GABB: A global dataset of alpine breeding birds and their ecological traits

Abstract

Alpine ecosystems represent varied climates and vegetation structures globally, with the potential to support rich and functionally diverse avian communities. High mountain habitats and species are under significant threat from climate change and other anthropogenic factors. Yet, no global database of alpine birds exists, with most mountain systems lacking basic information on species breeding in alpine habitats, their status and trends, or potential cryptic diversity (i.e., sub-species distributions). To address these critical knowledge gaps, we combined published literature, regional monitoring schemes, and expert knowledge from often inaccessible, data-deficient mountain ranges to develop a global list of alpine breeding bird species with their associated distributions and select ecological traits. This dataset compiles alpine breeding records for 1,310 birds, representing 12.0% of extant species and covering all major mountain regions across each continent, excluding Antarctica. The Global Alpine Breeding Bird dataset (GABB) is an essential resource for research on the ecological and evolutionary factors shaping alpine communities, as well as documenting the value of these high elevation, climate-sensitive habitats for conserving biodiversity.

Rock cavity nesting as the norm: Breeding songbirds of the temperateHighAndes

“…Using a global dataset of alpine breeding birds (de Zwaan et al, 2022a(de Zwaan et al, , 2022b, we found that the proportion of passerines nesting in rock cavities was greater in the southern Andes (this study site; 54%; 13 of 24 species) than in other major temperate alpine communities globally (excluding species that breed above treeline rarely or incidentally). In the southern ranges of Europe (e.g., Alps, Pyrenees, Carpathians), 39% (12 of 31) of alpine breeding passerines nest in rock cavities, compared with 24% (9 of 38) in the coastal and Rocky Mountains of North America, and 22% (26 of 117) on the Qinghai-Tibetan Plateau.…”

“…We also provide natural history notes on breeding phenology, parental care, and resource competition to provide a baseline for future studies to build on within these data-deficient communities (Table 1). Finally, we compare the predominance of rock cavity-nesting species above treeline in the temperate Andes with other temperate alpine songbird communities using a global alpine breeding bird dataset (de Zwaan et al, 2022a(de Zwaan et al, , 2022b and generate a hypothesis framework for investigating variation in nest traits among alpine communities.…”

“…Alpine habitats are defined as the area above the climatic treeline where vegetation growth is limited to cold‐tolerant grasses and forbs, low‐lying shrubs, or small patches of stunted trees <3 m in height, resulting in less diverse niche space relative to below the treeline (Körner, 2012 ; Körner et al, 2011 ). Despite these constraints, as well as limited habitat availability above treeline relative to the total landmass (Nagy & Grabherr, 2009 ; Testolin et al, 2020 ), ~12% of bird species breed in alpine habitats (de Zwaan et al, 2022a ).…”

“…The alpine breeding bird community in the southern Andes consists of ecologically and evolutionarily distinct species relative to lower elevations and other alpine communities globally (Altamirano et al, 2020 ; Martin et al, 2021 ). The underlying factors that drive the predominance of rock cavity‐nesting behavior in alpine breeding birds of the temperate Andes is an intriguing question that could yield insights into the evolution and maintenance of life‐history strategies in these rapidly changing environments (de Zwaan, Barras, et al, 2022 ). Here, we outline several nonmutually exclusive hypotheses that may explain the particularly high proportion of rock cavity nesters in the temperate Andes.…”

Variable choice affects estimations of vulnerability to climate change

“…Further, Rockjumpers fulfil multiple criteria necessary to be considered an indicator species for the adverse effects of climate change (see Carignan & Villard 2002). For instance, they occur only on continental sky islands (McCormack et al 2009), are probably climate relicts (Woolbright et al 2014), and they show a high degree of habitat specialization and restriction, in common with many mountain endemics (Scridel et al 2018, de Zwaan et al 2022. Additionally, they appear unable to shift their range if current habitat becomes thermally unsuitable (Kupfer et al 2005), and their Mountain Fynbos habitat is at high risk of size reduction from climate change (Simmons et al 2004).…”