HOMING ABILITY OF BREEDING MALE TREE SWALLOWS

We inadvertently examined homing ability in Tree Swallows (Tachycineta bicolor) when we removed twelve males from their nestboxes in 1993 as part of another study. These males were removed just prior to their m ate's fertile period and released either 125 or 250 km away. Six of th em were documented as having returned to the study area that same seas on. Three of these males subsequently nested successfully, with two br eeding in their original nestbox with their original mate, Another thr ee males returned to the study site the following pear. Tree swallows have excellent homing ability, and are strongly motivated to return to their breeding site. They appear to navigate because one of the homin g males was released north of the study site in what was most likely a n unfamiliar area.