|Posted by Brian on May 26, 2017 at 4:15 PM||comments (0)|
I recently just wrapped up a 75-day field season. I caught a total of 132 birds, making the last few months successful. I'll be slowly uploading pictures and videos from the trip in the coming days. Here's a breakdown of my travel by county: San Diego-Los Angeles-Santa Barbara-San Luis Obispo-Monterey-Mendocino-Humboldt-Del Norte-Curry, OR-Lane, OR-Coos, OR. That's eight counties along the California coast, and three more from southern to central Oregon.
Although I enjoyed my time out there, it feels great to be back home and sleep in my own bed. Also, I can finally put together all of my data and map out the hybrid zone! Plans for the summer include submitting a manuscript describing the Allen’s x Rufous Hummingbird hybrid zone for the first time to a scientific journal, presenting my research at the American Ornithological Society conference in Michigan, and beginning genetic work on all of my samples from the last several field seasons.
Highlights from the trip include some awesome wildlife sightings: Mountain Lion (although I never want to see one again), American Black Bear, Rubber Boa, a lot of garter snakes, Gopher Snake, Pileated Woodpecker, tree frogs, a few foxes, and some raccoons (including the one that jumped into the back of my vehicle and stole my tortilla chips). I also saw several instances of aggression between territorial males of hummingbirds, including a couple instances physical attacks (one bird flies into the other by repeatedly hitting him on the side). One time I even saw a female hummingbird attack a displaying male. Most of the time, females are simply looking for their next meal, and if they happen to be on a male’s territory while searching for that meal, the male sees it as an opportunity to mate. Pretty much every single time. Give them a break; during the breeding season, the testes of a male hummingbird can expand to become 10% of his body weight. Thanks for checking out my blog throughout the field season, and check back for more pictures and videos soon!
|Posted by Brian on May 12, 2017 at 5:20 PM||comments (0)|
I’m in the homestretch! The transect is finished-it officially runs from Arcata, CA to Florence, OR, gradually shifting smoothly from an Allen’s-like phenotype in the south to a Rufous-like phenotype in the north. Over the next couple weeks, I’ll be posting a lot of pictures and a few videos that show what it is I’m doing out here-videos of how I catch birds and the data I gather. All of them were taken over the last few months. It’s been a successful trip, as I accomplished sampling for phylogeography and finished the coastal transect of the hybrid zone. Next year, the goal will be to find out how far it extends inland, as migratory Allen’s Hummingbird is a strictly coastal species in northern California and southern Oregon, with Rufous found both inland and along the coast throughout Oregon.
Here’s a summary of my travel over the last several weeks: it all started in Los Angeles County, shifted to Santa Barbara, then to San Luis Obispo, Monterey, Mendocino, Humboldt County, Del Norte County, southern Oregon, central Oregon, and will end either in Bandon, Oregon (in the center of the hybrid zone) or inland as I might search for some hybrid populations to get a head start on next year.
Most people know that a lot of birds migrate, but how do they do it? It’s pretty amazing to think something weighing three grams can fly thousands of miles over a short period of time, back and forth from Mexico as far north as Alaska and Canada, year in and year out, like the Rufous Hummingbird does. Although there might be some movement from year to year depending on mating success in the previous year and the presence of adequate resources, birds often return to the same population for the mating season, which is how populations, such as the hybrid hummingbird populations I’m studying, can be compared to each other at the genetic and phenotypic level. They don’t live there year-round, but migrate in and out of the area every year! Birds are able to use the stars, the sun, the Earth’s magnetic field, topography, and odor to figure out both how to find their mating grounds and how to return where they came from. Experiments have shown that, because sometimes information is complete or unavailable (such as overcast nights or an inability to detect the sun), birds can also get lost using other cues.
In a week or so, the cold temperatures and rainy weather will have to wait until next year to come around again, while I work on presenting and publishing all of this data. Thanks for checking in!
|Posted by Brian on May 5, 2017 at 2:15 AM||comments (0)|
As of last Saturday, sampling in California has concluded for this year. I’ll be working along the southern Oregon coast for the next few weeks, I might head to central Oregon in the Florence area (where the hybrid zone ends, and pure Rufous Hummingbird populations begin), and end the field season. The weather has gotten a lot better; less rain, more sun, and highs in the high 50s, which sometimes feels like a heat wave. I saw my first bear of the season last week at Del Norte Coast Redwoods State Park in California; one of the few black bear that actually had black fur that I’ve seen.
