Biometric data (wing length, tail length, head + bill, maximum tarsus) were collected from 255 individual Skylarks in winter at Musselburgh on the Lothian coast. Winglength and head+bill were measured most consistently by a single operator in the field. Winglength and tail length measurements were polymodally distributed, which allowed most birds to be allocated a sex class. Variation in the pattern of streaking of the under-tail coverts was noted, and is thought to represent individuality in plumage, although there may be an age-related bias in UTC streaking in males, which would repay further investigation. There were no significant differences from unity in the ratios of males to females caught in each of three winters with 'normal' weather, but in the one winter of severe weather, significantly more females than males were caught. From this 'cold' winter, there were significantly more retraps in later zuinters of birds caught during normal winter weather than of birds caught during severe weather. The only distant movements (three) reported were from the cold winter. Skylarks at Musselburgh appear to be rather site-faithful between winters. Results of the study are compared to those few from elsewhere, and it may be that nomadic flocks of Skylarks in winter, especially during spells of severe weather, are comprised largely of females, which are probably immatures.

There is an urgent need to understand how climate change will impact on demographic parameters of vulnerable species. Migrants are regarded as particularly vulnerable to climate change; phenological mismatch has resulted in the local decline of one passerine, whilst variations in the survival of others have been related to African weather conditions. However, there have been few demographic studies on trans-Saharan non-passerine migrants, despite these showing stronger declines across Europe than passerines. We therefore analyse the effects of climate on the survival and productivity of common sandpipers Actitis hypoleucos, a declining non-passerine long-distant migrant using 28 years' data from the Peak District, England. Adult survival rates were significantly negatively correlated with winter North Atlantic Oscillation (NAO), being lower when winters were warm and wet in western Europe and cool and dry in northwest Africa. Annual variation in the productivity of the population was positively correlated with June temperature, but not with an index of phenological mismatch. The 59% population decline appears largely to have been driven by reductions in adult survival, with local productivity poorly correlated with subsequent population change, suggesting a low degree of natal philopatry. Winter NAO was not significantly correlated with adult survival rates in a second, Scottish Borders population, studied for 12 years. Variation in climatic conditions alone does not therefore appear to be responsible for common sandpiper declines. Unlike some passerine migrants, there was no evidence for climate-driven reductions in productivity, although the apparent importance of immigration in determining local recruitment complicates the assessment of productivity effects. We suggest that further studies to diagnose common sandpiper declines should focus on changes in the condition of migratory stop-over or wintering locations. Where possible, these analyses should be repeated for other declining migrants.

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