South African raptors in urban landscapes: a review

Globally, but especially in Africa, increasing human populations and anthropogenic land-use change are generally affecting diversity negatively. Urban environments in southern Africa typically comprise a mosaic landscape of anthropogenic infrastructure with some green spaces. These urban cities have a range of fauna that have persisted or increased in population density compared with areas that are more natural. We analysed the occurrence of diurnal and nocturnal raptors using South African Bird Atlas Project (SABAP2) data and reviewed literature. We found 66 raptor species occurred in South African cities. Thirty species had reporting frequencies greater than 10% in at least one of the 11 cities assessed, revealing impressive diversity of the raptor clade in South African cities. Five species were both abundant and widespread, occurring >10% in five or more cities each, of which three belong to the scavenger guild: Black-winged Kite Elanus caeruleus, African Fish Eagle Haliaeetus vocifer, Common Buzzard Buteo buteo vulpinus, Yellow-billed Kite Milvus aegyptius and Black Sparrowhawk Accipiter melanoleucus. However, only a few of these 66 raptors had been extensively studied in urban areas: the Black Sparrowhawk, African Crowned Eagle Stephanoaetus coronatus, Lanner Falcon Falco biarmicus and Peregrine Falcon Falco peregrinus. This lack of research is specifically severe, given that Africa is hosting a unique and diverse range of raptor species and that numbers and diversity of raptors have declined dramatically over the past decades across the continent. In fact, these four extensively studied species occurred in higher densities in urban areas than rural areas, which indicates that urban areas might create valuable opportunities for urban conservation, not least through public engagement.

从全球范围来看，尤其是在非洲地区，日益增长的人口规模与人为土地利用变化通常会对生物多样性产生负面影响。南非南部的城市环境通常呈现为人为基础设施与零星绿地交织而成的镶嵌式景观。相较于更为原生的自然区域，这些城市中栖息的多种动物类群，其种群密度不仅得以维持，甚至有所提升。本研究借助南非鸟类图集项目（South African Bird Atlas Project, SABAP2）的观测数据，并结合文献综述，分析了昼行与夜行猛禽的出现情况。研究发现，南非城市中共记录到66种猛禽。其中30个物种在本次评估的11座城市中的至少1座内，报告占比超过10%，这彰显出南非城市中猛禽类群的丰富多样。有5个物种既分布广泛又种群繁盛，在至少5座城市中的报告占比均超过10%，其中3种隶属于食腐生态类群：黑翅鸢（Elanus caeruleus）、非洲渔雕（Haliaeetus vocifer）、普通鵟南非亚种（Buteo buteo vulpinus）、黄嘴鸢（Milvus aegyptius）以及黑雀鹰（Accipiter melanoleucus）。然而，在这66种猛禽中，仅有少数在城市环境中得到过深入研究，分别为黑雀鹰、非洲冕雕（Stephanoaetus coronatus）、兰纳隼（Falco biarmicus）与游隼（Falco peregrinus）。考虑到非洲拥有独特且多样的猛禽类群，且过去数十年间整个非洲大陆的猛禽种群数量与多样性均出现了大幅下降，当前研究的匮乏问题尤为严峻。事实上，这4种得到深入研究的猛禽在城市区域的种群密度要高于乡村区域，这表明城市区域或许能为城市保护工作创造宝贵机遇，而公众参与正是其中不可或缺的重要环节。