Evaluating how lethal management affects poaching of Mexican wolves

Despite illegal killing (poaching) being the major cause of death among
large carnivores globally, little is known about the effect of
implementing lethal management policies on poaching. Two opposing
hypotheses have been proposed in the literature: implementing lethal
management may decrease poaching incidence (‘killing for tolerance’) or
increase it (‘facilitated killing’). Here, we propose a test of two
opposed hypotheses that poaching (reported and unreported) of Mexican grey
wolves (Canis lupus baileyi) in Arizona and New Mexico, USA, responded to
changes in policy that relaxed protections to allow more wolf-killing. We
employ advanced biostatistical survival and competing-risk methods to data
on individual resightings, mortality, and disappearances of collared
Mexican wolves. We aim to provide recommendations for improving the
effectiveness of US policy on environmental crimes, endangered species,
and protections for wild animals. Our results have implications beyond the
USA or wolves because the methods promise to transform understanding,
scientific methods, and management interventions of processes and patterns
in human-caused mortality among wild animals subject to high rates of
poaching.