Wednesday, March 25, 2009

Migration


Waders at Sungei Buloh Wetland Reserve;
(Photo by chia_alfred)

That many species of birds migrate is a fact known to most of us. But we often forget about the struggles and threats faced by many migratory birds. Habitat loss at every stage of their journey, from breeding and wintering grounds, to critical stopover and staging areas for birds to refuel and take refuge from bad weather along the way, is a great threat to most migratory bird species. Deliberate hunting and trapping is another severe challenge, especially at key points where entire flocks are funneled into a small area due to geography. Agriculture intensification, pesticide use, urban expansion, power lines, and the proliferation of wind energy and high-rise buildings can also exact a severe toll on some of the world's great travellers.

This inspiring and moving video by the Born To Travel campaign shows the amazing annual voyage undertaken by some birds, and illustrating the seemingly insurmountable challenges they face at every stage of their epic journey. That some of these birds travel great distances across entire continents, and over mountains, deserts and oceans, is simply stunning and awe-inspiring.



Although the Born To Travel campaign appears to focus on birds that utilise the African-Eurasian Flyway, it is important to note that similar migrations are to be found in other continents. For example, there are birds that travel from Canada to Argentina and back, making the trip across the Gulf of Mexico, while others travel between the Russian Arctic and India, crossing the deserts of central Asia and the Himalayas.

Singapore itself is a vital stopover for many waterbird species using the East Asian-Australasian Flyway. For much of the year, residents in our forests and wetlands are joined by a retinue of visitors from distant lands. For many birds, the loss of a single feeding and resting site can make the difference between surviving to carry on the next leg of the journey, and perishing from exhaustion.


Waders at Sungei Buloh Wetland Reserve.
Left: Whimbrel (Numenius phaeopus);
Right: Mongolian plover (Charadrius mongolus);
(Photos by kampang)

There are many books available on bird migration; recent titles include Atlas of Bird Migration, Living on the Wind, How Birds Migrate, and Bird Migration. I haven't read any of these titles myself, but I have read Silence of the Songbirds and No Way Home, which devote a fair bit of space to discussing the decline of migratory bird species.

To end off, here's a couple of trailers from a most excellent movie that is all about bird migration. Le Peuple Migrateur, also known as Winged Migration, is a 2001 film that captures the journeys of birds in amazing detail.





May these journeys continue to amaze and inspire us for generations to come.

(Hat-tip to GrrlScientist)