In the previous blog, I said I wanted sixty-five Western Screech-owls for Christmas. That is, I was hoping we could count sixty-five during the annual Grand Junction Christmas Bird Count (CBC) on December 15. What we got was 52. Sounds well off the mark, but, let’s explore a bit more about the Grand Junction CBC.
This was the 114th CBC held in the US. The first Grand Junction count was held in 1953. CBCs were started as a means of learning what birds were out there, how their populations were changing, and as a counterweight to annual Christmas-time hunts which, in some cases, had reputations as wintertime slaughter.
Christmas counts are based on counting all of the birds within the same ten mile circle, year-after-year. The Grand Junction count is centered at H and 24 roads.
Back to Screech-owls: Long-time Grand Junction birder, the late Rich Levad, essentially discovered the Western-screech owl in the Grand Junction area by deciding, “There must be more of them.” Rich set out to find them by rising very early morning after morning and going out calling for them. From that humble beginning, when previously only 2 or 3 Western Screech-owls were reported, our counts have risen and risen. We found so many that Rich began referring to the Western Screech-owl (or WESO in birder’s code), as the Grand Valley’s “signature bird.” This was back in the mid-1980s. Soon we had a program for installing nest boxes for WESOs at schools, cemeteries, golf courses and private yards. We had to do this because the valley’s growth was causing too much loss of the old cottonwoods that have the cavities WESOs need for nesting. We now have more than 100 WESO nest boxes in our count circle.
More numbers perspective: Owls are not like house finches or mourning doves in terms of numbers. Typically, we count approximately a thousand each of the latter two species during our CBC. A good count of WESOs, on the other hand, was typically in the 30s with our highest counts being in the 40s. Still, this was enough to make us #1 in WESOs—at least sometimes. We all have to be number one in something, don’t we?
Human population growth affects WESO numbers, but we have another problem. At least half of our count area is in the desert or in pinyon-juniper areas where no WESOs live. In contrast, there are count circles in California that are entirely WESO habitat. How do we beat them? Two reasons! First, we have a uniquely high population here. Grand Junction regularly counts more WESOs than the rest of Colorado and the States of Utah, New Mexico, and Wyoming combined. We almost beat all of Arizona as well—with no count circles in any of those states approaching us. We don’t know what is special about Grand Junction versus the Glenwood Springs or Montrose areas. We can only speculate. Perhaps, our slightly-lower elevation and typically fewer days of snow cover are “just right.”
The other reason we count a lot of WESOs is effort. On the Sunday morning of count day, if you had been out early—especially in the Fruita area where there is a lot of line-of-sight; you would have seen cars moving around in the pre-dawn and stopping every so often. Inside, were bundled up birders. Each had a list of 10 or so “stops.” At each one, they would get out, play the call (http://www.youtube.com/watch?v=rCHdsdx2fpg), and listen and record what happened. Most stops were unproductive where the only thing noticed was the numbing fingers. (Gloved hands don’t work so well fumbling with an iPod or iPhone to play the call.) But, every now and then, there would be the soft answer. Notice how the call is so different from the loud slow “hoots” that most people associate with owls. The “hoots” are from Great-horned owls—also common in the valley, and much more visible than WESOs.
Sometimes, if the group was lucky, an answering WESO would fly into overhead branches. Sometimes, the owl would be only a voice in the darkness. Sometimes, one flew in silently. But, all were counted. Seventeen teams participated in this effort, and many groups had more than two participants. That’s right, approximately 50 of your friends and neighbors were out calling and listening—with hope for the dawn and a nice cup of organic coffee (couldn’t resist-- http://www.cafecristina.com/).
As the sun rose, everyone called me with their results. We had 34. How did we get to 52? Well that involves what Rich called “the peeper.”
We have two, and two more volunteers from Rifle brought two more over. These two teams spent the entire day driving the count circle to look in most of the 100+ owl boxes that were not near areas where owls had been found in the pre-dawn. (We have to be honest to stay #1. No double-counting allowed.)
I think 52 was a spectacular number. We have no hard data, but our experience and preliminary research data elsewhere indicates that WESOs do not like to call when the moon is near-full—as it was on count day. This may be because of increased risk of predation. Great-horned owls, for example, will happily dine on WESO. It was also cold. It is difficult to call just a little longer at a spot on such a cold day. So, even though 52 is quite a few less than last year’s 64, there were good reasons, other than a drop in the owl population, why we counted fewer. Time, as always, will tell.
52 was our third highest count ever—all in the last three years—coinciding with morning routes that now cover all of the valley’s areas—although not every likely WESO location. (We could do more with more volunteers!) The high numbers are also a result of the two camera crews out all day to check all of the boxes. Here’s what 52 means. Last year, 138 count circles reported at least one WESO. That’s one perspective. Now, in all of those 113 years of CBCs, more than 50 WESOs in a count circle has only been reported nine times—three by Grand Junction.
(One we missed! This owl was in the owl box in my own yard--but on Monday--the day after count day.)
So, why do we do this? We do it for fun. It is exciting to hear an owl answer or see it fly in from the darkness. But we also do it for science. Here’s more number perspective from the Grand Junction CBC (Keep in mind, there is now more participation/effort than ever before): Lewis Woodpecker in 1995 was 10. This year: zero. Ring-necked pheasant 1999 was 84. This year 1. Why? Probably loss of orchard and agricultural habitat to development. Eurasian Collared Dove in 2004 was zero. This year 593! Whoa! What’s up with that? Yes, this invasive species has now become one of the most common birds in the valley.
How about White-winged doves—common in Southern Arizona? We found three this year, and have reported them four of the past six years. Before that? Never! Why? We need more data, but perhaps the generally-warmer winters of recent decades are causing some to move north. CBCs have documented evidence for climate change over much of the US. So, even though it is just “citizen science,” the data in aggregate mean something, and provide a snapshot of how our valley and its birdlife are changing.
Christmas bird counts are now an international effort. Everyone who helps is part of a huge scientific enterprise. You still have one more chance to participate in a CBC in our area. The Grand Mesa CBC is held January 1. Check our website (audubongv.webs.com) for details or send an email to firstname.lastname@example.org.