Sexual selection in the little-known Kinda baboon (Papio kindae)

PhD dissertation; New York University

For my PhD dissertation, I am studying sexual selection in the little-known Kinda baboon at the Kasanka Baboon Project in Zambia. Kinda baboons are morphologically, genetically, and behaviorally distinct from other baboon species. I am interested in the evolution of their unique reproductive strategies, particularly in regards to female sexual signals, to better understand how socio-ecology influences mating system variation in primates.

My dissertation research is generously supported with funds from Fulbright U.S. Student Program, The Leakey Foundation, National Science FoundationSociety for Integrative & Comparative BiologySigma Xi, Explorer's ClubAmerican Society of Mammalogists, American Association of University Women, and DAAD German Academic Exchange Program.

My PhD advisor is James Higham, though I also work closely with Cliff Jolly and Todd Disotell. This project is in collaboration with the Kasanka Baboon Project. 

Relevant publications:
Petersdorf M, Weyher AH, Kamilar JM, Dubuc C, Higham JP. (2019). Sexual selection in the Kinda baboon. Journal of Human Evolution 135: 102635 (download).

Exploring mechanisms of sexual selection acting on a primate color signal 

MA thesis; New York University; 2016

Male sexually selected traits can evolve under different selection mechanisms: armaments evolve via intrasexual selection, and ornaments usually via intersexual selection. It less clear, however, how both types of selection act together to influence the evolution of a trait. The colorful signals found in many primates appear to be products of intrasexual selection as they typically indicate social status, like most mammalian armaments. This, however, is not true in male rhesus macaques; red facial coloration does not correlate with dominance rank and is attractive to females, suggesting it evolved primarily under intersexual selection. Nonetheless, males pay attention to other male’s facial coloration. For my MA thesis, I examined the role of facial coloration in free-ranging male rhesus macaques, to determine if this signal influences the outcome of agonistic male-male interactions, is more strongly expressed in contexts generating intense competition, and is therefore also under intrasexual selection.

I was supervised by James Higham and worked in collaboration with Constance Dubuc and Alexander Georgiev.

Relevant publications
Petersdorf M, Dubuc C, Georgiev AG, Winters S, Higham JP. (2017). Is male rhesus macaque facial coloration under intrasexual selection? Behavioral Ecology 28: 1472-1481. (download)

The guenon microbiome

2016-present; New York University

images:  Will Allen

images: Will Allen

We are characterizing the guenon vaginal and oral microbiomes to determine how the composition and diversity of the microbial communities compare to one another, and if the microbial phylogeny maps onto the guenon species phylogeny.

This project is supervised by James Higham and is in collaboration with Maria Gloria Dominquez-Bello.

Osteological markers of cheek flanges in Mandrillus

2014; New York University 

A major challenge in paleoanthropology is reconstructing the behavioral strategies of extinct primates represented only by fossils. Canine size and estimates of body size are used to infer sexual dimorphism as a proxy of socio-sexual behavior; however, these are somewhat limited and other bony correlates of soft tissue sexual traits may be more informative. This study assesses the cheek flanges that characterize adult male drills but not closely related mandrills in an attempt to identify potential osteological markers that characterize this secondary sexual characteristic.

This project is supervised by Scott Williams and James Higham; we are currently in the process of expanding our dataset.

Preliminary results were presented at the 2015 American Association of Physical Anthropology annual conference: download our abstract here.

Sexual swelling symmetry, individual quality, and attractiveness in wild female olive baboons (Papio anubis)

Master's thesis; University of Roehampton; 2012

The sexual swellings that characterize many female papionin primates have been examined in relation to their function as a signal of reproductive quality or fertility. I measured the fluctuating asymmetry of the sexual swelling via photogrammetry and morphometric analyses to expand the assessment of this multicomponent signal to determine if it advertised female reproductive quality and/or was attractive to conspecifics.

I was supervised by Dr. Caroline Ross as part of the MRes in Primate Behaviour, Biology, and Conservation. My research took place at Gashaka-Gumti National Park in Nigeria.

Download my poster from the 2014 Northeastern Evolutionary Primatology conference.

Reproductive suppression in captive female cheetahs (Acinonyx jubatus)

Undergraduate research project; 2008


At the San Diego Zoo Institute for Conservation Research, I worked in the Behavioral Ecology division to understand the reproductive implications of social housing on captive female cheetahs. I used a combination of behavioral observations and hormone monitoring (measured non-invasively from fecal metabolites). We wanted to determine if group-housed cheetahs were reproductively suppressed in comparison to a solitary-housed cheetah, and if this relationship was mediated through social interactions.
I was supervised by Dr. Fred Bercovitch, Dr. Matt Anderson, and Corinne Pisacane. I was funded by a Summer Student Fellowship.
San Diego Zoo blog: How to Spot a CheetahCheetahs: Playing Favorites