COMPARATIVE ANALYSIS OF BURROW SYSTEMS OF SEVEN SPECIES OF POCKET GOPHERS (RODENTIA: GEOMYIDAE)

Burrow systems of 43 individuals representing 7 species of pocket gophers (Geomyidae) in Texas (Geomys breviceps, G. bursarius, G. personatus, G. texensis, Thomomys bottae) and Jalisco, Mexico (Cratogeomys fumosus, Pappogeomys bulleri) were excavated, measured, described, and compared. All burrow systems consisted of a main tunnel with several to many side branches. Burrow systems of most species included chambers serving as nest sites, food caches, and latrines. Vertically oriented spiral tunnels are reported for the first time for G. breviceps, G. texensis, and C. fumosus. Regression analyses revealed that mean tunnel depths and diameters varied significantly by species in direct relation to body size. Mean length of tunnel systems varied significantly by species (longest in G. breviceps and shortest in T. bottae), but variation was not correlated with body size.