA), Dr. Erica Leder (Univ Turku, ), Dr. Folmer Bokma (Univ Umeå, Sweden) and Dr. Gabor Herczeg (Univ Helsinki).

Click the link below to see full program.

Evolving_Sticklebacks_Minisymposium

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O’boy – they did it again?

By Juha 28.1.2010 – 7:00 in Random picks
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rymy

This is not a gadget blog, but today’s news from Apple stir some excitement here. Have a look on their iPad here. I would say that with this they might have again placed the competition to the role of the snow pile above. Then again, isn’t this just a giant iPhone? Has the evolution of mobile phone size reversed back towards Gorbachev-models?

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Peer reviewed rap

By JL 25.1.2010 – 18:52 in Random picks
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Yo, yo, check this link out Egru:

Rap guide

Baba Brinkman appears to be the guy behind the Dawkins Rap (Edit 26.1.2010: Actually no he’s not! – see comments below. This Evolution rap seems to be catching…).

He’s put together a collection of 12 raps that will have high school biology teachers tossing out their text books and pumpin up the volume.

Quick Tuomas, you still have time to book this guy for your karonkka! For your defence you may just want to have a few of these lines ready, you can’t lose…

For instance, I could use a urine stream to put out a fire
But that doesn’t mean the penis evolved as bush fire fighter

(From ‘Sexual Selection’)

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Physiological responses to climate change in aquatic animals

By Juha 20.1.2010 – 13:51 in Random picks
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A PhD-course in Göteborg 22 Feb – 19 March 2010. See the enclosed flyer for details.

Advertisement PhD-course physiological responses to climate change

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Finding the flowers

By Juha 11.1.2010 – 13:36 in Random picks
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Kerala

Sometimes one has to travel to the end of the world to find what was right in front of you. Like clove oil.

Couple of days ago, a discussion in Trivandrum, India, slipped on a side-track and came to touch upon anesthetics used in research. I commented on the extravagant prices of MS-222 to hear about an alternative: clove oil.

As it turns out, oil from the seeds of clove (Syzygium aromaticum) is apparently widely used an anesthetic in fish research. As pointed out to me by A. Gopalakrishnan from the Indian National Bureau of Fish Genetic Resources (Kochi), the clove oil should be familiar to anyone who has ever visited a dentist: have a sniff on clove seeds and think about your last visit to a dentist. I believe you will make the association in a split second.

Here couple of references to uses of clove oil as an anesthetic:

Wagner, E; Arndt, R; Hilton, B (2002) Physiological stress responses, egg survival and sperm motility for rainbow trout broodstock anesthetized with clove oil, tricaine methanesulfonate or carbon dioxide. Aquaculture 211: 353-366.

Kennedy, BM; Gale, WL; Ostrand, KG (2007) Evaluation of clove oil concentrations for use as an anesthetic during field processing and passive integrated transponder implantation of juvenile steelhead. Northwest Science 81: 147-154.

Wagner, GN; Singer, TD; McKinley, RS (2003) The ability of clove oil and MS-222 to minimize handling stress in rainbow trout (Oncorhynchus mykiss Walbaum). Aquaculture Research 34:1139-1146.

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Rensch’s rule inverted – female-driven gigantism in nine-spined sticklebacks.

By herczeg 10.1.2010 – 12:31 in In press
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Sexual size dimorphism (SSD) is a common phenomenon in both plants and animals. Further, the degree of SSD is often scales allometrically with the mean size in the studied units (populations or species). One hypothesis to explain it is the correlational selection hypothesis (Fairbairn 1997. Annu Rev Ecol Syst 28:659-687):  allometry in SSD evolves as a consequence of directional selection acting primarily on one sex and correlational selection on the other sex. Read More »

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Ode to the plasticity of sheep horns

By JL 9.1.2010 – 23:25 in In press
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polygsketch

