Great Basin Bird Observatory has been heavily involved with all things Pinyon Jay of late, and among these many programs, is our first year of statewide Pinyon Jay surveys in Nevada. These surveys began in the early Spring and are scheduled to go through the end of September; surveyors were freezing their tails off in March, and some are still out there beating the heat! This is because Pinyon Jays can begin nest-building as soon as temperatures allow, sometimes as early as February. Nesting is a critical aspect of their life history, and we want to catch as much of it as possible with our surveys. By the fall, they are engaged in another very important behavior—the harvesting of Pinyon Pine nuts! The harvesting of Pinyon Pine nuts is potentially the most critical aspect of their life history, these birds are incredibly dependent on pine nuts. By observing their behavior and habitat use at these critical times of year, we can fill knowledge gaps and inform habitat conservation. This year, I got a chance to do some surveys, here is my ebird report!

Pinyon Juniper woodland in the Clover Mountains, note the hard edge of a treatment zone between PJ and sagebrush in the background. Photo by Ned Bohman

Pinyon Jay with nesting material. Photo by Ned Bohman

This may seem like unlikely Pinyon Jay habitat, but the birds were flying up and down these washes, visiting cache sites in the cliff walls and on the ground. Photo by Ned Bohman

Pinyon Jays use large areas of the landscape for their home range, and these home ranges typically include significant variation in habitat. This is because Pinyon Jays need different habitats for different parts of their annual cycle and life history. In late winter and early spring, they are establishing the flock’s nesting colony site. These are typically at the upper edge of the transition zone between open lands and Pinyon-Juniper woodlands. The specific composition of these open lands varies from region to region, but is typically made up of grasslands or shrub-dominated habitats consisting of sagebrush or blackbrush. Throughout the spring and early summer, the birds will travel from this colony site to caching and foraging locations throughout the flock’s home range, which can be miles from the colony. Caching locations are most commonly found at lower elevations of the home range, as well as on slopes and patches of large bare ground that tend to be free of snow more often in winter. Later in the summer and throughout the fall, the birds move to more densely forested areas of their home range. The Pinyon Pines that compose an important component of these forests are producing ripe nuts at this time of year. These Pine Nuts will be the winter sustenance of the flock. Throughout the coldest months of the year Pinyon Jays sole food sources are caches of these nuts that they have made throughout the preceding autumn.

Adults, encouraging their kids to flee. Photo by Ned Bohman

Because of this fascinating and unique life history, standard survey techniques aren’t the most effective way to survey for Pinyon Jays. The knowledge gaps remaining in their natural history are largely a result of this; and without this knowledge an effective conservation strategy can’t be developed. With a specialized protocol, we hope to fill these in and develop an effective conservation strategy. The protocol for these surveys was developed by the world’s Pinyon Jay experts of the Partners in Flight Pinyon Jay Working Group. These surveys are plot-based area searches on 2.5 kilometer square plots. To complete a survey, the surveyor must spend 3 hours and get within 1000 meters of all points on the plot.

Pinyon Jay fledgling begging. Note the pale yellow inner edge of bill (the gape), and overall gray color. Photo by Ned Bohman

In late May, I got a chance to help out with some of these surveys in southern Nevada. I hit the road from Reno, and got to survey in the Sheep Range and the Clover Mountains. The Sheep Range is on the opposite side of the valley from the Spring Mountains, east of the Corn Creek Visitor Center at Desert National Wildlife Refuge and the Clover Mountains run uniquely east to west, just south of Caliente. Before beginning my Pinyon Jay surveys, I did a few other surveys for other GBBO projects nearby. On these surveys I had my first Pinyon Jay detection of the tour, and also my first of many pseudo-Pinyon Jay detections. In Mount Potosi Canyon, on this same survey every year, I detect 2-5 Pinyon Jays. They are always moving up and down the valley, as if it is an important corridor between key areas of their home range. Perhaps more interesting, the Northern Mockingbirds on this plot were showing a fondness for the uniquely shrill Pinyon Jay fledgling begging calls. Surprisingly, I heard this in every single survey location I travelled to for the remainder of my tour, making positive aural detections a bit of a challenge at times!

