A Migratory Northern Ungulate in the Pursuit of Spring: Jumping or Surfing the Green Wave?

摘要: AbstractThe forage-maturation hypothesis (FMH) states that herbivores migrate along a phenological gradient of plant development in order to maximize energy intake. Despite strong support for the FMH, actual relationship between phenology and ungulate movement has remained enigmatic. We linked (MODIS–normalized difference vegetation index [NDVI] data) space use 167 migratory 78 resident red deer (Cervus elaphus), using space-time-time matrix “springness,” defined as instantaneous rate green-up. Consistent with migrants experienced substantially greater access early than did residents. Deer were also more likely areas where migration led gains springness. Rather “surfing green wave” during migration, moved rapidly from winter summer range, thereby “jumping wave.” However, and, lesser degree, residents track green-up through ...