Early springs and breeding performance in two sympatric duck species with different migration strategies

Abstract

The capacity of migratory species to adapt to climate change may depend on their migratory and reproductive strategies. For example, reproductive output is likely to be influenced by how well migration and nesting are timed to temporal patterns of food abundance, or by temperature variations during the brood rearing phase. Based on two decades (1988–2009) of waterfowl counts from a boreal catchment in southern Finland we assessed how variation in ice break‐up date affected nesting phenology and breeding success in two sympatric duck species, Mallard Anas platyrhynchos and Eurasian Teal Anas crecca. In Fennoscandia these species have similar breeding habitat requirements but differ in migration distance; Teal migrate roughly seven times as far as do Mallard. Annual ice break‐up date was used as a proxy of spring ‘earliness’ to test the potential effect of climate change on hatching timing and breeding performance. Both species were capable of adapting their nesting phenology, and bred earlier in years when spring was early. However, the interval from ice break‐up to hatching tended to be longer in early springs in both species, so that broods hatched relatively later than in late springs. Ice break‐up date did not appear to influence annual number of broods per pair or annual mean brood size in either species. Our study therefore does not suggest that breeding performance in Teal and Mallard is negatively affected by advancement of ice break‐up at the population level. However, both species showed a within‐season decline in brood size with increasing interval between ice break‐up and hatching. Our study therefore highlights a disparity between individuals in their capacity to adjust to ice break‐up date, late breeders having a lower breeding success than early breeders. We speculate that breeding success of both species may therefore decline should a consistent trend towards earlier springs occur.

Population change in breeding boreal waterbirds in a 25‐year perspective: What characterises winners and losers?

“…The finding that local increases were associated with early breed- Among European ducks, it has been found that mallard, common teal, and common goldeneye, which are all early-nesting species, are capable of adjusting their timing of breeding to temporal variation in spring thaw (Arzel et al, 2014;Clark, Pöysä, Runko, & Paasivaara, 2014;Oja & Pöysä, 2007). With this capacity in mind, and considering that ice-out dates of lakes have advanced in northern Europe (e.g.…”

Changes in the proportion of young birds in the hunting bag of Eurasian wigeon: long-term decline, but no association with climate

“…On the other hand, Arzel et al (2014) did not find adverse effects of precipitation and low temperature during the first week after hatching on brood size, a measure of breeding success, in mallard and teal in a study conducted in southern Finland.…”

Movement ecology of five Afrotropical waterfowl species from Malawi, Mali and Nigeria

“…Finally, the ability of migratory species to adapt to climate change may depend on their movement ecology (Arzel et al 2014). The majority (85%) of precipitation in the Sahel of West Africa falls from July to September (Zwarts et al 2009), and climate-induced changes to temperatures and the frequency, timing and quantity of rainfall may greatly alter their habitat availability.…”