Attract martins to your newly placed martin house with this Nature House Purple Martin Morning Vocalization CD. Adult male martins at established colonies offer vocalizations each morning between 4 AM and 6 AM, attempting to attract subadult martins to the area. This 71 minute long CD, recorded at a 300 pair colony in Washington, IL, is great for inviting these birds to your new housing. The digital recordings offer clear and crisp sound, for the utmost in realism. Lure young martins to your yard with this Purple Martin Morning Vocalization CD. Made in the USA.