I have no problem with the mosquitos sucking me dry. They can have their way with my neck, my arm and my thigh, as long as they do so quietly. That is exactly what female mosquitos refuse to do. Their buzzing, which is caused by the flapping of their wings, is designed to attract males. I consider this an evolutionary blunder. Of course, sex is at the top of a mosquito’s to-do list: they have to pass on their genes to the next generation. I just think it would make far more sense for them to suppress their sex drive during mealtime, because there is a considerable risk that their prey will jump out of bed to hunt them down with a rolled-up magazine.
Other animals are better adapted. Evolutionary biologist Menno Schilthuizen of Naturalis recently demonstrated this to me during an ‘urban safari’ in his hometown of Leiden. He pointed to the grey feral pigeon, whose ancestors once left the cliffs of southern Europe to move to the gutters and stone windowsills of man’s cities. Since that time, the feral pigeon’s colour has darkened. Schilthuizen explained that the melatonin that gives the pigeon’s wings its dark-grey colour absorbs heavy metals. That makes the birds less susceptible to these toxic substances and allows them to thrive in our city centres. Their behaviour has also changed. In the wild, it is in any animal’s best interest to be wary and to move away from danger as soon as possible. Our cities, however, reward the curious with surprising new food sources. City birds are more entrepreneurial and daring than their rural cousins. Even their wings have a slightly rounder shape, which allows them to fly out of the way of oncoming traffic at the last possible second.
We also spotted a bridge spider, which is related to the garden spider. While the latter prefers to build its web in dark places, the bridge spider constructs its home right in front of the city lights. Smart, because that is the best way to catch flies.
As I was scanning my room last night, dressed in nothing but my underwear and armed with a magazine, I presented this idea to the mosquitos: if they would stop their buzzing, they would have a greater chance to procreate! From their hiding spots on my bedroom walls, I could almost hear them thinking: ‘You’ll never catch us all!’
You can also find this column in the latest issue of our Science & Technology Magazine. Grab a printed copy at the UT campus or view the entire magazine online.
