Hello Everyone! Brittany here! Last Culi Tuesday I talked about some of the food the lorises at the Endangered Primate Rescue Center receive, with one of the most important foods being tree gum.

A not-quite-awake-Bengal slow loris lapping up some offered tree gum.

Gouging

For convenience sake with the large number or lorises currently at the EPRC, they’re usually given gum in a little metal bowl. In the wild, however, slow lorises would use their specialized bottom teeth, their toothcomb, to gouge bark in search for gum. As some of the lorises at the EPRC have been there for years, I wondered if they had lost their ability to gouge, either behaviorally (because it was a skill they didn’t need to survive at the Center) or physically (because their jaw muscles had weakened from lack gouging over the years). I was told that the Bengal lorises at the Center sometimes stripped bark off of the branches, and some enclosures had markings that could potentially be from gouging. The marks didn’t look exactly as pictures I’d seen in the literature, however, so I wanted to confirm they could gouge by seeing it for myself!

Some marks on a liana in an enclosure housing two pygmy lorises I saw soon after arriving at the EPRC. At the time, I thought they could potentially be gouge marks, but I wasn’t convinced.

Setting up a camcorder and a camera trap

I ended up setting up a camcorder and a camera trap in the enclosure of two pygmy lorises, Tweet and Chip, who in other ways had been identified as potential candidates for release back into the wild. I smeared gum on bark fixed inside their enclosure, but after about two days of recording, I realized that they were just licking the gum off the branches. No gouging was seen to my disappointment. Then, a keeper who had been working with me to set up the cameras and place different types of bark in their enclosure proposed that we drill holes in the branches to place the gum inside to entice the lorises to gouge. So, we drilled holes in some cut liana and placed gum inside every day. After a few days of recording, I was able to see some definitive gouging from both Tweet and Chip, with clear evidence left behind in the morning! I was so happy, as a loris that can’t gouge, can’t survive in the wild! I still have more work to do related to the lorises and testing their gouging abilities, but I feel like I’ve made some good progress!