Urban Hyena Update

Hello everyone, I'm Lily, a graduate student studying cognition in urban hyenas in Mekelle, Ethiopia. Here's an update on what's going on in Mekelle! 

We finally got to see Rake in the daylight. Usually we set up just around dusk when it's still light out and then as it gets dark hyenas start to trickle through. We set up on a "hyena highway" between their denning sites just outside the city and the sites inside and around the city where they forage. You can hear a lot of human activity on the road; the hyenas appear quite used to this. 

Some surprise visitors! These porcupines just waltzed into this trial like they owned they owned the place. The hyenas didn't seem afraid, but they definitely respected their space!

 

Another visitor: the African Golden Wolf. Originally thought to be the same species as the Golden Jackal which lives in Asia, scientists discovered that these "jackals" are actually more closely related to wolves. 

Meet Elmo: a young subadult that is pretty fond of the box. Notice the three adults who are keeping at a "safe" distance. 

Unfortunately this is Elmo's favorite thing to do when he's near the multi-access box. Luckily he's really adorable so we don't mind watching him! 

Finally: English opens the multi-access box using the drawer! This is the first urban hyena to solve the box and he's opened the drawer twice now. Unfortunately for us, English appears to be extremely low ranking. We've seen him several times, but he only approaches the box when there are no other hyenas around. We're keeping our fingers crossed that he'll come back and open it a few more times! 

Mekelle's Urban Hyenas

Hello, if you're new to the blog I'm a graduate student studying hyena cognition. I'm currently in Mekelle, Ethiopia to study a population of urban hyenas. Previous blog post: http://msuhyenas.blogspot.com/2017/02/urban-hyenas-in-ethiopia.html

This is the first update on the urban hyenas of Mekelle. Robyn and I have been testing hyenas at two sites on the outskirts of Mekelle. One is near a private high school along a road that the hyenas commute along every evening on their way into the city. The other site is at a landfill where a different group of hyenas forage. So far we've documented over 50 unique individuals by the road. After a few nights at the landfill we dropped it as a study site because they hyenas are busy foraging on their own and weren't very interested in the MAB.

The urban hyenas are completely nocturnal and are also afraid of white light. Therefore, we've been using IR spot lights and IR sensitive camcorders to observe and record them. We have to keep extremely quiet while we're sitting in the car. 

About half the time this is what we observe: 

 

But eventually the MAB tends to get really busy and it gets hard to keep track of everyone. It seems like these hyenas are really gregarious compared to the Mara hyenas, there's very little aggression over the food in the MAB. 

Things were pretty quiet at our Landfill sessions:

Radio, an adorable subadult, feeds from the MAB.

Some excited lope arrivers scare off Radio, a subadult who's fed from the MAB several times.

Koala is a really nervous subadult. Most of the subadults we've seen are fairly bold and many have eaten from inside the MAB but Koala just can't quite bring himself to contact it. 

Grizzly is definitely the gnarliest hyena I have ever seen. She looks like a really tough gal who's been through some crazy stuff. 

Males here are just like males in the Mara.. they'll aggress unprovoked on females when the opportunity arrises! This behavior is called baiting and male hyenas tend to do it more often when female hyenas are receptive which suggest some role in relation to mating. Here Copperhead bites Heron's leg while she's distracted investigating the box. 

See this link for more on baiting: http://onlinelibrary.wiley.com/doi/10.1002/ab.10065/abstract

Moose, an adult female, feeds from the MAB.

We nicknamed this guy Squitter-Face during this trial. Eventually I named him Wombat,  but he was easy to spot by his almost non-stop shrill squittering. Squittering is vocalization usually emitted by cubs and subadults towards their mother to elicit her to feed them.

Thermal camera footage from the landfill. I use a thermal camera to observe hyenas who are not within 5m of the MAB. Once they enter 5m we give them a "trial" and start filming them with the IR spotlights and cameras.

Robyn and I have also noticed that these urban hyenas all seem to be quite rotund... apparently they're getting a lot to eat here. 

Urban Hyenas in Ethiopia

Hello everyone, I just arrived in Mekelle, Ethiopia two days ago to study the urban hyenas of Ethiopia.

My route of travel from the Maasai Mara on the Tanzanian border, to Nairobi where I flew to Addis Ababa and took a connecting flight to Mekelle in Northern Ethiopia in the Tigray region. (Harar is the little red dot in eastern Ethiopia). 

 Ethiopia is somewhat unique among African countries because the people there believe that hyenas consume bad spirits. Because of this belief hyenas are less persecuted than they are in places like Kenya and has facilitated the rise of the "urban hyena". Almost all large cities in Ethiopia support large populations of hyenas that scavenge from rubbish dumps and domestic animals.

