The mating habits of birds can be spectacular. Some species use singing, others dance and do aerial acrobatics, others still show their strength. There are also females who choose a male based on the appearance of the nesting site he occupies, says ornithologist Grzegorz Neubauer, PhD, a professor at the Museum and Institute of Zoology of the Polish Academy of Sciences.
Spring is the time of courtship, and each bird species has its own methods of acquiring a partner. The most common strategy among Polish birds is singing. 'Most passerines, such as tits, chaffinches and blackbirds, use singing to attract females. Singing is a display of the male's strength and health, but also a signal to rivals and neighbours: +This is my territory, stay away+', says the expert from the Museum and Institute of Zoology of the Polish Academy of Sciences in Warsaw.
In most species, what matters is how loud the mating song is, how often the male sings and how complex his song is. 'The louder it is, the better the potential partner's condition and the female knows that it is worth getting involved with him', the ornithologist explains.
Another mating strategy, often also connected with singing, is dancing. In Poland, the most spectacular birds in this respect are black grouses and capercaillies. Most often in the morning, male black grouses gather at a lek, which has the form of an arena, and assume a characteristic posture: they fluff up their feathers, spread their tails and lower their wings, while raising the so-called roses, i.e. swollen, red parts of skin above their eyes.
During the dance, they make small, jumping movements and make two characteristic sounds: a quiet gurgling and a louder hissing, which may be accompanied by an attack on a competitor.
'Just 30 years ago, many males could gather at such leks. However, the number of black grouse in Poland has drastically decreased in recent decades and today only a few birds gather in the arena, and in some places only a single male is lekking', Neubauer emphasises.
Capercaillies, the largest fowl in Europe, conduct their mating in a more individual way. The male circles the territory of his choice, presenting a spread tail and a high head, while making characteristic sounds: flapping, trilling, smashing and grinding.
Unfortunately, capercaillies are also becoming increasingly rare in Poland. 'That is why there are few lucky ones who have managed to observe their mating', the scientist says.
Some birds conduct part of their leks in the air. For example, lesser spotted eagles and common buzzards show their strength through spectacular acrobatics in flight. Circling above the ground, they make sudden turns and spectacular swoops, which are intended to not only impress the female, but also scare away rivals.
Blue tits, flycatchers and other birds nesting in tree holes have developed a completely different strategy for competing for a partner. In their case, in addition to their appearance and song, the ability to occupy a good nesting site also counts.
'By spreading his wings after landing on the tree hole, the male shows the potential nesting sites located in his territory. The female assesses them and if she considers them suitable, this may mean the beginning of a joint breeding season', the expert explains.
The mating of snipes and woodpeckers is also worthy of special attention. The former emit a characteristic 'bleating' produced by the flow of air between their tail feathers. Woodpeckers, on the other hand, loudly bang their beaks on the dry branches of tall trees ('drumming'), which the female can hear from a distance of up to a kilometre.
'There are many mating strategies. Observing them is a fascinating experience for every nature lover', Grzegorz Neubauer concludes. (PAP)
PAP - Science in Poland, Katarzyna Czechowicz
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