Thinhorn sheep Ovis dalli in Yukon Territory, Canada have been exposed to selective harvesting (based on horn size) and a warming climate over the past four decades. Both of these factors could potentially have an effect on horn growth (hunting would be expected to decrease growth, while a milder climate would increase growth), and in this paper we had the mighty task of looking at over 50,000 growth measurements in over 8000 hunted individuals to try and figure out what has been happening with the horns. Read More »

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Adaptation of forests to future climate is slow but increased by high mortality

By Anna 5.1.2010 – 19:52 in In press
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tree

Global warming is expected to prolong vegetative growth season in northern areas, thus arising prospects for increased growth of forests. However, growth period length is under genetic control, so that the speed at which forests can adapt to increasing growth season critically constrains their ability to take advantage of improved environmental conditions. In terms of the adaptability, some species might be in a better position than others, e.g. due to larger amounts of gene flow and early maturation.

Using individual-based quantitative genetic simulations we explored the speed at which the adaption might occur and how it depends of species-specific demographic traits. In our analyses mortality of the established trees was found to be in a key position to regulate adaptation speed. In the presence of low mortality of adults, younger, better adapted trees have generally very small chances of getting established.

From economic point of view, forecasts of future forestry yields should account for the slow adaptation to changing climate; increases in forest growth will take place at a slower speed than that of climate change.

Kuparinen A., O. Savolainen O. & F. M. Schurr. Increased mortality can promote evolutionary adaptation of forest trees to climate change. Forest Ecology and Management (in press)

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Historical salmon catches revisited

By Anna 4.1.2010 – 19:30 in In press
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patob

Historical datasets can be true treasures in biological analyses because of providing information about systems that do not exist today, but working with those can also sometimes be frustrating due to a lot of unknowns.

Both these “sides of the coin” were present in our analyses of historical salmon weir catches recorded during 1870-1902. The data originated from rivers Oulujoki, Iijoki and Torniojoki, former two of which no longer sustain natural salmon population due to hydroelectricity. However, one hundred years ago situation was quite opposite: the populations were large and healthy even though the annual salmon catches were also substantial (from hundreds to thousands of salmon per river). Moreover, rivers were running free and populations were free from genetic disturbances such as stocking, so that the catch records provide rarely available information about variation in the timing of river entry in natural Atlantic salmon population.

New analyses of the old data revealed that even though there were some annual variations in the timing of river entry, differences between the rivers were substantial and very consistent. Assigning among year and among river variations to environmental variables was then a harder task due to lack of environmental and hydromorphological data from the old days. However, no matter what the source of the variation is, the message emerging from the analyses is clear: fixed regional opening date for coastal salmon fisheries can lead to uneven exploitation of different salmon populations. Today, in the Finnish coast of the Baltic Sea salmon fisheries are still managed in this manner.

Kuparinen A. & J. Merilä (2009) Variation in the timing of river entry of Atlantic salmon (Salmo salar L.) in the Baltic. Current Zoology 55: 342 – 349

Kuparinen A. & J. Merilä (2009) Sata vuotta tutkimuksia lohien vaelluksesta Pohjanlahden jokiin. Luonnon Tutkija 3: 108-109

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Fishing truncating salmon?

By Anna 30.12.2009 – 17:51 in Journal club
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lohi_blog 

Elegant approach to fisheries induced selection and its potential evolutionary consequences:

Saura M et al. (2009) Predictions of response to selection caused by angling in a wild population of Atlantic salmon (Salmo salar). Freshwater Biology (in press)

In this study the authors sample salmon returning for spawning in river Bidasoa in Northern Spain, estimate heritabilities for body size and weight, and predict how large changes in these traits would be expected under the prevailing selectivity of salmon fisheries. In the study system selection towards smaller age and size at maturation is very pronounced as fishing is exclusively conducted during the time large salmon enter freshwater. Predicted annual changes match fairly well with the decreasing trends in salmon size seen over the past decades. Interestingly, the observed trends are also very similar to those observed in the neighboring rivers, where fishing season is similarly restricted (e.g. Kuparinen et al. 2009).

