To familiarize or not?

Hello everyone, it's me again, that grad student testing hyena cognition. It's pretty standard protocol in the cognition testing business to familiarize your subjects with the testing apparatus so that fear doesn't stop them from participating. I've always thought that seemed like sound science and I've been doing this with the hyenas. Wild hyenas tend to be more fearful than captive hyenas and I want every hyena to have a chance to solve the box, not just the bold ones.

For those of you new to our blog, my "testing apparatus" is a multi-access puzzle box. It's a box that's baited with food on the inside that has four different "doors" or ways of opening the box to get the food inside. During a familiarization trial with the hyenas, I take the lid off of the multi-access box and put it on its side so that hyenas can just walk up and eat the food from inside the box. This way they get used to the smell and texture of the box and learn to associate it with food (and not scary things).

Hyenas investigating the box during a familiarization trial. 

However, I've noticed that a large proportion of hyenas who have opened the box did so on their very first time interacting with it. Yep, zero familiarization trials. This has happened enough times that I've started to wonder if giving the hyenas familiarization trials might also make them lazy. I.e. they've learned the box has free food inside it. When they're given a test trial they don't try to open it because they're used to getting the food for free. I've had many hyenas sniff around the box once and then sack out just a few meters away, to all appearances just waiting for the box to magically open.

Hyenas investigating the box during a test trial. Many of these hyenas had familiarization trials, but TERV (no familiarization trials) ended up solving it. 

Then I had this trial yesterday with Burger (BRGR). I put out the box for ADON, whose had 2 familiarization trials but ADON wasn't interested and remained sacked out in her spot under a shady bush. After I put out the box BRGR emerged from the bushes. BRGR has watched other hyenas' trials with the box but she'd never contacted it herself before nor had a familiarization trial where she fed from the box. Yesterday, however, she was quite curious about it; after less than a minute she opened it using the door knob. My excitement slowly turned to dismay as BRGR never got up the courage to eat the food from inside the box after the initial shock of the door knob opening. Most hyenas who open the box once are fairly good at opening it again. But since BRGR didn't feed, she won't be able to form an association between solving the box and getting food. I have no idea what her reaction to the box will be next time she sees it! Now I've learned though what the benefit of a familiarization trial can be! If BRGR had stuck her head inside the box to eat during a familiarization trial I'm sure she wouldn't have been afraid to stick her head inside this time. I've decided that I should still attempt to give all hyenas at least 1 familiarization trial which will hopefully balance the cost of potentially teaching the hyenas to be lazy with the benefit of teaching them not to be afraid.