Utku Perktaş

Dr. Utku Perktaş is a professor of biogeography in the Biology Department at Hacettepe University.

Climate change due to global warming causes different effects in many areas of life. Climate change causes not only microbe-generated outbreaks that threaten human health. They also cause other negative processes that affect the fitness of species that are components of biodiversity. These observations do not need to be spread over many years anymore. Negative processes show their effects so fast that it is no longer possible for species to adapt and reach this rate of change. Especially considering the long evolutionary processes they have already experienced. Birds provide the best example to illustrate this, notably the nightingales which have a very rich song variation. In the first days of April 2020, a study was published in the scientific journal of the American Ornithologists’ Society (The Auk). The study was on migrant nightingale breeding in the Mediterranean Region. The results were so striking that it quickly became one of the most read news on climate change in foreign news websites and various science blogs.

Luscinia megarhynchos, Common Nightingale
Photo: Prof. Dr. Mustafa Sözen
You can listen to the nightingale’s song from here. With hopes that global warming will not take away this beautiful birdsong.

What does this study say?

Researchers who made the study collected data on the wingspan of the common nightingales over 20 years. Based on this data, the results showed that the common nightingale developed a smaller wingspan compared to its body size. Researchers attributed this to the shifts in early spring and early drought in the Mediterranean region. In other words, climate change caused the narrowing of the wingspan of nightingales in the Mediterranean Region.

Researchers say that this could also negatively affect the species’ migration ability during winter. This is a major concern for the species because it can cause a drastic reduction in its population values. And this would happen in a short period, even a single migration period. In general, migratory birds like nightingales have longer wings than their body sizes. This enables them to travel fast during migration. Their lifetimes, though, are shorter. So they migrate fast and exhibit successful reproductive behaviors in a short life span, trying to yield fertile youngs. But according to Dr. Carolina Remacha from the research team, the results “show that spring is delayed and the intensity of summer drought is higher, which means a shorter breeding period for birds.” Global warming causes the nightingale to face a failed breeding period. Their long history of evolutionary processes granted this species many possibilities. But global warming, taking place at a high speed, took these away.

Well, are the nightingales decreasing?

Nightingales are bird species that breed in Europe and Asia and they have the richest song variety among European passerines. They sing especially at night, which is where they take their common name from. This small songbird species have more than 1000 different sounds in its repertoire. Seen almost everywhere in Turkey, they are widely spread out throughout many regions of Europe and Asia. But they are also well known in southern England.

It was also reported that population trends ​​in the UK have declined sharply over the past 50 years. The most important reasons for the decreasing numbers is habitat degradation observed in nesting areas and changing climate conditions. And reportedly, there has been a decrease of approximately 90% in the last 50 years. If there is such a decline in the UK, it would not be surprising for us to see significant declines in Turkey, too. There is an urgent need to plan and execute studies on this species. And would that only serve this one species? Of course not! If one type responds to environmental changes so fast, other species could also have the same response.

Let’s not forget the sixth extinction scenario!

The climate change problem of the past 20 years has put the future of a nightingale species in danger. Birds reproducing in the Mediterranean already begun to experience the Anthropocene, that is, the Human Age. So are the nightingales the only endangered species? Of course not! To understand this, all we have to do is be more sensitive to this kind of news. To draw the right lessons from these results we have obtained by looking at the past and thus to predict the future; as a result, to take conscious steps. This lesson we can learn from one species of nightingales. But we can take steps to protect both the nightingales and the remaining 10 thousand bird species, and put an end to these difficult times for biodiversity. Am I very optimistic? I think it’s worth trying …