Tag Archives: field work

Sage sampling

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Jen explains the protocol.

Our collaborator Jen Forbey came back for a second visit this year to get us oriented to measuring the habitat and sagebrush characteristics at sites used by our encounternet-tagged males.The process starts by downloading a male sage-grouse’s previous day’s gps locations. We throw the points onto Google Earth and look for areas the males were spending a lot of time (in other words, where several points are in within a few meters or 10′s of meters). During they day, presumably these points represent a patch where the male was foraging, and at night, likely a roost site. We load these points onto a hand-held GPS unit, then navigate to the site.

Daubenmire Frame for estimating ground cover.

Once we are at the high-use area, we look around for sign of grouse (and always find something indicating a bird’s presence the previous day, usually some poop or a cecal cast). Once we know where a bird was actually standing, we look at nearby plants for bite marks indicating the grouse was browsing on the plant. We measure browsing intensity and dimensions of the plant themselves. We also use a couple of methods to measure ground cover- a Daubenmire frame where we measure rough abundance of grass and forbs in a small area, and also take a photo of a larger patch of ground from a camera suspended a set distance above the ground. Finally, we clip a few small branches from the sage-plant so Jen and her team can measure nutrients and toxins in the browsed and unbrowsed plants in the area.

When sage-grouse browse, they often leave parts of leaves. You can see the fresh browse marks (cut leaves with green centers) on the left and right of this photo.

Even more than we anticipated, this sage-sampling has been both illuminating and fun. There’s just something really neat about being able to walk a mile (or at least a kilometer) in the shoes of our birds, and see where they are spending time on the landscape. I feel like we are finally studying a complete bird, and not just the fraction of one that displays and fights on the lek. The process of the sampling itself has been enjoyable (at least in the relatively nice weather we’ve been having); it’s nice to be able to work outside with a team of people and to be able to talk without fear of scaring the birds.

Encounternet Tags

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Encounternet Tag Solar Power edition.

We are making some progress with the Encounternet tags. Getting the tags out on the birds has gone quite well actually. Ten or 11 of our 13 tags are deployed on male sage-grouse at the moment, and we kept those last two back to be able to carry out tests back at camp. Frank and Julia have excelled in the role of banding technicians. I’ve been out with them several times now, and many nights we’ll catch ~4 birds- a good haul and much better than our past attempts at spotlighting.

 

The harnesses seem to be holding up as well- none have fallen off yet, and the tagged birds are showing up on the lek and performing their full suite of fighting and display behaviors.

Male "Tiny Dancer" wears a tag on his rump. He continued to mate with females after his tag was put on.

As a reminder, our goal with these tags is to collect positional data on the males, and to know something about their behavior at these positions. In particular, we want to know where the males are foraging so we can visit these sites and determine the nutritional and chemical quality of the sagebrush they are eating.

We are learning that getting these data off of the tags is a non-trivial task. One issue has been the relatively weak signal strength from the tags themselves. Traditional radiotelemetry uses lower frequency pulses that transmit long distances. The higher-frequency data transmissions from our encounternet tags do not travel well when transmitted close to the ground, and unfortunately sage-grouse spend virtually all their lives within a few inches of the ground. We’ve had to put our receivers higher up and a little closer to the birds. The grouse don’t seem to care about the pvc poles that are popping up on the leks. We included perch deterrents on our permanently placed receivers to ensure that raptors don’t start to use them.

We’ve also had to do some optimizing on settings and firmware to actually get usable data, and now are starting to get some nice positional data on at least a couple of our correctly configured tags. I’ve figured out how to get the data into Google Earth to display. Here you can see movements from “Steve”, a Chugwater grouse who was first captured as a young bird in 2010 and has been a reliable lek male for the past few years. The points are roughly every hour, and the tracks show him moving a little less than a kilometer from the lek each day. Each day he seems to use a different area.

GPS points from male "Steve". It is so exciting for us to learn more about what these males are doing off the lek.

Next up, in addition to getting the remaining tags properly configured, is to determine which points to visit for vegetation sampling. These decisions will be based on a combination of GPS accuracy and likely activity, hopefully eventually with the accelerometer behavior data as well.

