Brogi Rudy, Merli Enrico, Grignolio Stefano, Chirichella Roberta, Bottero Elisa, Apollonio Marco
Department of Veterinary Medicine, University of Sassari, via Vienna 2, Sassari I-07100, Italy.
Curr Zool. 2021 Sep 17;68(4):371-380. doi: 10.1093/cz/zoab077. eCollection 2022 Aug.
On a population level, individual plasticity in reproductive phenology can provoke either anticipations or delays in the average reproductive timing in response to environmental changes. However, a rigid reliance on photoperiodism can constraint such plastic responses in populations inhabiting temperate latitudes. The regulation of breeding season length may represent a further tool for populations facing changing environments. Nonetheless, this skill was reported only for equatorial, nonphotoperiodic populations. Our goal was to evaluate whether species living in temperate regions and relying on photoperiodism to trigger their reproduction may also be able to regulate breeding season length. During 10 years, we collected 2,500 female reproductive traits of a mammal model species (wild boar ) and applied a novel analytical approach to reproductive patterns in order to observe population-level variations of reproductive timing and synchrony under different weather and resources availability conditions. Under favorable conditions, breeding seasons were anticipated and population synchrony increased (i.e., shorter breeding seasons). Conversely, poor conditions induced delayed and less synchronous (i.e., longer) breeding seasons. The potential to regulate breeding season length depending on environmental conditions may entail a high resilience of the population reproductive patterns against environmental changes, as highlighted by the fact that almost all mature females were reproductive every year.
在种群层面，繁殖物候的个体可塑性会引发平均繁殖时间的提前或延迟，以应对环境变化。然而，对光周期现象的严格依赖可能会限制温带地区种群的这种可塑性反应。繁殖季节长度的调节可能是面临环境变化的种群的另一种手段。尽管如此，这种能力仅在赤道的非光周期种群中被报道过。我们的目标是评估生活在温带地区且依赖光周期现象来触发繁殖的物种是否也能够调节繁殖季节的长度。在10年时间里，我们收集了一种哺乳动物模式物种（野猪）的2500个雌性繁殖特征，并对繁殖模式应用了一种新颖的分析方法，以观察在不同天气和资源可利用条件下繁殖时间和同步性的种群水平变化。在有利条件下，繁殖季节提前，种群同步性增加（即繁殖季节更短）。相反，恶劣条件导致繁殖季节延迟且同步性降低（即繁殖季节更长）。根据环境条件调节繁殖季节长度的潜力可能意味着种群繁殖模式对环境变化具有较高的恢复力，几乎所有成年雌性每年都能繁殖这一事实就突出了这一点。
