Open Access Thesis
Arthropoda--Geographical distribution--Iowa--Delaware County; Pocket gophers--Habitat--Iowa--Delaware County; Coexistence of species--Iowa--Delaware County;
Pocket gophers are among the most asocial mammals, living a solitary existence except for mating and the rearing of offspring. They create expansive burrow systems underground while foraging for food and rarely surfacing above ground. As gophers burrow, excess soil is pushed to the surface or placed in older tunnels. This behavior creates a cave-like ecosystem where pocket gophers and associated arthropods live.
Few studies have been done on the arthropod fauna cohabitating with pocket gophers in these burrows. Most of these studies have focused on a family of arthropods over several sites. Many have focused on the southern United States, with few studies done in the Midwest (Minnesota, Nebraska, Wisconsin, Indiana).
I examined the arthropods living in Geomys bursarius burrow systems in northeast Iowa.I located a local farm with land in Conservation Reserve Program with a Plains pocket gopher population. There were two prairies with G. bursarius, and samples were taken from burrow systems in both during late July 2015. At each burrow system, I placed a control cup above ground and 3 cups inside the burrow system as a pitfall trap with molasses as bait. In Prairie 1, five G. bursarius burrow systems were sampled, yielding a total of 20 sample cups per day for each of three days. In Prairie 2 three burrow systems were sampled with 12 sample cups per day for three days. In July 2016, more samples were taken from Prairie 1with a focus on two pocket gopher burrows. The same method was used as the previous year, with samples collected for three days.
Through my study, I identified 19 species of macroinvertebrates associated with pocket gopher burrows. An additional eight macroinvertebrates were identified to genus level and nine more were identified to family level. In total, these macroinvertebrates belonged to 24 families, representing a diverse set of cohabitants within the burrows of pocket gophers. Several of the species identified were new local records for Delaware County: Ceuthophilus divergens, Ceuthophilus latens, Anisodactylus ovularis, Harpalus erraticus, Glischrochilus quadrisignatus, Pericompsus ephippiatus, Foxella ignota, Dendrophilus sexstriatus, Geomydoecus geomydus. One species, Stictolinus flavipes, was the first documented in the state. Previously S. flavipes had been identified as far west as Illinois and Wisconsin (Klimaszewski et al. 2005). Twelve species of macroinvertebrates were identified solely within (and not outside) the burrows. While some of these could have entered the opened burrows during the course of this experiment, each of these species may represent specialized burrow inhabitants.
Year of Submission
Master of Science
Department of Biology
John Ophus, Chair, Thesis Committee
1 PDF file (vi, 45 pages)
©2021 Brett Gourley
Gourley, Brett Lyle, "Arthropod fauna of Plains pocket gopher (Geomys bursarius) burrow systems" (2021). Dissertations and Theses @ UNI. 1077.