Climate change is going to cause warmer springs. This may seem like a good thing for various creatures, because more generous amounts of food are going to be available earlier. However, scientists say that it is not the case. In fact, researchers from the Universities of Exeter and Edinburgh say that the warmer springs actually reduce food for forest birds.
The matter of the fact is that birds rely on their mating season to be in sync with changing seasons of the year. Baby birds typically hatch when surroundings are full of caterpillars and various beetles, which allow parents to feed their offspring without much trouble. However, scientists now are noticing that hatching times are going out of sync with the peak of the crawler activity. This is caused by the increase of temperature in the spring. Scientists analysed data, collected largely by volunteers, how the seasonal emergence of oak tree leaves and caterpillars is matched with nesting by blue tits, great tits and pied flycatchers and found that nature is losing its rhythm.
In warmer springs caterpillars emerge earlier, but birds are not that adaptable and typically lay eggs at the same time. Naturally, the peak of the crawler activity should be coinciding with the time when chicks are the hungriest, but that is no longer the case. Nature is extremely adaptable, but birds struggle to keep up with ever changing seasons. Some springs are closer to the average than others. Caterpillars time their activity with temperature, but birds don’t have such abilities. And so that mismatch actually reduces the availability of food when it is needed the most.
Contrary to popular belief, warm springs are not good for animals and birds, because it messes up their timing. Also, warm winters and springs favour parasites. Despite previous predictions, scientists did not find any difference between south and north Britain in this regard. Dr Ally Phillimore, one of the authors of the study, said: “population declines of insectivorous birds in southern Britain do not appear to be caused by greater mismatch in the south than the north. This also means if spring temperatures rise then woodland birds may be mismatched everywhere, and not just in the south”.
The climate change is not good for the animals – it is surprising that there are people who think otherwise. However, it is likely that with time birds would adapt. The problem is that the climate is not just getting warmer – it is getting unpredictable. Some springs may be significantly warmer than others, followed by some long winters. That is what makes birds struggle with their timing.
Source: The University of Edinburgh