My first survey was at approximately 7,000 feet elevation in the Sheep Range, in closed canopy Pinyon-Juniper woodland. I did not expect to see Pinyon Jays on this plot, it didn’t feel like the right time of year for them to be in this habitat, and the fact that I had been to this location a few times before and never seen them also contributed to that sense. However, as they tend to do whenever you think you have them figured out, they proved me wrong! I saw just 4 or 5 birds, likely a family group exploring food resources. They perched at the tops of a few different pines with ripening cones, appeared to check them out, and moved through the area and were gone almost as quickly as they had arrived. While they weren’t extensively using the plot, it was interesting that they were there. Also interesting, and boding well for later in the year, was an abundance of ripening, green cones on a high proportion of the Pinyon Pines in the area. This turned out to be the case for each plot I surveyed this trip.

My successive surveys took me to a number of different areas and habitat types, and it was great to see so many cones at so many different elevations. My next plot in the Sheep Range, had a rather large group of Pinyon Jay families, attended by a couple dozen gray-plumaged fledglings. I could hear them begging from quite the distance, I could tell there were several birds begging, so I did not suspect Mockingbirds, but still had to confirm I was not being pranked. Once I clambered to the top of the ridgeline they were on, and barely caught sight of them, they moved it along to the next ridge.

Pinyon Jay perching briefly as it passed through my plot. Photo by Ned Bohman

These blurry, bright green cones photographed in May will be ripe in August. Photo by Ned Bohman

Once I got over to the Clovers, my surveys took me up a habitat gradient from shrub land to Joshua Tree-Juniper-Pinyon transition zone, to closed canopy Pinyon-Juniper woodland. One plot in the closed canopy woodland had clearings filled with Sagebrush steppe habitat, and evidence of an old tree removal treatment with telltale hard edges. The lower elevation plots did not have Pinyon Jays at this time. I did, however, have Mockingbirds singing Pinyon Jay fledgling begging calls and many other interesting sightings. Some of these included fledgling Rufous-crowned Sparrows and impressively abundant Gray Vireos on multiple plots. The flyover Zone-tailed Hawk probably takes the cake, though. Every spring in southern NV, it’s worth double checking your Turkey Vultures!

Rufous-crowned Sparrow (Adult) photo by Ned Bohman

I did eventually find Pinyon Jays using the higher elevations of the Clover Mountains. I first heard their calls in the distance, and had quite a time catching up to them. When I did finally catch up to them, they were using the cleared Sagebrush habitat and traveling along the edge of the woodland. It appeared that they were traveling from these open areas, to an area at the base of a large hill, surrounded by closed canopy Pinyon-Juniper woodland. It is interesting to note that most of my Pinyon Jay detections were in closed canopy woodland for these surveys in late May.

Pinyon Pine growing at a lower elevation, covered in soon-to-be-ripe cones. Photo by Ned Bohman

I had a brief opportunity for some fall Pinyon Jay surveys last week, and will hopefully have some more over the course of the month. The fall surveys aren’t just for birds—these surveys feature a cone-mapping component, too. As I mentioned previously, the pinyon pine nut is a critical resource to the Pinyon Jay, because of this, GBBO is tracking the productivity of Pinyon Pines across the state. Eventually we hope to be able to discern patterns in pinyon productivity across the landscape. This particular survey took me to the Desatoya Mountains of central Nevada, where I found the pine cones to be far less abundant than in the mountains of southern Nevada, back in May. I also found Pinyon Jays using habitat at a slightly lower elevation. The birds I saw were caching pine nuts on a sparsely vegetated, south-facing hillside. It was almost as if they were selecting an area that has a good chance of being snow-free in the winter months…. It will be interesting to see what the bigger picture is, after we have results from more survey locations! For more information, and all things Pinyon Jay natural history, check out the resources on our Pinyon Jay Conservation HUB: https://pinyon-jay-community-science-gbbo.hub.arcgis.com/pages/resources.

-Ned

Notes From The Field

Pinyon Jay Surveys