“Sperm collection, cryopreservation, and artificial insemination can mitigate the genetic and demographic effects of trophy hunting in affected wildlife populations.”

Spermatozoa cryopreservation is an example of just one ART that can facilitate a living cryobank capable of aiding in the genetic management of endangered species and has been achieved in many species

Our results also suggest that despite the protective effect of female reproductive traits, hunting-induced selection for higher productivity in the population may not suffice to avoid population decline, even under strictly enforced legal protection of family groups.

With working techniques for artificial insemination and sperm cryopreservation of both African and Asian elephants in hand, population managers can now enrich captive or isolated wild elephant populations without removing valuable individuals from their natural habitat.

GRBs can mitigate the effects of unnatural selection pressures, genetic drift, and inbreeding depression by providing a source of germ plasm (i.e., of new genes) that can be infused into small or fragmented populations.

Assisted reproductive techniques, including artificial insemination (AI), have been touted for decades as approaches that could contribute to the demographic and genetic management of rare species. … Our blackfooted ferret example here provided the first empirical evidence for any wildlife species that AI with long-stored spermatozoa was not only possible, but also enhanced population genetic diversity.

Banked material can be used to maintain or increase the genetic variation by effectively increasing the number of animals used as parents in each generation (Eynard et al., 2018).

Assisted reproductive technologies (ARTs) can have a significant impact on achieving species recovery targets through long-term storage of genetic material as assurance against on-going or future depletion of diversity.

For endangered vertebrates, the use of preserved material (i.e., spermatozoa) combined with assisted reproductive techniques is being evaluated for uses in genetic rescue of a species as in the cases of the Przewalski’s horse and the black-footed ferret, where genetically valuable clones have been produced (Sandler et al., 2021).

A major conservation benefit of AI lies in mitigating genetic deterioration caused by population fragmentation. In small or isolated populations, temporary capture of females for insemination with semen from genetically valuable males maintained in captivity can facilitate gene flow, after which females may return to their natural habitats to give birth (Pukazhenthi and Wild, 2004) [82] .

The main benefit of artificial insemination is the maintenance of the genetic diversity of populations through the preservation and use of semen from genetically valuable individuals.

Our theoretical work showed that, within the bounds of a series of empirically well-supported assumptions, compensatory culling of poor-quality individuals at an early life stage had the potential to at least partially compensate for the trait-altering effects of trophy hunting in the short and intermediate term (up to 100 years).

For mountain sheep, Coltman et al. (2) showed that harvest of trophy rams led to selection for lighter and smaller-horned rams. … However, gene flow has the potential to accelerate the rate of recovery by restoring alleles or multiple-locus genotypes associated with the trait. For example, trophy hunting might reduce or eliminate alleles for large horn size, but gene flow from areas with no hunting might quickly restore alleles associated with large horn size (12).

While ARTs are not the sole solution to the biodiversity crisis, they can offer opportunities to maintain, and even improve, the genetic composition of the captive and wild gene pools over time.

Within this framework, there are several circumstances in bird conservation programs that may require the use of semen-related technologies (STs) including the inability of a pair to mate naturally (due to physical or behavioral issues), maximizing fertility, producing more offspring from a given individual, distances between key individuals or populations, creating genetic backups, etc.

The main benefit of artificial insemination is the maintenance of the genetic diversity of populations through the preservation and use of semen from genetically valuable individuals. … The factors that may influence pregnancy rate during FTAI include semen collection, semen cryopreservation, estrus synchronization, and artificial insemination techniques.

To improve the success of these programs, the use of biological resource banks and assisted reproductive technologies has been proposed (Locatelli, 2024). As part of the development of a conservation program within the EAZA (European association of Zoos and Aquaria), a study was designed to promote the preservation of genetic diversity in the markhor goat (Capra falconeri heptneri) by implementing assisted reproduction techniques for markhor species.

National animal gene banks that are responsible for conserving livestock, poultry, and aquatic genetic resources need to be capable of utilizing a broad array of cryotechnologies coupled with assisted reproductive technologies to reconstitute either specific animals or populations/breeds as needed.

For mountain sheep, Coltman et al. (2003) showed that harvest of trophy rams led to selection for lighter and smaller-horned rams.

The Center specializes in expanding the practice of living cell biobanking (somatic cells, gametes, seeds, and other living material) for applications such as conservation genetic rescue and assisted reproduction, while also empowering the use of nonliving genetic material held in biobanks for genomic discovery for species management decisions.

