Tuesday, February 28, 2017

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. 

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. 


ToniAynia said...

Hello Lily and Robyn,

It’s great hearing from you and getting the first field report!

I find it intriguing when Hyenas turn down the prize because the puzzle box is, I guess, just too intimidating?

Aside of the landfill, are there any other food resources for Hyenas there? I checked the maps and I didn’t see any cattle pens. However, of course my view is from satellite so there very well could be livestock in the area.

I’m curious as well why these Hyenas would venture into town. How is the overall culture towards Hyenas here?

Some of Hyenas’ reactions to the MAB almost seem like when a human recognizes a bomb, quickly fleeing away from it. To your knowledge, has there ever been any kind of destructive baiting like this in that area?

One reason I had this thought is from the satellite imagery. There appears to be a great many pock-marks (for lack of a better word) across the landscape there. I have no idea what these marks could be (these could be oil and water drilling points), but is it possible some of these pock-marks are the result of some kind of explosives intended to deter Hyenas or other predators? And could they have placed those explosives in a box baited with meat? Or could it be that some Hyenas are just deeply afraid of anything having to do with humans?


Speaking of other predators, have you noticed any Lion activity in the area?

Wow, yeah, Grizzly sure does appear to have been “through the wars,” as they say. Poor Koala, he just laid himself down. Aww! I’d say most folks not part of a study group such as yours have no idea Hyena males can and do aggress on Hyena females.

As usual, I appreciate so much and am grateful for your sharings, reading the Hyenas’ names and learning their unique characters. Looking forward to more!

Take care out there and OhWhooop!

Toni… Pennsylvania, USA…

Lily J-U said...

Toni, yes, the hyena do feed on livestock. From what I've heard they usually just eat sick or injured livestock that are abandoned to the hyenas. Outside of the landfill there is also a lot of meat scraps dumped everywhere. Like most of Africa, meat isn't slaughtered in large slaughter houses but is sold in tiny little butchers on every street corner. This means a lot of meat scraps scattered all around town. People are generally very tolerant of the hyenas and treat them similar to stray dogs. People walking down the street will throw rocks at nearby hyenas but they don't hunt or poison them.

There are no explosives in Mekelle or the surrounding area or any of Tigray as far as I know. Some of the Mara hyenas were also very afraid of the box and startle easily... in fact, this is a very normal behavioral reaction to any novel objects that we give hyenas. There just appears to be a higher frequency of very nervous hyenas in Mekelle compared to the Mara. Though most hypotheses about urbanization suggest urban animals should be less neophobic towards novel objects due to habituation to humans, other hypotheses suggest that increased neophobia can be very adaptive in urban environments because it helps animals deal with novel threats that cities pose. It may be that one reason hyenas are so successful at becoming urbanized in Ethiopia is because they are very nervous of humans which in turn means that they have a healthy respect for humans (and will flee instead of attacking).

There aren't any lions here, but there are leopards that apparently live outside the parks.

ToniAynia said...

Hello Lily!

Thank you so much for taking a moment from all your work over there to write and share your observations and knowledge!

It’s quite fortunate for the Hyenas that there are those butchers’ meat scraps and some livestock available to them. As well, it sounds as if the culture there is not particularly hostile against the Hyenas.

I’m very glad as well to hear there are no explosives or such in the area.

Are there any naturally occurring prey species (e.g., antelope, pig, and so on) that Hyenas could hunt? Or is the area more or less entirely livestock?

If there are other prey species, would these Hyenas tend not to focus on those but instead in conserving energy avail themselves of easier food opportunities with butchers’ scraps and livestock left to them?

The reason I ask is if indeed the Hyenas there focus more on the easier to access urban food, does this have any affect on any other Animal species’ populations, provided of course there are any others in the area. I imagine though that there’s not enough time available to study in such depth the effects of Hyenas’ diets on surrounding biodiversity.

The affects of urbanization are interesting indeed and your study there does correct the notion some humans have that all urbanized carnivores are “always” a threat to humans. At least the Hyenas here seem to prove that notion to be rather incorrect.

It’s interesting that Hyenas can be neophobic towards novel items such as the puzzle boxes and yet will show curiosity towards vehicles. Is it possible that because the vehicles don’t necessarily smell like food, the stress of competition for food is less and so also the fear aspect is lessened? Did any of the Hyenas there show any interest in your vehicle or did they exhibit neophobia for the vehicle as well?

Sorry for all the questions and I thank you again for being so generous with your time and sharing your observations with everyone, and especially grateful for all the work you do in helping us all learn more about the amazing and wonderful Spotted Hyenas.

Thank you!

Take care out there and OhWhooop!
Toni… Pennsylvania, USA

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