Nest characteristics, egg attributes, and hatching success of river lapwing, Vanellus duvaucelii

We studied the nest characteristics, egg attributes, and hatching success of globally “Near-threatened” river lapwing, Vanellus duvaucelii , in four habitat types in northern India during four consecutive breeding seasons (2016‒2019). Out of a total of 300 nests, most of them were found in medium-sized colonies (3‒4 nests), openly on sandy ground with shallow scrape (70%, n = 210) and others were lined with wood twigs and dry stems (30%, n = 90). The mean clutch size was 3.37 ± 0.86, although there was no significant difference in mean clutch size and egg size in different years and habitat types. Moreover, there was slight difference in clutch size and egg volume during the breeding season. The median incubation period was 28 days. Hatching was synchronous and completed one after the other within 24 h. Hatching success varied in different years and habitat types. Hatching success was high in 2018 at open unvegetated river bank compared to other habitats and years, as egg laying period and probability of egg survival were high. Moreover, hatching success rate significantly varied across the habitats and years. Results of generalized linear model analysis revealed that factors that affect daily predation rate were most closely related to habitat of nesting, distance to river bank, nearest nest location, and egg laying date. Egg failure occurred predominantly due to predation and farming activities. Furthermore, trampling, human disturbance, and egg non-viability were other factors responsible for egg loss.