Figure 5.
More new neurons are found in the chickadee hippocampus (solid bar) than in the house sparrow hippocampus (open bar) in both spring and autumn. There was no difference between autumn and spring in hippocampal neurogenesis in chickadees in this study. (a) The density of new hippocampal neurons per mm3, (b) the number of new hippocampal neurons and (c) the per cent of all hippocampal neurons that are new. Birds received BrdU the day following capture and were sacrificed 6 weeks later. Sample sizes are: autumn chickadees, n = 9; autumn house sparrows, n = 5; spring chickadees, n = 6; spring house sparrows, n = 4. For differences between species on all measures, F1,20 > 6.3, p < 0.02. Asterisks indicate significant differences by post hoc tests p < 0.05. Error bars = ±1 s.e.m. Adapted from Hoshooley & Sherry (2007).