I started drafting this post almost two weeks ago now, but the maelstrom of field work and packing at the end of the season delayed its completion. I’ll try to briefly summarize the last week of the season now…

As the calendar flipped to May, we had ceased our normal behavioral observations, and wrapped up the recording. Our goal for the last few days with the crew was to do some more drop netting, check the field data for data entry errors, and collect as much as our field gear as possible. It turns out our successful capture of two birds at Monument foreshadowed a productive day at Chugwater. After a stunning sunrise, we caught seven males in the net there! That’s as many males as we got in the rocket net, so we feel pretty good about the drop net as a less expensive replacement for rocket nets as we try to catch more birds in the future.


It was a hectic few days, but we did manage to get almost all of the data entered and checked, and also got the microphone cables pulled up at Chugwater and Preacher, and all but four up at Monument. Pulling the cables out of the ground is generally pretty easy since they are not buried very deep in the soil, but they need to be wiped down to remove the mildly corrosive dirt, and also coiled up properly so they are ready for deployment next year. We also have to pack down the now-empty trenches so we don’t provide any place where water can erode the lek surface and create a new gully.

We said goodbye to Mary, Dan, and Erin on the 4th with quite a bit accomplished. However, there was still much to do. We tried one more drop-net attempt on Monument to try to get a couple more males. Sue and Tim came out, as well as Sue’s husband Dennis, to give us extra hands. Unfortunately we had a weirdly blustery dawn- the wind picked up quite a bit after we had set the net, and one corner of the net fell enough to disuade any grouse from going under.

Gail and I also got another round of counts in at some of the leks. We really started to notice declines in numbers the last few days- Gail’s final count at Monument was only 3 birds, that stayed for only a few minutes. My last visit to Chugwater only yieled about half of the maximum number of males from the season. It was interesting to actually see the end of the breeding season. In most years we stopped visiting leks at the end of April, when the males were still going strong.

One big task on my agenda was to GPS the leks. I was worried I wouldn’t squeeze this in- since it requires leaving expensive equipment unattended on tripods it difficult to impossible to do in strong winds, and I’d had quite a few afternoons lost to that already. Thankfully we did not have that many points to do on any given lek, and I was able to find gaps of a few hours when I could visit our three focal leks. While the wind was not an insurmountable problem, I did face a new obstacle- cows! We had always left before the ranchers were permitted to release their cows on the land up here, but with our work extending so far into May this year, we were no longer so lucky. This was only a problem at Preacher Lek, where the small pond drew in several dozen cows who were more than a little curious about me and my gear. I had to set up the static tripod in the bed of the Rhino, then work as quickly as I could to GPS the stakes before the cows knocked them over. Apparently they make pretty good neck-scratchers.







I also finally got a couple of photos of two of the sparrows that we hear around camp and near the leks. Sage sparrows are one of the first birds to show up, and one that apparently is not that easy to see since many Wyoming birders have contacted me about our sightings.



Brewer’s sparrow is another species that can be tough to see without some effort. Although it is one of the dullest birds you’ll ever come across, the song is quite elaborate. The descending series of buzzy trills has been described as “like an alien spaceship landing”- a pretty great description.

Yesterday we closed the book on 2011 behavioral observations; this was the last day that Erin, Dan, and Mary hauled cameras and tripods to their lek overlooks to film males and map their locations. We’ve collected what I think is a really exciting data set on our three focal leks this year, and it will be interesting to look at the data and see who the winners and losers are, and what makes them different.
With no more new data coming in, the crew are busy checking the data files against their field sheets to make sure we didn’t have any data entry errors. They have thousands of lines of data to go over- when they read it aloud they sound like auctioneers.
The free mornings also mean we can use the next few days to try to capture some more grouse. We spent the weekend installing and testing the drop net down at Monument Lek, and we finally had a chance to use it this morning. We awoke well before 4 to an unexpected half-inch of snow- fortunately not enough to delay our plans. We had the net set a little after 4:30, which ended up being pretty good timing as the birds started flying in by 4:45, when the sky was just starting to get light. The males and females did not seem too scared of the net. We waited until it was light enough to start identifying the males. Unfortunately the females started leaving the net area then, and dragged some of the males with them. We were finally left with three birds under the net, when a nervous one (“Picard”) decided to flush. Worried that we would lose all the birds if they all decided to fly way, we pulled the net. It dropped perfectly! We ended up with two juvenile males that we may be able to ID from video and buttprint data.


We are probably going to try again tomorrow on Monument in order to try to catch some adult males, then move the net to Chugwater before and try their before the crew leaves.

This happens every year out here. It seems like only a short time ago that we were unpacking all our gear and showing the crew the leks for the first time, yet here it is the last week in April and we are less than a week from bidding our assistants farewell. We only have a few days left to make the most of our season- after that, we will have to make the most of the data we did collect, and plan for next year.


The past week has been pivotal in terms of what the 2011 will give us. Some things worked, and some didn’t. One project that didn’t work, unfortunately, was the fembot. She worked very well in 2007, well enough in 2008, but this year most males were pretty aversive to her. While we did get some courtships, they will probably not be enough to make any generalizations about how male courtship behavior relates to other behaviors. Very disappointing, since this tool proved so useful in the past. We are thankful that we will have new, more realistic robots by next season. Possibly the most frustrating aspect of this is that we don’t know what has changed. Has the fembot aged in some way that makes her look dramatically different to the grouse, or do they behave that much differently in boom years compared to at lower population densities or after particularly harsh winters?

