Here's my second attempt at a pastel - an adult male 'cheek padder' orangutan. I worked from a photo of an individual I believe is named Adik. Adik lives in Borneo and as you can tell from his cheek phalanges, he is a dominant male.
In Borneo, only dominant males develop secondary sexual characteristics such as full cheek pads, deep voice, and a huge size. Subordinate males who live in the dominant male's territory do not develop these traits. No knows quite why the so-called 'Peter Pan' males fail to develop. It may be stress-induced dwarfism or hormonal suppression possibly caused by pheromones emited by the dominant male. If the dominant male leaves or dies, the most dominant of the subordinate males in the area mature and become the dominant male with all of the associated physical characteristics. Orangutans are the only primate known to display two different coexisting adult male morphs. Of course there's a scientific term for it. It's called bimaturism, but some also call it arrested development.
Besides being physically stunted, the Peter Pan rangs might also be considered socially stunted. Females prefer to mate with the dominant males, so in order for subordinate males produce progeny they often resort to alternative strategies: rape or what primatologists call forced copulation. Females have evolved strategies for dealing with the threat of forced copulations. Lone females will travel to be closer to a dominant male. If she can't find one she seeks out other females. When no dominant male is nearby but a subordinate Peter Pan male is, females tend to stick closer together.
This is significant because orangutans are a solitary species. Fruiting trees are sparsely scattered in their habitat and don't come into season all at once so the habitat cannot support group foraging. Instead, rangs forage individually to be sure to get enough to eat and also leave enough to ripen for later. For females this artifact of habitat opens the door to being harassed by subordinate males. Dominant males rarely force copulations.
Obviously, one can draw some very interesting and provactive comparisons between humans and orangutans.
*** This pastel took a lot longer than the previous pastel I did on account of the time it took to put the tiny hairs on his face. I really like this one. I like how his eyes, nose, and lips turned out. I think he has a very typical orang expression.
My next pastel will be of a monkey without hair on its face. Candidates are: douc langur, snub-nosed langur, and bald uakari. I am leaning toward the snub-nosed langur because it has a very strange face - it's blue! Plus it is an incredibly rare species; I could not locate a single decent source to link to. The one I found contained plagiarized material.