Fig 1.
Red squirrel (Tamiasciurus hudsonicus) midden.
Photographs of (a) red squirrel (Tamiasciurus hudsonicus) midden cone-scale pile, (b) cached cones inside pit excavated by red squirrel, and (c) stored cones, which may number in the thousands at a single midden. Photo credit, E. E. Posthumus. Mt. Graham, Graham Co. Arizona, 2011–2012.
Fig 2.
Relationship between red squirrel residency rates and resources concentrated by red squirrels.
Relationship between resources concentrated by red squirrels, red squirrel residency during surveys, and residency rate (proportion of quarterly surveys during the previous five years) of red squirrels at middens, Mt. Graham, Graham Co. Arizona, 2011–2012.
Table 1.
Proportion of sites surveyed at which mammals and birds were observed.
Table 2.
Estimates ± standard errors and test statistics with associated P-values from models of species richness and abundance contrasting sites where red squirrel were and were not resident during surveys.
Table 3.
Parameter estimates, standard errors, and P-values from models assessing the importance of a red squirrel being resident and resources concentrated by red squirrels during surveys to species richness of mammals and birds.
Table 4.
Parameter estimates from models assessing the importance of resources concentrated by red squirrels and a red squirrel being resident during surveys to abundance of mammals and birds.