Predatory birds take a dip

Posted on December 15, 2009

Researchers in Europe and North Americahave found that some riparian birds, such as dippers (Cinclus species), are very sensitive to habitat degradation, which reduces the availability of their insect prey.  As a result, dipper abundance has been proposed as a good indicator of stream habitat quality.   A study in theTachiaRiver, a monsoonal stream inTaiwan, shows that dipper – habitat relationships can be temporarily disrupted by flooding, which dramatically reduces the abundance of both aquatic insects and their bird predators.  It seems that dippers respond to floods by moving to nearby, less disturbed streams.  They may also suffer reduced adult survival and lower breeding success. Therefore, the use of dippers as environmental indicators should take into account the short-term effects of flood disturbance.

Reference:  Chiu, M-C., Kuo, M-H., Sun, Y-H., Hong, S-Y. & Kuo, H-C.  2008.  Effects of flooding on avian top-predators and their invertebrate prey in a monsoonal Taiwanstream.  Freshwater Biology 53, 1335–1344.