Production and costs of nesting attempts in Snow Buntings Plectrophenax nivalis: why do they attempt second broods?

• Published in: Ibis
• Main Authors: SMITH, R. D., MARQUISS, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1995
• Subjects: Plectrophenax nivalis
• Online Access: http://dx.doi.org/10.1111/j.1474-919x.1995.tb03255.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1995.tb03255.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1995.tb03255.x

During 1988–1993, pairs of Snow Buntings Plectrophenax nivalis on our study sites in northeast Scotland reared an average of 1.2 broods. Clutch sizes of first and second broods were similar, but partial losses were greater in second broods, leading to a difference of at least 40% in overall nest productivity between successful first and second broods. Over and above this, total nest failure was four times higher in the second broods, and autumn sightings of ringed nestlings from second broods were only a third of those of first‐brood nestlings. As a result, second broods produced a mere 10% of future recruits to the breeding population. However, there was also little evidence of costs associated with producing, or attempting to produce, second broods. Young from first broods were not less likely to reach independence if a second brood was attempted, between‐year return rates of double‐brooded adults were similar to those of single‐brooded birds and double‐brooded adults did not appear to be less fecund in the following summer. Therefore low costs to the adults of attempting second broods may allow the continuation of a strategy which appears to have only a marginal influence on overall reproductive success in the area studied.