Factors influencing nesting success of the river lapwing, Vanellus duvaucelii (Lesson, 826)

Nesting success is defined as the percentage of nests that have at least one chick that successfully fledges from them. In this regard, this study was conducted in the Gangetic plain of district Raebareli (Uttar Pradesh), India, to investigate nesting success, resolve factors affecting the probability of nest failure and identify the predominant nest predators of the river lapwing, Vanellus duvaucelii. The line transect method was adopted to count the nesting pairs, while nesting success was estimated by the Mayfield method. Results revealed that river lapwing nests were not homogeneously distributed at the study sites. The number of nesting pairs significantly diverged at various study sites in different years. Nesting success of river lapwings at all habitat types varied across the year of study from 67.9% in 2016, to 63.6% and 70.1 % in 2017 and 2018, respectively. In all years, river lapwing nests on open, unvegetated river banks achieved significantly greater nesting success than those in crop fields. However, nest failure was mainly due to predation (55%) and farming activity (32%). Furthermore, trampling (6%) by domestic castles such as cows and buffaloes, egg non-viability (4%), human disturbance (2%) and flooding (1 %) were reported as other notable factors influencing nest failure. We also found reptiles, birds and mammals as predators of eggs in the study areas. The most common predators were crow, dog, fox and snake. There is little information regarding factors influencing nesting success of river lapwings particularly in India and therefore this study increases our knowledge of this globally near-threatened species. Developing greater understanding of the river lapwing could help us to formulate effective conservation measures for this species.