Hot Enough For Ya? (Late Winter Edition)

Birds do not have the mammalian form of the neurotransmitter receptor known as “vanilloid receptor subtype 1” (VR1).  Mammals have this ion channel receptor, which is stimulated by heat and physical abrasion, in addition to exposure to chemicals from the vanilloid family.

Why do we care, you might be asking.  As it turns out, one of the more common vanilloid chemicals, readily available in most home gardens (or at the very least, in virtually every farmer’s market or grocery store), is capsaicin, the chemical responsible for the “heat” of hot peppers.

Plants from the Capsicum genus have evolved a particularly handy means of protecting their seeds from the grinding molars of mammalian herbivores, whilst and at the same time allowing avian fruit foragers to consume the seeds whole, then distributing them far and wide in ready-made packets of fertilized seed pre-treatment (gross, but effective).  The seeds of hot peppers (and related plants) do not contain any capsaicin, but the surrounding tissue – particularly the whitish placental tissue, though to a lesser extent all the rest of the fruit as well – is chock full of the stuff.

Birds feel no effects whatsoever when eating these fruits and seeds, which is why chili powder is considered a good squirrel deterrent in bird-feeders.  The squirrels can’t stand the stuff (more on that in a second), but the birds are entirely unaffected.  Provided you don’t scare them off with unusual scents or sights, you can get your birds to eat spicy versions of their current favorites, and they won’t even notice the difference.

So.  Why are squirrels (and other mammals) affected by hot peppers?

Recall that the VR1 receptor is stimulated by heat and physical abrasion, in addition to the presence of these chemicals.  Essentially, the vanilloid chemicals (in this case, capsaicin) overwhelm the neural pathways in tissues which have been exposed, resulting in altered heat and pain responses.  A 1997 research team first found that capsaicin selectively binds the TRPV1 protein, which resides on the pain and heat sensing neurons.  TRPV1 typically opens between 98.6° and 113° fahrenheit, but in the presence of capsaicin, it opens below 98.6°. 

Obviously, this is body temperature.   Under normal conditions, then, the nerves responsible for telling you that it is hotter than Hades outside – say, 114° or so – will start giving their “Danger, Will Robinson!” full body S.O.S. signals whenever you eat a sufficiently spicy pepper, regardless of what the actual temperature is.  And since the heat-sensitive neural pathways may be overwhelmed, conceivably the pain network might get in on the act, too. 

A little bit of the essence of pepper, say from a packet of hot sauce from your favorite taqueria, might make you notice:  “Ooh, this is spicy!”  A lot of the essence of pepper, say from a bhut jolokia “Ghost Pepper” on a hamburger, a la Man v. Food, might make you really notice:  “Oh, my.  Please douse my head in a bucket of frozen water, give me an intravenous morpheine solution, and maybe euthanize me for good measure.  If, you know, you’ve got time.  Otherwise, I’ll just crinkle up and die right here.”  A little bit of capsaicin tells you the ambient temperature is extremely hot, even if it isn’t.  A lot of capsaicin tells you you have just been impaled in an iron maiden, set on fire, and thrown off the Chrysler building. 

We love the stuff.

There are all sorts of ironic medical uses being investigated which take advantage of these neurological effects of capsaicin, including pain medications, diabetes medications, and topical treatments for arthritis or fibromyalgia.  Even lung cancer is on the radar for researchers trying to take advantage of the intense response of mammalian neurons to capsaicin.

We are not recommending anything so revolutionary in the home garden.  We are instead intent on focusing on a new application for the use the plants themselves make of this chemical.

We have a critter problem in our chicken coop, you see.  There is a creek which runs roughly parallel to our western property line, from which a long series of oppossum trespassers, for generations, has made the trek to our yard, first for the cover of the underbrush which we have painstakingly cleared, and then for the delicious goodies left in the chickens’ feed dish, and then for any eggs we may have missed on our evening collection run.

Mice, too, take advantage of our hens’ domestic arrangements.  If our birds could be free-ranged, we might not have to worry so much, given that they would be gathering their daily nutritional needs from a wider range, but since they have to stay cooped up thanks to the zealousness of the College Station city council in protecting our neighbors from marauding hens, every rodent in the neighborhood has at some point decided to partake of the evening buffet.

Heretofore, our solution to these problems has been to do our best to regulate how much feed is left out, and to do our best to gather all the eggs before turning in for the night.

Now, however, a solution is at hand.

We just need to sprinkle copious quantities of hot chili powder on the chicken’s feed, and on their laying boxes; we will also feed table scraps with peppers to the chickens, instead of putting such items in the compost bin, as we have been doing until now, on the assumption that hot peppers would somehow disagree with the birds.

This will serve multiple functions, which as you know is something we at Myrtle’s place really like.  First and foremost, capsaicin in everything edible in the chicken coop ought to provide all the deterrence we need for opossum and mice.  This is what happens in the wild; it ought to happen in our little domestic slice of heaven, too. 

Next, we already get significant numbers of volunteer tomato and basil plants growing from the numerous seeds which find their way into the garden compost which, as we have mentioned early and often, is basically just recycled deep-bedding from the chicken coop – leaves and chicken poop, a little water and a little neglect, that is the secret to happy plants.

Now, we are likely to also start getting volunteer pepper plants sprouting up all over the place.  We can think of no happier design than a garden in which plants of all varieties randomly crop up in the healthiest, though unexpected, locations.

In the spirit of scientific inquiry, we have verified that our chickens do not, in fact, seem adversely affected by capsaicin, at least not in any visible way.  We put out some jalapeños which had not only started to turn red, but had also started to shrivel.  The hens naturally went for the rice and strawberry tops which were also in the slop bucket first, since they go for the familiar at all times.  However, they did then start pecking at the peppers, and seemed to warm up to them, but only in the metaphorical, aesthetic, sense.  Otherwise, they may as well have been munching on bell peppers or cucumbers.  No jumping around screaming for water or anything.  And trust us, our hens are not shy about jumping up and screaming, should they feel so inclined.

So, along with our “chicken processed” volunteer tomatoes and basil, we will now add another form of volunteer nightshade.  And this will give us plenty of excuses to make even more salsa.  This is a win-win all the way around.  We defy you to produce a healthier or tastier form of mammalian pest control.

Happy farming!