For some species with unsuccessful breeding programmes (Lees & Wilcken 2009), cryopreserving (freezing cells with cryoprotectants enabling long-term viable cell and tissue storage), followed by cryobanking (indefinite storage of viable cells and tissue in liquid nitrogen at −196°C or ultra-low freezers) and assisted or advanced assisted reproductive technology (ART/aART) can save the genotypes that are being lost today (Mitchell & Williams 2022, for definitions please see Supplementary Table 1, see section on supplementary materials given at the end of this article).

Second, we reviewed the side effects associated with the selective removal of relatively few specific individuals, often large trophy males. Such selective harvesting can destabilize social structures and the dominance hierarchy and may cause loss of social knowledge, sexually selected infanticide, habitat changes among reproductive females, and changes in offspring sex ratio.

Ex situ conservation of genetic material from livestock and fish through cryopreservation is an important strategy to conserve genetic diversity in these species.

We find that body size is weakly inherited and that subsequently demographic change, and not evolutionary change, as previously thought, is the principle driver of trait shifts in hunted bighorn sheep.

The underlying principle behind these remarks was based on the recognition that spermatozoa could remain viable for many years, and still achieve pregnancies even long after the semen donor had died. Nowadays, live mammalian embryos, amphibian spermatozoa and cultured somatic cells can also be stored for future use in conservation breeding programmes, where the overarching aim is to mitigate the deleterious impacts of inbreeding on the fitness and survival of populations.

The underlying principle behind these remarks was based on the recognition that spermatozoa could remain viable for many years, and still achieve pregnancies even long after the semen donor had died. … Nowadays, live mammalian embryos, amphibian spermatozoa and cultured somatic cells can also be stored for future use in conservation breeding programmes, where the overarching aim is to mitigate the deleterious impacts of inbreeding on the fitness and survival of populations.

To ensure population sustainability there is a critical need to: (1) manage ungulates in large herds, increasing mate choice and reproductive efficiency; (2) improve husbandry and genetic management; and (3) develop consistent assisted reproductive technologies, including sperm cryopreservation and AI.

In theory, individuals that migrate from protected areas and breed in harvested popula tions could provide a genetic rescue (Tallmon et al., 2004; Whiteley et al., 2015) if gene flow through migration mitigated the evolution ary consequences of selective harvest (Baskett et al., 2005; Puckett & Eggleston, 2016; Tenhumberg et al., 2004).

These technologies allow for the exchange of genetic material without the need for natural breeding, enabling genetic transfer both within and between captive and free-ranging populations, thus, providing a synergistic approach to both in situ and ex situ conservation [4]. … Therefore, the collection of gametes postmortem can play a substantial role in addressing the loss of genetic diversity and preserving genetic resources.

The scientists said age restrictions that allow males to breed before being removed could reduce the impact of trophy hunting.

Cryoconservation (i.e. ex situ – in vitro conservation) of genetic resources through gene banking provides one of the most powerful tools governments and other stakeholders have to manage genetic diversity in both the short and long term and thereby provide future generations with the tools to meet the challenges ahead.

Biobanked materials serve as the foundation for a pivotal new set of conservation options that afford us the opportunity to safeguard genetic capital, support population sustainability, and reduce extinction risk.

The preservation of genetic diversity through biobanking is necessary in understanding, characterizing, and conserving biodiversity; biobanking is also an explicit component of the One Plan approach, helping bridge ex-situ and in-situ conservation.

As species continue to face threats to their long-term survival, ARTs provide some assurance that the genetics carefully stewarded in wildlife biobanks around the globe can be used to keep keystone species thriving and ecosystems intact.

As such, we propose the development of a hybrid conservation approach to the metapopulation management of African wild dogs, which augments assisted dispersal and natural breeding initiatives with genetic gains afforded by sperm banking and artificial insemination.

In this pa~, we investi gate one potentially deleterious effect of sex-skewed harves~ Both theory and experimental data suggest that male ungu lates are limited in their absolute ability to inseminate fe maleg Using a Leslie-Matrix model and published data on impal~ we show that the interaction between sperm limita tion and harvests with highly male-biased sex ratios can lead to greatly reduced female fecundity (defined us the number of young born) and population collapse

To mitigate these effects, the study recommends age- and trait-based harvest regulations, ongoing genetic monitoring, and education promoting sustainable hunting practices.