Does the Breeding Biology of the Eurasian Stone-Curlew Burhinus oedicnemus in South-Western Morocco Differ between Grazed Steppe and Irrigated Farmland?

Abstract

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 steppes and irrigated farmlands in south-western Morocco. Breeding parameters were collected during 2017 and 2018 breeding seasons on 59 nests. Egg volume was significantly higher 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 nestsurvival did not differ between 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. These results suggest that birds nesting in protected areas characterized by traditional pastoralism might find better conditions for reproduction which allow them to lay larger eggs. On the other hand, the ongoing process of agricultural intensification in the area does not seem to 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 Stone-curlew in the southern range of its distribution. Further data are needed in order to understand the conservation implication of our findings and in particular how the observed variability of egg size might affect chick quality and survival.

Conserving steppe-land birds under climate change: a gap analysis for the Eurasian Stone-curlew (Burhinus oedicnemus) in the Western Palearctic

“…Stone-curlews exploit agricultural areas with low vegetation density for breeding and foraging (Caccamo et al, 2011; Vaughan and Vaughan Jennings, 2005). Arid and steppic grasslands are among the elective habitats for the species (Green et al, 2000; Hume and Kirwan, 2013; Teyar et al, 2021; Vaughan and Vaughan Jennings, 2005) as well as low shrubs, often mixed with grass and bare ground (Traba et al, 2013; Vaughan and Vaughan Jennings, 2005). Finally, breeding attempts in urbanized areas are increasingly reported (Biondi et al, 2015; Cutini et al, 2007; Giovacchini et al, 2017).…”