Dead Bats and Cats

Hello, all Thetis Island friends of bats and batty friends. 

Listen up, there is trouble in paradise. 

May 2^nd a dead bat was found on the Lawerence valley trail and reported to me. The next day another dead bat found on the trail in a similar location, and over the following 2 weeks 8 more were found along the trail from the first location all the way to the Firehall on Mission Road.  I contacted the B.C. bat program to enquire about testing these bats with a full necropsy to find the cause of death.  I wondered if it could be the dreaded White Nose Syndrome finally arriving here or perhaps rabies or even starvation, at this point, a mystery.

The bat program agreed to the necropsy testing at a total cost of about $175.00 per bat totalling $1,750.00, a very serious effort to determine what is happening.  The results are disturbing. The bats were primarily the small brown myotis species with 4 females.  They all tested negative for any disease, not WNS, not Rabies, and not starvation, however, all the bats showed “Puncture” marks, a trauma, according to the lab report, indicative of CAT PREDATION!

Subsequent to sending the 10 bats in for testing a further 7 dead bats have been found in the same area with possibly more lying unfound.  This is a disaster for any bat colony.  The females only have one pup a year and a colony may only have about 20 individuals.  It is possible that the 17 bats are from one or two bat roosts and it is likely that they will never recover from this kind of loss. 

But what have we lost?  Certainly, some mosquito control at a potential 600 mossies consumed per hour per bat, do the math.  Bat guano is an excellent fertilizer spread through the forest by these little extraordinary flying mammals.  We are still learning from the many unique skills they have which we may apply in all manner of ways. 

Why the loss?  My opinion, given the facts we have.  The culprit is a domestic cat that is allowed outside at night for an hour or two or perhaps left out to roam for a day or days, as some are.  This cat leaves the owners home, it hunts or rather reacts to triggering stimuli, kills but does not consume and moves on, then returns home enjoying the food their owner has provided.  How can a cat kill a bat flying high and erratically?  Bats need to drink and will fly in very low to skim a water source.  Bats are hunting insects which may gather within a few feet of open ground, perhaps a trail. 

Cats are “smart” and can learn bat behaviors.  They observe and wait patiently, a low flying bat is swatted out of the air with a quick paw and then killed on the ground with a bite or two.  This behavior has been documented on Thetis before but not to this extreme extent.

I now have an appeal to all pet owners.  Pets are a responsibility that we assume and are a projection of ourselves out to the world.  I seriously doubt the owner of the cat has any ill feelings towards bats and may actually enjoy their presence around the home.  I encourage everyone to limit their cat’s outside time and if allowed out at any time equip your cat with a “cat bib”, found here  https://catbib.ca/ .  If your cat is a “barn cat”, make sure it stays in the barn.

We love our pets and they can be a great comfort and solace, but we need to take the responsibility that comes with ownership seriously.  We wouldn’t kill island creatures indiscriminately so don’t allow your pet to do something you would not do.

Thank you,

Rob Welsh -- coordinator for the Thetis Island Bat Program

rmwelsh@telus.net or 250-246-1547