Here's an update on the progress I have made during the second week of my field season. I have previously posted an introduction and summary of the first week. As you might be able to determine from the title, the field conditions continue to provide unexpected challenges. With that said, I am still optimistic looking forward as some early signs of spring are beginning to reveal themselves in the area.
The return to the study area for the second week was filled with optimism. Having seen a male goshawk in a particular territory and receiving some updated information on where the nest might be, we were excited to go find it. We first checked in on one of the previously discovered nests just to confirm that she was still incubating. She was! So we headed on our way. The road was snow covered, but looked doable. A couple of hundred meters down the road, we changed our minds... I tried to back out, but couldn't make it. We had to turn around. This is where it all went horribly wrong. The front end slid into the ditch. We were stuck.
The truck was equipped with two shovels (luckily), but the only other equipment we had was a floor jack (not so luckily). After working for 2 hours with these tools, we determined that better equipment was needed. We would walk back to the cabin and hope for the sheriff or forest service to come by in the next day or two. At least I had my motorcycle to get around. Good thing our territory was within hiking distance. Just after arriving at the cabin, the forest service enforcement officer (Kirby) stopped by! He took a look at our vehicle and said that he couldn't help. He suggested that we cover the Boise State door sticker with a University of Idaho door sticker and leave it there until the snow melted, which has to be within a few days... He did lend us a high rise jack (widow maker) before going on his way. Not wanting to ruin the entire day, I sent Lauren on to the territory while I worked on getting the truck out. Two hours later, it was free. I hiked down to join Lauren in the search. Hours later we had racked up 3 additional nests, but none of them occupied... It was a bust.
Next up, the Albion mountains! Its a pretty good drive out of the South Hills and in to the Albions. Luck was still not on our side. The first territory was high on a ridge across a raging stream. Just the night before, a flash flood had occurred wiping out half of the road and cutting a deep channel. The water was still raging and not offering us a safe crossing. We passed for the day and moved on. The next territory provided easier access, but when we found the nest tree it was not occupied. If this trend continues I will definitely be facing small sample size issues! We returned to the South Hills empty handed.
About mid-night we awoke to a banging noise outside. It appeared that someone was stuck in the Magic Mountain parking lot. There is a huge mud hole there. This would be the second vehicle in a week. Lauren suggested that we go see if they needed help. I wanted to make sure that we did not become over committed, but since we did have a radio that could reach law enforcement, we could offer that. As we walked down toward the vehicle we noticed the sheriff was already there. In fact, the sheriff was helping to pull the vehicle out. Hmm. The other vehicle was also a sheriff! This story was getting better!!!
We had previously met Sheriff Steve (pulling), but not Sheriff Kelly (stuck). Steve was happy to see us and the help we could provide. Kelly was a little less happy that the audience had expanded, but also welcomed our assistance. We returned for our truck and within ten minutes, he was free. I think this earned us a "Get out of jail free card." I am willing to bet that this isn't that last vehicle that will be stuck in the South Hills this spring.
Wednesday - two new territories to cover. Lauren was signed up for a ten mile round trip hike over the snow ridge to check on one of our occupied nests and to search a new territory. I had a 1.5 hour each way motorcycle ride to my territory (had to ride out of and around the South Hills). This could possibly provide access to another territory as well. The first territory was beautiful - a mix of Aspen and Lodgepole Pine. I would see a Wild Turkey, a White-tailed Jackrabbit, a Coyote, lots of woodpeckers, Mountain Bluebirds, Red-tailed Hawks, Ravens and an unbelievable number of Ruby-crowned Kinglets singing to their hearts content. Unfortunately, I would not find a goshawk nest. I tried to get to the second site another four miles further up, but snow drifts once again prevented my passage. Lauren would also come up empty on the day for her territory. Ouch.
|Typical South Hills Goshawk Territory - Aspen, Lodgepole Pine, Sub-alpine Fir, Sage.|
|Lodgepole Pine Maze.|
The news wouldn't get any better on Thursday. Our plan was to drive around the west side of the forest and camp there to access five potential sites. These sites are only 10 miles from our cabin, but the snow prevents vehicle access over the ridge. We awoke to three new inches of snow on the ground! When will it stop?!? Once we hit the gravel roads on the west side, we knew we might be in trouble. They were saturated and very muddy. As we drove higher and higher, the conditions worsened until we decided not to risk going further. We sat there in frustration for 30 minutes before heading back out of the hills and on toward home. Defeated for the week... No new nest sites... Very little progress in our searches... Frustration...
I have pondered a few of my learnings so far. The most obvious choice is to start the season later next year. Of course, next year the snow may melt weeks earlier (average melt is three weeks earlier than this year). A second thought is to design a project that is less dependent upon timing. Utilizing nest cameras to quantify prey consumed requires early access. The first cameras could be installed as early as next week. My other methods and questions do not require as early access. A third point has been the low quality of the historic data on which I depend. Some of the coordinates for the nest sites I have are in the middle of a sagebrush field. Clearly not even close to a "nest tree". Next year I will of course have much higher quality and more recent nest site data - mine. Some literature speaks to the high degree of nest site fidelity, but I have received word from other researchers with contradictory data. A review of the past research also notes that a large number of nests are blown out of trees and some of the historic trees are no longer standing. I expect that another limiting factor is our ability to detect the nest. Nests located in Aspen are fairly easy to see and locate, especially now before the leaves come in. Nests in Lodgepole Pine however are much less conspicuous. I imagine that our skills will improve with time. One of the challenges within the South Hills is the very large amount of parasitic mistletoe. Each mistletoe ball looks like a nest structure from a distance. Unlike many other raptors, Goshawks build nests below the canopy which is where the mistletoe also grows.Mistletoe in Sub-alpine Fir is very easy to write off, but in Douglas Fir or Lodgepole Pine it requires closer inspection.
We have a big week ahead. We will start broadcasting goshawk calls which will greatly improve detectability. Before the first of June broadcasts are discouraged due to the stress placed on incubating birds and the fact that they are less responsive before the eggs hatch. We will return to each site where we failed to detect a nest and use the broadcast search protocol. We will also begin our prey surveys. These surveys involve hiking a 750 meter transect in each territory and counting each potential prey species - ground squirrels, chipmunks, jackrabbits, and many bird species. Using a laser rangefinder we will measure the perpendicular distance from the transect to each individual mammal or bird. The resulting values, along with several repeat transects, will be used in a statistical procedure to produce a prey abundance estimate for each territory. These prey abundance estimates will then be compared between territories as predictors for occupancy and nest productivity. Lastly, I HOPE HOPE HOPE for access to the rest of my study area! If this occurs we will have more work to do than we can possibly complete! That would be awesome!