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Firecrackers

By Juha 30.12.2009 – 9:00 in Random picks
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The last year’s culinaristic tips are still good to go, but here also some behavioral advice for tomorrow’s celebrations: there should be no need for verbal elaborations if you have a look on this picture.

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EGRU-blog 2009 retrospect

By Juha 29.12.2009 – 9:00 in Random picks
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Perhaps it is too early to speak about a tradition, but last year at the same date and exactly at the same time, year 2008 retrospect was published. The logger has been ticking for a full year since (except that it was turned off – due to mistake – for over period of nearly four months during the summer; see figure below), and it is time to look back and see what really happened.

Lets start with salient visitor statistics – the figures in the parentheses refer to last year’s statistics for the sake of comparison. During the past 12 months, the blog pages have been viewed 24 598 (6205) times during 10 812 (2744) visits by at least 5304 (1499) individual visitors. Each visitor peeked on average to 2.28 (2.26) pages and spent roughly 2.2 (2.5) minutes on these pages per visit. These numbers translate to some ca 65 (100) views per day as shown in the graph below.

Graafi_2009

Not surprisingly, most (4589 [1406]) visitors were from Finland, followed by USA (1776 [422]), Germany (665 [51]), Sweden (534 [no rating last year]), UK (539 [119]), Canada (355 [234]), Italy (253 [nrly]), Hungary (232 [nrly]), India (187 [nrly]) and Spain (108 [nrly]). As shown in the map below, hits were received also from many other countries – 115 (74) in total. However, note that the map below does not reproduce all visitors for reasons beyond my understanding. Nevertheless, from Finland, we were visited most frequently from Helsinki, Vaasa [sic!], Lahti, Turku and Vantaa. Jyväskylä, Tampere and Oulu still stumble in darkness. There was also one visitor from Rovaniemi – I want to believe that it was Santa Claus.

Kartta_2009

As to the most viewed contents of the pages, the top-ten most viewed blogposts are listed below. This excludes the clicks on directory pages and tags, including the highly popular link to tag ’sex simulation machine’ (276 hits) which topped also last year’s stats (264 views). Note also that these statistics do not account for time-dependence: the earlier entries have of course had more time to be clicked than the more recent ones.

The top ten entries (# of times read):

1. Hardcore fishing in Hungary (Gabor Herczeg) 687
2. Fishy stuff (Juha Merilä) 466
3. Risks of wind energy (Anna Kuparinen) 455
4. Exit GST (Juha Merilä) 280
5. Siberian jays mapped (Juha Merilä) 199
6. Aliens of coral reefs (John Loehr) 184
7. Antipredator strategies for dogs (Juha Merilä) 177
8. Conservation genetics (Juha Merilä) 164
9. The great killer tits of Hungary (Gabor Herczeg) 155
10. Dressed up for success or something else (Juha Merilä) 153

Also twelve other blog entries broke the 100-line. However, once looking these figures, it is good to remember few things. On the one hand, the stats are likely to be downwards biased because the entries read directly from the blogroll will not tick a hit in the counter. The same is of course true if the writings were read through RSS feeds. Likewise, visits during the nearly 4 months the tracker was down are not included.

On the other hand, not all readers necessarily found what they were looking for. Or what do you think about these: ‘what are the risks associated with the production of wind?’, ‘a sex simulator’, ‘sexsimulation’, ‘sex simulator 2008’, ‘sex simulation machines’, ‘sex simulatie’, ‘sex simulatiers’, ‘sex mashine’, ‘machine sex’, ‘sex simulator machine’, ‘sex machine’, ‘simulation sex’, ‘making sex simulator’, ‘sex symulation’, ‘sex machine fuck motor’ or ‘tits of the year‘? One also wonders what the person using a search string “and i can’t put my dick in your phd” was looking for?. On the other hand, those looking information about ‘creative research in science‘, ‘when is best moon phase to catch marlin‘, ‘physiology of frog rectum’ and ‘wigs’ probably found what they were after. Unsettled are ‘what is fisheries induced evolution?‘ and ‘what would the dress code be for an ecologist?‘.

