Hi guys,
Just thought I'd mention something that I've noticed for quite a few years now, hope I'm not the only one, but in Sydney cicadas only call at night due to predation by mainly Indian mynahs. I don't remember ever hearing them call during the day recently but in the past I do recall them calling for most of the day. I've seen Indian mynahs actually hunting down the ones that call during the day. I think that they might disappear altogether soon due to habitat destruction and predation, summer won't be the same again without them, so sad.
Interesting. I can only remember them chirping during the day (in Melbourne). Usually on hot days. Hard to imagine that they have been forced to adapt their innate ways for indian mynahs. I wonder if the entymologists would know the answer.
Cicadas sing in the night when they are near a source of artificial light, in extraordinarily hot weather or when they are overcrowded. I read that online. I have noticed that they seem to be declining in Sydney and that I hear more in the evening.
Wow, now I know I must walk around not noticing half as much as I should but yes, now I think on it, I have not heard cicadas around our place for years. Hmmmm... I wonder why?
Happy Birding!
https://www.flickr.com/photos/138588528@N02/
I don't discount the possibility that cicadas are declining, but greengrocers ('common' green one) for example spend ~7 years underground before emerging as adults so there are natural fluctations between generations and accordingly their apparent prevalence. there are some every year as not all are in sync but there are major eruptions periodically.
Birds seem to love them, I've seen house sparrows take greengrocer cicadas, wattlebirds and mynas seem keen on them.
There are an array of smaller often brownish day singing species with a quieter chirping sound, the greengrocer (the familiar big green loud cicada of Melb and Syd) usually (but not always) naturally sings in the evening/night, it's perhaps not an adaptation to myna predation...
I remember seeing a bunch of articles last summer about fluctuations in cicada numbers, as 2013-14 was an especially big year for cicada numbers.
I can't say I've noticed in Sydney, but certainly when I'm down in the Newcastle area at Christmas the cicadas are almost deafening in the bush on hot days. That said, there are also very few Common Mynas in that area.
Cheers
Tim
Brisbane