EPOW - Ecology Picture of the Week

Explanation:  Filling the springtime air in southern Siberia are the sweet songs of this furtive creature -- a Black-browed Reed-warbler, arriving from its winter home in southeast Asia.  This is a very common and typical bird of the Far East.  

As the Siberian winter loosens its icy grasp, reed-warblers and other songbirds begin their annual breeding cycles in the marshes and meadows along streams and lakes.  By June, you can find the deep-cup nests of Black-browed Reed-warblers with their 4-6 olive-colored eggs hidden in grassy thickets.  

The males cling to the tops of taller grass stems or shrubs and solicit for mates or announce their territories with their churring songs and calls.  Click on the images below and listen to these variations in their songs:

  1. Slurred churring song (81KB mp3).

  2. Slow song type (140KB mp3).

  3. Several trill songs, various rates (300KB mp3).

  4. Trill songs -- two fast, one slow (188KB mp3).

One study found that males mimic the songs of up to 5 other bird species, although having this ability apparently was not a factor in females choosing their mates.  Thus, vocal mimicry might not have evolved because of selection by females, although it might serve some adaptive purpose such as scaring away potential predators.

In Russia, this species is found only in the extreme southeastern part of the country.  It belongs to a group of birds that are allied with a Chinese fauna, whereas the other birds of Russia belong to groups of more Arctic, strictly Siberian, European, Mediterranean, Mongolian, and Tibetan associations.

Black-browed Reed-warblers have been honored on postal stamps.  The bird goes by many names in different places and languages ... including Schrenk's (or Von Schrenk's) Reed-warbler, Double-browed Reed-warbler, Small Reed-cutter, Black-browed Sharp-headed Warbler, and others.  Many names, many vocalizations, many mimic songs ... a diverse talent for so small a songster.

Information: 
     Hamao, S., and H. Eda-Fujiwara.  2004.  Vocal mimicry by the Black-browed Reed Warbler Acrocephalus bistrigiceps: objective identification of mimetic sounds.  Ibis 146(1):61.