Reptile & Amphibian Forums

I posted a message in the forum a while back about breeding greens and yellows together, I don't think I will even bother to try from what people said... BUT I figured I would ask about breeding 2 green anacondas... Do you think you could house a male and a female in the same cage? Both being babies when put together. The cage size would be 8'x2'6"x2' and would have a 3'longx 10" deep water bowl (until they grow out of it of course) Greens are my favorite snake... that's why I want to breed them so bad... If anyone has anything to help me, I would really appreciate it

thanks
Ben

As I have always posted, I am against keeping two anacondas together regardless how small or large. If she doesn't eat him right away the possibility is still there. Why would you risk it? If the answer to that question is "because I don't have the space or money for another cage." then you are not ready for the large task ahead in breeding anacondas. If you've already invested in one cage why not get another?

I dont think things are quite as extreme as arik said..but there is some point to it. I dont trust anacondas wont eat anything i care about (i very much trust my anaconda wont eat a mouse or rat). As far as breeding...kelly is the pro and i hope he responds here. if you do not have his article in reptiles magazine on captive breeding of green anacondas..email me at gmbrink@ilstu.edu and i will send it to you (assume i will do it by purchasing a back order and mailing it to you and not any illegal way). snakes can be very close in size and still eat each other. just remember that breeding season these snakes are a whole different story and you can walk right by a male that hasnt eaten in a year when he is going for that female and he wont even look at you if you are a young capybara. I love green anacondas to death and have often considered a hybrid project. But i still tell myself that i cannot house 2 condas together for plenty of reasons. Just as a note i think the word sexual dimorphism is tossed around a but much and in the case of anacondas..i dont think it to be true since i see sexual dimorphism as animals like the angler fish that look completely different in size and feature...not just a little length and quite a bit of weight. ok..back to the subject. I guess i wont get as harsh on you like i did on the green and yellow but just keep in mind that there is a posibility one of the snakes will be gone one day. I dont believe this is a cage space issue for you with money (since i know first hand that if you dont have money..or are not willing to spend money you dont have..you dont have anacondas)I think you just have one big cage and you want to get some use out of it until these anacondas get bigger (thats kind of where i was at..but dont want to do it with an animal care about). I guess i should tell you that there was a period for about a week where i housed a bci in with my green and nothing happened..but this does not mean i was not checking all the time until i moved the boa and was not scared as hell(dont ask why i did it)..plus the bci was pretty good size(still could have been eaten). if you do this..always keep an eye amd if one gets bigger than the other by a lot(since i dont believe in this sexual dimorphism junk i wont say the female will be the one for sure snce it depends on eats eating habbits...im sure there are males the same age as my female that are bigger since she didnt take food for 8 months and even now is wierd) i would split them up to be safe..but maybe if you dont care too much and could use the education..go for it and tell us how it works out and if they live good together or not. good luck

Ben,
I think a cage of this size is too small for a breeding pair. I would partition it in half and raise them that way until they get larger. That would give you time to build an additional cage. Unless the cage is extremely large, adults do best and are easier to maintain when kept separately. That cage would work for breeding, but not for permanent housing of them together. As far as cannibalism of smaller males, I have never heard of this happening in captivity and it probably relates to the fact that captive females are extremely well fed, and would not have the need to resort to this practice. It is probably restricted to wild females, with low energy reserves, trying to get into breeding condition. I would not say that it is impossible in captivity, just extremely unlikely. Sexual dimorphism is apparent in greens, as typically, an adult male is about half as long, and has about 6 to 10 times less mass than an adult female. Just my take on it. Good luck and let us know how it comes along.

