This was our final week with the owls and I’m very sad to be ending that part of the job. On the whole, as the owlets fledge and the territories break down, birds get less territorial and it’s very hard to catch anyone. That means that it’s been a bit slower of a week in terms of number of owls in hand—it’s starting to be lucky to even hear a male, let alone catch a bird. For the most part we’ve just been finishing our very last nests, catching males outside the study area to put geolocators on, and transitioning to vegetation work. However, for my part, I’ve had several personal achievements this week.
I’ve always been nervous about capturing birds at the nest site. The first time I watched Alice work a capture pole it seemed like a difficult, uncomfortable task that I would likely never really master. The method is basically creeping up to the nest with a net attached to a capture pole, raising it up without getting caught on surrounding vegetation or bumping the nest tree, and getting it positioned with the help of people spotting for them (which is tricky since the capturer usually has a difficult angle for judging where the cavity is). For females, if she is already on the cavity, the capture is easy enough: the capturer puts the net over the cavity, waits for her to flush, and hopes that the net is in the right position. The biggest difficulty with catching females is making sure she doesn’t get scared out before the net is in place. For males (or females later in the season when they don’t sleep in the cavity), it’s slightly more difficult, because they don’t start on the cavity. In these instances, the capturer holds the net a foot or so away from the cavity and waits for the bird to come in to make a prey delivery and moves the net over the cavity when he perches on or enters the cavity (or in unlucky conditions, just does a fly-by prey delivery). This is very difficult because the male will get scared off if the net is too close or moves in too early, and it can be difficult to get the net in the right place when it’s high up. Add to this that it is dark (headlights can scare the birds off so they’re only used at the very moment of capture), the capturer may or may not have a great view of the cavity or the perches the birds use for prey delivery, and it may take hours standing, keeping the pole steady, and craning straight up before the bird even shows up.
The first time I attempted a capture, I stood at the net for two hours and missed the male three times before my neck and back ached so much I had to switch off with Julia. He was a previously captured bird, and knew the best escape tactics. He kept using the tree to shimmy his way out of the edge of the net. We had to bend the net before Julia finally got him.
The second time I was on a capture net I went after a female. I got the pole up and in position without spooking the fairly alert female, but Scott was adjusting the net for me when she actually flushed, so it’s dubious to claim it as my first real capture.
This past week I finally felt confident capturing owls, and both occasions were a bit unexpected for me. The first was kind of a crazy situation to begin with. We were lure netting outside of the study area to find suitable males to put geolocators on. Julia, Matt, and I had finished and went to pick up Scott at his net. As we got out of the car, Scott radioed to tell us he had just heard a male, so we decided to wait. All of a sudden, Julia perked up. She whispered that she just heard a nestling beg (think of a very quiet hiss from the back of the throat). I’m still not sure how Julia heard it. Already past the time we would usually be headed home, we started sneaking through the forest, listening for the barely perceptible noise, I finally started picking up the calls as well, and as luck would have it, Julia happened to glance up and see a female making a prey delivery to a tree. Within ten minutes, we had discovered a new nest.
Julia headed in with the capture net and soon caught the female. The others started showing up and bustling to get the female processed. In the commotion, Julia said we needed to catch the male, and handed the pole to me as she rushed off to band the female. I was left standing below the nest, as the others started coming in. Everyone had such a sense of urgency that I felt we needed to catch the male quickly. I had never done a capture without guidance, but everyone seemed to already have jobs to do. I glanced a little helplessly at a few of the other rookies who were already at the nest, but I was one of only three people who knew which cavity the nest was, so I decided I would just do it. I got the net up and held it away from the cavity to wait for the male. Thankfully, Brian came in just when the male made a prey delivery and put his light on the cavity when the owl’s head was inside. The male flew perfectly into the net, and Brian talked me through lowering the net safely down as they extracted him. It happened so fast, I was a bit stunned I had actually captured him on only my second time. The whole processing of the birds and putting on the geolocator was amazingly fast, and everyone chipped in—it was one of those moments where we really felt like an impressive, cooperative, birding machine.
