Tarantula Social Behaviors

[Justin H]

Hey you guys!

I've been watching videos of M. balfouri communal enclosures, and I'm super intrigued. There's a variety of apparent social behaviors being caught on film; how do you guys personally interpret these behaviors?

One thing you see them do is tap on each other, which often ends in one tarantula crawling beneath the other. Tom Moran speculated that they might establishing dominance/pecking order. Another youtuber speculated that they use their setae to identify individuals within the community.

Another thing they do is work together. Not only do they share food (which can be seen in slings of a lot of species), but they appear to have set times in which they're all constructing at once, as well as shared times of wandering or being reclusive. There must be some sort of communication, environmental trigger, or circadian rhythm that leads to these communal behaviors.

There appears to be zero scientific studies regarding M. balfouri communal behavior. Is this something that happens in the wild, or did hobbyists discover that they can adapt to coexisting?

Are there any other social behaviors you've seen in your tarantulas?

 

[Minty]

This should be fun.

 

[Chris LXXIX]

One thing you see them do is tap on each other, which often ends in one tarantula crawling beneath the other. Tom Moran speculated that they might establishing dominance/pecking order. Another youtuber speculated that they use their setae to identify individuals within the community.

Another thing they do is work together. Not only do they share food (which can be seen in slings of a lot of species), but they appear to have set times in which they're all constructing at once, as well as shared times of wandering or being reclusive. There must be some sort of communication, environmental trigger, or circadian rhythm that leads to these communal behaviors.

Indeed all of that is quite interesting and those are IMO very credible and legit theories

I'm not a fan of 'communal' set up/s, honestly. Never was, nor I'm today, so I can't really help on this aside stating that, obviously, the whole thing needs always to be performed with a particular 'eye' of attention, otherwise the next social behavior would be the old good 'the strong prey on the weak'

 

[Polenth]

There appears to be zero scientific studies regarding M. balfouri communal behavior. Is this something that happens in the wild, or did hobbyists discover that they can adapt to coexisting?

Previous discussion didn't turn up any wild studies and the current political situation would make it difficult to run such a study. Someone on the forum was setting up to do a study in a lab population, but the supply fell through. There will probably be answers one day, but not anytime soon.

I don't know if anyone knows who tried a communal first and why they tried it. I haven't heard it mentioned, but maybe someone else knows.

 

[Teal]

Tom Moran speculated that they might establishing dominance/pecking order. Another youtuber speculated that they use their setae to identify individuals within the community.

I do not believe spiders have the higher brain function for "dominance"... it has no place in their little worlds.

Having done pairings and watching how those two spiders interact, I am a firm believer that tapping is used for communication. In the instance you cited, I would interpret it as one spider tapping to let the other know they are not a threat or a meal before moving through. Since spiders react on movement/vibration, it is logical that they would communicate their presence.

I don't know if anyone knows who tried a communal first and why they tried it. I haven't heard it mentioned, but maybe someone else knows.

Humans don't think of it in such terms, but as a social species themselves thwy operate on the unconscience assumption that ALL animals are social and want to be around others of their species. I see it all the time in dog training, and quite often on the boards here when people ask about housing spiders together.

 

[Justin H]

Previous discussion didn't turn up any wild studies and the current political situation would make it difficult to run such a study.

I had no idea there was a civil war in Yemen... that really sucks.

I do not believe spiders have the higher brain function for "dominance"... it has no place in their little worlds.

Being able to assert dominance for mating rights in a colony allows for only the most fit specimens to breed. Tom recently did an update on his balfouri enclosure. He had a small mature male reappear after hiding for over a year. Meanwhile there's another, much larger mature male in the enclosure who is often seen mating with the females. If this is observed in other communal enclosure, it would give somebody reason to study communal mating behavior when more than one mature male is present.

I'm not so sure that the higher arachnid brain doesn't exist; I think we don't understand it yet. Take a look at studies like this one (it's about insects, but even fruit flies are examined). The way balfouris process information and the cognitive capacity required for their social dynamics to exist could be enough to imply that they have higher brain function.

 

[Teal]

Being able to assert dominance for mating rights in a colony allows for only the most fit specimens to breed. Tom recently did an update on his balfouri enclosure. He had a small mature male reappear after hiding for over a year. Meanwhile there's another, much larger mature male in the enclosure who is often seen mating with the females. If this is observed in other communal enclosure, it would give somebody reason to study communal mating behavior when more than one mature male is present.

I'm not so sure that the higher arachnid brain doesn't exist; I think we don't understand it yet. Take a look at studies like this one (it's about insects, but even fruit flies are examined). The way balfouris process information and the cognitive capacity required for their social dynamics to exist could be enough to imply that they have higher brain function.

I think the term "dominance" is being misused here, as it has been misused in dog training for decades.

