Cuttings
The voles seek particularly the tender heads of grasses and the terminal leaves of sweet clover (Melilotus alba). To obtain these parts, the voles begin by cutting through the base of the plant. The surrounding plants are often near enough to support the freshly cut piece in an upright position. The vole makes successive cuttings, 40 or 50 millimeters from the ground, until the desired parts of the plant are within reach. The cuttings that have accumulated at the base of the plant may be eaten, but frequently they remain as evidence of the vole's feeding activity.
On May 12, 1946, an analysis was made of the cuttings found in an area of alfalfa, grasses, and weeds. From [table 1] it may be seen that quackgrass, alfalfa, wild lettuce, and cleavers were common. In three nights 70 traps caught 8 prairie voles and 3 deer mice; no pine mice or cotton rats were caught on the area. The stomachs of the voles and the deer mice were examined, and only the stomachs of the voles contained green material. Analysis of the cuttings (see [table 2]) indicates that alfalfa was eaten in greater quantity than any other plant; it made up almost three quarters of the cuttings although but one quarter of the cover. All other plants occurred less commonly in the piles of cuttings than they did in the estimated composition of the cover. Grasses and wild lettuce were next to alfalfa in importance.
Table 1.—The Relative Abundance of Plants in an Area of Alfalfa, Grasses, and Weeds[A]
| Species | Percentage by number of plants |
|---|---|
| Quackgrass (Agropyron repens) | 30 |
| Speargrass (Poa annua) | 01 |
| California brome (Bromus carinatus) | 01 |
| Smooth brome (Bromus inermis) | 01 |
| Alfalfa (Medicago sativa) | 25 |
| Peppergrass (Lepidium densiflorum) | 02 |
| Cleavers (Galium aparine) | 15 |
| Wild lettuce (Lactuca scariola) | 25 |
Table 2.—Composition of Ten Piles of Cuttings[B]
| Species | Ten piles of cuttings | Frequency of occurrence | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Agropyron repens | 1 | 0 | 0 | 2 | 0 | 0 | 6 | 19 | 0 | 4 | 13 |
| Poa annua | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 00 |
| Bromus carinatus | 0 | 0 | 0 | 0 | 0 | 10 | 0 | 0 | 0 | 0 | 04 |
| Bromus inermis | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 00 |
| Medicago sativa | 40 | 14 | 30 | 30 | 31 | 5 | 0 | 0 | 21 | 4 | 73 |
| Lepidium densiflorum | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 00 |
| Galium aparine | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 01 |
| Lactuca scariola | 6 | 2 | 1 | 2 | 5 | 0 | 0 | 0 | 2 | 4 | 09 |
[A] Analysis made on May 12, 1946, on an area 20 × 80 yards, at Lawrence, Kansas.
[B] Each of the first ten vertical columns gives the composition of one pile of cuttings. The last column gives the percentage of occurrence in the piles of cuttings of each species of plant in the area. Place and date for data in table 2 same as for table 1.
Approximately one out of every ten voles caught in snap traps had a piece of plant in its mouth. Occasionally a vole took a piece of food into a live trap. Evidently the food is not always eaten where it is procured. Grasses of the genus Poa are the kinds most frequently found in the mouths of dead voles. Bromus carinatus, B. inermis and sweet clover (Melilotus alba) were found in the runways. The pulpy fruit of the horse nettle (Solanum carolinense) was found partly eaten, especially near the entrances to underground passages.