Predicting a Clark's Nutcracker Irruption

I photographed this Clark's Nutcracker in northern Utah on 28 July 2013, but if it can't find enough pine nuts, it might be headed to your neighborhood.

I've seen two unusual events in the last few days that make me think this year might be a big one for vagrant Clark's Nutcrackers in the ABA area.  On Sunday, I was birding in typical Clark's Nutcracker habitat at about 8,100 ft. elevation near my home in northern Utah.  This is a species that is relatively common here, but we were doing a big day, and it's not so common that it is guaranteed to be found in the two or three hours we could afford to spend in its habitat.  In two or three hours of birding, we would expect to probably run in to a few of them.  Our expectations were off: in just a few hours last Sunday, we counted almost a hundred, moving around high overhead in flocks of up to 40.  Although the species is expected here, these kinds of numbers are not typical for this area and time of year in my experience.

This view of Cache Valley is from a point almost high enough to expect Clark's Nutcrackers.  That species is also expected across the valley, in the peaks covered with snow in this picture.  To find one down in the bottom of the valley, where you can see Cutler Reservoir shining, is very unusual, and is unheard of any time other than winter.

On Tuesday, a couple friends and I were birding in the middle of Cache Valley, at about 4,500 ft. elevation.  This is well below typical CLNU habitat, especially in summer.  In the seven years I've lived in this area, I know of just a few credible reports from the valley, almost all from the "benches" very near the mountains and all between October and December.  Yesterday, we saw a flock of 28 Clark's Nutcrackers flying over the middle of the valley, barely in to September.

This is what a Clark's Nutcracker can look like in a good year, with a crop full of pine nuts that it will cache around the area to feed on in the winter.  I photographed this one in 2011 in northeastern Nevada.

The Birds of North America account for the species indicates that Clark's Nutcracker irruptions are most likely to happen when two years of above average pine cone production is followed by a year of very poor production.  In years of good pine nut production, Clark's Nutcrackers are successful in raising young and mortality is low.  Two years of good production can build up population sizes well above normal.  When a bad year follows, there are way more Clark's Nutcrackers than nutcracker food, and the birds have to wander widely to find the nuts they need to survive.

In both 2011 and 2012, pine cone production by whitebark pines, one of the nutcracker's two main food sources, was higher than average.  The very dry winter last year (about 60% of typical snowpack locally, and around that or lower in much of the inland west) has caused poor production by whitebark pines this year, in Wyoming the lowest since about 2002.  Coincidentally, in 2002, Clark's Nutcrackers were reported from as far out of range as Alabama and Missouri.

This figure shows the standardized whitebark pine production from the Greater Yellowstone ecosystem for the last 24 years.  Note that both 2011 and 2012 were above average years, but 2013 is about the lowest since 2002.  This figure is from here and is in the public domain.

Based on my observations over the last few days, and the current status of whitebark pine production compared to previous years, I'm guessing that this will be a good year for vagrants of this species in North America.  Most movements of Clark's Nutcrackers are relatively local, so this is most likely to affect birders who live near Clark's Nutcracker habitat, but are a bit outside their usual range.  However, there is also potential for long-distance wandering, perhaps well outside of the species' expected range.  It might be helpful to study the call, and to be sure you're familiar with this species, so you're prepared if a Clark's Nutcracker should find its way near you this winter.

Himalayan Snowcock Expedition with BAS

This weekend, I led a Bridgerland Audubon Society field trip to the Ruby Mountains of Nevada in search of Himalayan Snowcocks. The Himalayan Snowcock is a large grouse, about the size of a Greater Sage-Grouse, that is adapted for living in the high rocky peaks of the Himalayan Mountains. In the 1960s and 1970s it was introduced to the Ruby Mountains of Nevada for hunting. The introduction was successful, and now this isolated mountain range is the only place outside of the Himalayas where this species can be seen. This species is sought after by the top birders of North America, and a visit to their habitat was depicted in the recent movie, The Big Year.