Where I’m at now presents the largest unknown of the transect. The Siskiyou mountain range rises to about 6,000 feet in elevation really close to the coast, potentially keeping Rufous Hummingbirds from interbreeding or interfering with potentially pure Allen’s populations. However, thus far, the populations seem to be just as intermediate as the one in Crescent City, northern California. There seem to be two possibilities, which will (hopefully) be sorted out in the coming weeks: the hybrid zone is disjunct, meaning there is a transition from a Rufous-like to an Allen’s-like phenotype (a summary of overall physical characteristics) from Florence, Oregon, to Port Orford, Oregon, a stretch of about 40-50 miles where no hybrids (and possibly pure Allen’s) are found due to the presence of the Siskiyou mountains, and a recurrence of hybrids in northern California where that mountain range is no longer present. The other possibility is that the hybrid zone forms a fairly smooth cline, where there is an overall transition from a Rufous-like to an Allen’s-like phenotype from Florence, OR, straight to the Eureka, CA, area. As of now, the latter seems most likely. One thing is certain; the populations are sparse (or at least less accessible) in this area compared to anywhere else I’ve worked.
After a couple weeks of field work in my first year, two months of field work last year, and nearly three months of field work this year, I’ll have sampled over 200 birds. Over the course of my dissertation, I will probably have sampled in the neighborhood of 400 birds. Why so many? First off, the hybrid zone is a lot larger than any of us anticipated, and sample size will thus need to increase. Also, using a technique called admixture mapping, we’re going to try to find the genes responsible for the pendulum display in Allen’s Hummingbird using recombination that takes place in the hybrid zone. If you have pure Allen’s and pure Rufous interbreed, a hybrid’s genome will include the genetic makeup of both species. Because of this, only bits and pieces of the phenotypes expressed by a “pure parent” might be present, as is the case with the pendulum display. So, we’re looking to correlate the genomes of hybrid birds with the different elements of the pendulum display they perform, and determine how it might have evolved.
Sometimes territorial male hummingbirds I’m getting courtship data from will visit feeders as often as every five minutes. Hummingbirds feed about 14 times an hour because of their extremely high metabolic rates, so some of these guys are getting most of the nectar in their diet from my feeders! When a hummingbird consumes nectar, it fills its crop, which is a storage space for food in birds. Often an individual will perch somewhere for a short while following feeding. This is so the crop can empty and digest the food into its system. Once the crop is about half full, the bird will go feed again. When a bird doesn’t go to a feeder, it can seem impossible to catch it. That’s where mist nets can be useful. A few weeks ago, we built a mist net that has been working out well in catching target birds that won’t visit the feeders. When a bird flies into a mist net, it gets tangled in the net and is typically stuck until safely removed by somebody (with no harm done to the bird). Lots of pictures and videos to share when things start slowing down, including a video of myself and the lab tech at UCR (David) catching a bird using such a net.
|Posted by Brian on April 20, 2017 at 11:45 PM||comments (0)|
The last couple weeks have been characterized by a raccoon that jumped into my car, some questionable deer, and elk herds walking nearby. Last Thursday I had to wake up super early, and I left the back hatch of the car open as I went to grab my tent. I walked back to the car, and a raccoon jumped out and left a trail of tortilla chips behind. Just before I left, he reappeared, and wouldn’t run when I approached him. I had to honk the horn to scare him off and get open the back of the car! At Prairie Creek Redwoods State Park, I was walking through a meadow, and as I approached the hummingbird I wanted to set up a feeder for, a couple deer popped up in the grass a few yards away. It startled me, but no big deal. I took another step forward, and a few more did the same, then I turned around, and there were more. Lots of fawns with their moms, so I got out quick. Today, I began work at a field site with a huge elk population. As I was getting recordings, I’d see them trying to get a feel for me from far away, and every hour or so one would run by for some reason. I kept imagining the entire herd running at full speed, trying to figure out if I’d be able to climb a tree in time to get out of the way, but remembered this isn’t The Lion King and I’d probably be okay. However, nearby I did see a herd of about 50 or so elk. Finally, I saw my first ever mountain lion, and it scared the hell out of me. I was walking on the roadside to get back to camp, and the sun had just set, and I thought I saw a deer a few yards away. It wasn’t a deer.
I finished up in Mendocino and arrived in Humboldt Sunday afternoon. There’s only been one day without rain in the last week, although things have still been pretty productive given the circumstances. A couple of my field sites are in redwood forest, which has been awesome to work in. I’ve even been able to work in a closed campground surrounded by redwoods. Northern California is beautiful-endless redwoods, pine trees, ocean, wetlands, etc. I’m grateful to have met CJ Ralph, a legend up here who runs a banding station on his property and contributes a lot to ornithological research.
