This movie clip depicts a female Mason bee starting to use the nesting cavity of a female Hornfaced bee. The Mason bee is indeed the stronger of the two. The Hornfaced tries with all her strength to push and pull the Mason bee out of her hole, but to no avail. Apparently the Mason bee does not acknowledge the Hornfaced bee’s use of this nesting hole.
Field notes: Hornfaced vs. Mason bee
Date: May 17. 2006
Updated June 2, 2010
Place: Washougal, WA