Factors affecting the distribution, abundance and chick survival of the Lapwing ( Vanellus vanellus )

• Main Author: Sheldon, Robert David
• Format: Thesis
• Language: unknown
• Published: The Open University 2003
• Subjects: Vanellus vanellus
• Online Access: https://dx.doi.org/10.21954/ou.ro.0000f741; http://oro.open.ac.uk/id/eprint/63297

This thesis was conducted to investigate Lapwing Vanellus vanellus breeding ecology and its relationship with the modern agricultural landscape. Scientific research has suggested that changes in modern agricultural practices have been responsible for the declines in a suite of farmland bird species, including the Lapwing. Fieldwork was conducted over the breeding seasons of 1999 and 2000 over a range of farm locations in Shropshire and Staffordshire, with additional supplementary data obtained from a parallel study undertaken in Cambridgeshire. This research assessed the effectiveness of the ‘Lapwing Option’ (Option IB) in the pilot Arable Stewardship agrienvironment scheme. A total of 225 nests were located and monitored. There were few detectable effects of agricultural variables on clutch size, egg volume, intra-clutch egg size variation or hatching rates. Cultivation dates stipulated by Option IB avoided the peak nesting period for this population of Lapwings. At the start of the breeding season Lapwings selected a wide variety of crop types as nest sites, however, crop choice declined as the season progressed, with the majority of replacement nests on Option IB and spring crops. Lapwings were shown to select nest-sites that had a short, patchy sward structure. Nest survival was high, yet the most common causes of nest failure were predation and losses to agricultural operations. Losses on stubbles and spring cereals were primarily associated with agricultural operations. Nests that were greater than 50m distant fi*om a field boundary had a greater probability of survival than nests that were less than 50m away. Chick weight and condition were shown to be positively correlated with mean egg volume. There was no evidence that any of the measured agricultural variables had an effect on chick growth, condition or survival. Results show that chick survival was low and productivity estimates were less than that required to maintain population stability. Chicks that were known to have fledged had a better body condition index than chicks that had been predated. It was found that the variety of crop types used as foraging habitat declined as the season progressed. Option IB, set- aside and sugar beet were the latest crops that could be utilised by chicks. A variety of invertebrate taxa were found in faecal samples of chicks, with earthworms, beetles and spiders the most frequent. There was a positive relationship between the number of earthworms in the diet and chick age, chick condition and daily growth rates. Option IB appears to have a number of benefits for breeding Lapwing, although it does not address low chick survival. Further research is required to elucidate the key factors affecting chick survival and to develop management prescriptions to enhance breeding productivity.