Assessment of Male Reproductive Skew via Highly Polymorphic STR Markers in Wild Vervet Monkeys, Chlorocebus pygerythrus

Abstract

Male reproductive strategies have been well-studied in primate species where males' ability to 35 monopolize reproductive access is high. Less is known about species where males cannot 36 monopolize mating access. Vervet monkeys (Chlorocebus pygerythrus) are interesting in this 37 regard as female co-dominance reduces the potential for male monopolization. Under this 38 condition, we assessed whether male dominance rank still influences male mating and 39 reproductive success, by assigning paternities to infants in a population of wild vervets in the 40 Eastern Cape, South Africa. To determine paternity, we established microsatellite markers 41 from non-invasive fecal samples via cross-species amplification. In addition, we evaluated 42 male mating and reproductive success for three groups over four mating seasons. We 43 identified 21 highly polymorphic microsatellites (number of alleles = 7.5±3.1 (mean±SD), 44 observed heterozygosity = 0.691±0.138 (mean±SD)) and assigned paternity to 94 of 97 45 sampled infants (96.9%) with high confidence. Matings pooled over four seasons were 46 significantly skewed across three groups, although skew indices were low (B index = 0.023 to 47 0.030) and mating success did not correlate with male dominance. Paternities pooled over 48 four seasons were not consistently significantly skewed (B index = 0.005 to 0.062), with high-49 ranking males siring more offspring than subordinates only in some seasons. We detected six 50 cases of extra-group paternity (6.4%), and four cases of natal breeding (4.3%). Our results 51 suggest that alternative reproductive strategies besides priority of access for dominant males 52 are likely to affect paternity success, warranting further investigation into the determinants of 53 paternity among species with limited male monopolization potential.

Male characteristics as predictors of genital color and display variation in vervet monkeys

“…Longitudinal data collected include dominance interactions (i.e., submission, displace, supplant, facial threat, vocal threat, lunge, physical contact; Freeman 2012), mating interactions (i.e., genital sniff, grab, female refusal, mount, and ejaculation) as well as inter-troop encounters, all collected via ad libitum sampling (Altmann 1974). As part of the longitudinal data collection, 10-min group scans were conducted every 30 min in which the general activity (i.e., locomotion, foraging, grooming) was recorded of as many individuals of the group as possible within that time period (for more details, see Minkner et al 2018).…”

Group structure, but not dominance rank, predicts fecal androgen metabolite concentrations of wild male mountain gorillas (Gorilla beringei beringei)

“…Mating opportunities may not disappear entirely even if they are knocked further down the dominance hierarchy or forced to emigrate to a new social group. While there is certainly variation in the degree of reproductive skew from species to species, it is rarely the case that only dominant males reproduce (e.g., Alberts et al, 2003; Engelhardt et al, 2017; Minkner et al, 2018; Surbeck et al, 2017; Vigilant et al, 2015). Males in single‐male groups do not face the continual intrasexual pressure that those in multimale groups do, but when they do have competitive encounters, the stakes are likely to be very high (Fernandez‐Duque & Huck, 2013; Saj & Sicotte, 2005; Zhao et al, 2011).…”

A refined panel of 42 microsatellite loci to universally genotype catarrhine primates

“…As many microsatellites can be cross‐amplified in phylogenetically related species, primers designed for one species are often tested in related species and then applied if successfully amplified and informative (i.e., polymorph) (Barbara et al., 2007; De Barba et al., 2017). For example, various microsatellite loci characterized for humans can be successfully amplified in nonhuman catarrhine primates (Old World monkeys, apes) (Coote & Bruford, 1996; Ely et al., 1998; Kayser et al., 1996; Morin et al., 1998; Newman et al., 2002; Roeder et al., 2009; Smith et al., 2000) and have been used since then in numerous studies (e.g., Arandjelovic et al., 2014; Kopp et al., 2015; Minkner et al., 2018; Städele et al., 2019). Yet, attempts to reduce PCR product size or to adapt primers specifically to the study species have been rare (but see Bradley et al., 2000; Engelhardt et al., 2017; Inoue et al., 2016).…”

“…For example, various microsatellite loci characterized for humans can be successfully amplified in nonhuman catarrhine primates (Old World monkeys, apes) (Coote & Bruford, 1996;Ely et al, 1998;Kayser et al, 1996;Morin et al, 1998;Newman et al, 2002;Roeder et al, 2009;Smith et al, 2000) and have been used since then in numerous studies (e.g., Arandjelovic et al, 2014;Kopp et al, 2015;Minkner et al, 2018;Städele et al, 2019). Yet, attempts to reduce PCR product size or to adapt primers specifically to the study species have been rare (but see Bradley et al, 2000;Engelhardt et al, 2017;Inoue et al, 2016).…”