title: Natural twilight phase-response curves for the cave-dwelling bat, Hipposideros speoris.
abstract: Phase-response curves (PRCs) for the circadian rhythm of flight activity of the microchiropteran bat (Hipposideros speoris) were determined in a cave, employing discrete natural dawn and dusk twilight pulses. These PRCs are reported for the first time for any circadian system and they are unlike other PRCs constructed for nocturnal mammals. Dawn and dusk twilight pulses evoked advance and delay phase shifts, respectively. Advance phase shifts were followed by 3 to 4 advancing transients and a subsequent shortening of free-running period (tau); whereas, the delay phase shifts were instantaneous without any transients but with a subsequent lengthening of tau.
authors.affiliation: Zoology Department, Ahmednagar College, Ahmednagar, India.
authors.forename: C
authors.initials: C
authors.lastname: Vanlalnghaka
authors.forename: V L
authors.initials: VL
authors.lastname: Keny
authors.forename: M K
authors.initials: MK
authors.lastname: Satralkar
authors.forename: P V
authors.initials: PV
authors.lastname: Khare
authors.forename: P D
authors.initials: PD
authors.lastname: Pujari
authors.forename: D S
authors.initials: DS
authors.lastname: Joshi
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D004777:Environment; D005426:Flight, Animal / Q000502:physiology*; D017440:Photoperiod; D013472:Sunlight