1) Like the swallows 
of, like or pertaining to swallows
• (a.) Like or pertaining to the swallows.
Hi·run'dine adjective (Zoology) Like or pertaining to the swallows. 
hirundine Of or pertaining to swallows and martins.
A member of the swallow and martin family. When flocks of House Martins, Sand Martins and Swallows hawk over water they are often referred to simply as flocks of hirundines.
of, pertaining to, or resembling the swallow.