Monday, June 16, 2008

The Null Survey

A few months ago I volunteered for the U.S. Nightjar Survey Network. This is a multi-year survey of Nightjar populations.  The Nightjar is a family of birds. The survey is led from the Center for Conservation Biology of the Department of Biology at the College of William & Mary. The Nightjar survey is taking place in 37 states with volunteers each signing up for a survey route. The survey must be performed within a certain window in June when the moon is near full. I signed up for a route near Cape Horn near Stanley Idaho. This past weekend was the optimal time allowing the survey to occur just after dark.  Next week was an option, but the moon doesn't come up until 2 am.

Nightjars make up a family of 8 species of birds in the United States. Here in Idaho we primarily have two species the Common Nighthawk (not actually a hawk) and the Common Poorwill.

Karyn and I took advantage of the weekend to go camping in the Stanley basin, one of our favorite places. Karyn's parents decided to join us although I was skeptical about their commitment to spend most of the night out counting birds. In the end they were great troopers and helped a great deal. We chose Friday night for our first attempt since the weather had to be clear. If it wasn't we would have to try again on Saturday. As it ended up, Friday was clear and unbelievably calm and beautiful. We started in an old ghost town named Wagontown near Cape Horn Idaho. The route had been predetermined by the survey network. Our job was to wait until dark, count all of the Nightjars we heard in a six minute interval and then move down the road one mile.  We would then repeat the six minute count and once again move a mile down the road. Ten counts later we would be done.

We started right at 10pm. The moon was high and the last light of the sun had just left the sky. We started the timer.  There were birds singing everywhere.  How could we hear the Nightjars with all of the noise? Two minutes into the first count the forest fell silent. All the day birds had just finished singing for the evening. In hindsight we should have waited a few more minutes to begin.  The first count completed with no Nightjars. We moved on to the second stop. None here either. At the third stop we didn't find any Nightjars but we did hear an owl.  I couldn't place which type. In the van I quickly played all of the owl sounds I knew to be in the area. No match. On to the fourth count. No Nightjars.

The weather was completely calm and the sky was clear.  The stars shined brilliantly above as we hoped to hear the whistle of the Poorwill. Nothing. At the sixth stop there were no Nightjars, but we heard another owl in the distance, same type. The remaining stops produced the same results. No Nightjars, unknown owls in the distance. At one stop two Sandhill Cranes not far from the road started their call. That definitely wakes a person up in the dark near midnight. A protesting Killdeer could be heard in the distance. Was it our disturbance or was there a predator about?

The tenth stop finished just after midnight. No Nightjars for the evening. Regardless, it was a very enjoyable evening and well worth the effort. A survey indicating that there were no birds is just as scientifically important as one the returns many birds. After filing the paperwork I have fulfilled my obligation for the survey for this year. I plan to be back out on the same route next year.

The next day I was still intrigued by the owl call. I took out my ipod with BirdJam loaded on it and played the nocturnal playlist (bird calls of all the nocturnal birds in the western United States). As Karyn and I listed the answer played over the speaker. The Boreal Owl! I didn't even know we had them in Idaho. Multiple guidebooks confirm that there should be a population in this area. Rare but not unusually so. In a couple of weeks when we return to Stanley I hope to go try to find one of the birds.

In all it was an excellent weekend of bird watching, tandem cycling, and on Sunday we hiked the Boundary Creek trail for a great vista of the Sawtooth mountains. Here is Karyn posing from our lunch spot.

Update: July 7, 2008: After consulting with some Idaho bird experts it is highly unlikely that we were hearing Boreal Owls in the distance. This past week we returned to some of the survey locations to see if we could either find Wilson's Snipe or Boreal Owls (sounds very similar). We found multiple Wilson's Snipe, thus I conclude that it was Snipe we were hearing in the distance on the survey night.

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2 comments:

John said...

Surveys that fail to find the target birds can definitely be enjoyable. Great find on the boreal owl? Are you reporting it?

wolf21m said...

John, Thanks for stopping by. Yes, I have reported the Boreal Owl to ebird.com and to my local Idaho list. I am the list compiler for Custer county where I performed the survey.