Environmental manipulation and breeding in captive Tarantulas

[Frogdaddy]

Yeah, sucked you in with that juicy title huh?

I've been thinking for more than a few days (scary, I know) as this has kinda been touched on lightly in a few different threads.

I know we cannot create our enclosures to match a T's natural climate and habitat, impractical and impossible to recreate in a tiny box.

From what I know T's are seasonal breeders not opportunistic breeders.
Opportunistic breeders will mate any time of year given that the adults have enough metabolic reserves to produce eggs and sperm. T's rely on seasonal cues to trigger breeding, right?

I read the news story last week that the "tarantula migration" was set to begin in Colorado. Migration is a misleading term as it's just mature males wandering around searching for a female to mate with. But it's an environmental cue that makes them molt and seek out females en masse.

I'm interested in how we can use these cues as "tools" to help breed T's in captivity.

I would like to discuss how manipulating conditions would
A. Cause males to molt into their penultimate form and trigger a breeding season, and
B. How changes could lead to more successful sacs or a higher percentage of viable eggs.

There are only a few factors which we can control. These are what I would like to discuss in depth.
1. Day/Night length- easy to manipulate especially for species from Northern ranges, but what about species from close the equator that have a near constant day length all year?
2. Humidity/Moisture- not reopening a can of worms so be nice to each other, but surely wet/dry seasons are a factor in breeding seasons. Enclosure flooding should also be included here.
3. Temperature- seasonal variations do occur and these might be a trigger.

I'm sure large, successful breeder manipulate these environmental factors. I'm not looking for corporate copyrighted trade secrets. But please share for the knowledge will help all of us. I hope this information will help me when I'm ready to breed T's, years down the road.

I hope to hear from everyone, the best and brightest from AB, oh and you too @EpicEpic. (Just poking ya dude)
Any information wether it be scientific or anectodal is appreciated. Let's discuss the fascinating topic.

 

[Dorifto]

Daytime (lighting) can be achieved pretty easily with a controller and a dark room, so the T only receives the light from the lamp. You can set up the controllers to mimic their seasons conditions such, light, humidity, ventilation (via active fans), rain...

In my case the controller is useful in winter, since we have less hours of sunlight, so I setted the controller to "mimic" their natural daytime.

Regarding to my beloved humidity my controller activates the fan if the humidity raises eg: after plants misting, substrate moisting... for example, so it estabilizes the overall humidity and also improves the ventilation. You can set it up to decrease temps in summer, if the temps rises too much. We have a temp range from -5°C to 42°C +-3°C...

To recreate their seasonal conditions, I use my own seasonal contitions in my favor, so in winter I decrease the enclosures temp to match their temperatures but I have to increase their daytime, since here in winter we only have 9 hours of light, so at night my house looks like a weed growing grenhouse


Some time ago I saw controllers who also mimic, moonlight and lightnings. But those are overkill imho.

 

[viper69]

The same migration happens in other parts of the country around the same time, year after year like clockwork- like frogs breeding, turtles laying eggs etc.. It's certainly envionrmental cues in my opinion, could be other factors in the male biology too beyond just a final molt.

 

[DomGom TheFather]

Successful breeding requires more than just the correct photoperiod, temperature and humidity!
You should also feed the female, light a fire and play some Barry White.

 

[KaroKoenig]

...and play some Barry White.

... or some Slayer, depends on the species.

 

[Jesse607]

Day length and temperature are more significant or applicable for species further from the equator, such as North American Aphonopelma. Where as, wet/dry seasons may be more significant for equatorial species. I also wonder, if like plants, do North American Aphonopelma require something like "cold degree days" to efficiently keep their biological/chronological clock on schedule.I suspect they do.

 

[cold blood]

The vast majority of ts will pair and drop sacs at any time of the year and dont require seasonal cues.

 

[DomGom TheFather]

The vast majority of ts will pair and drop sacs at any time of the year and dont require seasonal cues.

In captivity?

 

[Frogdaddy]

Day length and temperature are more significant or applicable for species further from the equator, such as North American Aphonopelma. Where as, wet/dry seasons may be more significant for equatorial species. I also wonder, if like plants, do North American Aphonopelma require something like "cold degree days" to efficiently keep their biological/chronological clock on schedule.I suspect they do.

I agree. So how do we implement a wet/dry season for those equatorial species? A long period of a bare minimum of moisture in the substrate followed by a flooding of the enclosure?

The vast majority of ts will pair and drop sacs at any time of the year and dont require seasonal cues.

Would reluctant females be more accepting of a male given environmental cues that signal it's mating time?

 

[Jesse607]

It seems most equatorial wet/dry region species don't require these same environmental cues in captivity for successful mating/egg laying/growth, so it wouldn't be necessary to deprive them of moisture. Examples being (not exclusively), Tliltocatl species, most Harpactirinae, and Poecilotheria.

 

[Dorifto]

I agree. So how do we implement a wet/dry season for those equatorial species? A long period of a bare minimum of moisture in the substrate followed by a flooding of the enclosure?

Firstly checking their habitat seasons climate chart, taking a the average measurements, temp, humidity, rain, sunlight...etc for every season. After that, the best way it could be to use your own seasons climate values to try to mimic their seasons.

But if someone is going to try to mimic those values, better to start preparing a good enclosure, with a good substrate, a good ventilation system... etc or the things can go wrong pretty fast.

A controller can be made for cheap using some generic controllers from internet.

 

[Frogdaddy]

@Dorifto I don't know if I trust technology that much. Things can go wrong with automatic controllers. My preference would be to monitor and adjust conditions manually.
You mentioned the use of fans which could be used to suck air out of the enclosure but potentially could be reversed to blow air into an enclosure.
I agree that the programming of moonlight is probably overkill, but since T's are creatures of the night maybe their is something to that? After all many corals synchronize their spawn to a particular full moon. I'm not saying T's are like corals just drawing an analogy.

