A Brief History of Coyote Research at Hopland Robert M. Timm Extension Wildlife Specialist emeritus UC Hopland Res. & Ext. Center

Coyote Research at Hopland mid-1970s to 2007 ca 120 publications ca 120 publications Most studies were conducted by UC Davis and UC Berkeley faculty and graduate students in cooperation with USDA

UC’s Experience at Hopland 1951 – 1965: essentially no coyote loss 1965 – 1975: coyote losses common 1985: return of mountain lions to area 1990s & 2000s: Loss of ~10-15% of lamb crop annually despite employing many non-lethal measures and all legal lethal methods

Potential Reasons for Sheep Industry Decline: Lamb & Wool Prices Lamb & Wool Prices Real Estate Values & Rancher Demographics Real Estate Values & Rancher Demographics Predation Losses Predation Losses Nesse et al. (1976), Wagner (1988)

Predation Losses Increasing range and populations of coyotes Increasing range and populations of coyotes Fewer predator control tools and methods Fewer predator control tools and methods Less predator control effort, and decreased ability to suppress coyote numbers Less predator control effort, and decreased ability to suppress coyote numbers “Snowball effect” “Snowball effect”

Increasing range and populations of coyotes Inland vs. Coastal Rangelands Inland vs. Coastal Rangelands

1970 Shooting Shooting Foothold traps Foothold traps Snares Snares Toxic draw stations Toxic draw stations Place baits Place baits Sodium cyanide ejectors Sodium cyanide ejectors Den hunting Den hunting Coyote Control Methods - CA after Connolly (1981)

Methods of Lethal Coyote Control and Percentage of Coyotes Taken by Federal Wildlife Damage Control FY 1971 (U.S.) 37.5%Foothold traps 27.3%Sodium cyanide ejectors 9.1%Aerial hunting 9.1%Aerial hunting 9.0%Other toxicants 9.0%Other toxicants 7.0%Den hunting 7.0%Den hunting 6.5%Ground shooting 6.5%Ground shooting 3.3%Snares 3.3%Snares 0.4%Use of dogs 0.4%Use of dogs

Non-lethal methods used (by ranchers) Fencing Fencing Pasture selection Pasture selection Increased protection at lambing and soon thereafter Increased protection at lambing and soon thereafter Timing of breeding / lambing Timing of breeding / lambing

1970s USDA funding to UC Davis faculty – William M. Longhurst Walter E. Howard facilitated establishment of coyote research at Hopland beginning about 1972.

Connolly, G. E. and W. M. Longhurst The effects of control on coyote populations. Div. of Agric. Sci. Bulletin 1872, Univ. of California. 37 pp. To exterminate coyote populations by lethal removal, >75% of coyotes would need to be harvested annually for approximately 50 years. * * * Nesse, G. E., W. M. Longhurst, and W. E. Howard Predation and the sheep industry in California Agric. Exper. Sta. Bulletin 1878, Univ. of Calif. 63 pp. Survey data of No. California sheep ranchers indicated that coyotes by far were the largest predator of sheep and lambs, accounting for 82% of predation losses.

Survey of CA Sheep Ranchers Most critical concerns to ranchers regarding sustainability: “most important production problem” Predation (50% of ranchers) Property Taxes (15% of ranchers) Market Prices (13% of ranchers) after Nesse et al. (1976)

Connolly, G.E., R.M. Timm, W.E. Howard, and W.M. Longhurst Sheep killing behavior of captive coyotes. J. Wildl. Management 40: photos: G. E. Connolly

1980 Shooting Shooting Foothold traps Foothold traps Snares Snares Toxic draw stations – banned 1972 Toxic draw stations – banned 1972 Place baits – banned 1972 Place baits – banned 1972 Sodium cyanide ejectors – banned , 1998 Sodium cyanide ejectors – banned , 1998 Den hunting – prohibited by USDI in 1979 Den hunting – prohibited by USDI in 1979 Coyote Control Methods - CA

1980s Scrivner, J.H., W.E. Howard, R. Teranishi, and D.B. Fagre Toward a more effective coyote lure. Rangelands 7:52-54.

