Northern Wings – Connecting People and Birds of Northern Arizona

Paul Dougherty: A Discussion of his Research in Northern Arizona

• Northern Arizona Audubon Society • Season 1 • Episode 4

Share episode

In this episode, I chat with Paul Dougherty, Ph.D., about the research he is conducting that brought him to northern Arizona to collect data.   Dr. Dougherty is a National Science Foundation Postdoctoral Research Fellow at the University of Massachusetts Amherst.  One of his primary interests is molting behavior, a chronically understudied aspect of avian biology that can render bird populations vulnerable to climate change.  Listen to this episode to learn more about his interesting research and academic journey.  

This episode includes a new Name That Song segment (birdsong, that is).  We are grateful to Rich Hoyer and the Macaulay Library, part of Cornell Lab of Ornithology at Cornell University, for the use of the audio clip.  

Thank you for listening. Please visit our website and subscribe to our Instagram feed.

The Northern Arizona Audubon Society has been the voice for birds in Northern Arizona since 1972. Join us. Add your voice.

SPEAKER_01:

Welcome. This podcast is brought to you by the Northern Arizona Audubon Society, the voice for birds in Northern Arizona since 1972. We envision a future in which birds are thriving in Northern Arizona and throughout the world. Visit our website to learn more about this dynamic organization and the work it does for the love of birds and nature, especially in our part of the world. Welcome to this episode. My name is Matt Anderson, and I'm so happy today to be talking to Dr. Paul Docherty about the exciting research he is conducting that has taken him to Northern Arizona. Dr. Doherty is a National Science Foundation postdoctoral research fellow at the University of Massachusetts Amherst, where he is advised by Drs. Maria Stager and Nathan Senner. He recently completed his PhD with Dr. Matthew Carling in the program in Ecology and Evolution in the Department of Zoology and Physiology at the University of Wyoming. Dr. Doherty's research aims to improve understanding of their evolutionary processes that generate and maintain biodiversity, particularly in birds. He cites his lifelong love of natural history as the primary motivation for his work. Wow, Paul, so much to discuss. Thank you for being here today. Let's start with the big picture. Can you give us an overview of your research interests?

SPEAKER_00:

Sure. So I have always been really interested in birds, and I guess I would say that I'm interested in pretty much anything involving birds. But when I started grad school, I was particularly interested in evolution, speciation, stuff like that. And that led me to study hybridization between indigo buntings and lasuli buntings. And I became really interested in how thinking about how differences in molts and migration strategies influence reproductive isolation and speciation in birds. And that eventually led me to just become interested in molting in and of itself, and eventually how molt sort of plays into or relates to conservation. And yeah, so I guess because of that, my my research now is sort of aimed at trying to learn about how we can more effectively incorporate molts into conservation. Okay.

SPEAKER_01:

Well, let's just stop there for a sec, because I think a lot of people might skip past molting as just a stage in the developmental activities of a bird, but it's really much more than that, isn't it? And so tell us the significance of molting, how it plays out, what the different kinds of molting uh sequences are, and those kinds of things.

SPEAKER_00:

Yeah. Well, in my opinion, molting is the most interesting thing that a bird does. But the reason why it's so important is because if you think about things that birds do, they fly, they have beautiful plumage that they use to display to one another, or for camouflage, or for insulation and thermoregulation. But all of those critical functions depend on their feathers. But unfortunately for birds, their feathers wear down over time from exposure to the sun and abrasive vegetation and parasites and things like that. So in order to maintain these essential feather functions, they need to regularly replace their feathers in this process known as molts.

SPEAKER_01:

Do all species molt and then migrate? Some of them migrate and then molt. How does that happen and what are the determinants of which path it is taken?

SPEAKER_00:

Yeah, yeah. So that is, I guess, one great thing about molts. So if you think about the things that a bird does every year, and you think about variation among different bird species, some of them, not all of them, migrate, not all of them breed every year, but every single year, every bird has to molt because maintaining these feather functions is so critical. Okay.