Harar, Ethiopia is the most well known city for seeing these urban hyenas because of the "hyena men" who feed the hyenas nightly as a show for tourists. 

In Mekelle I'm collaborating with a scientist, Dr. Gidey Yirga, who was been studying the urban hyenas of Mekelle. In Mekelle, hyenas congregate around the rubbish dumps on the outskirts of the city and this is where Dr. Gidey has been studying them. Interestingly, the result from a genetic study done by Master's Student Elien Schramme suggests a massive break down of clan structure in Mekelle with little to no genetic structuring despite an extremely high density of hyenas (1.84 individuals/sq km). This density is far higher than any other hyena density on record, the next highest figure is 1.5 individuals/sq km in the Ngorongoro Crater in 1972. 

Though domestic animals almost entirely make up the diet of spotted hyenas, Dr. Gidey has found that the economic loss is minimal. On average hyena depredation of livestock costs households about 0.7% of their annual income (disease in livestock costs 1.6x this much). This is largely because most of the food hyenas obtain is through scavenging at waste dumps, rather than active hunting of domestic animals. The exception to this rule is during the Christian fasting period when hyenas make up the largest part of their diet from hunting donkeys due to reduced waste availability. 

I'm planning on going to the rubbish dumps of Mekelle at night to give these urban hyenas my multi-access box and cylinder detour-task to see how the urban life might affect innovation and inhibitory control! Hypotheses for the evolution of large brains and cognition predict that urban animals will be better problem solvers than rural animals due the demands of surviving in an evolutionarily novel environment.

Disclaimer: I did not take any of these photos! 

Schramme, E., 2015. Social Structure of Spotted Hyena (Crocuta crocuta) Populations around Mekelle city in Tigray, Ethiopia.

Yirga, G. et al., 2013. Spotted hyena (Crocuta crocuta) coexisting at high density with people in Wukro district, northern Ethiopia. Mammalian Biology - Zeitschrift für Säugetierkunde, 78(3), pp.193–197.

Abay, G.Y. et al., 2010. Peri-urban spotted hyena (Crocuta crocuta) in Northern Ethiopia: diet, economic impact, and abundance. European Journal of Wildlife Research, 57(4), pp.759–765.

Yirga, G. et al., 2012. Adaptability of large carnivores to changing anthropogenic food sources: diet change of spotted hyena (Crocuta crocuta) during Christian fasting period in northern Ethiopia. The Journal of animal ecology, 81(5), pp.1052–5.

Audet, J.-N., Ducatez, S. & Lefebvre, L., 2016. The town bird and the country bird: problem solving and immunocompetence vary with urbanization. Behavioral Ecology, 27(2), pp.637–644.

Maklakov, A.A. et al., 2011. Brains and the city: big-brained passerine birds succeed in urban environments. Biology letters, 7(5), pp.730–2.

Papp, S. et al., 2014. A comparison of problem-solving success between urban and rural house sparrows. Behavioral Ecology and Sociobiology, 69(3), pp.471–480.

Preiszner, B. et al., 2017. Problem-solving performance and reproductive success of great tits in urban and forest habitats. Animal Cognition, 20(1), pp.53–63.

Snell-Rood, E.C. & Wick, N., 2013. Anthropogenic environments exert variable selection on cranial capacity in mammals. Proceedings. Biological sciences / The Royal Society, 280(1769), p.20131384.

  

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.

Hyena Cognition - Hall of Shame

Opening the multi-access box is proving to be a challenging task for wild hyenas. The MAB tests a hyena’s ability to innovate, i.e. learn something new. So far only a few hyenas have shown that they have what it takes. In November, I blogged about hyenas who are champion box openers. This time, I’ll share a little about hyenas who have made contact with the box on multiple occasions, but still have yet to open it.

Bindi – BIND

BIND is the #1 moocher. She’s a high ranking subadult female (her aunt is PBUT, the alpha) and she’s had MANY chances to open the box. However, she’s learned that if she sits and waits, someone else will open the box and then she can use her high rank to push the other hyenas out of the way (including the unfortunate soul who opened the box) and eat all the food inside. In the video MUSS opens the sliding door, runs off with his meat, and BIND promptly comes up and monopolizes the box in her typical fashion.

Clarity – CLTY

Clarity is a subadult male of unknown parentage, which also means unknown rank. Sometimes he hangs out with high rankers but often acts submissive and nervous. CLTY has had many familiarization trials and made contact with the box every time he’s been presented with it suggesting that he’s not afraid of it. However, as well as being socially timid he’s also timid in his interactions with the box and despite contacting the box he’s never tried to bite or paw at it, two behaviors that are necessary to open the box.

