Do Arctic breeding geese track or overtake a green wave during spring migration?
Geese breeding in the Arctic have to do so in a short time-window while having sufficient body reserves. Hence, arrival time and body condition upon arrival largely influence breeding success. The green wave hypothesis posits that geese track a successively delayed spring flush of plant development on the way to their breeding sites. The green wave has been interpreted as representing either the onset of spring or the peak in nutrient biomass. However, geese tend to adopt a partial capital breeding strategy and might overtake the green wave to accomplish a timely arrival on the breeding site. To test the green wave hypothesis, we link the satellite-derived onset of spring and peak in nutrient biomass with the stopover schedule of individual Barnacle Geese. We find that geese track neither the onset of spring nor the peak in nutrient biomass. Rather, they arrive at the southernmost stopover site around the peak in nutrient biomass, and gradually overtake the green wave to match their arrival at the breeding site with the local onset of spring, thereby ensuring gosling benefit from the peak in nutrient biomass. Our approach for estimating plant development stages is critical in testing the migration strategies of migratory herbivores.
1] Ministry of Education Key Laboratory for Earth System Modeling, and Center for Earth System Science, Tsinghua University, Qinghuayuan 1, 100084, Beijing, China [2] Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, S10 2TN Sheffield, UK.
Yali
Y
Si
Ministry of Education Key Laboratory for Earth System Modeling, and Center for Earth System Science, Tsinghua University, Qinghuayuan 1, 100084, Beijing, China.
Qinchuan
Q
Xin
Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands.
Willem F
WF
de Boer
Ministry of Education Key Laboratory for Earth System Modeling, and Center for Earth System Science, Tsinghua University, Qinghuayuan 1, 100084, Beijing, China.
Peng
P
Gong
Department of Biological Sciences, Centre for Wildlife Ecology, Simon Fraser University, V5A 1S6 Burnaby, BC, Canada.
Ronald C
RC
Ydenberg
Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands.
Herbert H T
HH
Prins
D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001110:Arctic Regions; D018533:Biomass; D001947:Breeding; D017753:Ecosystem; D005260:Female; D005777:Geese / Q000502:physiology*; D060434:Herbivory / Q000502:physiology; D008297:Male; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D013997:Time Factors