Kelly

I guess I just see sexual dimorphism as a term which describes a species where one sex looks like another species compared to the other sex like Madagascan Vinesnakes and like I said before, the angler fish which is probably the best example. I just don't see how anacondas can be considered sexually dimorphic when there would be not even a little confusion that they are the same species when placed side by side. I see this as simply..females get quite a bit bigger than males. I think another reason I don't much care for the term in this case is I talk to a lot people who watch jeff corwin and think only the female anacondas get big. I am pretty sure some of the adult green males I have seen could eat my girlfriend...she is pretty tiny but to think a snake is big enough to eat a person...I think I would classify that as a big snake. Just my opinoin and I don't mean to disagree at all since Kelly pointed out that females can get twice as long and much much more mass. I just think of the word a little differently..doesn't change anacondas at all : )

I know what you are saying, but we are describing the same thing. Dimorphism is the existence of morphological differences that cause groups within a species to appear differently. You and I are both describing examples of sexual dimorphism. That is, sexual differences, that are the result of sex-linkage of the genes that are coding for that particular trait. This can express itself in the form of differences in size only, color only, overall body shape only, etc, or any combination of several differences. Color and size differences between the sexes, is the most common type of sexual dimorphism, but there are other types of dimorphism other than sexual. Males looking exactly like a female but attaining a much smaller adult size, is a form of sexual dimorphism, just like your example of the two sexes looking like two separate species.
This is just an educated guess, but as far as maximum size of males, from the data I have seen, I would expect record size individuals from the larger Amazonian river systems to reach into the 13 to 15 foot range. That is still half the length of a record size female. If anyone has seen actual measurements in the literature of extra large males, I would be interested to see the data. Thanks,

Kelly

Just as a note...my girlfriend is 4'10" and well under 100 lbs...so a 13-15 ft snake could take her, lol. But i do think 10-15 ft is a very large snake. I guess I just look at humans and see my girlfriend is 4'10" and my best friend is almost 6'7"...I would not consider humans to be sexually dimorphic eventhough males tend to be at least 2x females. and I do not consider my best friend and my gf to be extreme cases of humans since I have never dated a girl over 5 ft tall (i guess its a bit of a fetish for little gymnasts)..and i am living with 3 guys next year well over 6 feet (tallest 6'8". I think another thing I don't like is that I only hear this when females are bigger than males...I mean I would not consider hyenas dimorphic, just different from humans. Maybe I should be a little less biased toward the term.

never mind..i guess humans would be sexually dimorphic too with that deffinition. I can use it easier knowing that.

The largest male I have ever encountered is well under 15 feet. The theory, in part, for evolution of smaller male size is that if they get too big, once they are in the big spaghetti dish of a breeding ball, the female scent is all over the area, and thus it is necessary to determine who's "tail" is the female's by tactile sense, instead of chemosensory abilities. In other words, there can be 10 to 12 or more males wrapped around a female, vying for position. So how do they know who's tail is the female, and who is the male, when they can't see the difference, their heads aren't watching, or ususally anywhere near, the tails. Girth therefore plays a significant role in determining exactly who to try and postion with to mate with.

In fact, once when I put a breeding ball of 11 animals found together (in the wild) in an enclosure, as usual they continued all trying to mate. One male was very big, over 9 feet, and several smaller males were trying to mate with it, most likely because his large size confused the others into treating his tail as the female's. (The female was about 14 feet.) This, of coure, inhibited the really large male from mating - since he was wrapped up by other tails - at least while we were observing.

Also, males move quite a bit more than females, since the males seek out the females during breeding season. Because of various limiting factors during dry season (which is also mating season), this would limit the male size to a degree greater than that of the females.

Without going into greater detail, these factors, in part, account for the high sexual size dimorphism in the anacondas.

RO

Renee,
Thanks for the information. Do you know of any sources for data on sizes of males originating from the larger Amazon basin rivers? These dense, primary rainforest areas have been thought to produce slightly larger anacondas than the more open northern habitats due to the theory on prey availability. The largest male I have heard of was around 12 feet, unfortunately I don't know the area of origin. Jud’s male was at 11.5 feet last year, and I know this because I personally measured him. Taking his current rate of growth into account, he will ultimately probably top out at least 12 feet also. I would assume a record size male would go at least a foot or two beyond that. I have a two and a half year old male that is currently at 8.5 feet. His sister is 9.5 feet and probably at least 50% heavier. He has been fed fairly steadily, but I have been careful not to over feed him and he is not overly heavy at all. He was slightly cooled this year, not by choice, but because his cage is on a rack that was cooled for the purpose of breeding some other pythons. Interestingly, he has been off feed lately and has been producing sperm plugs weekly for the last two months. This would indicate sexual maturity occurring at a fairly young age in males.