As far as hummingbirds go, it looks like the hybrid zone extends at least as far south as Arcata, CA, which is much further south than initially expected. The next few weeks of sampling should paint a complete picture of my coastal transect, which will allow me to study phenomenon such as sexual versus natural selection, which characters might be most important in divergence between Allen’s and Rufous Hummingbird, and the role of the environment in their evolution. If a species winds up needing protection, how can you protect it if unsure about the climate, resources, and it’s evolutionary history?
Six weeks down with a few more to go!
|Posted by Brian on April 6, 2017 at 10:15 PM||comments (0)|
When it rains in southern California, it usually stops after a short while. When it rains in Mendocino, it doesn’t seem to have an end. At least there’s time for an update! I’ve traveled from San Diego, to Los Angeles, Santa Barbara, San Luis Obispo, Monterey, and now Mendocino. Next up (hopefully by the end of the weekend!) will be Humboldt County. It’s beautiful out here. Freezing, but beautiful. Tons of pine trees, dense forest, and riparian areas to aid the transition from forest to ocean. Also, I can’t forget the invasive Himalayan Blackberry (Rubus armeniacus) and it’s painful thorns. However, the hummingbirds love it. The campground I’ve been staying in at MacKerricher State Park, is my favorite of the trip. Towering pine trees, lots of separation between campsites, the sound of the ocean, peace and quiet after dark, and rain pattering the tent throughout the night. Nothing better than that.
I'm pretty excited to get into Humboldt County, because earlier in the year I made a model based on rainfall and temperature data predicting the hybrid zone would begin there. It has consistently aligned with the localities and divisions of the hybrid zone I've sampled thus far (divisions include pure Rufous Hummingbird populations, Rufous-like hybrids, 50/50, Allen's-like hybrids, and pure Allen's Hummingbird populations), so I am hopeful. Humboldt County would comprise the beginning of the Allen's-like part of the hybrid zone. If so, it might highlight the relationship between the climate and these two species, the types of habitats they are able to hybridize in, and the habitats and conditions they are dependent upon. Basically, Rufous Hummingbird requires wetter, colder, habitat than Allen's Hummingbird.
Rufous Hummingbird are still migrating, and they often make things very confusing when I’m trying to track and capture breeding Allen’s Hummingbird. Outside of courtship behavior, it’s very difficult to tell the two species apart. Often (but not always), the back of Rufous Hummingbird males is relatively close to being 100% orange in color, while the back color of Allen’s Hummingbird males is usually 60-100% green. Other than that, unless you have a bird in your hand, or they are performing courtship displays, good luck telling them apart. Females are even more difficult to differentiate, and have to be “in the hand”. There are a lot of Rufous passing through here, and several of them are displaying, which might seem strange considering they haven’t yet arrived at their breeding grounds. They just have a little trouble holding in their…excitement. This morning I watched a male Rufous Hummingbird perform a really long shuttle display (which is a close quarters courtship display that can also be used as a form of aggression) to a White-crowned Sparrow (Zonotrichia leucophrys) who was probably a little puzzled.
How often do you think a hummingbird beats it’s wings per second? Some can beat their wings well beyond 50 times in a second! Everyone knows they’re exceptional performers in flight with the ability to hover, but they can also fly backwards with ease (watch a video here). Did you know the Ruby-throated Hummingbird (Archilochus colubris), found in the eastern United States, has a metabolic rate nearly 100 times that of an elephant? If you have a feeder up at home, you might notice the same hummingbird visit several times a day, and probably even more often than you think. This is because of their high metabolic rates and the fact that they burn so many calories so quickly. Some hummingbirds consume up to three times their bodyweight in nectar and insects per day!
That's all I've got for now. See you all soon!
|Posted by Brian on March 29, 2017 at 1:10 AM||comments (1)|
Three weeks down! Everything’s gone as planned thus far (that often doesn’t happen working with nature), and I’m currently in Monterey. The ticks out here are ridiculous. I pulled five of them off of me this morning. There are usually at least one of three nuisances present when working outdoors in coastal California: poison oak, mosquitoes, and ticks. Poison oak will ruin your life for weeks, mosquitoes are some of the most annoying organisms on the planet (and can spread disease), and ticks, to me, are the worst of the worst. There’s nothing quite like an animal that tries to burrow inside your body without your knowledge, drink your blood, and have the courtesy to leave you with an infection or disease before departure. Out of frustration, sometimes when one runs into any of the above in the outdoors, it’s reasonable to wonder what good any of these nuisance organisms are, their roles biologically, and whether the environment is better off without them. Many animals, the California Towhee (Melozone crissalis) for example, form a symbiotic relationship with poison oak (Toxicodendron diversilobum), building its nests among the plants and feeding on the white berries, then spreading the seeds through excrement. Ticks are hated by many, including myself, but they (and mosquitoes) serve as an important food source in most ecosystems. However, one biologist says the extinction of mosquitoes might have no effect at all on the environment. Anyways, back to birds.