SPEAKER_01:

You and I were were wandering around Picture Canyon this morning. And I told you I had seen a Franklin's gull. Uh-huh. And you told me some interesting stuff about their molting pattern. Tell me what that is again.

SPEAKER_00:

Oh, yes. So, yeah, a fun fact about the Franklin's Gull is that it's one of only two North American bird species that has two complete molts every single year. So because molting is expensive and it takes time and birds are often vulnerable, their flight is often compromised during molts, most birds will replace their body and flight feathers just once per year. But many birds also replace their body feathers, or at least some body feathers again prior to breeding, which is how you have birds that have cryptic non-breeding plumage and a flashy, alternate breeding plumage in many cases. But it's really rare for birds to molt their flight feathers more than once per year just because those feathers are really expensive to replace, and it's also challenging for them to compromise their flying ability. But it's thought that Franklin's gull and bobalink is the other species that replaces both body and flight feathers twice per year, evolve that strategy because they are such long-distance migrants. They breed in North America and they breed in very exposed grassland or wetland habitats, and then they winter in Argentina, so they are exposed to so much sun in both the boreal and austral summers, that that probably takes a pretty serious toll on their feathers. So the strategy that they've evolved is to molt all of their feathers twice a year. But it's also interesting to think that there are other birds that migrate just as far that don't do that. So interesting stuff.

SPEAKER_01:

Yeah, more puzzles for you to try to solve in the future. Sure, yeah. That's great. Now, one of the reasons that you and I are sitting here together today is that I had a chance to learn a little bit about your research at the meeting sponsored by the Northern Arizona Audubon Society here at the library in Flagstaff. Tell us a little bit about what that research is exploring and how is it that you came to be here collecting data in Northern Arizona?

SPEAKER_00:

Sure. So, you know, if you think about developing strategies for bird conservation, they're most effective when you think about the entire annual cycle. You think about how can we protect birds throughout the year. And historically in ornithology, most research has been during the breeding season, just because it's it's been historically the most convenient time to study birds, at least in North America. But over the past couple decades, with advent and increased accessibility of tracking technology and things like stable isotopes and just more research happening in places where birds spend non-breeding periods, there's been a really big push to study birds during migration and during our winter. But piece of the puzzle that I think has been, I mean, it's received some research attention, but certainly not as much as these other stages is molting. But I think that it's really important to study birds while they molt, and it's important to study how these ongoing environmental changes are affecting birds when they molt, because molting is essential for birds. It's the time when they can do it is constrained because molting is expensive and they can't really fly as well during it. The prevailing idea is that birds can't really overlap molts with breeding or migrating, these other intensive events that they do during the year. So molting is important, it's temporally restricted, and it's also expensive. They need to have access to sufficient resources. And the reason why we think that's particularly important to study now is because the patterns in resource availability, when and where resources are available, is changing really quickly with climate change and also just changes that humans are having on the landscape. And the reason why we first started thinking about that was many bird populations that breed in Western North America have all independently evolved this strategy called molt migration. And what that looks like is when they finish breeding at the end of the summer, it's too dry and unproductive throughout most of Western North America to support their molts. So the strategy that they've evolved is they, like when they finish breeding, they migrate down to southwestern United States, western Mexico, and they molt during an extended migratory stopover that aligns with this pulse and resource availability that is brought on by the North American monsoon. There are uh climate models that project that as the oceans are getting warmer, the monsoon is shifting later into the fall and may become weaker, or the periods of uh precipitation may become more spread out. And so there just may be longer periods of drought in the summer, which is concerning when you think about these birds showing up to this region, expecting there to be abundant resources brought on by the monsoon. But if the monsoon is shifting later into the fall or if it's just overall drier, it's possible that there might be, they may struggle to, I guess, secure adequate resources to supply their feather growth. And there's been some studies that have demonstrated that if birds don't have access to sufficient resources during molts, they'll grow poor quality feathers that are likely to break during the upcoming year, and the bird will have a much higher chance of mortality. Or there's even one study that showed that, one study with captive birds many decades ago that demonstrated that because for many species the like genetic regulation of molt's timing is so strong, birds will still put all these resources into feather growth at the expense of their own body condition and might might die in extreme cases. So resource deprivation during molt is an overlooked threat to birds, we think. So I guess the purpose of this project now is to develop a better understanding of where and when these birds are molting, how much variation there is in these molting strategies among individuals and also among different populations, uh, and also how flexible birds can be in where they molt, just to better predict how they'll respond to changes in resource availability during molts.

