Living the high life: remarkable high‐elevation records of birds in an East African mountain range

The way organisms cope with the dual threat of habitat and climate change varies across species and locations. Among birds, we see that some species move their ranges instead of adapting to new climatic and environmental conditions, for example, by moving up the slope of mountains or toward higher latitudes. However, we can only detect such shifts in species’ distributions if we are able to compare past to current ranges. This is a problem in the tropics, where there is a lack of baseline data on a host of ecological processes and patterns, including simple distributional records (Collen et al. 2008). The Afrotropical Albertine Rift is recognized for its biological diversity and has long been the focal area for biological research (Plumptre et al. 2007). Nevertheless, some parts and certain denizens of this largely mountainous region are still little studied. For example, although the birds of Volcanoes National Park (Rwanda) in the Virunga Massif (in the central Albertine Rift) have been the topic of previous short‐term surveys and inventories (most of which are opportunistic surveys, summarized in Vande Weghe and Vande Weghe 2011, though Owiunji et al. 2005 used both point counts and mist‐netting), they are hard to monitor intensively because of a challenging combination of rough terrain, elevations over 4,000 m above sea level (a.s.l.), and logistic restrictions. In recent years, we made an effort to establish a continuous bird monitoring program in the region, with the objective to provide a host of novel insights in species’ ecologies at high elevations. And indeed, we made astonishing discoveries, including that many birds occurred hundreds of meters above the elevations they were “likely to” be found (Fig. 1). Now, though new distributional records of one or a few species may be interesting, they do not constitute particularly groundbreaking observations—unless they showcase a particularly large extension of a species’ range, induce a complete shift of understanding of the avifauna of a particular region, or have some direct management or conservation impact. Our new observations apply to all of the above. Between 2013 and 2019, we sampled all of Volcanoes National Park up to 4,303 m a.s.l., across a vegetation gradient that stretches from bamboo and mixed forest at low elevations (~2,400–2,800 m) to high‐elevation meadows and stands of Lobelia and Rubus shrubs (for Methods see Appendix S1 and Derhé et al. 2019). We recorded 132 species during these sampling efforts, of which a remarkable large number were found at elevations well above their