TVP WEEKLY: It is said that if man were to leave cities and large conurbations, it would only take nature three years to master these spaces. Would you agree with this?

MICHAŁ KSIĄŻEK: The city is a forest, only cut down; a meadow, only that it has been destroyed. No wonder they are trying, forest and meadow, to come back and will keep coming back. German biologist Ingo Kowarik has called this nature returning to the cities, the fourth nature. The first is the remnants of natural forests that are being cut down by the State Forests, the second is commercial forests, avenues, midlands. The third is urban nature, such as parks, greens, flowerbeds, and the fourth is the one you ask about. The nature of urban wastelands, car parks, lawns, vacant lots and ruins that we see in Chernobyl, Detroit or the Skra Stadium in Warsaw.

I have been living on a recently built housing estate for a year now and to my surprise there are some individuals making noise in the trees I have under the block throughout May and half of June at night or in the morning, even though these are not some old, spreading and tall trees.

It does not surprise me that birds live in the treetops. Most of our species use trees in some way: they either nest there, feed or protect themselves. They do not need particularly impressive trees for this to happen. Trees are multipliers of biodiversity and other social goods.

These birds were chirping and having conversations. I had the impression that it was some kind of mating, but maybe not necessarily. Does this mean that birds are very quick to colonise available bits of greenery, that they can quickly achieve symbiosis with the human world?

Unfortunately, we are not in symbiosis with them. Rather, we are in conflict. People cut down trees, bushes, thus destroying the breeding grounds of birds. We know so little about them that we do not even know it. For example, most building renovations in Poland are carried out during the breeding season: we wall up thousands of swifts, sparrows, praying mantis, turning our apartment blocks into tombs. There is not just idyll, there is also struggle. As naturalists who try to stop renovations or protect the bricked-up birds are well aware.

As far as birds are concerned, we mainly see one on the streets and dislike it very much, the pigeon of course. Where has the sparrow gone, which we used to see in large numbers and now hardly ever see at all?

Many people like pigeons, I don't personally know any who don't or won't admit it. It's just that those who don't like pigeons are very loud, which is a biophobic trait in general. There wouldn't be so many pigeons if it wasn't for our behaviour: leaving leftover food or feeding them unwisely. I think that where there would be no pigeons, eating the leftovers from us, there would be more rats. SIGN UP TO OUR PAGE Sparrow numbers have declined dramatically and one of the reasons is the preoccupation with perfect, airtight and sterile buildings. Modern architecture is not conducive to bird life. They simply lack holes and gaps in metal and glass structures. The decreasing amount of inner-city greenery is also doing its part. It is difficult to find something to eat on impermeable surfaces like concrete and asphalt. Research by Professor Marta Szulkin of the Institute of New Technologies at the University of Warsaw shows that it is enough to increase the impermeable surface area in a praying mantis breeding ground by 20% to kill one young. So it is enough to build one more walkway.

Where and which birds can we meet in the capital and other large Polish cities? What unobvious places do they occupy?

A kestrel falcon might nest somewhere on the ledge of a building, or in a window recess. There is a chance that a jackdaw or a rock pigeon, or rather its descendant: the city pigeon, will also live nearby. The pigeon nests on a block of flats because the block reminds it of a large rock, a mountain. Behind the gutter, on the other hand, we can find sparrows, but also a tiny bird - the garden creeper. Over millions of years, it has learnt to build its nests behind the protruding bark of trees, and today it probably associates the pipe with what it knows from the forest or the park.

A black redstar may nest behind a lamp post, in a faucet recess or in a cavity left by a fixture. Holes in the plaster will be used by the redshank, the rosefinch or the common snipe. Interestingly, the latter three also use such holes on winter nights. The birds sleep with us behind the wall. So do woodpeckers, whose tapping on the wall has probably woken many of us.

How do these birds live in the big city? What do they feed on? What do they drink and when?

In addition to the ones I've mentioned, we also have the warblers: fritillary, hooded warbler, thornbacked warbler, swallows: lapwing, springtails. There's also the redstart, redshank, blackbird, nuthatch, white-bellied woodpecker, starlings and grey crows. In the western part of the country, we can also meet crested larks and black-crowned warblers.

It is not uncommon for birds in the city to suffer from hunger and thirst, e.g. most birds drink their young with insect food. If they bring bread or pizza instead of insects the young suffer. Adult sparrows suffer from what might be called a pre-diabetic state, from an excess of carbohydrates; rolls, kebabs, and just scraps of pizza. This is why, among other reasons, city birds often have fewer young than forest birds. They are also smaller in size. There are studies that report high levels of heavy metals in the feathers of tits. We also know that they have poor intestinal flora, so they have digestive problems. They simply get a stomach ache.

