Bird Ecology Lab, Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
Estación Experimental Quempillén, Chiloé, Facultad de Ciencias, Universidad Austral de Chile, Ancud, Chile.
PLoS One. 2019 Mar 13;14(3):e0212441. doi: 10.1371/journal.pone.0212441. eCollection 2019.
Human presence at intertidal areas could impact coastal biodiversity, including migratory waterbird species and the ecosystem services they provide. Assessing this impact is therefore essential to develop management measures compatible with migratory processes and associated biodiversity. Here, we assess the effects of human presence on the foraging opportunities of Hudsonian godwits (Limosa haemastica, a trans-hemispheric migratory shorebird) during their non-breeding season on Chiloé Island, southern Chile. We compared bird density and time spent foraging in two similar bays with contrasting disturbance levels: human presence (mostly seaweed harvesters accompanied by dogs) was on average 0.9±0.4 people per 10 ha in the disturbed bay, whereas it was negligible (95% days absent) in the non-disturbed bay. Although overall abundances were similar between bays, godwit density was higher in the non-disturbed bay throughout the low tide period. Both days after the start of the non-breeding season and tidal height significantly affected godwit density, with different effects in either bay. Time spent foraging was significantly higher in the non-disturbed bay (86.5±1.1%) than in the disturbed one (81.3±1.4%). As expected, godwit density significantly decreased with the number of people and accompanying dogs in the disturbed bay. Our results indicate that even a low density of people and dogs can significantly reduce the foraging opportunities of shorebirds. These constraints, coupled with additional flushing costs, may negatively affect godwits' pre-migratory fattening. Hence, as a first step we suggest limiting human presence within bays on Chiloé to 1 person per 10 ha and banning the presence of accompanying dogs in sensitive conservation areas.
人类在潮间带的存在可能会影响沿海生物多样性，包括迁徙水鸟物种及其提供的生态系统服务。因此，评估这种影响对于制定与迁徙过程和相关生物多样性兼容的管理措施至关重要。在这里，我们评估了人类在智利南部奇洛埃岛非繁殖季节对哈德逊神鹬（Limosa haemastica，一种跨半球迁徙的滨鸟）觅食机会的影响。我们比较了两个具有不同干扰水平的类似海湾的鸟类密度和觅食时间：在受干扰的海湾，平均每 10 公顷有 0.9±0.4 人，而在不受干扰的海湾，人类的存在（主要是伴随着狗的海藻采集者）可以忽略不计（95%的天数不存在）。尽管两个海湾的总体丰度相似，但在整个低潮期，神鹬的密度在不受干扰的海湾更高。非繁殖季节开始后的第二天和潮汐高度都显著影响了神鹬的密度，在两个海湾中的影响方式不同。在不受干扰的海湾中，觅食时间明显更长（86.5±1.1%），而在受干扰的海湾中则较短（81.3±1.4%）。正如预期的那样，在受干扰的海湾中，神鹬的密度随着人数和伴随的狗的数量的增加而显著下降。我们的研究结果表明，即使是低密度的人和狗也会显著减少滨鸟的觅食机会。这些限制，加上额外的冲洗成本，可能会对神鹬的迁徙前育肥产生负面影响。因此，作为第一步，我们建议将奇洛埃岛上海湾内的人类数量限制在每 10 公顷 1 人以内，并禁止在敏感的保护区内有伴随的狗。