2014 Fembot Experiments

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Fembot "Salt" approaches the target area as males get excited.

Knock on wood, our behavioral tests with the robotic female grouse are going very well this year. With the robots already built, we were able to start right away. We’ve gotten (I think) 10 experiments in already, with hope for another 6 or so in the next few weeks. This has been fun for me, since this is the first time I’ve gotten to do real robot driving. Thus far I’ve driven in three experiments- two at Chugwater Lek and one at Cottontail Lek. A couple of times Gail and I have done simultaneous experiments on different leks- a first for us and a big advance in our ability to collect enough data to answer our questions.

A good experiment requires both opportunity and response. Opportunity comes in the form of males sticking around long enough in the morning to make it worth sending the female out on the lek. As with our previous experiments, we need to have a lek free of live females so we know who the males are courting and so our robot doesn’t need to compete with real females for attention. Some years these female-free windows are hard to come by, and males leave within minutes of the last female departure. Males need to be responsive as well- not too exhausted to care about courting one last female trundling on to the lek. Thus far we’ve done very well on both accounts.

So what are we actually doing this year? Our goals this year is to look at persistence in courtship. How long will a male engage in courtship, and how does this depend on factors such as seasonality and the female’s interest level. We are repeatedly testing males with trials that contain both interested and disinterested behavior, and getting measures (hopefully) early, mid, and late in the breeding season. We think differences in males behavior within each trial, as well as changes in his effort across the season, will reveal a lot about how he allocates his energy and his success on the lek.

Getting to participate in these experiments by actually controlling the robot has been a little stressful but also incredibly rewarding. It can be nerve wracking to drive the robot out and try to make her movements as life-like as possible. Not only do you have to keep the female upright and not tip over, but you have to maintain life-like movements throughout the trial. Don’t move too fast! Keep her head moving periodically! Don’t drive backwards! Aside from this, getting to interact with a wild animal in this way is just an indescribable experience. One recent experiment at Cottontail illustrates this. One male “Circle Butt” approached a little closer than we wanted for our protocol. I backed off a bit, and he also backed off somewhat and returned to his core territory. I moved back towards the intended target area, and “Circle Butt” came back closer. I backed off again, and again he retreated. It was such a thrill to be able to be an active part of this interaction.

A couple of previous posts on our robot experiments here and here. When I get a chance and more bandwidth I’ll add some video, but here’s a clip from 2012.

Mid-Season Update (2014)

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March has almost literally blown by out here in Windy Wyoming. It’s been a pretty good month so far, in spite of some cycles of mild snowfall and mud that have made our field work difficult at times.

The breeding season started in earnest with a Cottontail Lek copulation on March 19th. This was tied for our earliest one on record. My impression is that the peak in breeding is fairly spread out this year, with female attendance and numbers of copulations not necessarily following the quick increase and decrease that marks some years. Maybe bad weather early in the season tends to synchronize the females more as the earliest hens delay breeding, but the lack of severe early storms or deep snow cover has spread things out this year? Just speculation.

Although it’s early in the season (and these data are only field observations  and still pending new events collected from our video records), reproduction seems particularly skewed this year. The top guy on Cottontail seems especially strong. I’ll have a quick post about him soon. He’s now got our single-day record for copulations, and really dominates the lek in ways we’ve not seen in the past.

Jess digs a cable trench.

Study-wise, we’ve got pretty much everything going now. Microphone arrays have been deployed at our two leks (Cottontail and Chugwater), and we’ve collected two mornings of recordings on each lek. We’re getting used to the new cameras as well. There are good points and bad points (mostly good points I’d say). It’s really nice to be able to view the videos so quickly, and in our initial data collection from the tapes we realized you could even zoom in on certain areas of the screen! That is a pretty nice feature.

We did not put in a microphone array at Monument Lek, nor have we been monitoring it on a daily basis. Bird numbers there are about what they were last year, so we’re not going to invest as much in it since the males seem to have shifted their territories to places we can’t easily observe them. Sad to take a break from this lek- but hopefully it will rebound next year and we will be able to record behaviors and conduct experiment there again in the future.