What other animals can we encounter in the city? Insects, or perhaps bugs, because the latter are probably not in short supply, although the cracks are getting smaller and smaller?

It is not correct to say 'worms' about insects. Worms are an ancient type of invertebrate, which included hermaphrodites and flatworms, i.e. tapeworms, pinworms, human roundworms etc. What impresses me most are the bees, but not the 'honey bees', but the solitary ones. Of the world's 20 000 bee species, most are solitary bees. We don't realise how rich this world of forms, colours, and evolutionary solutions is. Or other insects of the order Hymenoptera, to which bees belong. For example, wasp-like spider mites, which kidnap spiders, tear off their legs and lay their own eggs on them. A real horror show in broad daylight in the city centre!

Bees have been in vogue for some years now - hotels, Warsaw's Palace of Culture and other buildings have their hives and boast about them, but are there any bees anywhere that have chosen to live their own way? Not in hive hotels? Is it good that we want to help nature and bees with these hives?

In the centre of Warsaw, or more precisely in the city centre, there are already about 12 million honey bees, some 200 colonies, and it looks like a threat of overcrowding. Such overcrowding can lead to diseases among the bees, but also has a negative impact on biodiversity: a farmed bee can deprive other pollinators, the wild ones, i.e. solitary bees, buzzards, bumblebees, wasps, of food. Wild pollinators pollinate more impressively than the farmed bee, because they often do so with their whole body, and they also fly to more plant species than the farmed bee. But people want honey, so we put hives wherever we can. Paradoxically, urban honey is free of the agricultural chemicals that happen to be found in rural honey.

Well, that's the flora. In addition to urban animals, there are probably quite a few plants that grow among us and of which we have no idea. Which ones and where can we try to find them? Which ones were the biggest discovery and surprise for you?

Perhaps the biggest surprise was the tomatoes in a gap in a block of flats in Mokotow. How about anther, a field roadside plant, on the viewing route, on the 30th floor of the Palace of Culture and Science? Someone brought a seed there on a shoe and it germinated. I also like the erigeron, called conyzza. It is the first plant to become resistant to glyphosate, a powerful herbicide.

In the city, apart from these smaller plants, we also have trees, over which there has been one big dispute for several if not more than a dozen years now. The old ones are disappearing, they are often cut down senselessly, and they are replaced by plane trees which, according to the architects, fit 'perfectly' into the squares and plazas they have designed, where there is no shortage of concrete and where these trees are also often built into the ground. What can we say about them? Do they perform any functions that are good for us, e.g. oxygenation, air purification, or the opposite?

The benefits of ancient trees in the human neighbourhood are innumerable. The fact that we still need to remind ourselves of them is proof that the climate crisis is also a knowledge crisis.

How does the urban ecosystem work? Where does it get the water, the things it needs to live green, when there are so few of those holes and crevices from the title of your book?

The city heats up very easily and cools down slowly, with so-called heat islands forming in the inner cities. In the world's largest metropolises, these islands can be up to 12 degrees warmer than the suburbs. This results in, among other things, a wave of illness and increased mortality among the elderly. How can we cool inner cities? Or not heat them up? By skilfully juggling three types of surface: water, green and concrete/asphalt. The temperature differences over these three types of surface lead to movements of air, or wind, which cools us. But above all, I think that in the inner city we should be able to do all our business in the shade. We have a right to shade!

What, then, should we do and not do towards this urban wildlife? How do we help it and how do we not disturb it?

Don't cut down trees except those that pose a threat, don't mow the grass except where necessary, don't rashly discharge rainwater into drains and collect it in barrels and ponds - as Joanna Rayss does in my book - don't rake up all the leaves, don't cover the surface of the city with concrete cubes and asphalt. Well, and read in my 'Atlas of Holes and Gaps' how you can water old trees cleverly.

– Interviewed by Marta Kawczyńska

TVP WEEKLY. Editorial team and jornalists

– Translated by Tomasz Krzyżanowski

Michał Książek – Poet, reporter, cultural expert, forest engineer and ornithologist. Award-winning author - winner of the Gdynia Literary Award (2016), the Magellan Award (2016) and the Silesius Wrocław Poetry Prize (2015). Nominated for the Nike Literary Award (2015). Author of the reportages "Yakutsk. Dictionary of Place' (2013), 'Route 816' (2015) and the poetry collections 'Science of Birds' (2014) and 'North East' (2017). His latest book is 'Atlas of Holes and Cracks'.