Between-year vocal aging in female red deer (Cervus elaphus)

Area of Science:

• Animal behavior and bioacoustics
• Mammalian vocalization and aging

Background:

• Animal vocal aging research offers insights into animal welfare and human voice aging.
• Understanding vocal changes in farmed red deer (Cervus elaphus) hinds is crucial for welfare assessment.

Purpose of the Study:

• To investigate age-related changes in acoustic variables of nasal and oral contact calls in red deer hinds.
• To assess yearly changes in weight, body condition, and social discomfort alongside vocalizations.

Main Methods:

• A repeated measures approach was used to track changes over one year.
• Acoustic analysis of nasal (closed-mouth) and oral (open-mouth) contact calls.
• Measurements included fundamental frequencies, frequency modulation, peak frequency, duration, power, body weight, body condition score, and social discomfort score.

Main Results:

• Nasal contact call acoustics (frequencies, modulation depth) decreased with age.
• Oral contact calls showed a decrease only in end fundamental frequency.
• Body weight and condition improved, while social discomfort decreased with age.

Conclusions:

• Aging directly impacts nasal contact call acoustics in red deer hinds.
• Emotional arousal during oral calls may mask age-related vocal changes in female red deer.