Climate change intensifies war of the birds

From EurekAlert!

Public Release: 10-Jan-2019

Why great tits kill pied flycatchers in their next boxes

University of Groningen


IMAGE: This is Jelmer Samplonius with a pied flycatcher.  Credit: Rob Buiter

University of Groningen (UG) biologists have discovered that climate change has an effect on the regular clashes between great tits and pied flycatchers during the breeding season. In some years, great tits killed 10% of the male pied flycatchers. UG researchers have published an analysis of this behaviour on 10 January in the journal Current Biology.

Great tits are not just the funny, fluffy birds feeding off the fat balls in your winter garden. ‘During the breeding season, they can become very aggressive indeed’, says biologist Jelmer Samplonius. He studied great tits and pied flycatchers for his Ph.D. thesis at the University of Groningen.


While checking the nest boxes used in his field studies, Samplonius would regularly find the results of this aggression: a dead flycatcher in a nest box occupied by great tits. ‘When a flycatcher enters a box with a great tit inside, it doesn’t stand a chance’, Samplonius explains. ‘The great tit is heavier, as the flycatchers are built for a long migration from Europe to Western Africa and back. Also, great tits have very strong claws.’ In this case, the dead flycatchers usually have fatal head wounds. ‘And it appears that the great tits then eat the brains.’

There has always been competition between the two species for nesting locations. ‘Pied flycatchers try to steal nesting facilities from the tits. They may be no match when fighting inside the nesting boxes, but they are more agile flyers’, says Samplonius. Flycatchers fly around the great tits while they are building their nests, thus driving them away.


The question that Samplonius and his Ph.D. supervisor Christiaan Both tackled in the Current Biology paper is whether climate change has any effect on this behaviour. ‘Both species need to time the birth of their young with a peak in the availability of caterpillars’, says Samplonius. This peak is linked to the appearance of the first leaves on trees, and higher average temperatures mean that this period has shifted to earlier in the year.

Great tits are non-migratory birds, and they respond to higher temperatures by laying their eggs earlier. ‘Pied flycatchers now migrate to Europe earlier, but their adaptation is not as good as that of the great tits. Their earlier arrival is not linked to the actual temperature at their breeding grounds.’ Samplonius knows this because, over a period of 10 years, he and his colleagues have recorded the arrival of pied flycatchers and the start of egg laying of both great tits and flycatchers in two national parks.


Milder winters are one result of climate change. ‘This increases the survival of great tits, so the number of breeding birds will be higher.’ More great tits mean more competition for the flycatchers – and more conflict. It should be noted, however, that climate change is not the only factor in this: mast years – years in which there are more beechnuts – also increase great tit survival.

A second reason for the increased competition is that great tits and pied flycatchers have adapted to climate change differently. The biggest problems occur in colder springs, when tits start building their nests relatively late but the flycatchers still arrive early. ‘In this situation, the overlap in breeding time is greatest, and so is the number of conflicts.’ Great tits killed up to 10% of territorial male flycatchers inside a nesting box in just two weeks of competition. As the mortality for flycatchers across the entire year is about 55%, this is quite a lot.

Climate change

Interestingly, we didn’t see an effect on the overall flycatcher population of about 300 breeding pairs in our study’, remarks Samplonius. ‘We noted that the males killed were usually those who arrived late in the season. These late birds quite often don’t find a female to breed with, so that may explain why this behaviour has no impact on the population.’

Overall, the study shows that climate change affects the behaviour of both bird species, as well as the interaction between them. A group led by Christiaan Both, Professor of Ecology at the Groningen Institute for Evolutionary Life Sciences (GELIFES), will continue to study tits and flycatchers to discover if there are any long-term effects of this behaviour. Samplonius, meanwhile, has moved to the University of Edinburgh, where he is now studying blue tits. ‘I’m looking at similar questions here, along a 220-kilometer transect in Scotland. It’s really interesting to witness all these changes caused by climate change.’


Reference: J.M. Samplonius and C. Both: Climate Change May Affect Fatal Competition between Two Bird Species. Current Biology 10 January 2019.

77 thoughts on “Climate change intensifies war of the birds

  1. Another young PhD guy doing a thesis about the dangers of global warming.
    So sad.
    I bet they are importing foreign tech workers and other skilled workers into his country

    • It’s really interesting to witness all these changes caused by climate change.”

      He’s not old enough to (personally) witness any changes caused by climate change! Climate now is the same as it was the day he was born!

      (And I passed on the chance to say, I would be excited to see a pair of great tits! There. Aren’t you proud of me?)

    • Maybe young bird loving PhDs should be studying the war on birds; i.e. the kill-offs at Ivanpah and on wind farms. That would be more useful to real ecology.

