Monday, June 22, 2015

#16 - S.A.D.S. - "SUDDEN AVICULARIA DEATH SYNDROME"

Hobbyists like to name things and a few amusing acronyms and invented terms have popped up over the years. One is a play on "S.I.D.S.", the tragic and unexplained death of an infant. This "Sudden Avicularia Death Syndrome" or "S.A.D.S" is something I hear about often even if not referred to by that semi-clever name. I have always specialized in arboreal tarantulas and, of late, have focused on Aviculariinae. The species that many hobbyists think is difficult to raise is Avicularia versicolor, but all Avics tend to have the undeserved reputation of being "death prone". In today's blog, I will give you some tips on avoiding "S.A.D.S."

I get many emails from people asking me what they did wrong to result in a dead spiderling. This isn't limited to Avics, of course, and many of these messages are about species that are typically extremely hardy. It may very well be that they "did something wrong" and I try my best to educate and correct any incorrect husbandry methods. However, these emails seem to presume that I never have a dead spiderling. I always try to comfort the writer by first letting them know that I often have dead spiderlings or juveniles of my own. To put it bluntly, death happens. I have lost many spiderlings over the years and many of them were very rare and expensive. I understand the writer's pain. However, one of the reasons that "death happens" is that the reproductive strategy of tarantulas is to produce many young. Very few will survive to adulthood in nature. Of course, much of this is due to predation, but you can't expect that every spiderling from a sac will be as strong as its siblings. Some will not do as well. I'd love to do an experiment where I take a species that is notorious for "S.A.D.S" like Avicularia versicolor and raise an entire eggsac to see what percentage I can raise to one year of age. Of course, captivity is an unnatural situation. There is no predation unless you count parasitism and have a problem with mites or phorid flies, for example. And if I paid special attention to this study group of A. versicolor by caring for them more often than the thousands of other spiderlings in my care at any given time the results would be unnatural. But death happens and it isn't always due to "something wrong".

So the question is: are Avicularia spiderlings less hardy? The honest answer is yes. But it is because they are more sensitive to environmental conditions outside of a narrow range than drier climate spiders. You'd have to compare Avicularia to a genus that shares its habitat and habits. Tropical rainforest spiders are going to be less hardy than drier climate spiders. You can't compare apples and oranges. But even if you compare two species found in the same location the comparison will be unfair. For example, if I take the Avicularia sp. I found in Suriname and compare it to the Theraphosa blondi I found living sympatrically it wouldn't mean anything. T. blondi are burrowers that live in microenvironments that are dissimilar to the tube sock retreats of Avicularia. The closest comparison I would be able to make in my Suriname example would be comparing the Avics to Tapinauchenius gigas and T. plumipes. My personal experience in arachnoculture (i.e., captivity) is that "Taps" have similar mortality to "Avics".

So, why do Avics have such a bad reputation and not Taps? Because they are much more popular and, more importantly, prevalent in our hobby. And why does A. versicolor have the worst reputation? Again, because it is the most popular and prevalent Avic. As a specialist in Aviculariinae, I can tell you that A. versicolor are no more susceptible to the imagined and unfounded "S.A.D.S". Let's dispense with the notion that Avicularia are difficult to raise. Let's leave this silly acronym and hobbyist invented "condition" behind and focus on why hobbyists are killing their Avicularia spiderlings. Again, let's remember that not all spiderlings are intended to survive. Let's realize that 100% success is unachievable and unrealistic! You are going to lose a percentage of the spiderlings you acquire. It's going to happen more often with tropical rainforest species that are less tolerant of environmental conditions outside of a narrow range. It's going to happen more with arboreal species that live in true "jungle". So, it will happen slightly more often with Avicularia, but your success will increase if you heed the following warning: YOU CANNOT REPLICATE A JUNGLE IN A VIAL!

I've said it before, and I'll say it a bazillion more times, VENTILATE, VENTILATE, VENTILATE! This may be counter-intuitive, but YOU NEED MORE VENTILATION FOR TROPICAL RAINFOREST SPECIES THAN FOR MORE ARID CLIMATE SPECIES! Think about that before moving on. Ask yourself why before I give you the answer.

