Contrasting effects of the onset of spring on reproductive success of Arctic-nesting geese

• Published in: The Auk
• Main Authors: Nolet, B.A., Schreven, K.H.T., Boom, M.P., Lameris, Thomas
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: national; Plan_S-Compliant_NO; Arctic
• Online Access: https://pure.knaw.nl/portal/en/publications/76d2a39b-ca2c-4f39-87a6-91a751ae3c9f; https://doi.org/10.1093/auk/ukz063; https://hdl.handle.net/20.500.11755/76d2a39b-ca2c-4f39-87a6-91a751ae3c9f; https://pure.knaw.nl/ws/files/11389898/6803_Nolet_AM.pdf

Breeding output of geese, measured as the proportion of juveniles in autumn or winter flocks, is lower in years with a late onset of spring in some species, but higher in at least one other species. Here we argue this is because the timing of spring affects different stages of the reproductive cycle differently in different species. Because the effects on two different stages are opposite, the combined effects can result in either a positive or a negative overall effect. These stages are the pre-laying, laying and nesting phase on the one hand, and the hatchling, fledgling and juvenile phase on the other hand. The first phase is predominantly positively affected by an early snowmelt, with higher breeding propensity, clutch size and nest success. The second phase on the other hand is negatively affected by early snowmelt, because of a mismatch with a nutrient food peak, leading to slow gosling growth and reduced survival. We argue that recognition of this chain of events is crucial when one wants to predict goose productivity and eventually goose population dynamics. In a rapidly warming Arctic, the negative effects of a mismatch might become increasingly important.