## Abstract Newborn and weanling fawns were held under reversed annual light cycles to learn if the subsequent replacement of their antlers would coincide with the anniversary of their births, as occurs in nature, or adapt to the artificial seasons of increasing day lengths even when these fall at
Photoperiodic control of antler cycles in deer. III. Decreasing versus increasing day lengths
โ Scribed by Goss, Richard J.
- Publisher
- John Wiley and Sons
- Year
- 1976
- Tongue
- English
- Weight
- 462 KB
- Volume
- 197
- Category
- Article
- ISSN
- 0022-104X
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โฆ Synopsis
Abstract
Deer were exposed for three years to photoperiods which increased or decreased two hours every four months, starting at 4L/20D or 20L/4D, respectively. Under both sets of conditions, antlers were repeatedly shed and replaced, usually in synchrony with every other time the day lengths were changed. On decreasing days, antler cycles were omitted as the photoperiod passed the equinox (12L/12D). On increasing days, the equinoctial photoperiod induced prolonged episodes of antler growth.
The tendency for the antler replacement cycle to lock onto alternate changes in artificial photoperiods is consistent with the seasonal growth of antlers every other time the day lengths change in the natural environment. It is suggested that antler replacement is triggered neither by shortening nor lengthening days, but by the alternation of such changes irrespective of the direction of the shift in the photoperiod.
๐ SIMILAR VOLUMES
## Abstract Yearling sika deer, when exposed to constant unequal photoperiods since the autumnal equinox, replace their antlers the next spring and at irregular intervals thereafter. On equatorial light cycles (12L: 12D) they retain their original antlers indefinitely. The changeover occurs between
The antler replacement cycle in the sika deer (Ceruus nippon) is abolished on simulated equatorial photoperiods (12L/12D), the old antlers failing to be regenerated for indefinite durations. Constant but unequal light and dark periods have been shown to permit expression of circannual rhythms,