Speaking of experiments, we actually got a complete set of early season fembot experiments in. More about this in a future post.

 

Frank watches while John tests the range of the receivers.

Our collaborator John Burt just left. John has been building the advanced telemetry tags we are deploying this year. We got a couple on last spring– these new ones have solar to help deal with the power needed to run both a GPS chip and an on-board accelerometer. We’ve got 13 tags in hand, and are looking forward to collecting data on where these males are getting their meals (and how that impacts their ability to put on a good show). We’ve already caught a dozen males, so hopefully it won’t take long to catch a few more and get all of these devices out on birds and collecting data.

Encounternet Tag Solar Power edition.

We also enjoyed having Yale student Sam visit the camp for a few days. Sam is interested in the relationship between female preferences and male aggression, and thinks the sage-grouse might be an interesting system to look at this issue.

 

An exciting couple of days

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Gail giving driving lessons to the Boise folks.

An early visit from our collaborator Jen Forbey and a few other members of her lab should have been exciting enough for early March at our camp. Jen has been looking at the interactions between grouse and sage- basically how sage nutrition and chemical defenses affect grouse physiology and foraging behavior. Her visit was for some mutual training possibilities. Her graduate student Marcella has a lot of trapping experience, and was able to show us a new spotlighting technique that we’ve now adopted. It’s an “on foot” method, where birds are first seen from a truck driving on an established road, then a pair of people walk out to the bird, one with the spotlight and a portable speaker blaring music, and the other close on their heels with a net. We trained Marcella on our video and buttprint protocols, and also got her going with a recording unit to get some recordings from her Idaho population. The Boise team also completed sage-sampling at three leks to look at forage quality surrounding these display grounds. Jen and her crew were fun even when we were squeezing 13 people in to the trailer for dinner!

Gyrfalcon & grouse

I mentioned some excitement. First was the once-a-decade (or more) visit of a large arctic falcon called a Gyrfalcon to Cottontail. Sean and James got some digiscope photos of a falcon that we initially assumed was Prairie Falcon, but further review of the images suggested it might be the larger Gyrfalcon. Not only did they see it, but they saw it make several passes over the lek before finally killing and eating a male sage-grouse! Sadly it was a male who was already a favorite- named Roundasaurus Leks due to his buttprint looking like the head of a T-Rex. We almost never see predation events on the lek, and to see one so early in the season, and by such an unexpected predator, was pretty mindblowing.

The gyrfalcon came back the next day and James and Sam were able to get some more diagnostic images from a zoomed in video. Unfortunately it hasn’t been back since then, and I haven’t gotten to see it yet. Maybe I shouldn’t say unfortunately, since this bird seems pretty capable of reducing our sample size in a rapid manner!

Jen and her technician Brecken dissected the unlucky male grouse to see what it had been eating (all sage, in spite of the presence of some forbs and insects during the warmer days). I’ll probably have more about that in a subsequent post.

Pygmy Rabbit tracks (top), and Cottontail (bottom). Photo Gail Patricelli

Second: another wildlife sighting. Jen and Gail were at Monument Lek and noticed the burrow and tracks of Pygmy Rabbit! This is another sage-specialist that Jen studies, so she knew what to look for. In some places this is a threatened species. I’m not aware of it’s status in our neck of the woods, but neither Stan nor Sue our agency contacts were aware this species resided in the Hudson area so we will count this as a cool discovery.

Last was something exciting but not quite as fun. I tried to take the crew and Jen’s crew down to the Monument Rocks for a quick but fun excursion. There was still some snow on the road, but not enough to be a problem. Or so we thought. Maybe a half-mile past the lek, the snow covered up what turned out a treacherous mudhole. Trying to power through it only succeeded in me getting astoundingly high-centered. Day 1 we tried using the ATV to help pull it out, but the truck didn’t budge at all in spite of an hour or two of digging. Next morning, we tried another pick-up, but still no budging. It wasn’t until we’d deployed two jacks and dug almost completely under it, and then used the truck, that we finally got it out of there. Definitely not how we wanted to spend two days.

It took quite some feats of engineering to get the truck out.