Spiders are very complex creatures and we have barely begun to scratch the surface of understanding how they function and interact... but I still do not believe "establishing dominance" is correct. How animals behave socially and how they behave in mating rituals often are vastly different.

 

[Sarkhan42]

You may be interested in looking at some of the studies performed by Linda Rayor at Cornell on sociality in spiders. Her main focus is really Huntsman, but some of the concepts of reproductive dominance etc are seen in her studies.

Balfouri to my knowledge were first kept communally as a product of maternal care playing an important role in early spiderling development. Sacs kept with the mother for longer having higher survival rates etc, extensions of that practice leading to long term communals, with tests only extending from there. People have been successful with unrelated individuals, individuals of different sizes, and even breeding in communal groups, which leads me to believe we'll likely see natural cases once we can get surveys done in their natural range. What might instigate communal vs non communal as far as conditions go however, I have no idea, but I'd like to look into it.

I was planning on performing a study on Communal vs non communal growth and behavior this year, but unfortunately it fell through at the last minute. Hoping to continue on the idea in graduate school perhaps, with a little bit broader time to perform the experiment, as well as a better budget. I'm confident they are a naturally communal species under certain conditions, even if we did just happen to produce those in captivity.

 

[Justin H]

I think the term "dominance" is being misused here, as it has been misused in dog training for decades.

The social behavior I'm speculating about, the larger male mating and the smaller male hiding, would be referred to as a dominance hierarchy. Tom's dominance theory would be tied to a larger idea, like evolutionary fitness.

 

[Teal]

The social behavior I'm speculating about, the larger male mating and the smaller male hiding, would be referred to as a dominance hierarchy. Tom's dominance theory would be tied to a larger idea, like evolutionary fitness.

I disagree. I have had smaller males of a species hide/be overly cautious even with a receptive female, whereas larger males then marched right in. One example of a smaller male hiding while a larger male has been observed pairing does not a "dominance heirarchy" make.

 

[Justin H]

One example of a smaller male hiding while a larger male has been observed pairing does not a "dominance heirarchy" make.

If this is observed in other communal enclosures, it would give somebody reason to study communal mating behavior when more than one mature male is present.

The social behavior I'm speculating about

Haha, I don't know what else to say. I don't think I've misused the word dominance here. It doesn't really matter.

 

[Teal]

Haha, I don't know what else to say. I don't think I've misused the word dominance here. It doesn't really matter.

Dominance, when used in reference to animals, tends to mean when an animal displays certain behaviours to ascertain its authority over others. I do not believe spiders do this. I believe that size is a direct factor... sometimes, smaller mature males are more shy and larger mature males are more brave. I have never seen nor heard of two mature males interacting in a dominance display.

 

[boina]

Haha, I don't know what else to say. I don't think I've misused the word dominance here. It doesn't really matter.

If you are talking about dominance you need to establish first what you are meaning by it.

'Dominance' usually refers to a long term relationship that is based on individual recognition. Dominant and submissive animals accept their roles once they are established to reduce fighting in a social community.

Proving this for spiders is very difficult. One large male mating while a smaller male hiding does not establish an individual recognition or a hirarchy. The smaller male may simply be staying back because he's scared. That has nothing to do with social dominance.

That's what Teal meant with abusing the word 'dominance'.

That's what makes behavioural studies by amateurs so incredibly difficult: people tend to assume too much and confuse observation and interpretation.

 

[Justin H]

If you are talking about dominance you need to establish first what you are meaning by it.

All references to dominance have been in subtext to either Tom Moran's theory regarding the tapping or my insinuation about his theory regarding sexual preference. I haven't abused the word dominance.

Being able to assert dominance for mating rights in a colony allows for only the most fit specimens to breed.

This is called establishing a dominance hierarchy.

If this is observed in other communal enclosures, it would give somebody reason to study communal mating behavior when more than one mature male is present.

And I never claimed that this one instance means anything at all. I'm trying to facilitate a discussion about social behaviors. I'd like to stay on topic, not completely close the book over something silly.

 

[viper69]

how do you guys personally interpret these behaviors?

Induced by captivity

There appears to be zero scientific studies regarding M. balfouri communal behavior

I concur.

Is this something that happens in the wild

No one has reported this.

or did hobbyists discover that they can adapt to coexisting

Likely

 

[Justin H]

Well, I'm still digging for information... and have a few more questions .

When did this species enter the hobby? I'm finding conflicting information on this one.

Is there some sort of record for when new species are imported? For any country?

Who collects specimens for illegal export? How do you make contact with these people? I'm not trying to poach anything, just collect information.

I can find only one account of M. balfouri being observed in the wild from Reginald Innes Pocock, the guy who classified the species:

"All the known specimens of this spider, the largest found in Sokotra, are males that have been met with wandering about after dark in search of females. The latter, no doubt, live in burrows, and have on that account eluded up to the present time the search of collectors. The example captured by Mrs. Bent was caught in the tent at night. One of the other specimens was met walking along a steep path in the push at about 5:30 p.m. Instead of attempting to escape by flight, it immediately rose up in an attitude of defence, showing fight in the manner depicted on the Plate referred to above."​

He ended up naming them after Isaac Bayley Balfour, the first guy to bring specimens back to Europe. Balfour was more of a plant guy and brought back thousands of specimens; none of his publications mention the arachnids his team caught.

