Nighttime migration calls of Eurasian Bittern

Nighttime migration calls of Eurasian Bittern

Written by Maarten Wielstra
Photo by Menno van Duijn

I just need to write something about a bird sound that not many birders know of. This blog is about the flight call of Eurasian Bittern, which can be heard at night while these birds are migrating. Since I’m familiar with this phenomena, I’ve heard several in the coastal village I live in. The nice thing is that it is not a rarity and it can probably be heard everywhere and year round.

Places that normally won’t give any sightings of Eurasian Bittern, should deliver them by migration call, even in urban areas. The first time I heard one was while catching moths next to my house in October 2012. The second experience was that of two birds together while grabbing a beer from my shed in December 2012. A few days later another one flew by. October 2013 I heard one, so I posted for an hour to score the next one! After migrating myself, to another house in the same village but at a much more inland location, my bedroom window gave me excellent hearing of another nighttime Bittern in October 2015. Last week, March 2016 brought my first spring record, while I was just walking for a few seconds between my car and my front door.

All the Bitterns I heard migrating at night were calling on very clear and quite nights, for example during incoming frost. So with lots of stars and without any noticeable wind. When you first hear the very loud and hollow Greater Black-backed Gull-like call, it will take another few tens of seconds to hear the next one. It will give you some time to get to your sound recording device. If calls are repeated more rapidly, you’re probably listening to more than one individual.

The sound I’m writing about can also be described as a slowed down Black-crowned Night Heron, but without the frog-like quality. Possibly part of the Night Heron claims are indeed Bitterns! I managed to record it five times, which can be listened to at the following links:

As one can hear, this sound is just awesome! It is really very characteristic, but still much unknown to many. I’m just loving it…

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