SPEAKER_01:

Well, Paul, this research sounds really exciting. Tell us a little bit more about how the results might be used in the future and maybe some details about how the data are collected, where they're collected, those kinds of things.

SPEAKER_00:

Sure, yeah. So I guess as as a bit more background, we are focusing on Lagelli buntings. And the reason why we're focusing on that species is, well, because buntings are my favorite bird. I studied them during my PhD. But because Lazelli buntings exhibit this molt migration strategy, because they spatially and temporally isolate molts from breeding and the rest of the non-breeding period, that means that if we were to study the movement data of individual laguelli buntings, we could theoretically identify where and when they're molting by identifying periods during the late summer and fall where individuals are seemingly not moving for a while because going back to this idea that birds can't really migrate or move around very much during molts, like periods of kind of hanging around in the same area for a while would to us indicate likely the area where that bird is molting. And our strategy to do that is to put out these individual tracking devices, these geolocators, on male lasli buntings breeding in Arizona and Montana as well. And our reasoning for choosing those two places is we are trying to get tracking data from birds at the southern and northern edges of the species breeding distribution to hopefully encompass as much variation in molts and migration strategies as possible. And as for how these results could be useful for conservation, the main thing is just sort of identifying where and when these birds are molting as a way to identify areas that are important and also to be able to describe how much variation there is, both within a breeding population and also between the two populations, to more accurately predict population-level responses to shifts in resource availability during molts.

SPEAKER_01:

It seems that once you've identified the likely location where the birds are molting, you can assess those areas to see whether the resources to support that kind of high-energy, high expense effort is optimal or not optimal, or what resources might be able to be added to that area to increase the survivability of that particular group.

SPEAKER_00:

Yeah, yeah, totally. I think one thing that would be really important is if we can identify these rough areas where birds are likely molting, it would be possible to prioritize habitats in those areas that are maybe a bit more resilient to variation and precipitation. So for instance, areas along rivers, maybe a more predictable source of resources regardless of when the monsoon comes. So identifying places where we can potentially protect critical habitats like that, I think could be really important. Interesting.

SPEAKER_01:

So I think listeners are probably familiar with the MODIS system and how it's used to track birds. This is a different technology, they're just geolocators that you're using. Can you describe what those look like, how they work?

SPEAKER_00:

Yeah. Um, so when you put any kind of device on a bird, the rule is that it has to be less than 3% of the bird's mass. And Elasley bunting weighs anywhere from 13 to 16 grams, so 3% of that is is very, very small. So unfortunately, uh the that kind of precludes us from putting out like satellite transmitters that would give you real-time updates on the bird's location on a bird that small. But yeah, when if you're trying to study the individual movements of a bird that small, right now you really just have two different options. One is the MODIS network, as you mentioned, and the way that works is you can put this, you put these transmitters on these individual birds, and there's a network of these MODIS towers that are act as receivers for these transmitters. So whenever whenever the bird flies near one of those towers, you get a ping that the bird was there. So the advantage of of MODIS is that you can just put the you can put the transmitter on the bird, you never have to see the bird again, and hopefully when it flies close to a tower, you'll learn where it was. But the downside of that is if the bird doesn't go near any towers, you're gonna have no idea where where it was. In Eastern North America, the MODIS network is is pretty it's pretty dense, there's pretty good coverage there. In Western North America, it's it's still pretty sparse. So that's definitely a challenge for studying bird movements here, a limitation of the MODIS network. So your other option for studying movements of individual birds that small are these devices called geolocators, which is what we're using. And the way they work is they just go on the bird's back, you give them a little uh harness that loops around their legs. And the geolocator has a little stalk with a light sensor on the end, and every five minutes it records light every day. And from those data you can estimate sunset and sunrise times every day, and from those estimates you can estimate the latitude and longitude of the bird with with some error. Um but so the advantage of geolocators is you can get data wherever the bird goes, but the major downside is that they're archival. So in order to access the data logged in the geolocator, you need to catch the bird again the next year and remove the geolocator. So that's what we're doing this year in Arizona, trying to trying to track down as many of the birds that we tagged last year as possible, catch them again and and remove their geolocators, which is at times fun, but also very frustrating when you can't find the birds or they're uh they're being difficult to catch. Right.

