For the season itself, based on my experience, only 6-8 times a year, including the mating seasons, and usually they came out from their nest on the rain season only.
Right now the weather changed, it's rainy season, and guess what, it's hunting time!!
To catch this beetles, is quite different from the others, because this beetles always came out in the early morning, around 06.00 AM, and return to their nest at 11.00 AM.
Based on my experiences in collecting stag beetles, this one is the only beetles that capable flying out in the day.
They flies and search for this special bushes, and in local we call it Cengkodok trees.As you can see on the picture below, if you watched it carefully, there's a mandible hiding under the Cengkodok leaf.
Can you spot it ?!!

They feed on the nectar from Cengkodok flower, and usually the flowers itself blooming 8 times a year, that's is why the seasons comes (I think !!).
This Cengkodok trees is a native trees and can be found only around South East Asia, and the habitat is around the river bank and a great plains.
To catch this stag beetles, I uses a net, and to find where's the beetles colony hiding , sometimes I use my own methods,
first; find a bushes that has no farmers activity, because when there's farmers, sometimes they used insecticide to kill insects, and guess what, absolutely there will be no more Cyclommathus Tarandus living there.
And the second method, I like to use a river path, the reason is, I don't have to spend much times on searching the beetles when they fall into the bushes.When they fell on the river, it's so easy to caught it, because they can't swim!!!!ha,ha,ha,ha...(They should learned how to swim....)

The most difficult task in catching this Tarandus is to find where is the colony, sometimes it's takes a day, even a week, but the most impossible thing for me until now is to find their nest. I don't know what,where and how, until now I can't find it.
The season itself only takes a couple of weeks, sometimes 3 weeks or a month.After that, I need to wait until the other seasons.Sometimes in 1 season, I can't catch even a single beetle.
To unable catch some nice and big Tarandus, I need to wait for the mating season, because in this times, the superb and beautiful males is out for mating.I hope this is the times, because I don't have any idea when they will come.
The biggest Cyclommathus Tarandus that I ever had is 70 mm, and that's extremely rare, only 1 in a million, 8 years ago.But, to catch that size again, I don't think so, it's like almost impossible for this times,this current situation where everywhere in Kalimantan, so many forest destroyed by the palm plantations.
The largest that I ever caught since that day is only 69 mm, about 2 years ago.For the Record, the largest Cyclomatus Tarandus in record is 74mm, from Kuching, Sarawak, Malaysia in 1902.And second largest is 72mm,1904 from Sarawak,Malaysia.This info I get from my Australian friend, Stephen Hey, he really loves Cyclommatus.
I hope for this season, I can find those giant male of Cyclommathus Tarandus again.
mating
Feeding the nectar