Decades of artificial nests towards African Penguin conservation – have they made a difference?

African penguins are amongst the most threatened of seabird species
globally and an African Penguin Biodiversity Management Plan (BMP)
published in 2013 guides conservation strategies to prevent their
extinction. To counter the impact of past guano exploitation which reduced
nesting habitat of these burrowing seabirds, rendering them vulnerable to
predators and extreme weather events, a suite of artificial nests was
deployed in various colonies over the past decades with varying success.
The BMP called for new nest designs to maximise breeding output. • This
study assessed African penguin breeding success over the past 14 years in
four types of artificial nests and in natural nests at all major colonies
in South Africa.  Overall, artificial nests outperformed natural
nests and successfully increased breeding output of African penguins by
16.5% (95% CI: 6.7–26.2%). No design was, however, consistently most
effective across locations. For example, fibreglass nests had the poorest
hatching success of all nest types at one colony (Bird Island), but
out-performed cement nests at another (Boulders Beach). The latest design
of double-layered ceramic nests tended to perform better than other
artificial nests, although not consistently at all colonies and occupancy
rates were low in some areas.  Practical implication: The
deployment of artificial nests proved to be a successful conservation
measure for African penguins although the variety of habitats in the
different colonies seems to have prevented a one solution-fits-all
approach. The consistent poor breeding output in some areas in all nest
types (<30% at the mainland colony in Simons’ Town and the islands
in Algoa Bay) further calls for colony-specific conservation strategies
beyond artificial nests, while the continuous decline in African penguin
numbers globally calls for broader measures urgently, primarily increasing
access to their forage fish prey.

非洲企鹅是全球范围内受威胁最严重的海鸟物种之一，2013年发布的《非洲企鹅生物多样性管理计划》（BMP）为防止其灭绝的保护策略提供了指导。为应对过去鸟粪开采导致这些穴居海鸟筑巢栖息地减少、使其易受捕食者和极端天气事件影响的问题，过去几十年中，一系列人工巢箱在不同栖息地部署，效果各异。BMP呼吁采用新的巢箱设计以最大化繁殖产出。• 本研究评估了过去14年里南非所有主要栖息地内四种人工巢箱与自然巢箱中非洲企鹅的繁殖成功率。总体而言，人工巢箱表现优于自然巢箱，成功使非洲企鹅繁殖产出提升16.5%（95%置信区间（Confidence Interval，CI）：6.7–26.2%）。然而，没有一种设计在所有栖息地始终保持最优效果。例如，玻璃纤维巢箱在某一栖息地（鸟岛）的孵化成功率为所有类型中最低，但在另一栖息地（Boulders Beach）的表现优于水泥巢箱。最新设计的双层陶瓷巢箱往往比其他人工巢箱表现更好，尽管并非在所有栖息地都一致，且部分区域占用率较低。实用意义：人工巢箱的部署被证明是保护非洲企鹅的成功措施，但不同栖息地的环境多样性似乎阻碍了“一刀切”方案的实施。所有巢箱类型在部分区域（西蒙斯镇大陆栖息地及阿尔戈阿湾岛屿栖息地）的繁殖产出持续低下（低于30%），这进一步要求制定超越人工巢箱的栖息地特异性保护策略；而全球非洲企鹅数量的持续下降迫切需要更广泛措施，主要是增加其摄食鱼类猎物的可获得性。