The Sex Diary of a Fly

Some researchers have all the fun. Take Russell Bonduriansky and Chad Brassil of the evolutionary ecology group at U of T. They were able to sit in Ontario’s Algonquin Provincial Park for 72 days and watch flies mate.

The pair wanted to determine if male antler flies – critters that breed on the discarded antlers of deer or moose – show signs of aging in the wild. “When you study flies in the lab, they live for a long time because they don’t have any predators or risk,” says Bonduriansky. “Eventually, however, they do start to deteriorate. Now we have shown that this deterioration also occurs in the wild.”

The researchers captured several hundred male flies, and painstakingly painted an identification code on their backs. Then they released the insects and watched them breed.

In the journal Nature, the two zoologists reported that as a fly’s age increases, its ability to survive – and to mate – deteriorates. The decrease in mating may result from the declining attractiveness of older males or their reduced ability to defend territories.“A decrease in both survival and reproduction unambiguously demonstrates aging,” Bonduriansky says.