As part of efforts to develop The Livestock Protection Collar (U .S. EPA Reg. No. 56228-22), we videotaped sheep-predation events by 23 (15 male and 8 female) wild-caught, confined coyotes (Canis latrans) in a 31 × 41-m enclosure. Coyotes were paired individually with a sheep (Ovis aries) during 1-h daily trials. Nineteen (13male and 6 female) of the coyotes made 75 fatal attacks of 1 to 7 sheep each; 4 coyotes (2 male and 2 female) made no fatal attacks despite 19 to 39 daily pairings. Of coyotes that made fatal attacks, 13 (9 male and 4 female) always attacked at the neck of sheep; 5 (4 male and 1 female) always attacked by nipping at the legs/head/back of sheep; and 1 attacked at the legs/head/back of sheep during two initial events, but subsequently attacked at the neck of sheep. Greater time in captivity was not correlated with trials preceding a fatal attack (rho= +0.23). Among coyotes making ≥2 fatal attacks, subsequent predation events occurred after fewer intervening pairings with sheep. Initial feeding sites occurred most frequently at the flanks/ribs of sheep. Although collected between 1976 to 1980, these observations represent a never-to-be-acquired-again data set that remains timely. Data showed that not all coyotes display sheep-predation behaviors or kill sheep efficiently. Instrumental learning and stimulus-habituation models of coyote predation behavior are discussed.

Controlled laboratory and field test protocols were developed to assess the repellent efficacies of six commercially manufactured ultrasonic rodent repellent devices. The laboratory test structure (68.7 sq m) was divided into two rooms (32.5 sq m each) with a central harborage area (3.5 sq m) containing a colony of 12 wild Norway rats (Rattus norvegicus). For each test, a single ultrasonic device was attached to the far end of one room and rat activity measures (oat consumption, packet damage, photocell counts) were taken during 1-week baseline and 2-1/2-week test periods. Field test structures varied in floor area (6.5 to 197 sq m) and were of either metal or wood construction. All contained existing Norway rat, house mouse (Mus musculus), or field mouse (Peromyscus maniculatus) infestations. No rodent control was conducted at these sites other than the application of selected ultrasonic devices. Rodent activity (packet damage, food consumption, rodent tracks) was measured twice per week during three successive 3-week intervals with devices operating only during the second interval. Repeated measures analysis of variance and chi square were used to statistically evaluate the reliability of ultrasound effects.

Colony roosting species of blackbirds (Icterinae), including European starlings (Sturnus vulgaris), can be significant pests. The chemical avicide CPT has been applied experimentally in the U.S. and France to roosting blackbirds. However, apparent effective aerial application rates are high, 44-101 kg/ha (40-90 lbs/a), and the actual efficacy, expressed as percent mortality, is difficult to determine. We assessed CPT as a respirable aerosol for potential use as a roost avicide. Starlings exposed to 17 ppm CPT for 5.5 min received lethal doses. The birds appear very sensitive to CPT administered in this manner. The methods of CPT entry into the birds include respiratory, ocular and dermal. It is proposed that a field application rate of 3.4-5.6 kg of CPT per hectare (3-5 lbs/a) would be effective.