This summer is our first field expedition on the new barn swallow grant, and Matt and I will be traveling across Russia studying three different subspecies- H. r. rustica, H. r. tytleri, and H. r. gutturalis. One of the big goals of this project is understanding why the subspecies look different (check out the About page for more info). Traits such as plumage, song, and morphology are used in mate choice decisions, and population-level variation in these traits can therefore initiate the speciation process by generating reproductive barriers. It's particularly important to study these traits in contact areas between different subspecies, because this is where barriers between differentiated groups are most likely to break down. When we visit these "contact zones," we can see if there's any evidence for hybridization (i.e., weak reproductive barriers), or if neighboring populations are very differentiated (i.e., strong reproductive isolation). These different patterns provide clues to the processes causing subspecies to diverge from each other.
Getting all this information is not as easy as it sounds. If you check out the range map above, based on observational data, it looks like there's really nice contact areas between the rustica, tytleri, and gutturalis subspecies. Unfortunately, if we look at where museum specimens have actually been collected and measured, it's a whole different story: the map below shows locations of rustica, tytleri, and gutturalis specimens in Western museums. There are huge gaps in sampling, and no one has actually visited the all-important contact zones between the different sub-species. This means that not only do we not know what the birds look like in these areas, we're not even sure exactly where the contact areas are.
To fill in those gaps in the map and find out what the barn swallow contact zones look like, Matt and I are spending 2.5 months traveling across all of Russia. The yellow pins on the map above show the cities we'll be stopping in. In each place, we're meeting with local Russian ornithologists, heading out to rural villages, and spending a week or so catching birds. We'll take measurements, blood samples, feather samples, photos, song recordings- every bit of information we can think of. Then, to intensively sample those contact zones, we're meeting up with ornithologist Georgy Semenov in Krasnoyarsk and spending a month driving around Lake Baikal to Chita, hopefully crossing through the rustica-tytleri and tytleri-gutturalis contact zones. Along the way, we'll be staying in small research stations and camping out in agricultural fields, getting up before dawn, and eating a lot of mayonnaise-drenched Russian food. We're traveling between villages on the Trans-Siberian railroad, which will be an adventure unto itself- the first leg of our trip, from Moscow to Yekaterinburg, will take 32 hours. We're pretty excited- fieldwork like this is why many of us became biologists. We're hoping to have internet access every week or so, so we'll post updates and photos along the way!