On Saturday morning, I met the other birders on this BAS trip in the hotel in Elko at 4:30 AM, and we were on the trail at the end of Lamoille Canyon a little after 5:30 AM. We arrived at the bench above Island Lake just as the sun was starting to hit the tops of the mountain peaks around us. At least four Himalayan Snowcocks were calling from various points around the cirque of cliffs. (The calls were all heard within about a half hour after sunrise, then the birds stopped vocalizing). Collectively, we saw two individuals, and the whole group had leisurely scope views at one individual as it foraged around a ledge in the cliffs. We also watched several flocks of Black Rosy-Finches flitting around the scree below the cliffs. We had found our target bird before 7:30 AM, so we spent a little while looking for more of them, and watching the mammals of the area, which included Mule Deer, Pika, and Mountain Goats. We then headed back down to the trailhead to start another hike.

The next hike we took was a loop to Lamoille Lake. Some parts of the trail were a bit icy, and the early parts of the trail were very birdy, so the hiking was slow. Clark's Nutcrackers were actively gathering and caching pine seeds in a large open stand of pines. We were impressed by the numbers here, and estimated about 300 individual birds in this 3.5 mile loop, most of which were in the first mile. It was fun to watch the nutcrackers extract the nuts from the cones with ease and fill their crops to the point it looked like they might pop, before flying off to a suitable place to hide them for the winter. Other species seen along this loop included Golden-crowned Kinglets, Red-breasted Nuthatches, a White-breasted Nuthatch, Brown Creepers, and three Dusky Grouse, among others. GCKI and BRCR are apparently pretty rare in northern Nevada: eBird has only five and four (respectively) previous records for these species in Elko County.  We ended back at the parking lot at about 3:00, tired from our early start and many miles on the trail at high elevation, but thrilled with finding many great birds including our target bird, the Himalayan Snowcock.

Field Trip this Saturday: Cache County's High Mountains

This Saturday, 16 July 2011, join me and the Bridgerland Audubon Society as we hike around Cache County, Utah's Tony Grove Lake and towards Naomi Peak in search of the specialties of our high mountains. Target birds include Red Crossbill, American Three-toed Woodpecker (above), Clark's Nutcracker, Golden-crowned Kinglet, and Steller's Jay, among others. Rarities seen in this area in previous summers include Band-tailed Pigeon, Red-headed Woodpecker, and White-winged Crossbill (below). Pack a lunch and lots of water, and be prepared for a strenuous hike, but at a slow birding pace. The trip is free, but bring a few dollars to help cover the $5 parking fee. Meet at 8 a.m. in the parking lot between Caffe Ibis and the Logan Fire Station (50 East, 150 North, Logan). All skill levels are welcome. We will be back in the mid-afternoon.

More Mountains

Today Craig Faulhaber (above) and I hiked from Tony Grove to White Pine Lake. Again, I was in search of some of the many high-mountain birds I am still missing. I was able to pick up one of those, with my first Steller's Jays of the year. This is probably the most common species I had yet to find. We also saw several mountain specialties I had already seen, like Red Crossbills, Olive-sided Flycatchers, Williamson's Sapsuckers, and Clark's Nutcrackers. But the highlight was a single Band-tailed Pigeon (photo below). This species is common further south in Utah but has only been seen in Cache County a few times.

Mountain Birding

As my list of birds seen gets longer, it gets predictably harder to add new species to the list. However, there is one habitat type that I have not spent much time birding yet this year, and which potentially holds a dozen or so species that are probably present right now waiting for me to add them to my list. That habitat is the high mountians, and last weekend I spent a bit of time on both Saturday and Sunday birding in this habitat. On Saturday, Craig and I birded around Tony Grove. Although we missed some must-have species in the area like Three-toed Woodpecker and Purple Martin, I did pick up several new species for the year, including Clark's Nutcracker, Red-naped Sapsucker, and Williamson's Sapsucker (photo at right). On Sunday Stephanie and I returned to some hummingbird feeders in the area, trying to track down the Rufous Hummingbird that had been reported there. We didn't see the Rufous, but we did get great looks at Black-chinned Hummingbirds and Broad-tailed Hummingbirds, both of which I'd seen earlier in the year.