Do you wonder about the peak at the end of December 2008 in the figure above? It was the entry ’Fishy Stuff’ – linked to one sport fisheries page. So much about the scientific glory.

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Merry Christmas & Happy Year of the Tiger

By Juha 24.12.2009 – 9:00 in Random picks

MC_HN_2

FYI: Vilppu won the race for identifying this: it is, as she correctly pointed out, a Snow Finch (Montifringilla ruficollis). Picking a yak poop at + 5300 m a.s.l. on Tibetan mountains in mid July 2009.

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Merrier Christmas – again

By Juha 22.12.2009 – 14:00 in Journal club
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Exactly 364 days ago, I blogged (here) about impact factors and Molecular Ecology retrospective for the year 2008. The year 2010 [sic!] retrospective is now out and worth reading – for many reasons.

Among other things, a new category of manuscripts will be introduced (‘From the Cover’) and a new data archiving policy will become effective from January 2011. Once this policy is in force, authors are expected to archive the data supporting their results and conclusions. This with the necessary details so that a third party can interpret them correctly.

Apart from the news and new policies, the article includes a retrospect looking what was published in Molecular Ecology in 2009. Theresa’s moor frogs are mentioned, as are Kimi’s goldeneyes. Interestingly, it turns out the intraspecific brood parasitism in Barrow’s Goldeneyes might be a disease:

‘Some of the ecological topics that have been addressed with molecular tools over the past year include: … behavioural ecology (Beekman et al. 2009; Berg et al. 2009; Du & Lu 2009; Johnson et al. 2009a), disease ecology (Abrego et al. 2009a; Almeida et al. 2009; Jaatinen et al. 2009; Rudge et al. 2009), macroecology…‘

I always thought that there could be something sick in it – flying around dumping unborn kids here and there – but it never occurred to me that Kimi might be entitled to apply funding from the medical research council.

Rieseberg L, T Vines & N Kane 2010. Editorial and retrospective 2010. Molecular Ecology 19: 1-22.

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Twitching – Herps

By Juha 21.12.2009 – 7:00 in Random picks
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R_arvalis_Svogerslev_Danmark_9904_TS4 copy

I have often thought that the frequency of people gone nuts about amphibians is particularly high among Swedes – I know many of them personally, but I keep on encountering more.

Have a look on these wonderful pages of ‘Club 100’ – a group of Swedish guys interested on amphibians and reptiles. The pages contain lot of nice photography, including wonderful shots of common species in their natural environments.

The pages also have sections containing hints and reports about where to watch amphibians in Europe and around the world. They also have page including nice lists (Excel sheets) to tick off species and maintain one’s personal species lists.

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Cleaning genotyping errors – crucial step in the data analysis

By Menghua 16.12.2009 – 10:14 in Journal club
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Microsatellites have been widely used in evolutionary, ecological and conservation genetics, for example in linkage map construction and parentage analysis. In these cases, the correctness of the genotypes is very important. Genotyping errors can result in biases and wrong parentage assignments.

The genotyping errors can be introduced by several factors such as the DNA quality, PCR protocols, the genotyping software, the differences in genotype reading by different persons and even by genotype transfer into new files. Although genotyping errors can not be totally avoided, their frequency can – and should be – reduced, especially in large data sets including hundreds of loci from hundreds of subjects.  

Several solutions have been proposed for the reducing the rate of genotyping errors. Usually the genotypes are read by two persons independently for the purpose of their correctness, and by this way, also a rough estimate of error rate can be obtained. Another common solution is to use the control individuals for the errors introduced by the PCR, for example due to the different enzyme used. In addition, the basic population genetics indecies – such as the frequency of null alleles, deviations from HWE and LE and the comparision of allele frequecy among the populations – can also be used for detection of genotyping errors.

However, very few publications have detailed or discussed about the strategies different authors have adopted to cope with the genotyping errors. This albeit the fact that this is important especially when the aim is to combine the data sets genotyped by different resaerchers or different groups.  Recently, several publications discussing the causes, consequences and solutions for the genotyping errors in microsatellites have appeated (see list below).