Coyotes were highly attracted to short-chain fatty acids, a product of protein decomposition. One of the most successful lures was trimethylammonium decanoate (TMAD)

Fagre, D.B., B.A. Butler, W.E. Howard, and R. Teranishi Behavioral responses of coyotes to selected odors and tastes. Proc. Worldwide Furbearer Conf. Vol. 2, pp Aversive conditioning of coyotes was ineffective in preventing predatory attacks, as was the application of repellents.

Scrivner, J.H., W.E. Howard, A.H. Murphy, and J.R. Hays Sheep losses to predators on a California range. J. Range Manage. 38: Sheep and lamb losses for an 11-year period were analyzed; for all known ewe and lamb deaths, 45% and 26% were killed by predators. Of predator kills, coyotes caused 89% of deaths, with more sheep and lambs killed Oct – Mar than from Apr – Sept.

1990s Symposium : Predator Management in North Costal California March 1990

HREC guard dog ‘Brutus’ with flock

Sacks, B.N., K.M. Blewjas, and M.M. Jaeger Relative vulnerability of coyotes to removal methods on a northern California sheep ranch. J. Wildl. Manage. 63: Sacks, B.N., M.M. Jaeger, J.C.C. Neale, and D.R. McCullough Territoriality and breeding status of coyotes relative to sheep production. J. Wildl. Manage. 63:

Alpha coyotes (especially males) were significant predators of sheep and lambs, and were the most difficult coyotes to control. Selective removal of problem individuals would reduce losses, especially if timed strategically. Healthy population of bobcats existed at HREC alongside coyotes with apparently little competitive overlap.

Timm, R. M Controlling coyote predation on sheep in California: a model strategy. Final Report to CA Dept. of Pesticide Regulation. Used the Livestock Protection Collar (active ingredient: sodium monofluoroacetate – ‘1080’) as the sole lethal tool to selectively remove problem coyotes, in conjunction with guard llamas. Established a local Predator Research Advisory Committee.

Timm, R. M., and G. E. Connolly Sheep-killing coyotes a continuing dilemma for ranchers. Calif. Agriculture 55:26-31

Proposition 4 (Nov. 1998) California Banned use of foothold traps, including in research Banned use of foothold traps, including in research (Exception: public safety emergency use) (Exception: public safety emergency use) Banned use of sodium cyanide and 1080 for control of predators Banned use of sodium cyanide and 1080 for control of predators

2000 Shooting Shooting Foothold traps – banned 1998 Foothold traps – banned 1998 Snares Snares Toxic draw stations Toxic draw stations Place baits Place baits Sodium cyanide ejectors Sodium cyanide ejectors Den hunting Den hunting Coyote Control Methods - CA

Knowlton, F. F., E. M. Gese, and M. M. Jaeger Coyote depredation control: an interface between biology and management. J. Range Manage. 52: A very thorough, science-based summary of our knowledge of coyotes and their management. Integrates HREC research with other research from various localities.

2000s Williams, C.L., K. Blewjas, J.J. Johnston, and M.M. Jaeger A coyote in sheep’s clothing: predator identification from saliva. Wildl. Soc. Bull. 31: DNA from coyote saliva can provide positive identification of individual coyotes that have killed prey, chewed bait delivery devices, or bitten people or pets. K.M. Blejwas, C.L. Williams, G.T. Shin, D.R. McCullough, and M.M. Jaeger Salivary DNA evidence convicts breeding male coyotes of killing sheep. J. Wildl. Manage. 70(4):

A. R. Berentsen, R. M. Timm, and R. H. Schmidt The Coyote Lure Operative Device revisited: a fresh look at an old idea. Calif. Agriculture 61(1):20-23.

photo: Guy E. Connolly