Interspecific hybridization between greater kudu and nyala

Abstract

Hybridization of wildlife species, even in the absence of introgression, is of concern due to wasted reproductive effort and a reduction in productivity. In this study we detail an accidental mating between a female nyala (Tragelaphus angasii) and a male greater kudu (T. strepsiceros). The hybrid was phenotypically nyala and was identified as such based on mitochondrial DNA. Further genetic analysis based on nine microsatellite markers, chromosome number and chromosome morphology however, confirmed its status as an F1 hybrid. Results obtained from a reproductive potential assessment indicated that this animal does not have the potential to breed successfully and can be considered as sterile.

Molecular cytogenetics of tragelaphine and alcelaphine interspecies hybrids: hybridization, introgression and speciation in some African antelope

“…As with the alcelaphine hybrid, the greater kudu × nyala cross was considered sterile following detailed clinical and reproductive potential assessments [ 6 ]. This may be anticipated given the 11 trivalents (4–4.5–5; 3–3.10–10; 1–1.29–29; 6–6.20–20; 7–7.18–18; 8–8.17–17; 12–12.16–16; 9–9.27–27; 19–19.21–21; 14–14.26–26; 15–15.28–28) and chain of five (24–24.22.2–2.22.11–11.23–23) expected in the hybrid's meiosis.…”

“…This was done to test historic [ 5 ] and anecdotal reports of the species hybridization (electronic supplementary material). The second, a Tragelaphus strepsiceros (greater kudu) × Tragelaphus angasii (nyala) F 1 male arose from hybridization on a game farm in the North West Province of South Africa [ 6 ]. We report the outcome of a molecular cytogenetic investigation of these hybrid animals to raise awareness of the broader evolutionary significance of hybridization in African antelope, the variability in evolutionary time distinguishing hybridizing species pairs and the implications this holds for antelope diversity and conservation.…”

‘Intentional Genetic Manipulation’ as a conservation threat

“…3; Supplementary material 3). However, farming both species on the same land with few or no con-specific mates may encourage hybridisation (Grobler et al 2011;Dalton et al 2014) and this is a general risk of game farming (e.g. Blanco-Aguiar et al 2008).…”

“…However, negative effects of hybridisation include loss of local adaptations and unique traits, reduced fertility and offspring viability which can lead to extinction (Wolf et al 2001), and outbreeding depression which has, for example, been documented in southern Africa (e.g. greater kudu-nyala; Dalton et al 2014). Furthermore, species are routinely introduced beyond their historical distributions (different climatic conditions/vegetation/ecosystems), e.g.…”

Quantitative evaluation of hybridization and the impact on biodiversity conservation

“…Hybridization may disrupt adaptive gene complexes or may result in genetic incompatibilities. Hybridization is known to reduce fitness in at least one species pair in South Africa, namely kudu ( Tragelaphus strepsiceros ) and nyala ( T. angasii ) (Dalton et al., ). An additional threat of hybridization is complete swamping, as in the rediscovered Giant sable antelope ( Hippotragus niger variani ), where natural hybridization with roan antelope ( H. equinus ) was proceeding rapidly and would have led to a complete hybrid swarm without intervention (Vaz Pinto et al., ).…”