Induced by captivity

Perhaps you're right in that we're seeing these behaviors in highly unrealistic situations, but it's very unlikely that they don't exist at all in the wild. Such behavioral adaptation to captivity would be insanely advanced for them. They clearly have the ability to recognize individuals within their species, the question is why. It could be a simple survival response to highly competitive species in their environment, or any other number of things since so much is unknown about them.

 

[EtienneN]

Well, I have a couple of thoughts. One, why has communal behaviour never been observed in the wild? Like people took the first imported ones out of the wild so what was happening when and where they collected them? As the question was asked in this thread, who was the first person to decide to put this species in a communal? This really doesn't sound like a trait arising out of a vacuum. Surely, they have some kind of propensity for it or else every Balfouri communal would have been an utter failure. But why? Would the "pollo araña" tarantulas also be receptive to communal living in captivity? If this species were more available it seems like people would try to house them communally as well. I just have so many questions. What makes Balfouri communals last longer than say a Pokie communal? I do not subscribe to any theories that the tarantulas have developed any higher order brain functions such as the capacity to form a social hierarchy. I watched Tom Moran's vid and I think that big female was drumming to the male to "get away". I think someone said it was also a male but I'm 80% sure it was a female.

 

[Sarkhan42]

Well, I'm still digging for information... and have a few more questions .

When did this species enter the hobby? I'm finding conflicting information on this one.

Is there some sort of record for when new species are imported? For any country?

Who collects specimens for illegal export? How do you make contact with these people? I'm not trying to poach anything, just collect information.

I can find only one account of M. balfouri being observed in the wild from Reginald Innes Pocock, the guy who classified the species:

"All the known specimens of this spider, the largest found in Sokotra, are males that have been met with wandering about after dark in search of females. The latter, no doubt, live in burrows, and have on that account eluded up to the present time the search of collectors. The example captured by Mrs. Bent was caught in the tent at night. One of the other specimens was met walking along a steep path in the push at about 5:30 p.m. Instead of attempting to escape by flight, it immediately rose up in an attitude of defence, showing fight in the manner depicted on the Plate referred to above."​

He ended up naming them after Isaac Bayley Balfour, the first guy to bring specimens back to Europe. Balfour was more of a plant guy and brought back thousands of specimens; none of his publications mention the arachnids his team caught.



Perhaps you're right in that we're seeing these behaviors in highly unrealistic situations, but it's very unlikely that they don't exist at all in the wild. Such behavioral adaptation to captivity would be insanely advanced for them. They clearly have the ability to recognize individuals within their species, the question is why. It could be a simple survival response to highly competitive species in their environment, or any other number of things since so much is unknown about them.

When I was doing research on the species the earliest mention of them in the US was about 2006. As far as Europe goes, definitely a good amount earlier but I don't know how much. The first mention of a communal from what I found was 2009- so a pretty significant amount of time before anyone went about keeping them that way.

Also- it sounds like I may be getting university funding for my research project on the species, which would make it possible to run! Fingers crossed that I'll be able to run everything as planned, just with a few months delay.

 

[viper69]

last longer than say a Pokie communal?

Except Poki's are not communal in the wild. I know a biologist who has observed them quite a bit, no communal.

 

[Justin H]

Except Poki's are not communal in the wild. I know a biologist who has observed them quite a bit, no communal.

This study conducted from 2011-2013 in Sri Lanka touches on the social behaviors of wild P. smithi:

"Further, a colony of adults and sub adults were observed in hollow of a coconut tree (Cocos nusifera) and several other individuals were observed in a fig tree (Ficus sp.) within a radius of 5 km from the new recorded site. The female was first observed at 2000 hrs and remained near the entrance of the hollow until 2115 hrs, when it move a little away from the hollow, and stayed there (Figure 2). However, when it was disturbed it quickly retreated into the hollow and remained there. The main activity was the movement to and from the tree hollow. With the other individuals recorded, no aggression was recorded; feeding, movement to and from the hollow, in all individuals. The juveniles were considerably more active than adults."​

They go on to speculate whether this communal behavior was "natural" or due to the low availability of suitable habitat in the area.

There's another study in Vol. 20 of the British Tarantula Society (scroll down for contents) journal entitled "Communal Behavior of Poecilotheria regalis" by C. Portman that's been cited when claims are made that Poecilotheria live together in the wild.

This study focuses on commensalism (eating together) between certain frogs and P. ornata/subfusca. I just threw this in there cause it's fascinating . Frogs are often found living communally with other tarantula species as well.