Having a small brain could increase your chances of being shot – if you’re a bird, at least. According to a new study in the journal Biology Letters, dim-witted birds with tiny brains are less able to escape from hunters before they pull the trigger, which could contribute to avian evolution by ensuring that those lacking in intelligence are killed while those with larger brains survive.
The actual impact of hunting on avian intellect is unlikely to be particularly significant, as only a very small proportion of the world’s birds are killed at the hands of shooters. But the practise could nevertheless have some impact in driving brain size among some populations. However, the study authors stress that they don’t yet have any evidence to suggest that this evolutionary shift is actually occurring.
What they do have, however, is a collection of 3,781 stuffed birds, all of which were brought to Danish taxidermists between 1960 and 2015. Representing 197 different species, the birds were all weighed upon arrival, before having their brains removed and weighed as well.
Of these, 299 were killed by hunters, while the rest had all died of other causes. Interestingly, the researchers found a striking connection between brain size and the likelihood of having been shot.
The probability of being shot down was 29 percent for birds with brains weighing 0.23 grams (0.008 ounces), but just 1 percent for birds with brains that weighed 19.96 grams (0.7 ounces). In other words, those with large brains were almost 30 times better at escaping hunters than those with small brains.
While there are a number of possible explanations for this trend, the study authors propose that their findings may be down to the fact that small-brained birds lack the intelligence to recognize that someone holding a gun represents a threat, and may therefore wait longer than brainier birds before flying away.