  2. Meanwhile in other news, climate change (solutions) indiscriminately kills large percentages of bats and raptors

  3. This would have been an acceptable piece of work except for the absurd insertion of climate change as the culprit as a given so precisely understood that no explanation is needed. I read again and climate change has almost beed inserted after the fact. What is the basis, i.e. the study using accepted modern methods from the 19th century which found no evidence for this practice? How about during the Little Ice Age? Indeed if our intrepid claimer of climate woe is correct then there must have been wholesale murder of flycatchers during the Medieval Warm Period! How does this juvenile waffle get past reviewers unless the job of the reviewer now is to asess papers for quantity of references and claims about the catastrophic effects of minute imperceptible changes in temperature since 1850

    • “I read again and climate change has almost beed inserted after the fact.”

      Very likely it has. Same as praising the regime in a communist country of old; you go through the motions, kow-tow to authority and hope for the best, which is money.

      Hopefully this is being done almost instinctively, hopefully the young man has not seriously contemplated CAGW or other such nastiness, but simply accepted this as just another fact of life, like court etiquette in a monarchy, or knowing which soccer team to support in any given part of Glasgow city.

      Then, this will be a ritual that can just as easily be shed, when the time comes. I have faith in youth.

    • Jon, I certain the CC was not just added…..this kid has studied these birds for over 10 years…and either purposely left out their mating habits…or was not even aware of it….I think he was looking for a CC cause

      …but what he did say…is the slow male flycatchers are being culled…leaving only the early males to pass on their genes

      • Excuse my typo…. glasses should be warn at all times. But where does climate change come in? He must have a reference to “before” the change which he claims it as the overal controlling factor. He does not do this and again I call out those who reviewed this piece of work. Possibly authentic observations are made garbage by the political content . Why I wonder? Is there a dollar sign attached to each handwringing claim of the woes of climate change looking for the next paper to be written with the nose in the climate industrial complex trof?

  4. “next boxes” is hard to “tern” down my age, you never know when the “next” will come along ! Groooooan……

  5. Wonder if they did a study on windfarms killing raptors and bats disruption of the fauna. They should be able to qualify for funding as that is related to “climate change” In the picture is that not a fleece jacket being worn? Oh my the fossil fuel of it all.

  6. Dang, 10 years I lived in Daytona Beach, Florida and nobody ever paid me to watch/study all those “Great Tits” from around world that happened to cross my path…

  7. I miss a scientifi paper about natural effects without relations to climate change.
    On the other hand, since live on earth exists, there is evolution and adaptation to (climate) changes, isn’t ?

  8. “Overall, the study shows that climate change affects the behaviour of both bird species, as well as the interaction between them.”

    Behavior and interaction between species that compete for nesting, foraging, are constantly evolving and changing. Population and interaction dynamics. So is climate also always changing over scales of a few decades.

    In a natural setting you cannot isolate the two – population dynamics and changing climate.
    This is just more junk science equating correlation with causation.

  9. What?! What?! Is there nothing that cannot be blamed on global warming? This one puts a new meaning to the word “ridiculous” !!

  10. How far are we now from Alfred Hitchcocks “The Birds” ?
    Have we to fear an escalation in that direction ??

  11. Who doesn’t love great tits? I’ve been a tit man all my adult life.

    The possibility of aggressive great tits blows my mind!

  12. Typical leftist take: pay lip service to the supposed underdog, make it look like you are the champion of the oppressed, and demand that others should sacrifice to force equal outcomes.

  13. Same old story, add the words “Climate change “, and one not only gets a Grant, but is then given a easy ride via “The Chums who review such papers.

    As a reader says, what about a study of the deaths of birds by the windmills, no way, that sort of study is not what the reviewers want to see.

    Would be of interest if one of us were to do such a study, first to ask for a grant, almost certain to be refused, then to submit such a study to the various publications, then to publish the result.


  14. The biggest problems occur in colder springs,…”

    So how is that the fault of global warming Climate Change™?

    • We’ll know more when Samplonius completes his work in those colder climates:

      Samplonius, meanwhile . . . is now studying blue tits.

  15. Just a silly article taking a natural competition that has existed forever and blaming it on climate change.

    Great Tits have always had the natural advantage; they breed locally and can begin nest building with certain knowledge of the weather. Once the nest is complete their superior fighting ability means that the flycatchers have very little chance to displace them.

    Pied Flycatchers have to migrate to the breeding area over a long distance; migrate too early and they arrive weakened and with inadequate food supply (they do not eat the winter foods that sustain the Great Tits). So naturally they have evolved to arrive at a conservative date relative to the start of spring and food supplies. Climate change has no impact on this; the species adapts to temperature change, but they can’t just turn on the TV in their tropical hotel rooms and find out the if it’s going to be warm next week in Scandinavia.

