The Vocal Repertoire of the Key Largo Woodrat (Neotoma Floridana Smalli)

The Key Largo woodrat (Neotoma floridana smalli) is an endangered rodent endemic to the island of Key Largo, FL. There is little information on vocal communication in this species and descriptions of the acoustic structure of calls are lacking. A captive breeding program was established as part of the recovery plan for the species, providing the opportunity to investigate the vocal repertoire and acoustic structure of calls in both wild and captive contexts. Audio and video recordings were conducted at the Crocodile Lake National Wildlife Refuge in Key Largo and at Disney's Animal Kingdom(®). Analysis of the acoustic structure of calls resulted in four provisional call types: "Tonal calls" consisted of "ultrasonic vocalizations" (40 kHz fundamental frequency, F(0)), "high squeaks" (10 kHz F(0)), and "squeaks" (1.8 kHz F(0)). "Noisy," broadband calls known as "raspy" vocalizations did not exhibit fundamental frequencies, but contained several prominent spectral peaks (from 9 to 40 kHz). The social contexts of vocal production showed that all four call types were associated with pup need or interactions between pups and dams, and that raspy vocalizations were associated with courtship and copulation. Adults without pups exhibited little or no vocal activity, which may result from solitary lifestyles and predator avoidance.