Postnatal development of morphological and vocal features in Asian particolored bat, Vespertilio sinensis

Abstract

a b s t r a c tWe studied the postnatal development of morphological and vocal features in a free-ranging population of the Asian particolored bat, Vespertilio sinensis. There were no significant differences in postnatal growth rates between males and females on the basis of morphological changes. Body mass and forearm length followed a linear pattern of growth until 28 days of age at mean growth rates of 0.38 g/day and 1.15 mm/day, respectively and thereafter increased slowly. The length of total epiphyseal gap of the fourth metacarpal-phalangeal joint initially showed a linear increase for up to 16 days, followed by a linear decrease until day 46 at a mean rate of 0.18 mm/day. When forearm length was used in combination with changes in total epiphyseal gap length, we derived reliable age estimation equations for the 1-46 day age range. Of the three nonlinear growth models (logistic, Gompertz, and von Bertalanffy), the von Bertalanffy and logistic equations provided the best fit to the empirical curves for body mass and forearm length, respectively. Studies of vocal development showed that infants could emit short calls as precursors of echolocation calls after birth. Isolation calls and precursors of echolocation calls were both characterized by multiple harmonics. We observed a systematic increase in the value of the starting frequency without a significant change in the terminal frequency over the 3 week period of development. In addition, the duration of isolation calls increased until day 4 and then decreased, whereas, the duration of precursors of echolocation calls decreased continuously to reach a stable level.

Morphological Correlates of Personality in Female Asian Particolored Bats (Vespertilio sinensis)

“…Asian particolored bats (Vespertilio sinensis) often cluster as groups within natural or artificial cavities, suggesting a highly complex social structure [43,44]. Outside the mating season, males and females separate [45,46].…”

Separating Overlapping Bat Calls with a Bi-directional Long Short-term Memory Network

“…However, a comparison of temporal-spectrum parameters between separated calls and nonoverlapping calls was included as an evaluation metric. The seven parameters used in this study are commonly used in bat studies to describe the temporal-spectrum features of syllables [25,31]. Statistical results for this comparison showed no signi cant differences and small deviations in parameters between separated calls and original recordings, indicating the system was able to separate calls without affecting syllable quality.…”

Separating overlapping bat calls with a bi-directional long short-term memory network

“…However, a comparison of temporal-spectrum parameters between separated calls and non-overlapping calls was included as an evaluation metric. The seven parameters used in this study are commonly used in bat studies to describe the temporal-spectral features of syllables [26, 29]. Statistical results for this comparison showed no significant differences and small deviations in parameters between separated calls and original recordings, indicating the system was able to separate calls without affecting syllable quality.…”