While you are mulling over the above question let me add a few images. Two were posted in an earlier blog and illustrate how I add water to the substrate in a 50 dram vial and how I ventilate the same size vial. I do lightly mist ("spritz" would be a better word) Avic spiderling vials once in awhile, but there is a method and reason to do it.

As I've stressed elsewhere and will repeat here, tarantulas of any age should be acquiring hydration from good prey items. If you are using crickets make sure they are hydrated well. I use "cricket quencher", but orange slices, rinsed leafy dark greens, apple, etc. can also be a water source. I clean and feed/water my crickets every single day. Healthy, gut-loaded and hydrated prey items contribute dramatically to healthy spiders and spiderling survival.


But back to the "spritzing" ... this is just an occasional way to put a couple of droplets of water on the silk tube that the Avic has made as a retreat or on the side of the vial. This is just in case the spider does in fact have a need to drink. However, the maintenance of the well-ventilated vials I use for Avicularia largely involves using the 3ml pipette in the first image to remoisten the substrate. I won't go into depth here because I have already covered this in #12 - PART TWO: THE MOISTURE CYCLE - HUMIDITY & HYDRATION. You may want to pause and read that blog now even if you did when it was published.

What's important here is the ventilated vial you see on the right (second image). The water I add is allowed to evaporate and this maintains the humidity. POOR VENTILATION AND EXCESSIVE MOISTURE IS WHAT KILLS MOST AVICULARIA SPIDERLINGS!!! As I wrote early on, you can't replicate a tropical rainforest in a vial and if you don't get "jungle" out of your mind you are going to kill your Avic with kindness. You are more likely to kill your Avicularia spiderlings with excessive moisture than with excessive dryness. VENTILATE! FEED OFTEN! Remoisten the substrate as needed; perhaps as often as you feed depending on your spider room's ambient humidity. Keepers in southern Florida and keepers in Arizona will have different situations.

Much of this is covered in #12 - PART TWO so let's talk again about feeding. I feed my Avic slings twice a week. Don't listen to self-appointed experts about "power feeding". You can harm a snake by "power feeding" because it is a vertebrate with organs similar to mammals and you don't want it to grow faster than it's skeleton or organs are developing. (That's an oversimplification and not entirely accurate, but I've made my point). But your spiderling will eventually have an expanded abdomen and will molt and grow. Twice a week feeding ensures that the spider is hydrated. Then if you are careful with remoistening the substrate and creating the repeating moisture cycle in your WELL-VENTILATED vials you will be giving the spider what it needs. You will have success. But, again, some spiders just "weren't meant" to survive. You'll still have failures. But you will learn that with proper husbandry and attentive care your success rate with Avicularia will greatly increase.

Let's return to my statement that Avicularia require more ventilation than drier climate tarantula spiders. We'll stick with the popular and undeservedly notorious for dying versicolor for our Avic species and use one of my favorite scrub climate tarantulas Idiothele mira (the blue-footed trapdoor baboon spider from Africa) as our dry climate species. I will drill 1/16" or 1/8" holes in the vial lid for I. mira or perhaps even use a #0 Phillips screwdriver or a nail to poke air holes like almost every hobbyist does. The I. mira will do fine in this set-up. At the same time, I will drill a 1" hole in the lid of the same 50 dram vial and hot-glue aluminum insect screening over the opening from the outside of the lid. This is the set-up the A. versicolor requires. Why is that? Seems the opposite of what you'd think at first, doesn't it? It is because I only add more water to the substrate of the I. mira every couple of weeks or so. It depends on the ambient humidity in my room. When I feed once or twice a week I pay close attention to how moist the substrate is. That is the attentive care that I referred to earlier. You have to be on top of your spiders' needs! But since the I. mira doesn't require a great deal of humidity I can allow it to be drier. And because it is in my mind that this is a hardy, dry climate species I don't worry about them. Conversely, because Avicularia versicolor does require elevated humidity I worry just like you. I add moisture. But because of the increased ventilation it dries out - naturally - over a day or three or whatever and I moisten again as needed. Remember: You can always add more moisture, but when conditions become wet or stagnant - the conditions that kill Avic "slings" - you have to completely rehouse the spider. Be smart!


