Seeking light, small GPS tracker for flying fox study

How much does a baby fruit bat weigh?

-m-

Mikey,

The weight of an adult Grey Headed Flying Fox range from 700gm-1Kg with up to a 2m wingspan. The infants, when born, are 60-70gm and are carried by their mothers each night as they fly off to forage until they are around 120gm at which point they are left each dusk in the colony creche until the mothers return at dawn.

cheers

Tristan

do search on researchers who track small birds in this manner. This problem may have been solved.

Your range requirement is a hard one to deal with. Bats fly low, nap of the earth, and 50-100KM is over the radio horizon for them. Something that could be picked up and tracked by a sat network might work if it uses the relic of the iridium system for example which has a high number of satellites on lower orbits. Such a transmitter needs no GPS because the multiple intercepts from the satellites produce a specific location. The battery life can be extended by having the transmitter on a 1-2% duty cycle where is transmits a short burst every 5 seconds or so. Your transmitter would have a 'whisker' trailing antenna and you would only get the signal in flight above the treets, not in a roosting cave or deep under tree cover. Higher power items tracked by portable radios suitable for deep bush would have a short life. Are bats aggressive groomers and will they tolerate something stuck to them or will they groom/bite it off?

The signal could be coded for individual bats to some degree.

One thing would be a small radar retro reflector and a MM radar. This can be light and you radar has the power to give you 10KM range. No individual tracking with this, just a flock of dots

Hi Ardua,

Your sugestion on small birds having been tracked in this manner is one I'll investigate.

We don't have to worry about them entering caves as Flying Foxes are not like micro bats or other small bats in that they don't use echo location but rely on smell and eyesight. They are not closely related to other bats, in fact the latest DNA studies show that the old world primates such as Lemurs and Howler Monkeys are their closest relatives. This probably explains why they groom in the way they do but I think one would accept a collar as long as it is light enough.

They roost in open eucalyptis forrests 'Gum Trees' and rely on these for much of the nectar they eat so loseing the signal should not be a huge problem. I had hoped there may be existing hardware and programs already developed for the study of large birds? For example a large study of Wandering Albatrosses was conducted in the Southern Ocean last year which tracked individual bird movement across hundreds of miles of ocean in a triangle between South Africa, Australia and Antartica which is the sort of I.T I'm looking for. Any other thoughts you have I would very much like to hear,

Thanks

Tristan