Congress Ave Bridge bats on the full moon
CAB bats head out to forage in the pasture land and agricultural fields between Bastrop and San Marcos on a full moon night.
They don’t seem to be deterred by the full moon, they are flying in big numbers even as the moon rises, although more seem to be staying within the city limits than usual.
One would think that Mexican free-tails would be lunar phyllic, since they feed in wide open spaces away from tree-loving owls and the moonlight might even allow them to better locate prey visually, before kicking in their echolocation when they get within range.
At this time of year (even on a wet year like this one) there is likely less insect prey in the agricultural fields and the bats are eagerly awaiting the reverse migration of the Corn Ear-worm Moth that usually starts in late September. CEM return south in the fall because their pupae can’t overwinter up north. Mexican free-tailed bats depend on this reverse moth migration to put on weight prior to the bats’ own migration south in late October.