COMPARISON OF SIMULATED GROUND NEST TYPES FOR GRAZING TRAMPLING RESEARCH/

Ornithologists often nse simulated nests consisting of game bird or do mestic poultry eggs to study nest survival. Researchers investigating cattle trampling of ground nests have sometimes used clay targets inst ead of actual eggs to avoid the confounding effects of nest depredatio n. To determine whether livestock respond similarly to clay targets an d egg nests, we compared inadvertent trampling and intentional disturb ance of clay targets versus clutches of 3 pheasant eggs by Angus x Hol stein heifers, Overall trampling levels for clay target- and egg-nests were similar (35 and 36%, respectively), Cattle noticed and responded to both types of nests. When noticed, simulated nests were kicked, sn iffed, licked, or picked up in the mouth, Cattle disturbed an average of 25% of the clay targets and 8% of the egg nests during 4 trials. Ou r results suggest that cattle are as likely to inadvertently trample e gg nests as they are clay targets, but targets are more likely to attr act attention and are therefore disturbed more often than egg nests. T he greater likelihood of intentional disturbance of clay targets by ca ttle reduces the confidence of extrapolating the fate of this type of simulated nest to that of actual nests.