The second “real” capture of mine was actually a double-header. As Jayne, Julia, and I drove to the CN10 nest, we discussed the plan: we had to capture the female to do blood work on her but we also had to search for a potential fledgling, which meant that the person capturing wouldn’t have someone silhouetting them (this entails telling the capturer when the bird is coming in and putting a light on the cavity as the bird makes a prey delivery). I was also familiar with the nest and knew that the male had been a difficult capture even for Julia, who is one of the most veteran members of the crew. So as we discussed the plans, I pretty much assumed Julia would be capturing again. To my surprise, she declared that I was ready to capture at the nest. The will of the operation was all her; I would never have stuck it through so many misses (I think there were probably more than six) if Julia hadn’t insisted that I keep on trying. The area around the base of the net was so overgrown I couldn’t get a good angle on the capture, and there was no silhouette except for on the tree they perched on before making prey deliveries, so I had to estimate the timing from when they left their perch, but I kept moving the net too early and scaring them off. The nestling was helpful though, since after every aborted prey delivery, he got even louder, practically screaming for food and forcing the parent to come back again. I finally caught one, and after lowering it down, was devastated to discover it was the male after all that work. We had already captured the male previously, so all we could do was check on how his feathers were molting. However, it was not an entirely fruitless effort since it suggested that there was no fledgling after all if the male was still making prey deliveries at the nest, and it was helpful to look at his molt patterns again. I tried to trade the net off yet again, but Julia told me she wanted me to get the goal and capture the female, which I admittedly wanted as well. I had a few more failures (and an ant that tried to climb up my pants and distracted me), before I finally timed it right. I was completely blind at that point, and wasn’t even sure I had caught her when I turned my light on. I had come in so fast on that final capture that I was worried that I might have injured the bird. A stick had gotten caught in the net and for a terrible moment as we were bringing it down I thought it was a bunch of feathers or a leg sticking at a weird angle. She was of course fine (it’s a testament to the design and technique of the study’s nest captures that they have never injured a bird), but I was so nervous that I was going to mess something up.
Julia let me bleed the very feisty female as a sort of reward for the capture. The female made this as difficult as possible, biting us all impressively hard. Nevertheless, it was one of my best adult bleeds and just put a cap on the night. It was really fun to have both the male and female in hand to look at since it was the first pair I’d seen handled at the same time. This pair in particular we thought had distinctive-looking facial patterns, and both had really funny personalities. The female was so angry that when I released her, she took a spare moment to give me an extra (and totally unnecessary) bite after I opened my hands before flying off back to her nest.
I feel like I’m starting to understand more and more the theoretical basis behind the study. As we look at more articles, I’m reminded of what is so incredibly fascinating about ecology as a subject—everything is so interconnected (the red tree squirrels, the ponderosa pine ecosystem, the spruce budworm, the flams, etc.) that the more you learn about the system, the more complex and engaging it becomes. There’s always a new aspect to explore and it’s boggling at how some aspects (say, a bad cone crop because of drought) could impact our study (because squirrels then predate the nestlings more because their usual food is in short supply) that might at first seem like a narrow single-species focus. As I start thinking of what I want to study, I’ve been worried that just studying a single species wouldn’t ultimately be helpful from a conservation perspective, but on the contrary, learning as much as possible about a single species brings in aspects from all over the ecosystem and actually sheds light on interactions that a broader focus wouldn’t be able to pin down. At the end of the day, even if you don’t really care about flammulated owls, the study focused on them brings forth information that can help conserve the entire ecosystem, both here in their U.S. breeding habitats (the threatened ponderosa pine ecosystems) and ultimately perhaps in their wintering grounds in Central America as well.
This has also been a cool week for insects. Every once in a while I am reminded how weird and interesting creepy-crawlies are. Sometimes it can be hard to sustain attachment without the sort of emotional connection you can get to animals that are a bit bigger and (seemingly?) more expressive, but I don’t doubt I could be perfectly happy as an entomologist.
