Does climate change explain the decline of a trans-Saharan Afro-Palaearctic migrant?

Abstract

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.

Survival of Afro‐Palaearctic passerine migrants in western Europe and the impacts of seasonal weather variables

“…), Common Sandpiper Actitis hypoleucos (Pearce‐Higgins et al . ) and Red Knot Calidris canutus (Baker et al . ).…”

Using diet to assess the sensitivity of northern and upland birds to climate change

“…Many such species find their southern range margins in the uplands of the UK, where they occupy unenclosed moorland, grassland and blanket bog habitats and comprise an internationally important bird community (Thompson et al 1995). Recent population trends of the rarest of these species indicate that they have declined as climatic suitability is reduced , and there is evidence for others being vulnerable to climate change (Cattadori et al 2005, Beale et al 2006, but see Pearce-Higgins et al 2009b). For one species, the golden plover Pluvialis apricaria, warming may result in population declines mediated through reductions in the abundance of tipulid prey (Pearce-Higgins et al 2010), matching the principles outlined above for seabirds and insectivorous woodland birds.…”

Advanced Autumn Migration of Sparrowhawk Has Increased the Predation Risk of Long-Distance Migrants in Finland

“…The decline of LDM has been argued to be related to increased mismatches during arrival and breeding leading to hampered breeding success [7], [8], [38], [39] whereas declining wintering or stopover conditions are causing lower survival of fully grown birds [19], [21]. The results of this paper show that LDM are facing increasing problems also during autumn migration.…”

“…LDM are displaying more general declines in population densities compared to SDM [19], [20], [21], whose populations have typically remained stable or even increased [20], [22]. The predator/prey ratio did not show decreasing trend in SDM even though their migration season overlaps less with sparrowhawks.…”

“…Migration is already demanding and risky [36], and it is becoming increasingly risky as predator densities increase [29]. Increasing predation risk combined with worsening stopover conditions [21] could entail crucial negative impacts on survival.…”