Insect and Mammal Sampling Methods for E014

Yearly since 1984, grasshoppers are sampled in the fields that have been abandoned. Collections in fields 22, 29, and 69 were only done in 1984 and 1989.

Grasshoppers are sampled in the old fields by taking sweep samples along the four transects. All fields are typically sampled in a two day period, when it has not rained. Fifty sweeps are taken on each 40 meter transect, and the contents for each transect are bagged separately. One sweep consisted of a single swing of a sweep net in one direction. Bagged samples are frozen until they can be processed. Grasshoppers are thawed and keyed to genus and species (where possible).  

Initially, sweep samples were taken once or twice during the summer, with the second sample taken in mid to late August. After thawing, these grasshoppers were weighed. Since 1988, samples are taken 4 times per year (June, July, August, and September) and no weights recorded.

Gopher mounds are counted in each old field during vegetation sampling. In 1983 and 1989 the number of mounds between transects in each field were counted.

In 1984 small mammals were trapped. Snap traps were baited with oatmeal/peanut butter and a trap placed at each stake (0, 10, 20, 30, 40, 50m). All transects in 1 field were trapped on the same night. One trapping session for 1 field consisted of 3 consecutive nights of trapping. Fields were trapped twice (2 sessions) in August and once in September.