Hail – HAIL

HAIL is MVUA’s twin sibling, who is a champ at opening the box. He’s the dominant cub in the litter but he usually seems content to simply let his mother PBUT and his twin sister interact with the box. Anecdotally, it seems like dominant cubs tend to be less bold and explorative than their subordinate siblings. Perhaps the subordinate cubs are just more willing to take risks in order to obtain food! Are you just lazy from growing up as the dominant cub, HAIL?

Princess Buttercup – PBUT

PBUT was going to the be the star of the hall of shame. She was one of the very first hyenas to complete familiarization trials and the first hyena ever to receive a test trial. However, after sniffing the box for thirty minutes she gave up and walked away. I gave her trial after trial after trial including some where other hyenas started to open the box while she was sniffing it. Being alpha, when other hyenas opened the box she also got to feed. Maybe she learned something socially, because after many failures PBUT is now a champion box solver! 

PBUT is now the first hyena to have learned 3 out of 4 solutions. After opening it once, PBUT became a really persistent box solver and is flying through her trials. She opened the push flap first (usually the hardest for hyenas) by pawing it and nudging it inwards with her nose. 

After mastering the push flap in consecutive trials, she used her paws to pull open the drawer in several consecutive trials. Now she’s opened the door knob twice, this was the hardest one for her because she had to learn to use her mouth to bite and pull it open since it doesn’t easily open by pawing it.

 

You’ll notice BIND in the video asleep to the left, standing up the moment PBUT opens it to come in and get a bite!

Princess Tiana – TIAN

TIAN is, you guessed it, PBUT’s twin sister. She was the subordinate cub in the princess duo and like her daughter BIND, TIAN is a big moocher. Probably because PBUT and PBUT’s daughter MVUA are now masters of the box TIAN has learned that she can simply sit and wait for someone else to open the box. It’s interesting that just being high or low ranking does not predict who opens the box! However, her behavior is fairly similar to PBUT’s before PBUT realized that pawing and biting would open it, so you never know… TIAN could surprise me and figure out how to open it someday.

TIAN looks a lot like her sister PBUT, but she has much paler spots.

Trouble – TRUB

TRUB is a high ranking subadult hyena who has had fifteen trials total with the box including familiarization trials and still failed to open it. She’s mostly a “stand and watch” hyena, but she often comes up and sniffs around the box briefly before backing away to watch the other hyenas. Her mother is ADON so she’s not low ranking, but like CLTY she’s timid in her interactions with the box. She’s not a moocher like BIND, but she maintains some curiosity about the box so who knows how her future trials will go!

There are a lot more hyenas who have made contact with the box and even bitten or pawed at it yet still failed to open it even once. However, for a lot of these hyenas they’ve only had one chance at the box and many times there are higher ranking hyenas present that inhibit their ability to explore the box. I’m hopeful that with enough trials most hyenas will become proud members of the hall of fame!

Difficulty and humor when testing hyena cognition...

Update: Hall of Shame is still coming up soon.. but first... some goofy hyena videos.

Testing the cognition of hyenas in the wild can be really difficult, but it's also really fun. MVUA, a young subadult hyena in Talek West, just opened the multi-access box last night (Dec 5th). Unfortunately for me, she was one of 16 hyenas to come up and interact with the box. It's taken me hours to code the video and keep all the hyenas straight! I ended up taking screen shots with ID labels in order to remember who sacked out where. 

For those who are new: the multi-access box is a puzzle box baited with meat. There are four different "doors" for getting inside the box that all require different motor behaviors to open. I'm using it to test hyena innovation and learning. MVUA ultimately opened the box using the "door knob" side. It's a door with a hinge on the bottom and a door knob near the top that opens down and out like an oven door. It's proving to be the hyena's favorite way to open the box. 

Minute 3:28: EIGHT hyenas in my video. And they're all mussy subadults with bad spots.

Minute 5:43: A few more hyenas have sacked out... trying to remember who sacked out where. We're at 11 hyenas now.

Minute 6:55: Now there's a cub pile to the left of the box and I can hardly tell where one cub ends and the other begins! 

Minute: 10:25: Finally, here's the moment where MVUA opens the box. Identifying what everyone was doing at that second was a challenge. 

However, moments like the ones below make up for all the hard work! Hyenas rank at the top in terms of goofy, silly, and creative behavior... especially when they're playing with my cognition apparatuses (aka "toys" to hyenas).

RAST was pretty nervous about the tube, so she used the ditch to hide and sneak a look at it. 

South cubs explore the multi-access box and scare themselves! 

DAMA actually went entirely inside the box. 

GNUG tries to see if he can fit through the box. 

SOUP was really excited to come check out the tube, only the real puzzle here was how to get to it!

And then there was that time a stork walked over and got the meat before Wallflower did.