Phillip A. M., Karen K. M., Frederick I. A., Frank C., Debbie S., Jennifer J., and Barbara L. T. (2009) Applied conservation genetics and the need for quality control and reporting of genetic data used in fisheries and wildlife management. Journal of Heredity (In press; doi:10.1093/jhered/esp107)

Hoffman JI, Amos W. (2005) Microsatellite genotyping errors: detection approaches, common sources and consequences for paternal exclusion. Molecular Ecology 14:599-612.

François P., Aurélie B., Eva B.,  Pierre T. (2005) Genotyping errors: causes, consequences and solutions. Nature Reviews Genetics 6, 847-846.

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Why is Jolly Jumper horsing around?

By Juha 12.11.2009 – 8:45 in Journal club
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Likaa_töitä

Performing unconscious stereotypic behaviors – such as repetitive bobbing of head or windsucking – after work hours? Watch out, you might overworked and/or stressed. This is at least what the results of a recent French study of horses are suggesting.

By observing prevalence and types of stereotypic behaviors among horses in relation type of work they were used for, it was found that these depended strongly upon the type of work the horses were performing. The results are interpreted as evidence that stress at work may have variety of negative and durable effects on one’s behavior. As short as one hour spell of work per day may suffice to inflict the symptoms!

Hausberger et al. (2009) Could work be a source of behavioural disorders? A study in horses. PLoS ONE 4(10): e7625. doi:10.1371/journal.pone.0007625

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Open Access in Sweden

By Juha 10.11.2009 – 11:34 in Random picks
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Starting from 2010, all research financed by the Swedish Research Council should be available for public for free. In other words, research results need to be published in Open Access journals or journals allowing also this format. Unfortunately, there will be no extra budget to cover the costs of this requirement – research projects will take the damage (on the benefit of the public?).

Read more about this from Tentakel

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Narrowing scope of knowledge

By Anna 9.11.2009 – 19:41 in Random picks
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The observation that the accumulation of scientific knowledge has forced scientists to focus on narrower and narrower areas is by no means surprising. However, along this development attitudes about the broadness of education have also changed. A couple of centuries back an educated man was expected to know about arts, politics, sciences etc, but nowadays for one being considered educated it is sufficient to be knowledgeable in one’s own field but remain rather ignorant of any other. The same is reflected to school education: the choice of the subjects on which to focus is done earlier and earlier. In the latest issue of “Intelligent Life” (a quarterly lifestyle and culture magazine of “The Economist”) there was an article dealing with the narrowing scope of knowledge and how it is becoming harder and harder for polymaths (those knowledgeable and active on multiple fields) to exist. This development can hardly be halted, given how structures of knowledge are changing, but the article pointed out one drawback: largest scientific innovations tend to come from outside rather than from inside. Thus, narrowing scope of knowledge can also lead to degradation of thinking. This point is undoubtedly arguable but there is still something. Let’s for example think about the communication of science: the better one can place his/her findings into a broader context and the more fluently the story is written, the higher ranked the results usually are. Therefore, in addition to a good knowledge on one’s own field a successful scientist might need broader perspectives to science and society as well as literary skills. Interesting reading anyway: 

The last days of the polymath. Intelligent life: Autumn 2009

See also:

The age of mass intelligence. Intelligent Life: Winter 2008

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Siberian jays linked – extensively

By Juha 5.11.2009 – 16:00 in In press
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Linkage disequilibrium (LD) is something that most people working with standard population genetic analyses have traditionally considered as a nuisance – linked markers do not provide independent information about population history. However, in many other contexts, such as in estimation of effective size of populations, or devising strategies for identifying genes and genomic regions harboring factors responsible for expression of given traits, LD can actually be an asset. However, relatively little is known about extent of LD in wild populations.

In recent paper Menghua has worked out the details and extent of LD in the genome of the Siberian jay population in the margin of the species distribution range. The extent of LD was found to be very high, extending at high levels over considerable distances. Although the extent of LD decayed as function of increasing distance between markers, also long distance LD (e.g. among linkage groups) was common.

