We experienced many forms of personal exsanguination while in Mexico. Biting flies were diverse (Ceratopodinidae, Culicidae and even Simuliidae) though nowhere near as abundant as in Canada and only occasionally maddening. Ticks, on the other hand, were present in numbers that to me, as a resident of a province where human-biting ticks are relatively uncommon, were disconcerting. Tick-checks after fieldwork were a daily task, and Wayne and I competed for the honour of “most infested”. On our second last field day at Rancho Primavera, I won with a whopping N = 42 ixodids. We hope that none of the ticks we pulled from our integument were carrying noxious bacteria or viruses.
But ticks and flies are lightweights in comparison to the champion bloodsuckers of Mexico – vampire bats. We slept safely inside at night at so never got bitten; however, livestock aren’t so lucky. Bonnie Jáuregui, proprietor of Rancho Primavera, showed us fresh wounds on her horses that had been caused by feeding vampire bats (Desmodus rotundus).
She treated them by smearing a warfarin-containing cream on the wounds. When bats returned to feed on open wounds the next evening they would also ingest some warfarin. Then, because vampire bats frequently share their blood meals with roost-mates via regurgitation, the anti-clotting agent would not only affect the bat that fed on the wound directly but also its friends and relatives.