It depends on the age. Similar to us humans, a sparrow’s voice changes as it reaches its sunset years. As elderly swamp sparrows no longer sound the same as when they were younger, they also do not strike the same fear in other males who hear them, according to research led by Duke University.
Humans are remarkably good at guessing a person's age just by hearing their voice. But this is the first time the phenomenon has been demonstrated in wild animals, said Duke biology professor and study co-author Steve Nowicki.
During the early spring, a male swamp sparrow stakes out a breeding territory and threatens any male who dares to trespass on his turf. If a potential rival enters another male's territory and starts to sing, the resident male says "Get out!" by singing back with a rapid weet-weet-weet and flying toward the intruder. Eventually, if all else fails, he attacks.
The same team have found out previously that male swamp sparrows reach their peak as vocalists at age two. As they age, their voices decline, which make them sing less frequently and less consistently.
Check out how the research team conducted their study over at PHYS.org.
(Image Credit: Cephas/ Wikimedia Commons)