Are Hunters Making Birds Smarter?
A new study strongly suggests that the humans who hunt wild birds are making them smarter! The study conducted by researchers at The University of South Paris looked at data collected in Denmark. It became apparent that birds with smaller brains were more likely to be shot. This could be influencing how the various species evolve. With over 200 million birds shot in the US alone each year, the changes to birds’ brains could be occurring rapidly.
Danish law requires taxidermists to record the date and cause of death of every animal that they handle. Anders Pape Møller, an evolutionary biologist at the University of South Paris, assessed the brain sizes of 3781 birds from 197 different species which had been brought to taxidermists. Around 8% of the birds had been shot.
The scientist found that larger specimens were more likely to be shot, probably because they were bigger targets. Male birds were more likely to be shot than females because they are more visible due to their brighter plumage. But birds with larger brains relative to their body size were 30 times less likely to be shot.
Influencing the Gene Pool
Hunters could be influencing evolution because they are eliminating birds with smaller brains from the gene pool. Birds with smaller brains do not respond as quickly to danger and so are shot more often. There has been other research into how human activity may be influencing evolution. For instance, scientists have looked at how fish are affected by commercial fishing and have found that the fish are reaching sexual maturity earlier. It isn’t only people who are affecting evolution. Research has also suggested that prey species may be getting smarter as predators are more likely to catch animals with smaller brains.
Snipe and Curlew
The study conducted by the University of South Paris has only looked at retrospective data. Whilst it does suggest that hunted birds may be evolving to have larger brains, more research is needed. Møller is now looking at snipe and curlew. The hunting of these birds has been banned in Europe. He is comparing the brains of specimens from the time when hunting was permitted to the current population. This is to see whether the birds’ brains are getting smaller. If they are, then it would be possible to conclude that the hunting was influencing evolution and causing birds’ brains to grow larger.
Will Hunting Get harder?
It should also be considered that there may be several factors which are causing birds’ brains to get larger. It is possible to draw only limited conclusions from the study but it does raise some very interesting questions. Are some species more prone to evolving larger brains than others? What are the implications for the birds? How will evolution effect human hunters in the future? It could be that hunters are going to be in for a harder time!