Implementing immunocontraception in free-ranging African elephants at Makalali Conservancy

Abstract

The goal of programmes to provide contraception for elephants should be to formulate an approach that does not require the relocation or immobilisation of the same individual year after year, which would be long-lasting and cause minimal disruption to social and reproductive behaviour. The programmes should be simple to administer, safe and cost-effective, and must meet the objectives defined by managers in the field. An immunocontraceptive programme was initiated in a small free-roaming population of elephants at the Greater Makalali Private Game Reserve in Limpopo Province in 2000 to determine whether the porcine zona pellucida (pZP) vaccine can successfully control population sizes. Further objectives were to determine implementation costs and efficiency through a multi-faceted approach. We have demonstrated that immunocontraception meets the objectives set by managers in the field. Minimal social disruption was observed over the course of treatment, with the mode of delivery (ground or aerial vaccinations) determining the degree of stress within herds and speed of resumption of normal movement patterns. Aerial vaccinations resulted in the least disturbance, with target herds being approachable within a day. In 2005, implementation costs were R880-R1000 / elephant / year, inclusive of darts, vaccine, helicopter and veterinary assistance. Irrespective of the source or method of vaccine delivery, a non-pregnant elephant is rendered infertile from 1st vaccine administration. The sooner immunocontraception is implemented, the sooner population growth rates can be controlled. pZP contraception is a realistic alternative management tool, particularly if used as part of a long-termmanagement strategy. Mass-darting from the air eliminates the need for detailed individual histories of each elephant or for employing a person to monitor elephants. Thus, implementation of immunocontraception in larger populations is feasible and practical

EFFECTS OF A GONADOTROPIN-RELEASING HORMONE VACCINE ON OVARIAN CYCLICITY AND UTERINE MORPHOLOGY OF AN ASIAN ELEPHANT (ELEPHAS MAXIMUS)

“…It would be beneficial to compare the efficacy, duration of effect, reversibility, longterm health and genetic effects, and social and behavioral effects of GnRH vaccination in elephants with those of porcine zona pellucida vaccination, which prevents fertilization by blocking sperm binding to the egg and is currently used in female elephants for contraception. 2,12,14,15,38,47 Porcine zona pellucida vaccination would not be efficacious for resolving health problems associated with ovarian steroidogenic activity, however, because contracepted females continue to cycle.…”

Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine

“…These were delivered remotely from helicopter using methods modified from Delsink et al [33]. The vaccination protocol for the TPNR population was as previously described by Bertschinger [34].…”

Fertility control to mitigate human–wildlife conflicts: a review

“…Potential disadvantages include identification of previously vaccinated individuals, dose regulation and incomplete intra-muscular injection (DeNicola et al 1997(DeNicola et al , 2000Aune et al 2002). Remote parenteral delivery of contraceptives is regarded as suitable for small or isolated groups of animals, for instance, in urban parks (DeNicola et al 2000), on islands (Kirkpatrick et al 2009) or in fenced wildlife reserves (Delsink et al 2007;Delsink and Kirkpatrick 2012).…”

“…Syringe-darts, routinely employed to anaesthetise wild animals, have also been used to administer contraceptives (Aune et al 2002). Distance-adjustable CO 2 -powered dart rifles have been employed to fire 2-3-mL syringe-darts at ranges of 40 m into the hindquarter of large mammals (Rudolph et al 2000;Delsink et al 2007;Kirkpatrick et al 2009;Rutberg et al 2013). Such delivery systems have several advantages (Kreeger 1997), including the following: (1) they target individual animals, so specificity is assured; (2) they can administer an individually tailored dose based on a bodyweight; (3) they can deliver solid (e.g.…”

“…For instance, Rutberg (2005) estimated that the cost to render infertile a medium-largesize individual mammal varied between US$25 and US$500. Delsink et al (2007) calculated that in 2005 the average cost of managing elephants through aerial vaccination with immunocontraceptives cost US$98-110 per animal, inclusive of darts, vaccine, helicopter and veterinary assistance. The cost of capture, handling and administering contraceptives to whitetailed deer in various contexts was estimated to be in excess of US$1000 per deer, with 75% of this cost being due to veterinary time and drugs (Boulanger et al 2012).…”