10An improved understanding of life history responses to current environmental variability is 11 required to predict species-specific responses to anthopogenic climate change. Previous research 12 has suggested that cooperation in social groups may buffer individuals against some of the negative 13 effects of unpredictable climates. We use a 15-year dataset on a cooperative-breeding arid-zone 14 bird, the southern pied babbler Turdoides bicolor, to test i) whether environmental conditions and 15 group size correlate with survival of young during three development stages (egg, nestling, 16 fledgling), and ii) whether group size mitigates the impacts of adverse environmental conditions 17 on reproductive success. Exposure to high mean daily maximum temperatures (mean Tmax) during 18 early development was associated with reduced survival probabilities of young in all three 19 development stages. No young survived when mean Tmax > 38°C across all group sizes. Low 20 reproductive success at high temperatures has broad implications for recruitment and population 21 persistence in avian communities given the rapid pace of advancing climate change. That impacts 22temperature and rainfall patterns have led to adjustments to the timing and success of 46 reproduction in some bird species [19,20]. For birds in arid environments, higher rainfall is often 47 associated with improved reproductive success [21,22], droughts are associated with reduced 48 reproductive success [23,24] and periods of very hot weather are typically associated with lower 49 nest survival rates [15,25] and nestling growth rates [26][27][28]. Therefore, it is reasonable to expect 50 that reproductive success and population persistence of birds in arid environments will be 51 impacted as regions become hotter and drier under climate change [29,30]. 52Cooperative breeding, where more than two individuals rear a single brood [31], occurs 53 in ~9% of bird species [32]. Reproductive benefits of cooperation include earlier fledging age 54 and more broods raised per season [33]; reduced costs of breeding for females [11,34]; enhanced 55 egg investment [35]; increased fledgling recruitment [17,36]; and the ability to raise overlapping 56 broods [12,37]. Global comparative studies suggest that cooperative breeding evolved in 57 unpredictable environments [38], facilitated the colonisation of such environments [39], or 58 prevented extinction under increasingly harsh conditions [40]. One prominent explanation for the 59 occurrence of cooperative breeding in birds in variable environments is that it represents a 'bet-60 hedging' strategy [38], whereby breeding individuals share the costs of reproduction with helpers 61 and are thus able to reduce interannual variation in reproductive success in response to 62 unpredictable rainfall and food availability [9]. This implies that cooperation might buffer 63 breeding attempts from failure during adverse environmental conditions [13,41]. 64 A likely mechanism underlying such benefits of cooperation is load-lightening...

Climate change is affecting animal populations around the world and one relatively unexplored aspect of species vulnerability is whether and to what extent responses to environmental stressors might be mitigated by variation in group size in social species. We used a 15‐year data set for a cooperatively breeding bird, the southern pied babbler Turdoides bicolor, to determine the impact of temperature, rainfall and group size on body mass change and interannual survival in both juveniles and adults. Hot and dry conditions were associated with reduced juvenile growth, mass loss in adults and compromised survival between years in both juveniles (86% reduction in interannual survival) and adults (60% reduction in interannual survival). Individuals across all group sizes experienced similar effects of climatic conditions. Larger group sizes may not buffer individual group members against the impacts of hot and dry conditions, which are expected to increase in frequency and severity in future.

An improved understanding of life-history responses to current environmental variability is required to predict species-specific responses to anthopogenic climate change. Previous research has suggested that cooperation in social groups may buffer individuals against some of the negative effects of unpredictable climates. We use a 15-year dataset on a cooperative breeding arid zone bird, the southern pied babbler Turdoides bicolor , to test (i) whether environmental conditions and group size correlate with survival of young during three development stages (egg, nestling, fledgling) and (ii) whether group size mitigates the impacts of adverse environmental conditions on survival of young. Exposure to high mean daily maximum temperatures (mean T max ) during early development was associated with reduced survival probabilities of young in all three development stages. No young survived when mean T max > 38°C, across all group sizes. Low survival of young at high temperatures has broad implications for recruitment and population persistence in avian communities given the rapid pace of advancing climate change. Impacts of high temperatures on survival of young were not moderated by group size, suggesting that the availability of more helpers in a group is unlikely to buffer against compromised offspring survival as average and maximum temperatures increase with rapid anthropogenic climate change.

Variation in weather patterns can influence reproductive effort and success not only within but also between breeding seasons. Where environmental conditions can be highly variable between years, the weather, and particularly extreme weather events such as heat waves and droughts, may exert a strong influence on reproductive effort (number of breeding attempts) and success (number of surviving young) from one breeding season to the next. We used a 15-year dataset for a cooperatively breeding bird, the southern pied babbler Turdoides bicolor, to determine the impact of high temperatures and drought on reproductive effort and success. We tested the influence on reproductive effort and success of mean daily maximum air temperature and drought both within a breeding season, to determine the relative importance of current conditions, and during the previous breeding season, to determine the relative importance of compensatory effects in response to prior conditions. Reproductive effort and success were lower during breeding seasons characterized by drought, and higher in the breeding seasons that followed droughts, but were not predicted by mean daily maximum temperatures measured over the full length of the breeding season. We provide evidence of compensatory breeding following drought in a bird species endemic to a semi-arid ecosystem and suggest that compensatory mechanisms may be an important part of both long-term population persistence and post-drought population recovery.

Climate change adds an additional layer of complexity to existing sustainable development and biodiversity conservation challenges. The impacts of global climate change are felt locally, and thus local governance structures will increasingly be responsible for preparedness and local responses. Ecosystem-based adaptation (EbA) options are gaining prominence as relevant climate change solutions. Local government officials seldom have an appropriate understanding of the role of ecosystem functioning in sustainable development goals, or access to relevant climate information. Thus the use of ecosystems in helping people adapt to climate change is limited partially by the lack of information on where ecosystems have the highest potential to do so. To begin overcoming this barrier, Conservation South Africa in partnership with local government developed a socio-ecological approach for identifying spatial EbA priorities at the sub-national level. Using GIS-based multi-criteria analysis and vegetation distribution models, the authors have spatially integrated relevant ecological and social information at a scale appropriate to inform local level political, administrative, and operational decision makers. This is the first systematic approach of which we are aware that highlights spatial priority areas for EbA implementation. Nodes of socio-ecological vulnerability are identified, and the inclusion of areas that provide ecosystem services and ecological resilience to future climate change is innovative. The purpose of this paper is to present and demonstrate a methodology for combining complex information into user-friendly spatial products for local level decision making on EbA. The authors focus on illustrating the kinds of products that can be generated from combining information in the suggested ways, and do not discuss the nuance of climate models nor present specific technical details of the model outputs here. Two representative case studies from rural South Africa demonstrate the replicability of this approach in rural and peri-urban areas of other developing and least developed countries around the world.