Fertility Control for Wildlife: A European Perspective

Ovariectomy in mouflons under field conditions: a comparative assessment of midventral and flank laparotomy approaches

Ovariectomy is the best method to control the density of wild ungulate populations. The present study aimed to compare two surgical approaches of ovariectomy, via the flank and midventral, in mouflons under field conditions. A total of 20 female mouflons were enrolled in the study. The animals were divided randomly into two equal groups; group F animals were gonadectomized via the flank approach, while group L animals were sterilized via the linea alba access. The parameters evaluated were duration of surgery, duration of anesthesia, recovery time, intraoperative and postoperative complications, intraoperative nociception, and pain during the postoperative period. There were no intraoperative and postoperative complications. The evaluated parameters showed a very similar trend in both groups. Both techniques were found to be effective and safe in execution.

The prohibition of recreational hunting of wild ungulates in Spanish National Parks: Challenges and opportunities

A new regulation has led to the prohibition of recreational hunting on estates located within Spanish National Parks (NPs). Before the ban, eleven NPs in Spain had already reported negative ecological consequences associated with high densities of wild ungulates. The new situation that has occurred after the ban signifies that policies with which to control populations of wild ungulates in NPs, most of which do not have a sufficient natural capacity to regulate populations, depend exclusively on the parks' authorities. The banning of recreational hunting implies a series of social, ecological, economic and logistic challenges. The control of wild ungulate populations in NPs requires: i) the legal basis for culling; ii) social acceptance as regards removing animals and the extractive procedures employed in NPs; iii) the long-term monitoring of wild ungulates and the damages that they cause, and iv) sufficient financial and human resources. A more integrated management and policy plan is, therefore, required, which should be supported by two pillars: i) the sustainability of natural resources and the conservation of functional environments, and ii) providing society with explanations regarding the need to manage wild ungulates. In order to bridge the potential gap between these key pillars, it is important to involve stakeholders in the decision-making processes concerning wild ungulate management. The forthcoming changes in Spanish NPs provide a promising opportunity to make a substantial improvement to wild ungulate management in these protected areas. This management approach could, moreover, serve as an example and be transferred to other protected spaces.

Developing fertility control for rodents: a framework for researchers and practitioners

Fertility control is often heralded as a humane and effective technique for management of overabundant wildlife, including rodents. The intention is to reduce the use of lethal and inhumane methods, increase farm productivity and food security as well as reduce disease transmission, particularly of zoonoses. We developed a framework to guide researchers and stakeholders planning to assess the effectiveness of a potential contraceptive agent for a particular species. Our guidelines describe the overarching research questions which must be sequentially addressed to ensure adequate data are collected so that a contraceptive can be registered for use in broad-scale rodent management. The framework indicates that studies should be undertaken iteratively and, at times, in parallel, with initial research being conducted on (1) laboratory-based captive assessments of contraceptive effects in individuals; (2) simulation of contraceptive delivery using bait markers and/or surgical sterilization of different proportions of a field-based or enclosure population to determine how population dynamics are affected; (3) development of mathematical models which predict the outcomes of different fertility control scenarios; and (4) implementation of large-scale, replicated trials to validate contraceptive efficacy under various management-scale field situations. In some circumstances, fertility control may be most effective when integrated with other methods (e.g. some culling). Assessment of non-target effects, direct and indirect, and the environmental fate of the contraceptive must also be determined. Developing fertility control for a species is a resource-intensive commitment but will likely be less costly than the ongoing environmental and economic impacts by rodents and rodenticides in many contexts.

The Effect of the Wild Boar Hunting System on Agricultural Damages: The North-East of Italy as a Case Scenario

Hunting is a method commonly used in several European countries to reduce crop damages by wild boar Sus scrofa. However, results are still controversial and poorly treated. Using data on official claims (i.e., damages to crops) and wild boar local counts and hunting bags collected from 2019 to 2022, the purpose of this work was to evaluate the effect of the hunting system (divided into eradication and non-eradication areas) carried out in the north-east of Italy on the number of agricultural damages. The spatio-temporal distribution of wild boar hunting, density and damages as well as the effect of hunting, were evaluated through the hotspot analysis and the zero-inflated models, respectively. The results obtained revealed no clear spatial overlap among wild boar hunting, wild boar density and damages to agriculture in both the eradication and non-eradication areas. Moreover, the current level of harvesting did not significantly affect the number of agricultural damages. A multifaceted approach focused on the numeric control of the species based on accurate local counts and oriented towards more age classes in a similar percentage should be preferred to mitigate damages to cultivars.

GnRH-immunocastration: an alternative method for male animal surgical castration

Castration of male animals is intended to produce high-enhance quality of animal meat, prevent unpleasant taste, reduce aggressive behavior, and manage overbreeding. Over the years, Tranditional methods of mechanical and surgical castration have been employed over the years, but they fall short of meeting animal welfare requirements due to the associated risk of infection, pain, and stress. Immunocastration, specifically Gonadotropin-releasing hormone (GnRH)-immunocastration, targeting the hypothalamic-pituitary-testis (HPT) axis, has emerged as an animal-friendly alternative to surgical castration, effectively addressing these issues. This review seeks to systematically summarize the principles, development, current applications and challenges of GnRH-immunocastration, offering insights into its role in promoting animal welfare.