Monterey is my fourth stop on the trip thus far-I left San Diego, then sampled in Malibu, Santa Barbara, San Luis Obispo, and now Monterey. If I study hybridization in a contact zone between Allen’s (Selasphorus sasin) and Rufous Hummingbird (Selasphorus rufus), what am I doing sampling far away from the hybrid zone? Well, I’m also doing a phylogeographic study on Allen’s Hummingbird. Some organizations such as Partners in Flight claim this species is declining rapidly. Others are skeptical, especially given the fact that the non-migratory subspecies of Allen’s Hummingbird (Selasphorus sasin sedentarius) is currently expanding its range. By sampling Allen’s Hummingbird throughout its range, I’ll be able to quantify whether the species is really in decline or not. With limited conservation dollars available, knowing which species are threatened and which are not is extremely important to prioritization and management decisions. Second, in order to accurately describe behavioral differences between Allen’s and Rufous Hummingbird, and to use these differences to classify and sort out hybrid characteristics, I have to actually know how pure Allen’s Hummingbird behaves across its range to provide a meaningful comparison. This is important for all aspects of my dissertation.
You don’t spend most of your time working and living outdoors during the field season without running into some weird experiences. In Santa Barbara, for example, a full campground woke up in the middle of the night to a homeless couple screaming, shouting, and fighting at the top of their lungs, followed immediately by a drunk driver crashing his car into a tree. In San Luis Obispo, somebody seriously asked me to catch a hummingbird for her as a pet, and assumed that’s what I was doing there in the first place. I face-palmed pretty big on that one. Hummingbirds need more than sugar water/nectar to survive…they need protein! Insects make up a huge portion of their diet-hummingbirds are predators too! Finally, some advice: don’t book several nights in a campground built next to a railroad tracks with trains that run all night.
I’ve also added some pictures to the photo gallery. Thanks to Megan and Chris for letting me stay at their place in San Luis Obispo last week, and thanks for checking in!
|Posted by Brian on March 13, 2017 at 12:20 PM||comments (1)|
My first week was a successful and interesting one. I saw a hungry Cooper's Hawk rip a Northern Mockingbird into pieces, observed a pod of dolphins, and watched a Western Scrub-jay land on the arm of the chair I was sitting in to harass me for some food. Camping in the California State Parks I've stayed at has been $45/night-more expensive than some motels. I find it pretty odd that the powers that be, with it's monopoly on campgrounds, continues to drive prices up on public land and price out those who can't afford it.
As far as research goes, I tend to find Allen's Hummingbird in coastal sage scrub (CSS) habitats, many of which I notice are also degraded areas. Although Allen's Hummingbird populations are likely doing well (my work this field season aims to quantify that), in part due to the presence of ornamental and invasive plants that have popped up due to urbanization, there are a lot of species that rely on CSS to survive, many of which are in decline, such as the coastal Cactus Wren. CSS has been reduced to approximately 10% of it's original range, and a large portion of remaining habitat is degraded, so this spells trouble for such groups.
Upon release, one of the Allen's Hummingbirds I caught angrily performed courtship displays at a Song Sparrow, a bird about 6.5 times his size. Hummingbirds, especially Allen's and Rufous, often do this to not only each other, but different species of birds (even if they're much larger), small mammals, or anything that might be looking at them the wrong way. The philosophy of a hummingbird is to always be angry at the world-they don't take flak from anybody.
|Posted by Brian on March 8, 2017 at 1:15 AM||comments (0)|
Tomorrow, March 8, I begin my third field season. The goals over the next 2-3 months are to a) complete sampling for a phylogeographic study of Allen's Hummingbird, b) complete sampling of the first transect across the hybrid zone, and c) begin sampling of the second transect. I'll be starting in Southern California, working my way north along the coast until I arrive in Southern Oregon.
Over the next few months, I'll try to include some information you might not have known about hummingbirds before, noteworthy experiences (such as the Breaking Bad-like motorhome and it's many visitors at a specific field site last year), pictures and descriptions of the places I go, and updates about research progress.
Here's a quick fact: In general, hummingbird courtship displays are also used to neutralize potential threats. For example, territorial males will often perform dives to intruders not to woo them, but to express dominance. Other expressions of aggression in hummingbirds include louder, more intense chattering, body posturing, chasing, and physical attacks.