Primatology.net

Just want to quickly point out some interesting reading that popped up in this month’s issue of Behavioral Ecology and Sociobiology (and in a LiveScience post). Estrus cycle asynchrony in wild female chimpanzees, Pan troglodytes schweinfurthii. The authors (Matsumoto-Oda, et al.) highlight the prevalence of the synchronized cycle mating strategy (among primates and other animals) before examining their current research statistic: the Estrus Synchrony Index (ESI), which focuses on maximal swelling and periovulatory periods.

ESI = var (Fm/Fc)/[mean(Fm/Fc){1 – mean(Fm/Fc)}]

Fm = the number of females in maximal swelling
Fc = the number of cycling females

In short, the group of chimpanzees studied exhibited asynchronous estrus cycles.

While some animals synchronize reproductive cycles to benefit from typical things like the wet season (abundance of food), safety in numbers, alloparenting, etc., chimps are cycling at different times to potentially benefit from a reduction in female-female mate competition and a reduction in male sexual coercion.

“Synchrony avoidance may therefore represent a tactic that permits a female to exercise limited choice for high-ranking males, rather than mating the first male that encounters and coerces her.”

It’s an interesting and seemingly appropriate find given the social structure of chimpanzee groups. I wonder what else there is to it… is there any rhyme or reason amongst the asynchrony? Are dominant females cycling so that they give birth when environmental conditions are at their best?

Did you know that between October 2005 to September 2006, US airport inspectors “reported 50 incidents of discovered bushmeat, with each shipment averaging about 9 pounds? That works out to about one shipment being caught every week!”

That is what the CDC has reported in an article over at ABC News. The article, “Bushmeat: Curse of the Monkey’s Paw” reminds us that bushmeat trade is still prevalent, and there is an unusually high demand for this meat here in the US, which I outlined last year.

Aside from the ecological and conservation impact the bushmeat trade has made, it is an awfully disease ridden industry… one which potentially started off HIV/AIDS. This quote drives home the problem,

“But the amount of bushmeat discovered and confiscated by federal agents represents just the tip of the iceberg, said Heather Eves, director of the Bushmeat Crisis Task Force.

Based on “limited studies that we are aware of, it seems like [bushmeat sales on the U.S. black market are] on the order of 15,000 pounds a month,” she said.

Anecdotal evidence suggests a variety of ways the meat is smuggled into the country, Eves said.

“Carrying it in duty-free bags through customs, in luggage, shipping it in the mail and carrying it on their bodies. On the commercial level, shipments are often embedded in dried fish,” she said.

From there, it often finds its way into the markets of American cities that have large concentrations of immigrants from Western and Central Africa.

“We don’t have a handle on how much is coming in. The perception is that we’re only catching a fraction of what’s actually entering the country. It is difficult to know where to search. … There aren’t that many direct flights from Africa, but we’re wary of connecting flights,” said the CDC’s McQuiston.

The risk of diseases jumping from animals to humans is very real. In addition to the SARS and bird flu epidemics out of Asia in recent years, “it is generally understood that HIV arose through contact with nonhuman primates,” said Nina Marano, a veterinarian at the CDC.”

The article goes on to talk about Simian Foamy Virus, another topic we touched on too. But I appreciate William Karesh’s, director of the Department of Field Veterinary Programs at the Wildlife Conservation Society quote at the end of the article. He brings in how bushmeat, human population growth, and logging intersect,

“‘A lack of alternatives, a population boom and better access to forests along roads cut by logging companies’ have given people the desire and means to kill a diversity of wild animals…”