Kelly

Wow, 8.5 feet in 2.5 years! Captivity does wonders for growth in snakes...

No, unfortunately I do not have any good set of stats for rainforest, ie. Brazil or nearby, snakes and their size, basically b/ that info just doesn't exist, yet, at least not in any accessible recorded form.

I agree, I would certainly expect to find the largest individuals in the denser rainforest areas, but not primarily because of the prey, but instead because of the aquatic habitat. Individual size is limited in the Llanos, or flooded savanna (very similar to the Pantanal) due to the extreme variability between seasons. During dry season, much of the standing water really dries up, and in fact we found a lot of the snakes in the modulos that artificially held more water in dry season in order to grow grass for the cattle there.

Mortality increases significantly from dehydration/exposure/predation when animals have to travel across land to reach other sources of water, so natural selection obviously favors individuals where such behavior is minimized. On one occasion, we were called to help out at a large pool of water that had dried up to the point of having virtually no standing water, and had become one huge, thick mud pit. It was surrounded by very dry land for a ways, so the animals weren't going anywhere. We pulled 47 snakes out of this one mud pit that encompassed an area perhaps half the size of a football field. We also found one of the largest females in the are, completey buried (except for the nose) in mud that had already completey dried on the top layer...it is quite doubtful she would have survived the season (the situation was created by the landowners having abruptly changed the water regime in the area).

Without fail, the biggest individuals were found where the deepest water was, such as the one river tributary that never completely dried up. It is a balance between availability of shallow, long standing water (ie. with good vegetative cover that provides a habitat for prey species to feed, or travel across/next to, thus where prey are more available for the sit-and-wait hunter), and deeper, consistent water sources for travel avoiding crossing land as much as possible.

(I am describing the major factors in a nutshell, of course there are always more than one when it comes to size limits for species. Regardless, water is a major factor for an animal as heavy as anacondas. Also, it is very doubtful prey is a limitng factor in the Llanos, since density of all different sized prey are relatively much higher than in the rainforest, where animals are more regularly dispersed. Anacondas in the Llanos can take their pick of anything from small shorebirds to trutles to capybara, white-tailed deer, and very abundant caiman. However, they do tend to hang out in areas where these prey items are more densely clumped, which tends to be in shallower water.

This theory regarding permanent deep water for larger size was reinforced by the discovery made of an anaconda in the rainforest of Ecuador, this after spending an entire month in the same place where (teaching an ecology course, not diligently searching for anacondas): we found just one anaconda, female, and it was larger than any we had ever caught, larger than any of the 800 caught in the Llanos (she wasn't quite 16 feet). She was basking next to an igapo, an area where sufficiently deep water is consistent throughout the year.

Of course, there is also researcher bias in data collection. Where the water is deeper, and one is most likely to find larger animals, it is also MUCH harder to search and successfully locate the animals, except for those seen basking on the shore. So, you have to look for other hints at size, like snake trails. I've seen a few tracks, for example, in the mud leading to a deeper river, and from the girth of the track it was clear that the snake(s) was over 16 feet; larger than any caught in the Llanos where we searched.

To research animals where the water is deeper, like the rainforests, data collection will have to be based more on capture of basking animals, and telemetry of these animals (which leads to other anacondas, if the telemetry is done during breeding season).

If you've got the funding, I'd be happy to order the transmitters...
I've got the perfect place to begin in Ecuador...but I won't be going for a while yet, this administration has everyone's pockets pretty thin these days.

RO

Renee you are so lucky to have done and seen these snakes in the wild like this. I wish I had the funding as well because I think that I'd spend the rest of my life down there studing anacondas in the wild. One of these days I will go and do such things as that.---Eric---