SPEAKER_01:

And so you're collecting the data here in Picture Canyon and also in the northern part of our region, whereabouts up there.

SPEAKER_00:

Yeah, so we put out, I think, a total of 32 geolocators last year at a few different places throughout northern Arizona. So we tagged a few birds in Picture Canyon last year. We had a few birds around Prescott and Chino Valley, and then we had a lot of birds up by Jacob Lake and kind of the the northern district of the the Kaibab National Forest.

SPEAKER_01:

So your work is ongoing, you'll be here for at least another week looking for those buntings and trying to get the data that you need in order to move this project further.

SPEAKER_00:

That's the plan. Yeah, try to recapture as many as many birds as possible. So far we've recovered two geolocators, but it would be nice to have a bigger sample size from Arizona. But then after I leave Arizona, I'll be going to western Montana to try to recapture as many of those tag birds as possible.

SPEAKER_01:

Paul, tell us a little bit more about the timeline for completing this research and some of the next steps.

SPEAKER_00:

Yeah, so last year is when we put out this round of geolocators. I'm retrieving as many as possible this summer. And then once I get them back, once I'm back in Amherst, then I'll be spending some time analyzing them, figuring out exactly where they went. And then we're we're actually also hoping to put out another round of geolocators, hopefully on as many of the same individuals as possible in Montana this summer. So I'll be back in Montana again in, I guess, the summer of 2026 to retrieve more geolocators. And I think that will be really useful to have tracking data from the same individuals for multiple years to get some insight into how flexible individuals can be and try to learn if there if there is much variation in where an individual molds, if that's something that's linked to monsoon precipitation or phonology. But in terms of some other potential next steps, we're also collecting feathers from the birds that we tag here, which we could use to generate a stable isotope data, uh, which is uh maybe combined with the individual tracking data from the geolocators, could potentially teach us more about where more individuals are molting. And we're also collecting some blood samples from birds in these places. And I think that would be someday it might be really cool, especially if we can collect more more blood samples and be able to generate more uh genetic sequences throughout the species range to learn more about uh population structure uh within Lange Live buntings and if there's uh a variation in in molting strategies that's potentially linked to uh genetic differences in in different areas.

SPEAKER_01:

This is a huge project. Lots of people and agencies involved, your mentors and supervisors. How has Northern Arizona Audubon Society and other organizations that are similar helped you in your research efforts?

SPEAKER_00:

Yeah, well, I actually owe a lot to the Northern Arizona Audubon Society. Because Arizona is at the southern edge of phalagellite bunting breeding distribution, it's been kind of challenging to find a big enough sample size here. So I actually reached out to Northern Arizona Audubon last spring when I was here to see if they could be of any help to help me find. And buntings. And Kay Hawkley responded right away, and we organized a group to get out to Picture Canyon, and we worked with the city to get permission to net there, and they were they were amazing. Gave us permission to misnet and put a geolocators at Picture Canyon. Yeah, so very thankful to Kay. And then we also found about this great spot in the North Kaiba by Jacob Lake through Grant Pegram, who was part of Northern Arizona Audubon. So very, very thankful for people in Northern Arizona Audubon. This project would be a lot less successful without them. But apart from Northern Arizona Audubon, I've been really thankful for the National Forests giving us permission and Arizona Game and Fish, National Science Foundation for funding, and UMass, Amherst for assistance. We're working with a few undergraduate students at UMass on some uh sub-projects within this overarching idea. So yeah, it definitely takes a village.

