Does the breeding biology of the Eurasian Stone-curlew Burhinus oedicnemus in south-western Morocco differ between grazed steppe and irrigated farmland?

Birds associated with steppe and pseudosteppe habitats are one of the most threatened avian communities in Europe, given their recent decline due to agriculture intensification and land abandonment. Large-scale conversion of natural and rural areas into irrigated farmlands is ongoing in North Africa, but the effects of this habitat modification on steppe bird species are not investigated. In this study, we investigated the breeding biology of the Eurasian Stone-curlew nesting in grazed steppe and irrigated farmlands in south-western Morocco. Breeding parameters were collected during 2017 and 2018 breeding seasons on 59 nests. Egg volume was significantly bigger in grazed steppes than in irrigated farmlands (37.3 ± 2.30 cm3 vs 35.1 ± 2.11 cm3, average ± SD), possibly due to greater food availability in the former habitat. On the other hand, daily nest-survival did not differ between nesting habitats and it was quite high (nest survival over the incubation period: 0.85 [95% CI: 0.71-0.93]) even when compared to the data available for other regions. This result suggests that agricultural intensification in the area did not affect the likelihood of nest failure. Our data provide one of the few available evidence regarding the effect of breeding habitat on the reproductive biology of the Eurasian Stone-curlew in the southern range of its distribution.