The rusa deer (Cers'us timorensis) is more resistant to the cattle tick (Boop/iiltis tnicnop/us) than are British breed cattle in Papua New Guinea. The average yield of replete female ticks from deer was 1.6% (0.3–3.2%) as compared to 11.2% (3.4–23.1%) from calves. Ticks from deer were more slender, lighter in weight and produced fewer eggs (mean 1,800) than did ticks from calves (mean 2,200) but the deer was shown to be an effective host. A cervid population can maintain a tick population in the absence of bovine hosts thus presenting an important factor in eradication programs. Nutritional stress appears to result in a