SPEAKER_01:

Well, let's come back to some of the educational benefits of this because I think that you are paving paths for younger researchers to follow. So this is a great time for a short break and a message from the Northern Arizona Audubon Society. Let's come back shortly. So we're back with Dr. Paul Docherty in a conversation about his research in Northern Arizona. We've talked a little bit about uh what you're doing, where you're doing it, how you're doing it, all fascinating stuff. The geolocator technology is really interesting, how it you could infer location based on the times that you're able to archive. Paul, I want to change the direction of this conversation a little. Let's talk about how and when you developed your interest in birds and nature and the journey you've taken to become a postdoctoral research fellow.

SPEAKER_00:

Yeah. I've been interested in those things for a really long time, almost as long as I can remember. And I think it goes back to when I when I was very young and and my mom signed me up for uh a Massachusetts Audubon camp. So yeah, owe it all to that probably.

SPEAKER_01:

Okay, and years later you actually were a leader of bird walks for that same organization, weren't you?

SPEAKER_00:

Yeah, yeah, I guess I was.

SPEAKER_01:

It came full circle. That's really terrific.

SPEAKER_00:

Yeah. But yeah, I guess ever since then, I remember when I was a little kid, they had bird banding demonstrations and fun things like that. So I I always had, I guess, a more casual interest in birds that didn't really become too serious until until college when I took an ornithology class. And then I was really lucky to have my first official like bird field job after my sophomore year working for the National Audubon Society's uh Project Puffin in Maine, which was an incredible transformative experience where we were out studying Puffins and Turns and Gillamots and things like that out on these beautiful islands in the Gulf of Maine. And that was probably when I decided that I wanted to try to pursue ornithology as a as as a career.

SPEAKER_01:

And then you went from there to the University of Wyoming.

SPEAKER_00:

Yeah, yeah. I had a couple bird field jobs in between. But yeah, I did my PhD at the University of Wyoming, and now I'm a postdoc.

SPEAKER_01:

That's a lot of time and a lot of effort. That's a lot of amazing accomplishment. And the thing that I've really enjoyed seeing in your CV is that along the way you were giving back all the time. You were acting as a guide for bird walks. You helped edit the book Birds of Maine, which is a huge accomplishment. And you were doing outreach to school children. Yeah. And mentoring them as well earlier than your PhD days. How would you like that to work in the world in terms of embracing young ornithologists, if you will, into the discipline?

SPEAKER_00:

Yeah, I mean that's that's honestly my favorite part about being an ornithologist. That's sort of the when you can just get someone to become a little more interested in birds, pay attention to birds a little bit more, I feel like that's the biggest win, I guess, that any of us can can hope for. Just because I I feel like not everyone needs to be an ornithologist or a birder. But if if everybody just cares about birds a little bit more, I feel like that would that would go a long way towards making the world a better place. So I think getting out there and trying to spread the bird gospel is my my calling in life.

SPEAKER_01:

Uh-huh. Well, that's wonderful. And we do live in such interesting times, right? The technology now allows people to engage in citizen science at levels never before seen. And so the Audubon Society has got rich history of the Christmas bird counts. Uh and now we have eBird as well. And as early as your undergrad days, you were using those secondary sources on which to base scientific papers. So this is an interesting opportunity for you as a researcher to talk to people who are providing you with those data.

