Dumbacher J P, Beehler B M, Spande T F, Garraffo H M, Daly J W
Department of Ecology and Evolution, University of Chicago, IL 60637.
Science. 1992 Oct 30;258(5083):799-801. doi: 10.1126/science.1439786.
Three passerine species in the genus Pitohui, endemic to the New Guinea subregion, contain the steroidal alkaloid homobatrachotoxin, apparently as a chemical defense. Toxin concentrations varied among species but were always highest in the skin and feathers. Homobatrachotoxin is a member of a class of compounds collectively called batrachotoxins that were previously considered to be restricted to neotropical poison-dart frogs of the genus Phyllobates. The occurrence of homobatrachotoxin in pitohuis suggests that birds and frogs independently evolved this class of alkaloids.
黑头林鵙鹟属的三种雀形目鸟类，是新几内亚次区域特有的物种，含有甾体生物碱高毒毛蛙毒素，显然这是一种化学防御机制。毒素浓度因物种而异，但在皮肤和羽毛中总是最高的。高毒毛蛙毒素是一类统称为蟾毒素的化合物中的一员，这类化合物以前被认为只存在于叶毒蛙属的新热带箭毒蛙中。黑头林鵙鹟中存在高毒毛蛙毒素表明鸟类和蛙类独立进化出了这类生物碱。
