A little over half of humanity is already living in cities (in economically developed countries, this figure is significantly higher), and urbanisation continues. The opportunity, or perhaps even the necessity, to occupy a new living space is also driving birds into cities, and the number of bird species found there is increasing. Life in the city imposes new demands on former country dwellers. It can be generalised that city birds all over the world are bolder than their country cousins – they allow humans much closer, and their feeding and nesting behaviours have also changed. Thinking about Riga, besides pigeons and sparrows, three other species came to mind that are now true Rigans – the herring gull, the blackbird, and the goshawk. The herring gull is the most conspicuous and frequently seen of this trio – a large, white gull found year-round that nests on rooftops in both the city centre and the suburbs. Near the Central Market, herring gulls walk confidently along the canal railings within arm’s reach. Their morning screaming during the nesting season irritates more sensitive people who do not want to get up at sunrise. Car owners have to reckon with excrement splatters on their vehicles, and pedestrians are sometimes frightened by the aggressive behaviour of parent gulls defending their young when they have left the nests and are wandering around courtyards, still unable to fly. Interestingly, even in the ornithological literature of the early 20th century, the herring gull was described as a bird characteristic of bogs. The blackbird is the least visually conspicuous of this trio, but stands out with its melodic song. Thrushes wintering in the city can start singing late in the evening even in winter or early spring, using street lighting instead of sunlight. The blackbird, however, is no novice – it began to settle in European cities as early as the beginning of the 19th century. The goshawk, on the other hand, began nesting in Riga about a quarter of a century ago and now both hunts and nests not only in suburban forests but also in parks and cemeteries. Goshawks have been observed skilfully using the opportunities offered by the city in their hunting, for example, gliding low over rooftops and then diving sharply into a courtyard to surprise pigeons before they have time to react. Photographs of a hawk feasting on a pigeon or a crow near houses can often be seen on media portals or social networks. In the city, hawks are also fiercer: adult birds defend their nest so aggressively that, when trying to ring goshawk chicks, one must reckon with both injuries and torn clothing. It is clear that the arrival of birds in the city has changed their behaviour, or vice versa – thanks to their ability to change their behaviour, birds have been able to adapt to the city. Birds have had to acquire new skills and abilities, as well as the ability to coexist with humans at a much closer distance than in the country. Videos frequently appear on the internet in which birds distinguish themselves with particular courage or cleverness – for example, crows that drop nuts under car wheels to get to their contents, or urbanised thrushes that nest on a traffic light pole and get lighting and heat for free. Seeing this, one must ask whether birds in city populations are really becoming cleverer or have simply “learned a few tricks”.

Recently, a scientific paper comparing two groups of birds – Barbados bullfinches Loxigilla barbadensis, members of the finch family living in city and rural landscapes – gained the attention of several foreign online media outlets. Upon reading the headline “City birds are cleverer than their country cousins, say ornithologists”, it seems there is nothing unexpected in this regard. Indeed, one might think that life in the city is more complicated for birds and forces them to become cleverer. Looking a little deeper, however, it does not seem so simple anymore. To agree or disagree with the statement that city birds are cleverer, one must agree on what is actually meant by cleverness. There is no generally accepted definition, but it usually refers to the ability to solve complex tasks, to be aware, to learn, to understand, to remember, to plan, to express emotions, to play, and to use tools. Moreover, to survive and adapt to a new living environment in the city, it may not be necessary to be cleverer (whatever that is meant to imply). It may turn out that only a specific ability or set of traits is useful. Contrary to the widely held belief, Charles Darwin did not claim that the cleverest survive; the full title of his most famous work is “On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life”. Thus, those who adapt will survive.

Not relying solely on the report and reading the study itself (the article can be downloaded at: ej.uz/gudriputni), it turns out that the claim about cleverer birds in the city was made by journalists. Scientists writing about city birds, however, were more cautious and did not engage in the discussion of whether city birds are cleverer: they claim that in the experiments they only observed the city birds' ability to better solve certain types of complex tasks, while in other problem-solving tasks the abilities were similar (it would be appropriate to remember here that in solving some types of “cleverness” tasks, for example, rats and chimpanzees outperform humans). One might also think that in the study, city birds should be bolder not only in the presence of humans but also when reacting to changes in their surroundings, which was experimentally tested by placing foreign objects next to food and determining how long it took for the birds to “accept” them and start pecking at the food. However, it turned out to be the opposite: city dwellers proved to be more fearful of new things in their surroundings. The scientists also found that city birds have better immunity. This, however, was not a surprise, as the chance of encountering pathogenic organisms is higher in the city. In short, the results are interesting, but the researchers are cautious with their claims.

If we consider the question of whether the ability to better solve certain types of tasks is to be valued as cleverness as splitting hairs, then the next question is interesting, for which answers were sought in the study but not found: have city birds lost something while gaining new abilities? Gaining new skills and traits is usually a trade-off where nothing comes for free: in gaining something, one may also lose or sacrifice something. This can be the loss of some previously existing traits, or changes in the structure of the organism. Very advantageous, albeit expensive, deals are possible. As an example, one can cite the difficulties that the possibility of using their highly developed brains causes for humans. These are the long development of the embryo, a very long maturation period, during which the child must be supported and taught until it becomes independent. Likewise, for a child to be born with an already sufficiently large and developed head, the mother must endure difficult childbirth. How serious this is can be seen in the old cemeteries of Ruhnu Island – crosses with a small cross on the “shoulder” of the larger cross were placed on the graves of women who died in childbirth with their child. And there are strikingly many of these in the cemetery, confirming that life before modern medicine was quite harsh.

In short, the question of whether and what the Barbados bullfinches will have to pay for adapting to life in the city remains open.
The article was first published in the May 2016 issue of the magazine Rīgas Laiks