Bats in my Porch: 15. Is the roosting site also a salt lick?

On the early morning of 22nd August 2014, a male Common Fruit Bat (Cynopterus brachyotis) visited my porch to lick the wooden strips that line the roof (above). These strips of wood had been varnished about two decades ago and have yet to fade. However, the edges of some appear worn out. Can this be because of regular licks through the years?

This male bat flew in, attached himself onto a wooden strip and immediately began vigorously licking the surface as he moved about. This lasted a few minutes, after which he flew out. A few minutes lated he flew in and repeated the process of licking.

During my observations of this new behaviour from 04:00-05:30h the bat repeatedly flew in, licked the wooden surface and flew out (above). This probably went on even after I returned to bed.

On the morning of 5th September, between 06:00-06:46 hours, a male bat, not sure whether it was the same male, was seen repeatedly visiting the same site. This time he licked as well as repeatedly bit into the wooden strips, making distinct crackling sounds (below).

The two spotlights in the porch were on and this may have attracted other bats to fly in, interfering with his activities. Whenever a female bat joined him, his priority turned to courting – stretching his wings and flapping them. Invariably the females spurned his advances.

According to Voigt et al. (2008), pregnant and lactating bats have been recorded frequenting mineral licks in the Amazonian rainforest, just like what many other mammals and some birds are doing. But this was a male bat. However, the authors also suggest that bats behave this way not so much for the minerals than to buffer the effects of secondary plant compounds that they regularly consume in large quantities.

Can this be the reason why this Common Fruit Bat visit my porch, using these wooden strips as a “salt lick” to obtain certain minerals to supplement his diet?

YC Wee
Singapore
September 2014

Reference:
Voigt, C. C., K. A. Capps, D. K. N. Dechmann, R. H. Michener & T. H. Kunz, 2008. Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest. PLoS ONE 3(4), e2011 [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2292638/].