Department of Conservation Biology, Estación Biológica de Doñana-CSIC, C/Américo Vespucio, 26, 41092 Sevilla, Spain.
UGARRA, Avda. Carlos III 1, 31002 Pamplona, Spain.
Sci Total Environ. 2018 Jul 15;630:600-608. doi: 10.1016/j.scitotenv.2018.02.186. Epub 2018 Feb 26.
The expansion of road networks and the increase in traffic have emerged in recent years as key threats to the conservation of biodiversity. This is particularly concerning in many protected areas because the increase of recreational activities requiring the use of vehicles. Effects of roads and traffic within guild scenarios and ecological processes remain however poorly known. Here we examined how road proximity and traffic intensity influence patterns of resource use in an Old-World avian scavenger guild living in a protected natural park in northern Spain. We experimentally placed 130 carcasses at different distances from a scenic road in the centre of the park. Vehicles were recorded by means of traffic counters which revealed that maximum numbers were reached during weekends and holidays and during the middle hours of the day. Avian scavenger attendance at carcasses was recorded by means of camera-traps. Obligated scavengers, Eurasian griffon (Gyps fulvus) and Egyptian vultures (Neophron percnopterus) were frequently observed (59.4% and 37.7% of the consumed carcasses) together with five other facultative scavenger species. We found that the richness (number of species) and the probability of consumption of the resource were reduced the smaller the distance to the road and in days with higher traffic intensity. The same factors affected the probability of presence of all the scavenger species. Moreover, some of them, notably griffon vultures, showed hourly patterns of carcass attendance suggesting avoidance of maximum traffic levels. Our results highlight that roads and traffic would trigger consequences on the structure and functioning of scavenger food webs, which may be particularly concerning in protected areas with remarkable levels of biodiversity. Future regulations at protected areas should couple both traffic and tourist affluence with wildlife conservation. In this way important ecological processes would be preserved while maintaining a good dissemination of natural values.
近年来，道路网络的扩张和交通流量的增加已成为生物多样性保护的主要威胁。在许多保护区，这种情况尤其令人担忧，因为越来越多的娱乐活动需要使用车辆。然而，道路和交通对 guild 情景和生态过程的影响仍然知之甚少。在这里，我们研究了道路接近度和交通强度如何影响生活在西班牙北部一个自然保护区内的一个旧世界食腐鸟类 guild 的资源利用模式。我们在公园中心的一条风景道路附近不同距离处实验性地放置了 130 具尸体。通过交通计数器记录车辆，发现最大数量出现在周末和节假日以及一天中的中间时段。通过相机陷阱记录食腐动物对尸体的出现情况。强制食腐动物欧亚秃鹫（Gyps fulvus）和埃及秃鹫（Neophron percnopterus）经常被观察到（消耗的尸体中有 59.4%和 37.7%），还有其他五种兼性食腐动物。我们发现，距离道路越近，资源的丰富度（物种数量）和消耗的可能性越低，交通强度越高的日子也是如此。同样的因素也影响了所有食腐动物物种的存在概率。此外，其中一些物种，特别是秃鹫，表现出对尸体的定时出现模式，表明它们避免了最高的交通水平。我们的研究结果表明，道路和交通会对食腐动物食物网的结构和功能产生影响，这在生物多样性水平显著的保护区中可能特别令人担忧。未来的保护区管理应将交通和游客流量与野生动物保护相结合。这样，重要的生态过程将得到保护，同时保持自然价值的良好传播。