Part of the explanation for the high levels of LD is likely to depend on the fact the study population is relatively small and partially inbred. Just as Finns in general.

Li MH & J Merilä (2009) Extensive linkage disequilibrium in a wild bird population. Heredity, in press.

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Background of blackness remains unresolved in common frogs

By herczeg 1.11.2009 – 0:00 in In press
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Geographic variation in the level of melanism in common frogs (Rana temporaria) has been repeatedly observed. Vences et al. (2002) described a strong altitudinal cline (increasing melanism with altitude) and we observed a similar cline along a latitudinal gradient. A widely accepted intiutive explanation for these clines is thermal adaptation, as it has been shown for different ectotherm species that more melanistic individuals can heat up faster, which supposed to be beneficial in cold environments (e.g. Forsman 1995; Vences et al. 2002). Read More »

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Thick – they die quick?

By Juha 30.10.2009 – 7:00 in Journal club
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Jan

Reading a recent paper about growth rate differences among fish selected for high and low angling vulnerability, I started to think the possible explanations for these differences. And why would the fish with low vulnerability for angling possess higher growth rates than those selected for high vulnerability?

There are many possible explanations, but somehow the most likely explanations seem to boil down to behavioral differences. But since the angling vulnerability is also – at least in fishermen’s head – about cognitive differences, could these differences in vulnerability relate somehow to cognitive differences among individuals? If so, could there also be a common, underlying namer for growth rate and vulnerability differences?

Who knows. Such a possibility has been suggested at least in the case of humans. Increasing childhood IQ – measured at age 11 in a Scottish survey – correlates positively with likelihood to survive to age 76. In a study of 1 million Swedish military recruits tested around age of 19, IQ predicts their likelihood of survival over next two decades. In short, there are numerous studies showing that early-life intelligence and mortality are associated across different populations, in different countries and epochs.

One hypothesis to explain these human results is ‘system integrity idea’. According to this hypothesis, well-wired body is more able to respond to environmental insults – hence the association with cognitive capacity and reduced mortality risk. This hypothesis has gained some support from experimental tests, but the jury might still be out. As are some of the really big fish.

Deary I (2008) Why do intelligent people live longer? Nature 456:175-176.

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Is the three-toed woodpecker a genetically monogamous species?

By Menghua 25.10.2009 – 16:02 in In press

In socially monogamous birds, extra-pair paternity (EPP) is widespread as revealed by genetic analyses. In contrast, extra-pair maternity, also known as quasiparasitism (QP), is rare. A closer examination of previous studies reveals unequivocal evidence for occurrence of QP due to possibility of rapid mate switching and/or insufficient molecular work.

In a recent paper published in PLoS ONE, we found both EPP and QP in a population of three-toed woodpeckers in southern Finland. In this study, we genotyped a total of 80 samples from a field-study conducted during 2004 – 2007 in a close collaboration with researchers from Finnish Museum of Natural History. As compared to previous studies in this species, we used twice as many microsatellites in the molecular genotyping and more advanced stastitical methods and procedures in order to get high confidence in the parentage assignment.

We found co-occurence of low levels of both EPP and QP, which can be due to constrains set by the large paternal effort and intensive parental care. A previous study of the same species in Germany has also documented occurrence of EPP as well as CBP (conspecific brood parasitism, which is as a result of egg-dumping or QP). However, in contrast to our study, the German study could not resolve if the observed CBP was due to egg-dumping or due to QP.

On the basis of our results, it is for sure that the three-toed woodpecker is not a genetically monogamous species. It is also certain that both EPP and QP occur at low levels in this species. Last but not the least, we might have to reassess the occurence of QP in the wild birds – is it really rare or rare just because of the technical (cf. genetic and statistical methods) difficulties detecting it?

Li M.H., K. Välimäki, M. Piha, T.Pakkala  & J. Merilä. Extrapair paternity and maternity in the three-toed woodpecker, Picoides tridactylus: insights from microsatellite-based parentage analysis. PLoS ONE, in press.   

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