Thursday, August 8, 2013

What spooked the hamadryas baboons at Emmen Zoo?

Someone or something done did spooked the hamadryas baboons at Emmen Zoo in Netherlands last week. All 112 baboons in this Dutch zoo were exhibiting rather unusual behavior according to numerous news sources.

Here's what I gathered about the hysteria from different news sources:

  • The hamadryas baboons in Emmen Zoo suddenly became hysterical last Monday. It took about an hour to get the baboons to go back into their night enclosure in the evening, which normally takes about a minute according to the zoo spokesman.
  • For the next two days, one group sat in a tree and "refuse" to come down while another group sat on an exposed part of the island in the hot sun. This group later moved to a shadier location, but remained "depressed". The baboons were huddling together.
  • The zoo keepers brought apples for the baboons (awww, they do love apples) but the baboons ignored the treat. Keepers also placed food above ground, which are normally hidden in the ground to elicit foraging. The baboons also ignored the food. It it not until the third day that the baboons started eating.
  • "They [the baboons] would sit with their backs to the public. They wouldn't make much noise; 'it was rather silent, which is not normal for a baboon'", said Wijbren Landman, Emmen Zoo's press officer and biologist.
  • "If one of the leaders is shocked by something than most of the colony will obey him and then the whole colony will be shocked. But what really caused one of the leaders to be shocked, well, we didn't find out", Landman added.
  • This wasn't the first time these baboons were acting weird; it happened in 1994, 1997 and 2007 as well. In 2007, all the baboons were observed looking at a very specific direction. Since hamadryas baboons can live well over 30 years old, some of the individuals in the zoo have experience previous hysteria.

OK I used a lot of air quotes but bare with me on this one. If you really want to look at animal behavior and why animal exhibit these behaviors, one mustn't anthropomorphize the behaviors. The worse is when the baboons were described as being depressed. Or when the NPR article asks why the baboons were so sad. So instead of saying that the baboons were sad or depressed, one could say that the baboons were lethargic or not moving a lot? At least that's how I feel about it. But whatever, it's the news and not a scientific journal. 

Some of the theories put forth as to what had spooked the baboons:

Lighting and thunder

Probable. Maybe there was a thunder that strike near the zoo.


Though there no records of earthquakes in or around Emmen Zoo but the area does occasionally experience minor earthquakes. Did they felt something that wasn't on the radar, so to speak?

Aliens or UFO

This is not the History Channel. Let's not go there.

Predators such as a snakes, foxes or aerial predators

Very unlikely. Again, if they are easily spooked by other animals then there would have been more episodes of hysteria. According to Landman who consulted a "French baboon expert", hamadryas baboon exhibit hysteria in the wild, triggered by awareness of a predator but for a relatively short period of time.

Zoo visitors

Zoo visitors might have spooked the baboons or maybe wore a T-shirt that has a picture of a predator (according to one of the news article, a lion). This is also very unlikely. Probable but unlikely. Just like the predator explanation, the baboons would have exhibited more frequent episodes of hysteria. But there might be other ways that the zoo visitors had unintentionally spooked these baboons. Maybe wearing a specific type of clothing. The baboons I worked with reacts aggressively towards visitors that wear trench coats (I would too, ewww the 90s called and they want their clothes back). 

So what do I think spooked the baboons? I'm gonna go with the unpopular opinion. I think it is a fear response towards zoo visitors. But what spooked them? For the fourth time in 20 years? Your guess is as good as mine. Wish I was there to observe their behavior though!

Any guesses on why the baboons were spooked?

Mysterious Apathy: Baboons Go on Strike in Dutch Zoo from Spiegel online 

Spooked baboons baffle Dutch zoo in Emmen from BBC

Baboons At Emmen Dierenpark In The Netherlands Baffle Dutch Visitors, Zoologists from Huffington Post

Baboon updates from Emmen Zoo.

All photos from Spiegel Online.

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