This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
I've closed down my trapping grid and began the breaking down preparations of my field work. I've been spending my remaining days at APOPO shadowing the staff and taking measurements and observations of the rats here. Seeing animals of a known age really helps me estimate the age and condition of animals I encounter in the field. Plus, I have my own colony to manage when I return to Oklahoma in less than 2 weeks.
When I first arrived, I learned that APOPO had paired several couples together. If I had arrived sooner, I would have asked to watch the initial introductions of those animals, so as to learn more about their courtship and mating behaviors. According to their protocols, they pair a male and female together and begin looking for babies in the 8th week post pairing. Gestation is recorded as 23-30 days long, but this 2 month window gives couples plenty of times to have babies.
(The literature on Cricetomys is so sparse to begin with and the papers on reproductive patterns is patchy. By that I mean much of the literature was published before 2000 and some papers don't agree or such wide range of values are given that it is hard to say what is and what is not a trait.)
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So you can just imagine my glee when the Supervisor announced that there were babies!
Yes! Cricetomys babies. Today, I was able to witness with my own eyes, the adorable, helpless pinkies for myself. (And it is a treat because it isn't very likely that I will catch any animals this young in the wild.)
I came into the room with my 100 g/1 g increments Pesola scale and ruler ready! I was gonna get some long-sought DATA!!!! But was quickly halted by the animal care staff. Touching the babies is not allowed, even with gloves, over concern that the mother might attack and kill the babies. So I took pictures. LOTS and LOTS of pictures and notes on what I could see and what I was told.
The couple was paired July 17, 2012. The female gave birth to 3 babies and they were probably born last night or the most the night before - September 13 or 14. (Keep in mind that I am in Tanzania which is 7 hours ahead EST).
Cricetomys newborn pups are very altricial. They are pink, with no fur. Their eyes are fused closed, their digits are not separate and their ears are still folded down. They really do remind me of newborn Microtus pups, except much larger. Literature says that pups weigh between 20-30 grams at birth. From the look I would say closer to 20-25 g and the y are about 4-5 cm long (2 inches). And they squeak. So cute!
Mother and babies are doing well.