Will climate change put at risk European bird species?

White stork, photo: Monika Betley, CC BY-SA 3.0

The signs of climate change that Europe has been witnessing in the spring and summer of this year have severely impacted some of the country’s bird species. Persistent rain during the spring months, storms and heavy floods decimated the young population of white storks in an unprecedented measure. Many of the newly hatched young died in their nests, elsewhere nests remained completely empty. In this edition of Panorama I talk to ornithologist Petr Voříšek about the fate of this and other endangered bird species in connection with the ongoing environmental changes.

White stork,  photo: Monika Betley,  CC BY-SA 3.0
“Indeed our reports on white stork nests across the country suggest that the mortality of the young was exceptionally high this year. What happened was there were heavy rains for several days which came at the exact time when the young were newly-hatched and too fragile to survive the cold weather and their parents obviously had trouble getting enough food for them. Furthermore, white storks have this habit, when they see they are not able to raise the chicks they kill them, they throw them out of the nest and leave them to die. We see that sometimes but never before have we seen it on such a massive scale as this year."

"We have a nationwide survey –a survey of almost every white stork nest in the country – and we will have the results (collected and analyzed) sometime later this year so this is anecdotic evidence that we have now, but it is still quite hard when we see the reports from almost all the regions in the country about this high mortality of white stork young.”

How are these nests monitored?

“It is easy in the case of white storks. Everyone recognizes those and because it is an urban species in the Czech Republic which breeds close to people in the villages it is easy to observe. We have a network of local coordinators who get data from the locals, often these are not ornithologists just local people who send us reports on when the storks arrive, whether they are breeding, incubating, if possible the number of young, breeding successes and breeding failures – so we have quite a detailed data base going back for several decades.”

So it’s done by people –we are not talking about camera systems or anything like that?

Petr Voříšek,  photo: Czech Television
“No, it is done by people. We have a nationwide census every year and every ten years there is a European international census of white storks. The first one was in 1934 and at that time in the former Czechoslovakia there were police officers who were responsible for collecting data on white storks nests.”

I understand that white storks are monitored in close to 300 localities on the territory of the Czech Republic and there are about 900 nests. According to available reports in 15 districts at least there were no young at all – does that mean that after a while someone climbs up to the nest to check out the situation?

“Yes, in most cases the young are ringed. Someone climbs up and does that and reports on the situation. That is not the case everywhere, of course. Some nests are hard to reach but we try to cover as much as possible.”

Is there any way of helping these birds in such extreme conditions or is it not advisable to interfere?

“Well, it is very, very hard to help them. Of course, if someone finds an injured or exhausted bird there is a network of “rehabilitation centers” across the country where specialists will take care of them. But there is no way to influence the adverse weather and these extremes which are becoming more and more usual.”

From what we know of this spring - is it a significant loss to the stork population in this country?

White stork
“It appears to have had a very strong impact –as I said we will need to confirm it later this year- and it is not only the white stork which was impacted but other species as well. But if we are talking about the long-term impact of these developments on the white stork species I wouldn’t worry excessively because the white stork is a long-living species and one breeding failure in one season is not fatal since they have other attempts in the next breeding season and the next and the next. So in these populations of long-living species one extreme season usually doesn’t play a decisive role. The population recovers quite quickly. We do not see any difference the following year because there are always no-breeding birds, surplus birds in the population.”

“A different question is what the effect would be if these extremes come more and more often, which seems to be what is happening. As the climate changes, extreme weather events are becoming more common so what will happen in the long-term is hard to predict and we can already observe the effect of climate change on other species.”

How has climate change affected the bird population as such? Are some birds moving elsewhere and others coming here? Is there any point in trying to prevent this or should we simply let Nature take its course.

“We can hardly prevent climate change happening – though of course we should work towards reducing the effects of climate change, reducing green-gas emissions and so on, but some extent of climate change seems unavoidable now, so as regards nature conservation we just need to think about how to help birds to adapt to climate change. Definitely some species will suffer, some species will profit. European analyses suggest that approximately one third of European bird species will profit from these changes, but two-thirds will lose. So the question is how to help those losers to adapt, to move their distribution ranges, not to hit them with other things like intensive agriculture, persecution and so on. So it is indirect help and it is extremely difficult.”

Floods in 2013,  photo: archive of the Czech Government
But will these birds adapt or will it be natural for them to simply move elsewhere where there are suitable conditions for them? Is that not what we will see in Europe – that the birds we know as being indigenous to this region will go elsewhere and we will get other species which are not here now?

“ Yes, to a certain extent this is true, but for many species going elsewhere simply does not exist –there is no alternative, like for the high mountain species. They do not have the option to go further up…the northern species are in a similar situation and also some southern species which are confined to very specific habitats. If these habitats disappear they are in trouble as well. So for some species it is definitely true that they can move elsewhere –the question is how many birds cannot do it because there will not be any habitat available for them and the question is how many of them can move without being adversely affected by other things like the local agriculture or persecution or whatever. “

When you say help them adapt – what do you mean exactly?

“Well, not to hit them by other negative factors like intensive agriculture for example. Because say a species is living in an area suitable for it and the next suitable location could be hundreds or thousands of kilometers away. So the species needs to move which is a long-term process that takes years and the species must have the possibility to find enough food in-between these sites, it needs a suitable habitat not just for feeding but also for breeding. But there are other areas where we would hardly be able to help because the effects of climate change are very diverse."

White stork,  photo: archive of Radio Prague
"For instance, some long-distance migrants now have problems because when they arrive in our location food is not available in such amounts as it used to be in past years prior to the changes. They usually feed on insects and the amount of insects is dependent on temperature - when the temperature is higher insects occur in a higher amount early in the season. But the bird migrants have not yet arrived early in the season and when they do arrive it is all over, so to speak, and they have difficulty finding enough food. Or, another thing is when these long-distance migrants arrive their suitable nesting sites – nesting boxes or tree hollows may be occupied by the resident species which has taken advantage of the early spring and enough food and they simply occupy all the suitable nesting sites and these long-distance migrants have greater difficulties as a result.”

If we look at the combination of climate change, agricultural change and changes in architecture - is there any bird species particularly at risk – what about birds of prey for instance?

“Well, basically these long-distance migrants are at higher risk because of their time-constraints, they have difficulties adapting their arrival time to the mentioned changes. Birds of prey are not in this particular case really endangered, they suffer from direct or indirect persecution by humans and the situation in this respect is improving slightly, so as concerns climate change birds of prey are not particularly threatened. There are other threats for them.”

Is there cooperation on European scale to try and protect these birds?

“Definitely there is cooperation, for a start there is cooperation in getting proper data on the situation in numbers, on changes in numbers and so on. There is cooperation in studying bird migration –by using ringing, a traditional but still useful method, and of course there is widespread European cooperation in the protection of bird species, there are priorities for the highly-threatened species and much more conservation efforts are being targeted towards them.

White stork,  photo: Guido Gerding,  CC BY-SA 3.0
But, more and more, the conservation community is coming to realize that it is not just the threatened rare species who are in trouble but also common, widespread species that are everywhere, who need our attention as well. So probably the biggest global conservation organization Birdlife International has set as one of its main goals the motto “keep common birds common” which is very, very important. It is not only about rare birds, it is also about the common species."