Habitat-Dependent Provisioning Patterns Are Modulated by Weather Conditions in a Rapidly Declining Farmland Raptor.

Agricultural intensification and concomitant reduction in high-quality habitats represent one of the major threats to farmland biodiversity in Europe. The Little Owl Athene noctua is an avian farmland predator whose population rapidly declined across many European countries. Food limitation during the breeding season has been considered a key factor driving this decline. However, it remains unclear how the quality of agricultural habitats affects parental food provisioning across different Little Owl populations. In addition, little is known about how weather conditions may modulate provisioning patterns dependent on habitat quality. Using nestbox cameras, we monitored parental food provisioning of Little Owls in four European countries with contrasting farmland structure (Czechia, Slovakia, Germany, Netherlands), covering 40 nests and 58 broods during the period 2002-2022. In particular, we investigated the interacting effects of habitat quality within Little Owl territories and weather conditions on parental food provisioning and nestling diet. Across all countries, provisioning rate and biomass increased with the area of high-quality habitats, showed a quadratic relationship with temperature, and decreased with wind speed. Additionally, high-quality habitats, compared with low-quality habitats, acted as a buffer against adverse weather, allowing parents to provision more biomass at low temperatures and increase provisioning rates at high wind speeds. The changes in prey composition due to poor weather conditions differed considerably between habitats of high and low quality, suggesting that under poor conditions, Little Owls are able to access more insects and voles in high- than low-quality habitats. Our findings highlight that increasing the area of high-quality habitats, hand in hand with enhancing habitat heterogeneity within Little Owl territories, should represent the prime conservation activity to reduce the risk of food limitation across contrasting farmlands, particularly under poor weather conditions.