SPEAKER_00:

Well, first off, thank you. I mean, and my I try to collect those data as as much as possible. I I love contributing to eBird and the Christmas bird count. I think they're not only valuable, providing this unprecedented resolution of a data set that lets us study where birds are, when they are, so much better than ever before, especially eBird. But it's also just an amazing resource for researchers and providing opportunities for people who want to study birds because those data are all freely available online and super accessible.

SPEAKER_01:

I know from my time here in northern Arizona, there are people who are really committed to excellence in e-birding. Yeah. And I just love to see the lists that come out of places like Kachina Wetlands and Picture Canyon. Paul, you did a lot of birding on the East Coast, and you've been to Arizona a few times now. What are the species out here that you've been able to add to your life list?

SPEAKER_00:

Yeah, this year and also last year I've been able to get a decent number of lifers. Like bronzed cowbird, finally caught up with that one the other week, a western screech owl, zoned hawk, common black hawk, gray vireo, black chin sparrow, hepatic tanager, and Ebert's Toei. It's been a lot of fun.

SPEAKER_01:

Well done. That's a great addition. So let's celebrate that with a new segment here in our podcast called Name That Song. And I should tell everybody that this is a bird song that you chose. That's the only hint I'll give. Okay. Except that it's it's not a bunting. Oh. And the listener's task at this point is to identify the species after listening to a short recording. And we'll reveal the answer at the end of the episode. So get ready, here it comes. Hoyer and the Macaulay Library, part of the Cornell Lab of Ornithology at Cornell University, for the use of this clip. So, Paul, I've really enjoyed listening to you describe the research in which you're engaged here in Northern Arizona and soon, Montana. How vital is research like yours to conservation efforts?

SPEAKER_00:

Well, I like to think incredibly vital. I I think it's just critical to identify anything during the year that that limits bird populations, and that can happen whenever. But the thing that I think is so important about molts is that it's the thing that individual birds do to invest in their own survival. Everything else they do, migrating, everything that happens during the breeding season, it's all about raising the next generation, but molting is their investment in themselves. I like I like to think of molting as self-care for birds. So if there's something that is happening that is compromising the ability of birds to take care of themselves and influencing this adult survival, that is, I think, a very important thing to try to incorporate into these models for um predicting predicting bird population trends based on things that are happening throughout the year.

SPEAKER_01:

So as we wrap up our conversation today, what have you enjoyed most about your time in northern Arizona? Ooh.

SPEAKER_00:

That's a tough one.

SPEAKER_01:

He has some great cookies in Jacob Blake.

SPEAKER_00:

Ah, yeah, you you beat me to it. I was just about to say the Jacob Blake cookies are definitely up there. All the great birds that we've seen. Uh I mean, there's there's nothing like catching a bunting again and retrieving retrieving his geolocator and just thinking about just all of the magical data that's logged in this little little device on his back. Yeah, and getting to meet and interact with people in Northern Arizona Audubon.

SPEAKER_01:

Well, Paul, I want to thank you for your time today. It was really enjoyable chatting with you about this and also spending time with you at Picture Canyon as we hiked in pursuit of the Buntings. I wish you all the best on your research, and definitely would love to chat with you sometime in the future when you've got some data that you're able to share with us.

SPEAKER_00:

Yeah, thanks so much, Matt. It's been great, and uh yeah, I'll definitely keep you updated on what we find out.

SPEAKER_01:

Excellent. Yeah, thank you very much. Let's do the big reveal related to the bird song earlier. So it's time to reveal the species responsible for the beautiful bird song we heard earlier in this episode. It's the paraloxia, a species frequently seen in Arizona and a close relative to the Northern Cardinal. Again, we are grateful to Rich Hoyer and the Macaulay Library, part of Cornell Lab of Ornithology at Cornell University, for the use of this parallaxia clip. Thanks again, Paul. Thank you. We hope you've enjoyed this podcast. Please visit our website at northern Arizona Audubon.org and consider joining the Northern Arizona Audubon Society or your local bird group to support the work they do to help birds. And above all, we hope you will continue appreciating and protecting birds and the places they need.

Contributor

Matt Anderson

Host