Mexican Mammal Study in Coffee Farms

January 18, 2014 by Amanda Caudill


Our day starts before sunrise. It is cool and peaceful in the mornings and you can still see the moon with all the stars in the night sky while eating breakfast. The mammal traps that we use are small metal boxes that heat up quickly in the tropics, so we make sure to arrive early in the morning to check the traps and release the mammals before it gets too hot out. We are all hungry again by 9:30 a.m. from hiking around for a couple of hours and eating breakfast so early. We usually break to have a sandwich, our second breakfast, after checking all the traps and before continuing on with other parts of the field work like vegetation analysis to characterize the habitats for each site.

Fist-sized opossum being held after being captured
Mexican Mouse Opossum

We have had a slow start this first week of mammal trapping. It is not unusual for there to be few captures in the first couple of days of trapping, but I thought it would have picked up by now with this being our 6th sampling night. We did catch a Marmosa mexicana, which is an opossum the size of a mouse.

They are amazing creatures with opposable thumbs on their hind feet and prehensile tails. This little one was only 22 grams (approximately 4 U.S. quarters). In the couple of mammal studies I have seen from this area, Marmosa species haven't been noted, so it is pretty cool that we got to see one.

black and white photo of an opossum walking through the forest
Common Opossum (Didelphis marsupialis) from camera trap

From the camera traps, we have gotten photos of nine-banded armadillos, coatis, opossums, and agoutis so far. I'm glad the cameras are working well, at least. It is tough work setting up trap grids, then checking and baiting traps on a daily basis. It can be a little discouraging when you don't get many captures. I have a great crew though and everyone has a positive attitude which is so important when doing field work. Nothing ever really works out as planned in the field—which can be both the best thing and the worst thing about field work. The days can be long and physically exhausting, but it is also a ton of fun—you get to be outside every day, hike around, and see some really cool wildlife that you might not ordinarily get to see. We have 4 days left at these site locations for the first sampling session—hopefully things will start to look up and we will get more captures in these final days!