The playback experiments in which we broadcast alarm calls have in general been going much better. We have now completed at least one trial at each lek of each of three calls: Killdeer, Pronghorn, and Raven. Obviously final interpretation will have to wait until we quantify differences in behavior, but it looks like males respond little if at all to the Pronghorn, and most to the Raven. We probably won’t have time here to analyze all of the videos here, but the crew have been hard at work identifying all the males on the video so we can speed up the data collection once we get back.


Our experiment at Monument looked a little different yesterday- we had a couple inches of snow from a storm the night before. It was all gone very quickly though.

We also took a relatively calm afternoon to finish building our drop net. If all goes well we will have the last few days to set this up on each of the leks and try to catch some birds! We may not be able to match the measurements of birds we catch with the sounds and behaviors of this year (since this years’ ID’s are based on buttprints, and we may not be around long enough to see the males displaying again), but it will hopefully help us next year by giving us a few more banded birds to start with.

We’ve been collecting “background data” all season- measuring mating success, and getting sound recordings of displays and video tapes of natural courtship interactions and bouts of aggression. Every year we hope to pair these data with targeted experiments that will let us measure specific reactions of the males. We wait to do these until after the peak in breeding so as not to interfere with reproduction in this sensitive species, and because males may have their attention divided if lots of receptive females are nearby.

One of our goals is to measure environmental responsiveness of males- how quickly they notice important things in their environment, how dramatically they respond, and how soon they return to their normal behavior. After having trouble getting appropriate responses to objects, our last, best hope this year of measuring responsiveness was to play back the sounds of animals. We started with the alarm call of Killdeer- Gail got some killdeer recordings from the Borrer Lab at Ohio State University and edited them into a single playback file. We used the outdoor rock speakers from Jessica, placing three at each lek, and running the cable to the recording blind.

Fortunately these experiments appeared to work pretty well, although we will need to sift through the video tapes to quantitatively measure male reactions to the sounds. The males reacted, but not too much (i.e. they didn’t flush off the lek), and at least from the trials at Preacher it seemed like males were pretty consistent across trials. We are moving ahead with playbacks of two other local species: Raven and Pronghorn.

In the photo above, Gail is measuring the sound level of our playback so we can report how loud our playback was.



We are also prepping for the fembot experiments. We want to measure how males approach the robotic female, and how they adjust their courtship effort. This will give us a measure of social responsiveness. The questions are: is social responsiveness correlated with environmental responsiveness, and when we look at the relationship with mating success, do the males who mate the most share some level of responsiveness.

Setting up for the fembot experiment is quite a process. Once we’ve settled on the path she will take, we have to connect lengths of train tracks, then level them with bits of dirt or last year’s cowpies, polish off the tarnish to ensure good connection between the base of the fembot and the tracks, and pile up dirt along the sides to disguise the edges.







Once the tracks are set up we test the movement of the fembot to make sure she has a smooth ride!





Unfortunately our first couple of tests at Preacher have not gone terribly well. Hopefully we will have more success at Chugwater and Monument- these leks are much bigger, and therefore more critical in terms of measuring enough males for statistical analysis of the data.

It’s been more than a week since I posted the last update- this is due to 1) 12+ hour days with not much time for creative reflection, and 2) some inadvertent system updating caused us blow much of our monthly allotment of internet bandwidth. To quickly catch-up:
One of our goals this year is to measure how males vary in their environmental responsiveness, and how this relates to their social responsiveness and ultimately to their success on the lek. We’d planned to do a suite of 3 experiments testing different facets of responsiveness- sensitivity to acoustic cues, to food, and visually to novel objects. We tested the food and novel object protocols at a different lek (North Sand Gulch), and both failed spectacularly. For example, we set out an array of strawberries, tomatoes, and apples on the lek before dawn in hopes we could detect differences in how long it took males to approach the food, and how much they ate. Turns out the males (and females too) completely ignored the food. So plans change, as they often do in field biology, and we’re now hoping to do a more complex set of sound playbacks. We should start these soon, so I’ll have updates on those before too long.
I’ve managed another round of sound recording on all the leks except Preacher, where I will be tomorrow morning.
We are finally past the peak in breeding. The peak was fairly prolonged this year. Most years we have about a week and a half of intense activity, but it lasted 3 weeks or so on Chugwater and Monument. Now, for these two leks it was like a switch was flipped, and we’ve gone from long mornings with many females to empty leks by 8AM. As long as the birds don’t leave too early, this is actually good for our experiments, since the lack of female visitation means we won’t have to compete for the males attention as much.
Yesterday on Chugwater we had encounters with two different raptor species. First, at a little past 7, almost all the birds were scared off by a rough-legged hawk. Rough-leggeds are not much bigger (if at all) than a sage-grouse, and really have little chance to take down a male. This hawk made an attempt at the last guy on the lek, and swerved away at the last minute, I guess thinking better of it. The sage-grouse was not impressed.



We also had a small dark raptor zip through at sage-brush level. My first instinct was that it was a small falcon called a Merlin, but Dan noticed from the photos that it was actually a small forest accipiter called a Sharp-shinned hawk. We are miles from the nearest tree, so this was a big surprise for us!



Many busy days ahead with acoustic playbacks, and starting to set out the train tracks for our robot experiments.