    The interaction between the species has been studied in a lot of detail, and back in the 70s there were quite a few experiments designed to see how the competition works. The article makes it seem like this is some kind of slaughter but the birds are rarely killed in fights. In fact the male flycatchers will often reproduce with one female then try to take over other nest sites so that he can attract a second mate. This is why the males are aggressive even if they are not good fighters; having already reproduced they can afford to behave in a riskier way. Final point; the flycatchers are actually the beneficiaries of the competition since they use the Great Tits to locate food sources for their young, resulting in greater reproductive success when Great Tits are present. They are among the least endangered birds in Europe.

  16. Just more unsupported BS blaming climate change. As professors have joked in my biology department, “If only I can link climate change, my research could get funded”

    • What movie is this? Bit surprise San Mateo High School came up- I went there but it isnt mentioned in too many movies.

  17. “No impact on the population…” Since “… males killled … who arrived late in the season … don’t breed ….”

    Survival of the fittest redux? If the future male generations of pied fly-catchers get epigentic modification for climate instigated new seasonal time reaction & more arrive in time to find a female fly-catcher will there be less great tits outdoors? (Asking for a friend.)

  18. Well, young Mr. Samplonius (“collector of samples”?) has certainly made a name for himself in climate science. MAYBE not the name he would prefer, but such are the ways of the world.

  19. I believe the problem may be the nesting boxes. The flycatcher is a lighter more nimble flier more suited to fighting in open spaces. In nature holes in tree limbs used for nesting have random sizes and openings. The man made nesting boxes (birdhouses) uniformly confine the tit/flycatcher conflict giving the advantage to the heavier stronger tit. The flycatcher must also contend with the small circular entry/exit hole hindering a quick exit while under attack. No doubt avian enthusiasts like the study author have been placing large numbers of nesting boxes with as small as possible entry holes with the good intention of protecting eggs and immature birds from predators and have inadvertently forced male flycatchers into a “fight in a phone booth”.

  20. Since we´re all going to pass away very soon, due to Gorebull warming, I was naively hoping for better illustrations in this article.
    And happy new year to ya all from Denmark

    • I just love flycatching tits from Denmark !! I enjoyed the company of few in my much younger days…LOL

  21. “‘And it appears that the great tits then eat the brains.’”

    I have experienced this before.

    The author must have enjoyed writing this article, as the one who authored the “NASA to Probe Uranus in Search of Gas” no doubt did.

  22. Well, I was going to say something subtle, like when I was in school, I didn’t pay much attention to pied flycatchers.

    But so many hooter comments have already been made. So let me just opine: EurekAlert! Say no more.

  23. Politics, money, peer pressure and the lying, fact-free, fake news media’s censorship (BBC) have completely corrupted science. Climate change hysteria mongering has turned science, engineering and economics into full time bullshit factories – on all sides!

    The Radiative Green House Effect theory contains a fatal flaw.

    For RGHE to perform as advertised requires the earth’s surface to radiate upwelling LWIR as an ideal black body, i.e. 1.0 emissivity at 16 C, 289 K, 396 W/m^2. (TFK_bams09)

    The contiguous presence of atmospheric molecules participating in non-radiative heat transfers through conduction, convection, latent renders impossible such BB LWIR, the effective surface emissivity being 0.16, i.e. actual 63 W/m^2 / ideal 396 W/m^2.

    The LWIR upwelling 396 W/m^2 does not exist – the 333 W/m^2 GHG energy loop “warming” the surface and atmosphere does not exist – and the global warming and climate changes that are attributed to carbon dioxide do not exist.

  24. As a PhD in ecology I wonder if all these climate change people realize that they have rendered useless 70 years of ecological research. If climate change is so important, and for 70 years researchers were not measuring climate change variables during the studies, then those ecological data can not be interpreted and can not contribute to science. It would be like a stream fisheries biologist studying salmon but not taking any hydrological or geomorphological measurements.

  25. So why eat the brain?

    Some while ago now, in the UK, occurred an Agricultural Calamity (occasioned by ‘clever’ Government Scientits & Ministers being rail-roaded by cronies) – a calamity called Mad Cow Disease. Bovine Spongeloffely Encredulious istis. aka: BSE

    As a cow farmer I was caught up in this thing – not least the ensuing rules &regulations that have effectively resulted in the premature expiry (deaths) of many UK farmers.

    At the time, the BBC dispatched a sweet piece of young blond female reporter to a village somewhere in Africa. seemingly the residents of said village were showing of the human variation of BSE – namely= CJD
    Especially the womenfolk in this village.

    It transpired as we learned the reason for her reporting from this particular village, that the menfolk had seemingly been forcing the girls to eat the brains of monkeys that they’d been catching – and had been doing so since time memorial. The boys got to eat the rest of the hapless monkeys – OR – the Nice Parts.

