is right - too much pishing, or playback of vocalizations, can disrupt bird behavior and in very rare cases distract birds so a real predator nabs them
I never use pishing, squeaking, etc. when rare or threatened species are involved, or in heavily birded areas, or in refuges where such activity is prohibited. And I never pish for long. But birds figure out pretty quickly that nothing is there and go back to their normal business - it's almost impossible to keep their attention for long.
-- After today I can report that pishing ABSOLUTELY works in Kenya. Yesterday I pished up some Yellow-breasted Apalis, White-bellied Tits, Common Bulbuls and other birds (with just a few pish notes) on the wooded grounds of the Purdy Arms in Karen.
Today our guide Francis (from Ben's Ecological Safaris) and I had very good results pishing responsibly along our route down Magadi Road. Just in the stretch from Corner Baridi (near crest of the Ngong Hills) to Oltepesi, we had six species of Sunbirds, Four species of Barbets, Buntings and Canaries galore, African Gray and Spotted Flycatchers, more White-breasted Scrub-Robins than you could shake a stick at, several Spotted Morning-Thrushes, Absynnian and Yellow White-eyes, multiple Shlow's Wheatears, Yellow-spotted Petronias, Red-throated Tits, Red-fronted Warblers and many other species popped up to take a look at us in response to pishing.
I know @twaffle
's point is correct, but as some of my PhD ornithologist birding friends like to point out: no peer-reviewed publication has ever concluded that pishing is detrimental to birds. But there are a lot of truths out there that have never been sufficiently quantified for publication - nature is too slippery to pin down in so many ways...
PS I just got finished watching and listening to a Silvery-cheeked Hornbill getting mobbed by several Black Kites on the grounds of the Purdy Arms. What a delightful racket.
Edited by offshorebirder, 09 January 2016 - 04:00 PM.