April and May mark the peak of the spring migration. Every year, bird across the globe take to the air and embark on fantastic journeys from their wintering grounds to the breeding grounds. Often this journey takes them from one hemisphere to another; some species make flights that cover literally tens of thousands of kilometers.
Once this journey is complete, birds have only a few short weeks to breed and raise their young. Then they repeat the process in reverse, departing their breeding grounds for warmer climates to the south. This spectacle happens twice every year, but it happens so quickly that if you blink you can miss it. I make special efforts to get out birding as often as possible during this special time of year.
It would take too many words to describe all the migrants I’ve seen throughout the month of April, so I’ve compiled a short list of some of my favorite experiences over the past month. So here is the “Cliff’s Notes” version of spring migration in South Korea.
Migration in South Korea begins with arrival of the thrushes, at least in terms of the passerine migration. Some species, such as pale thrush and scaly thrush are resident species, but are rarely observed during the winter months. At this time of year the thrushes become more visible, and more vocal. Dusky and Naumann’s thrushes, preparing for their return to their northern breeding grounds, congregate in growing numbers before leaving Korea until the autumn. The forests begin to fill with the haunting melodies of pale thrush and scaly thrush. More unusual migrants, such as grey-backed thrush and Japanese thrush can put in brief appearances during their flights north. And as quickly as it began, the thrushes pass through and are not seen again until the fall.
Migration starts to pick up with the arrival of the first Old World warblers. The first arrivals are Japanese bush-warblers and Asian stubtails. The majority of warblers do not breed in Korea at all, and only make short stop-offs on their way to somewhere else. This makes the warbler migration very short, but also very exciting. Old World warblers are not nearly as colorful and visually appealing as their North American cousins, but they do match their relatives when it comes to melodious songs. In fact, with most Old World warblers, the only way to tell them apart is their song. Otherwise they all basically look the same.
The last passerines to arrive (or pass through) on the Korean peninsula are the Old World flycatchers. Unlike the tyrant-flycatchers of North America (small, drab, nondescript birds – usually only identifiable by their songs), Old World flycatchers run the gamut of colors. Residents like Daurian redstart and overwintering species like red-flanked bluetail make way for such exotic-sounding species as Siberian stonechat, Narcissus flycatcher, and Mugimaki flycatcher. As with many migrants, most of these species are only passing through, and no sooner do they arrive than off they go to their northern breeding grounds.
Birding during migration is all about timing. A day or two can make all the difference between seeing a migrant species and having to wait a few months until it passes through again. I’ve had some good fortune with timing this spring, and have been rewarded with adding some fantastic species to my Life List. On a recent birding trip to the Busan area, my friend Jason Loghry and I spotted a Japanese robin and had a brief encounter with a Sakhalin leaf-warbler, both species scarce migrants to Korea. We also had the opportunity to see the first of the new generation after locating six fledgling long-tailed tits being fed by adults.
A long weekend holiday is fast approaching, and Melanie and I have signed up to attend a Birdathon with Birds Korea on Eocheong-do. This will be my first official Birdathon, and our first visit to this premier birding spot off the western coast of Korea. Look for my full report on the trip in the next few weeks.