Here you see a 32 oz. deli cup being used for a juvenile Avicularia versicolor with a body length of about 1" (2" legspan). I transfer my Avic slings from the 50 dram vials to these cups long before they reach this size, usually when they have a legspan of 1.25-1.5". Sometimes I'll use the 24 oz. cup that is the same diameter even for 3rd instar slings. I want them to have more air space and great ventilation. Note that these are "fruit fly" style cups with very well-ventilated mesh lids. I prefer the aluminum screening lids to the paper covered lids because the paper sometimes peels away and allows escape. It is also common for crickets to gnaw on the paper and and allow an opening for the spider to get out. But these lids provide maximum ventilation.

This brings us back to attentive care. If you slack off on the time you spend checking your collection and ensuring everything is properly fed and substrate is periodically remoistened you will fail with this system. Proper animal husbandry is an investment in time. You are responsible for the lives of all the specimens in your care. If you're a slacker you might want to find a new hobby. Tarantulas are probably the lowest maintenance of all terrarium pets, but they still need a responsible keeper to ensure their health and safety.

If you are traveling or only have time to check on your spiders one day a week you may want to block half the ventilation in this deli-cup set up. It is easily done with some plastic taped over part of the lid. If you're going on an extended holiday or live in a dry climate where this use of this "fruit fly" style mesh lid may provide too much ventilation you may be best off using my other style of 32 oz. deli cup. To the right here you see an Alur brand 32 oz. pre-punched deli cup from Superior Shipping Supplies. The lid has had a 1 1/4" hole drilled using a hole saw and it was covered with aluminum insect screening affixed with hot glue (outside of lid). Of course, it also has the minimal cross ventilation that the small pre-punched holes provide. This is a better set-up for those who live in arid climates or are forced to spend extended periods away from their tarantulas.

Once the spiders get too large for the 32 oz. deli cups I use Mainstays gallon jars available at Wal-Mart. This final photo illustrates an easy set-up for a juvenile Avicularia diversipes. This set-up is also sufficient for adult specimens of this species or other smaller Avics like A. rickwesti, A. hirschii, A. sooretama, A. laeta, and A. minatrix. But the important part is the 2 1/2" hole drilled in the lid with a hole saw and covered with screen as previously described. Note also in these images that some Zilla Beaked Moss (or other sphagnum or green moss) covers the substrate. This slows down the evaporation from the substrate.

In conclusion I will summarize the key points I've made and provide "Cliff Notes" for Avic success.
  1. S.A.D.S. is a silly term and some Avicularia mortality is normal, but most Avic deaths are preventable.
  2. You can't replicate a jungle in a vial. Most Avics are "killed with kindness". The hobbyist hears that they require high humidity and a combination of excessively misting or otherwise damp and stagnant conditions kills the spider. Fewer Avics perish from a slightly dry environment than from an excessively wet environment.
  3. VENTILATE! 
  4. Poking air holes in a vial and misting often is a recipe for disaster. Use a well-ventilated enclosure such as illustrated in this blog and add moisture to the substrate periodically. Ideally the substrate should be moist when watered and noticeably drier a few days later.
  5. Attentive care is necessary. Use your energy to make ventilated homes and add a small amount of water once or twice a week rather than misting every day.
  6. WET, STAGNANT CONDITIONS KILL!
  7. Poked air holes are fine for drier climate spiders because you think of them that way and don't ever feel the need to make the substrate too wet. When you start thinking about "jungle" species you may have a tendency to incorrectly stress adding "high humidity". Humidity comes from evaporation over time, not from pressure washing a 50 dram vial containing a spider :)
Enjoy your Avics! A. versicolor are stunning and easier to raise than people think. Are they easy as, say, Poecilotheria regalis? No, absolutely not. I'd consider them more suited for more advanced keepers who will follow the methods described above. But you have just read the path to success. Heed its instructions and you will do well more often than not. Good luck, MJ




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