The effect of seed size on reseeding in the presence of heteromyids

by: William G. Standley
ABSTRACT: Heteromyid rodents, the main granivores in southwestern deserts, selectively forage for large seeds. Therefore, I predicted that in habitats where these rodents are present, reseeding with small seeds should result in less predation than with large seeds. Small plots located in southeastern Arizona were reseeded with small and large seeds sown separately and together. Seed survival was monitored by sieving soil samples collected periodically until 36 days after planting. The number of small seeds removed by rodents was significantly lower (p<.05) than the number of large seeds removed within 3 days of planting, whether the seeds were planted separately or together. The rates of seed removal during the 36 day period were also significantly different (p<.05) for the different sized seeds whether planted separately or together. Thus, reseeding with small seeds can reduce predation by the heteromyid rodents living in this study area.
1985. Masters of Science thesis. University of Arizona, Tucson. 15 pp. Reprints are available from
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