Someone brought in a gigantic beetle to Richard’s office (the caretaker for the MEF), and he showed it to all of us. It was as long as any of my fingers, and twice a thick. It is by far the biggest insect I have seen in the US. We found out the next day (after Richard checked with the state entomologist) that that was because it is the biggest beetle in the US: the pine borer beetle, or Ergates spiculatus. However, we didn’t have much chance to contemplate the revelation in person, because the morning after it was caught, it managed to pry the lid off its pill bottle cage and escape. I was sad to see it go since I figured the inside of an office building wasn’t the greatest place for a beetle to live out its days, but I should have figured an insect that size couldn’t stay hidden for long. The next evening we found it in the other room and Brian put it in a tool bucket it couldn’t escape from. We added an addendum to the note that Richard had left us asking to keep an eye out for the escaped beetle: “We found it…Guess where we put it.” Though we actually just left it on his desk.
The other cool insect encounter happened on our last day of peeping. I found a new un-enumerated cavity tree and started tagging it as Alice came up to peep it. When I tapped the tree and then started nailing the tag to it, a ton of ants swarmed out of the lower cracks. Then, when Alice raised the pole to peep the cavity, the hole began boiling over with ants. We decided to forgo actually trying to squish the peeper head inside and just called it unsuitable. The sheer number of individuals that ants can amass is shudderingly impressive. They arguably account for around 15% of all terrestrial animal biomass, which is a little disturbing when you think about it, but with that kind of weight, they must be a pretty fundamental pillar in the ecosystem.
We are now entering our final week of the project. I’ve learned so much but it still feels like this internship has rushed by. When I think of how accomplished our first year veterans were at the beginning of this year, it doesn’t seem like I’m in the same position now after my first year; even if I essentially know all the basics, I don’t feel like I understand them well enough to teach someone else.
These final weeks we have been doing vegetation work. The basic ideas behind this part are to look at what sort of qualities the birds are selecting in nest sites, what factors predict nest predation, what is their primary foraging habitat, and how these compare to the available habitat in the area. Essentially, we are looking at how the habitat that the flams use is different from random points in their territories and what that means about the flams themselves. For instance, it seems obvious (although we’ll have to wait for data analysis) after working for a week in the Hayman area that the owls use low and unburnt areas of forest much, much more than high burn areas.
The basic format is that we find the tree we are looking for (a forage point, a nest site, a random point, a random suitable tree cavity, etc), set out quadrants, and identify the nearest greater and less than 20 dbh (diameter at breast height, for me that’s actually on my chin) trees. We measure those trees and the focal tree, taking height, distance, crown shape, etc. We also look at surrounding vegetation, burn severity, percentage bare ground, and other factors. For nest sites we also look for the nearest squirrel middens, since that is a very high predictive factor for predation.
It’s a lot of hard work still, and we’ve switched our schedule from late night to early morning. I miss seeing the owls every day. However, the vegetation work is clearly very important, it’s just about the perfect amount of physical exertion, and I do like going to bed a little earlier. But I really miss the owls.
Julia and Jayne have been working towards someday getting their passerine banding licenses, so they decided to start practicing catching and banding passerines in the mornings before work. Since it means getting up at five, I’ve only come along twice, but it’s always a special experience and it’s nice to hold a bird again. Birding songbirds is a lot more difficult than owls. The bands are much smaller and malleable and I’m terrified of crimping the bands (when one end gets pushed beneath the other as you close it), which is easy to do with the softer metals and potentially life-threatening for the birds.
We’ve been setting nets up along some willow habitat on the edge of the creek that runs near the lodge. Even just while checking the nets it feel a bit magical to go wandering through tunnels of willow and hear birds all around, and watch them dart across the water. One time as Alice and I were taking down one of the nets, two broadtailed hummingbirds went flying through the area, and one stopped on a branch right next to us, making a low humming noise I’d never heard one make before and staring at us for a long time before flying away.
Another note about songbirds is that the barn swallows that have been constructing a nest on the porch where we eat dinner the entire summer finally hatched their chicks. Or at least now the chicks are big enough to be heard and seen. It’s been so fun to watch the whole process of nest selection, building, incubation, and nestling rearing from the comfortable vantage point of the dining room table. Though it is also a nice reminder of how much cuter baby owls are compared to baby songbirds.