Late Night Howlers- Tracking Monkeys Through the Rainforest

The first time I heard a male howler monkey I could've sworn I was back in my bedroom listening to trucks rumbling down the freeway five miles away.  Whether you are up close or far off, the sound of a howler monkey is loud and very distinct.  If you happen to walk into an area of trees where a family is quietly relaxing, the noise and activity above head can be downright frightening.   

Walking through the rainforest at night is a unique experience, I think the only place darker is a cave.  There are no lights, not even the moonlight can penetrate the rainforest canopy. 

On my second night in Costa Rica my professor insisted on taking a night hike, I am glad I went but probably won't do that again.  Minutes out we heard howler monkeys for the first time, man were they loud.  Our guide guessed that we were entering the territory the family had staked out for the night, and the male was howling because he heard possible predators (us) closing in.

After a long day hike the next morning my partner and I were feeling a little bummed that we had not yet seen any monkeys or peccaries, the animals we had been assigned to study.  As we walked back to the station we could hear a male Howler monkey, and the sound was getting louder.  We all but forgot about lunch as we and other students and biologists watched a family of Howler monkeys playing in the trees next to the dining hall. 

An entire family had taken to eating and playing in the trees while the male howled on.  Here is a picture of one female and her young.

The male that was doing the howling was not very active, and sat off to the side watching us and the surrounding trees.  Here he is, I wish you could tell how big he is, when he is sitting he looks less threatening.

 A young male is still with the family and goes from sitting off to the side and observing the family to playfully joining in.  Most of the time the dominant male does not allow even the young males to remain with the family, I think this guy is getting close to the age when they are forced to find families of their own.  That would explain the way he feels out the group before he joins in the play. 

Once he started playing we were sure he was a male, pretty clear even that far up in the canopy.  And he kept playing in the trees till we left- knew he had an audience.  

See.....

Up next, White Faced Capuchins on the River