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1. The break-up of the Soviet Union in 1991 led to the abandonment of >40 million ha of cropland, a collapse in livestock numbers and the recovery of depleted biodiversity on the steppe grasslands of Kazakhstan and southern Russia. More recently, large-scale reclamation of abandoned cropland and intensification of agriculture are observed, highlighting a need for strategies to reconcile agricultural development and biodiversity. 2. We related bird densities along a land-use gradient to yield estimates from arable and livestock systems in central Kazakhstan to decide whether a land-sparing, a land-sharing or an intermediate strategy would result in the largest benefits for biodiversity. 3. For 'loser species' (whose population size is reduced by farming), land sparing was predicted to support higher total populations of more species than was land sharing, at all production targets. 'Winners' (species benefitting from agriculture) profited from land sharing when judged from food energy or protein. Intermediate yields were best for very few species. Heavily grazed steppe grassland was important for several globally threatened and biome-restricted species. 4. Government statistics suggested that over 50% of abandoned cropland has been reclaimed since 2000 and crop yields have increased. In the same period, there was significant progress towards the designation of new protected areas, but the total area in Kazakhstan still falls short of the Convention on Biological Diversity's 17% target. 5. Policy implications. Further increases in agricultural production are likely to reduce populations of most birds, especially if they are achieved by conversion of abandoned cropland, or grassland. Our results suggest that production increases would do least harm if they resulted from increasing the output of existing cropland, using approaches such as snow accumulation, no-till and more efficient grain harvesting and storage, rather than from further reclamation of abandoned land that is now reverting back to steppe. Production increases should be offset by improved conservation planning through the designation of protected areas on land potentially suitable for cropland expansion.

Temperate grasslands have suffered disproportionally from conversion to cropland, degradation and fragmentation. A large proportion of the world's remaining near-natural grassland is situated in Kazakhstan. We aimed to assess current and emerging threats to steppe and semi-desert biodiversity in Kazakhstan and evaluate conservation research priorities. We conducted a horizon-scanning exercise among conservationists from academia and practice. We first compiled a list of 45 potential threats.These were then ranked by the survey participants according to their perceived severity, the need for research on them, and their novelty.The highest-ranked threats were related to changes in land use (leading to habitat loss and deterioration), direct persecution of wildlife, and rapid infrastructure development due to economic and population growth. Research needs were identified largely in the same areas, and the mean scores of threat severity and research need were highly correlated. Novel threats comprised habitat loss by photovoltaic and wind power stations, climate change and changes in agriculture such as the introduction of biofuels. However, novelty was not correlated with threat severity or research priority, suggesting that the most severe threats are the established ones.Important goals towards more effective steppe and semi-desert conservation in Kazakhstan include more cross-sector collaboration (e.g. by involving stakeholders in conservation and agriculture), greater allocation of funds to under-staffed areas (e.g. protected area management), better representativeness and complementarity in the protected area system and enhanced data collection for wildlife monitoring and threat assessments (including the use of citizen-science databases).

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Since the collapse of the Soviet Union in 1991, the abundance and distribution of many central Asian steppe birds have been affected by changes in agricultural land management, such as the abandonment of large areas of cropland and changing grazing patterns. However, the underlying population processes that drive patterns of abundance and distribution are poorly understood. We compared the population ecology of the Black Lark Melanocorypha yeltoniensis on natural steppe and abandoned cropland. Between 2009 and 2013, we used distance sampling to quantify Black Lark population density, monitored 220 nests to assess reproductive performance, and modelled habitat selection at several scales. Arthropod food availability was compared using pitfall traps. Mean population densities were three times higher on abandoned cropland compared to those in steppe, and varied with time since abandonment. Nest survival rates were significantly lower on abandoned cropland compared to steppe, probably due to higher predation pressure. Chick growth rates were also lower on abandoned cropland, despite higher insect availability in this habitat. Habitat selection was strongly influenced by grazing intensity Communicated by Didem Ambarlı.Electronic supplementary material The online version of this article (and vegetation structure. We suggest that Black Larks are generally attracted to abandoned cropland because of its suitable vegetation structure and higher food availability. The results of a fecundity model suggested that the number of breeding attempts on abandoned cropland necessary to produce the same number of fledglings as one nesting attempt in steppe habitat was 2.04 in 2011 and 3.62 in 2013. However, a phenological analysis revealed that there were only two peaks in first egg dates, making more than two re-nesting attempts per year unlikely. Therefore, abandoned cropland could, at least in some years, be an ecological trap for the species. Our results illustrate that the effects of land-use change on animal populations should not only be assessed using species densities, but also incorporate detailed demographic analyses. If current densities in steppe habitat corresponded to maximum carrying capacity, overall population densities of Black Larks are likely to decline in the near future as availability of abandoned cropland as nesting habitat is currently decreasing.