    The disgust and horror on this woman reporter were palpable.
    The story had everything. Horrible insensitive men mistreating women with sh1t food while they had a wild old time enjoying themselves.
    At first glance and by Western values/standards – yes.

    But but but – back to the birds and now introduce Romance.
    The Art of Human Romance – whereupon Boys bestow Girls with ‘gifts’ and the girls reciprocate by giving the boys gifts in return. THE Biggest and Best Gift any boy could wish to receive from any girl is the chance to be the father of her babies. As per the words exchanged in most marriage ceremonies.

    The boys in the village were giving the girls THE best gift they could find, something very rare, very hard to obtain while also (this is where the birds come in) being something of very high nutritional value.
    There is NOTHING in their world or culture of higher value.
    Hence why the birds were eating each other’s brains – for the food value of that amorphous blob of saturated fat.
    Giving the girls animal brains was THE most romantic thing the boys could do and the girls, until the arrival of the BBC, appreciated that – hence why the village was over-run by children.

    In the African village we never knew what was really happening. Had the girls been getting the disease all along or had something happened within the monkey colonies themselves. The real story just disappeared.

    That woman reporter could not have got the story any more wrong if she tried.
    Sound familiar in any other branch of science……………….

  26. Ok …. fly catcher …. great tits ….. how bout a fly catcher with great tits.

    This has to be one of those spoof articles submitted to show how stooooopid people are who are promoting the CAGW scam. Just a matter of time before this shows up in comgressional testimony in support of CAGW. …. probably by a fly catcher ….. with great tits.

    Just sayin

  27. Makes you wonder how the flycatchers survived the MWP, or the Holocene Thermal Optimum*.

    *Now called the Holocene Thermal Maximum – “optimum” implies it was good and we can’t have that, can we?

  28. Wow, using my favourite search engine to find an image showing what these birds look like is not as easy as it sounds.

  29. I wanted to study owls, so I thought the best way to do that would be at this place called ‘Hooters.”

    It turns out that there was nary an owl to be found there but the place was full of great tits.

    (I was just leaving….)

  30. i have noticed climate change affecting our seniors coffee group in the last 10 years. There are less of us, some are turning grey, some have changed their habits and drink tea instead. A couple have started arguing.
    Just think what will happen if we do not do anything about it in the next 12 years. I want a seat at the next IPCC meeting.

  31. From the article: “Overall, the study shows that climate change affects the behaviour of both bird species,”

    The CAGW Lie fools another scientist.

    First, in order to prove that human-caused climate change is affecting anything, you first have to prove that human-caused climate change is taking place.

    There is no evidence that human-caused climate change is taking place.

    This scientist is assuming things not in evidence and then applying them to his study. His error is assuming the Alarmists are telling the truth.

  32. Would be interesting to see if someone could replicate this study. Perhaps the results are only due a ‘small’ sample size.

    Supposedly global warming has been 1 degC over the past 50 years (sorry I am too lazy to look up the ‘precise’ figure. So in a 10 year study, one can see the effects of a 0.2 deg C warming? Amazing! 🙁 Sarcasm

    Obviously climate change has caused cancer too!

  33. So what’s the takeaway from this … If you get in the box along with great tits you’ll lose your mind?

  34. Wait a second. This study is based on an artificial construct introduced by the researcher!

    From the article (bold mine): “While checking the nest boxes used in his field studies, Samplonius would regularly find the results of this aggression: a dead flycatcher in a nest box occupied by great tits.”

    So what happens when there are no nest boxes? I dunno. Maybe the pied flycatchers travel in gangs and beat up any great tit they come across.

    Jelmer Samplonius built these highly desirable bird condos, setting up a “lets you and him fight over it” scenario. Oh noes! The brawnier great tit always kicks the pied flycatcher’s ass. It doesn’t seem fair to me or very scientific, for that matter.

    What happens in the absence of the bird boxes?

  35. Out of curiousity I googled to see what these birds looked like. It brought up the article in several MSM publications. I looked at several. In every case the competition between the two species was presented as a totally new phenomenon, clearly the result of climate change. Nowhere did you find anything to the effect of the line above: ‘there has always been competition between the two species for nesting locations.’

  36. What they really found was that bird biology and behavior is affected by weather — as it has always been. For migrating birds, they get a double hit of weather related variance — one set in the breeding range and another in the winter range.

    A ten year study can not identify “climate change” — as the climates of neither breeding or wintering ranges changes over such short time periods.

    I do suspect the nature of the clash between the two species — by the introduction of “bird next boxes” which are not natural.

  37. Funny jokes aside, it looks like another “What gruesome thing can we blame on climate change today?” study from grant-hungry academics.

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