This is an NDVI anomaly image, displayed in grayscale, of the Channel Islands for May 2007. This image was produced by averaging May NDVI 2003-2012 per pixel and subtracting this average image from each observation to produce a difference image. This park region experienced a severe winter drought 2006-2007 that persisted into spring, and severely impacted orange-crowned warbler (Oreothlypis celata) breeding that season (Langin, et al., 2009). However, the drought and avian response differed by island, and affected oak leaf-out. Langin (et al. 2009) did not have the data to formally compare leaf-out across the islands, but measured only 34% of oaks with new leaves by April 2007 on Santa Catalina Island, compared with a qualitatively higher proportion on Santa Cruz. This is reflected in the differential NDVI anomaly values of random points chosen from the center of the islands in this image; -0.0616 below average for Santa Cruz and -0.1251 below average for Santa Catalina. Visually, you can see the darker pixels of Santa Catalina Island, as compared with the lighter pixels of Santa Cruz.