 

[Dorifto]

With controllers I mean, every device who measure the enclosure's values, not only the automatic controllers, eg: thermometers, hygrometers, thermostats... etc. I don't run my setups fully automated, only If I'm on holidays and or for long periods out of my house.

I'm more inclined towards that the enviromental conditions are the ones that triggers their breeding response, in the case that those species are prone to breeding in certain conditions.

 

[KaroKoenig]

It does get vital with high end stuff, e.g. breeding species like Megaphobema mesomelas - wich seem to be hard enough to be kept alive in the first place.

 

[Vanessa]

Barometric pressure is also a factor and we can't do anything to manipulate that. Unfortunately, we don't have enough information to say how much of a role barometric pressure plays, but it does play a role along with temperatures and rainy seasons. How much of a role it plays might also differ from place to place and could account for why some species from a particular country/region are more difficult to get egg sacs from in captivity than others.

 

[myfavoritethingisspiders]

Firstly checking their habitat seasons climate chart, taking a the average measurements, temp, humidity, rain, sunlight...etc for every season. After that, the best way it could be to use your own seasons climate values to try to mimic their seasons.

But if someone is going to try to mimic those values, better to start preparing a good enclosure, with a good substrate, a good ventilation system... etc or the things can go wrong pretty fast.

A controller can be made for cheap using some generic controllers from internet.

This doesn’t work super well for small, stationary animals. You’d have to know exactly how those averages affect the stats of their burrows. I talked about this a bit in another thread, but tarantula microhabitat studies are extremely lacking and for most species, their reasoning behind choosing one burrow location over another is unknown, along with any natural communities (smaller habitats within larger biomes that often have different averages when parsed out) they may prefer over others.

Even for species where things are known, you’d have to figure out a lot of other things. Like I forget which species, but I recently read about one that primarily builds its burrows to be north-facing, so to accurately mimic their seasonal change, you’d have to work out how to mimic those changes on a north-facing burrow specifically since there’s obviously an environmental reason for building in that direction. Like maybe humidity drops significantly one season but there’s a steady northerly wind, so the humidity inside their burrows would be much higher than the surface.

 

[Jesse607]

This doesn’t work super well for small, stationary animals. You’d have to know exactly how those averages affect the stats of their burrows. I talked about this a bit in another thread, but tarantula microhabitat studies are extremely lacking and for most species, their reasoning behind choosing one burrow location over another is unknown, along with any natural communities (smaller habitats within larger biomes that often have different averages when parsed out) they may prefer over others.

Even for species where things are known, you’d have to figure out a lot of other things. Like I forget which species, but I recently read about one that primarily builds its burrows to be north-facing, so to accurately mimic their seasonal change, you’d have to work out how to mimic those changes on a north-facing burrow specifically since there’s obviously an environmental reason for building in that direction. Like maybe humidity drops significantly one season but there’s a steady northerly wind, so the humidity inside their burrows would be much higher than the surface.

Some insects are known to select diapause/hibernation locations in the soil on the north side of trees/hillsides. It is hypothesized that it is because north facing locations have less temperature fluctuation due to sun exposure. The sun can warm the soil significantly more than the ambient air, even in the winter.

 

[Dorifto]

This doesn’t work super well for small, stationary animals. You’d have to know exactly how those averages affect the stats of their burrows. I talked about this a bit in another thread, but tarantula microhabitat studies are extremely lacking and for most species, their reasoning behind choosing one burrow location over another is unknown, along with any natural communities (smaller habitats within larger biomes that often have different averages when parsed out) they may prefer over others.

Even for species where things are known, you’d have to figure out a lot of other things. Like I forget which species, but I recently read about one that primarily builds its burrows to be north-facing, so to accurately mimic their seasonal change, you’d have to work out how to mimic those changes on a north-facing burrow specifically since there’s obviously an environmental reason for building in that direction. Like maybe humidity drops significantly one season but there’s a steady northerly wind, so the humidity inside their burrows would be much higher than the surface.

Well I said average because nobody is going to change their enclosure conditions every day at every hour, but trying to maintain that average levels will get you close to their habitats condition, and better to stay close to nothing. Even trying to maintain those levels you will have variations in humidity, temperature, moisture etc. because your living conditions are variable too.

Regarding to the burrows, I passed some time looking how my Ts behave to different conditions in their enclosures. While my geniculata liked a more damped substrate across the year, even in winter, my pulchra swaps from moist to dry, depending on the conditions outside. You mentioned that some species like to make her burrows facing the north, here some species did the opposite since the sun warms more from the south, and and the north is a more humid, moist area. In trees for example, whe have a moss that only grows facing the north, because is a more humid zone. That orientation prefferences will give them a more stable burrow across the year.

 

[cold blood]

In captivity?

obviously

Would reluctant females be more accepting of a male given environmental cues that signal it's mating time?

While there are exceptions, most ts will pair and drop sacs whenever.

When i started breeding, i was all about simulating environmental cues....once i started ignoring such unnecessary complications, my breeding succes skyrocketed.

Humidity...i still laugh....still irrelevant...its just a matter of dampening sub to induce the female to drop and to keep sacs from drying.

I regularly breed and get sacs in mid winter when ambient humidity is single digits....they still breed, drop and healthy sacs are produced.

IMO humiditys relevance begins and ends with the incubator.

 

[Jess S]

I'd like to ask if any of you breeders out there has had a female that has taken an extremely long time to drop a sac (as in much longer than would be normally expected), and what your theory is for the reasons, i.e. lack of the correct environmental cues etc.