Reptile & Amphibian Forums

OK, here's another photo. It's actually a particularly interesting one, because we caught these 10 males and big girl, put them in the enclosure, and as usual, they started up again immediately.

I went back 15 minutes later, and noticed that the one huge male, vying for position at the female's tail, was so big that other smaller males were wrapped around IT - don't know if you can make it out in the photo. This supports our theory that male size is limited, in part, by this very scenario - tactile senses when mating, for who to mate with. After all, when the males are all this close to the female, in one big spaghetti dish, everything must have her scent on it, including other males who have come in contact with her, so the one major clue to who exactly is the female, which tail is the IMPORTANT one, is based on girth. The really large male is being prohibited from mating, simply b/ he's got the smaller males wrapped around him, and thus he probably won't mate successfully at all, nor pass along those extra big guy genes.

Renee

Let's try that again,... here it is:

Renee,
What are the stats on the female in your photo?

Kelly

` Here's something in captive Yellow Anaconda mating behavior that fascinated me. During breeding with a single male present, the male was not too concerned with controlling the female. He was pretty lazy about it.

` When more males were introduced, he wrapped her. He also shoved and slapped the other males with his coils, but got no more aggressive than that. Also, he left no sperm plugs when alone with her. When the other males were present, he left more than one.

` It's too bad Yellow Anacondas are not studied more, in their natural habitat. The three males who were pursuing the female live together, the rest of the year. They get along fine, and sleep and soak together.
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Wow, he left no sperm plug! Interesting - makes perfect senese, but I've never witnessed that. Then again, single male balls in the wild are rare.

That reminds me, when a film group from BBC was filming a show on wildlife and mating systems, they left the camera on the breeding ball for a little while so we could see it on time lapse. What was most fascinating was that you could see the males and their coils actually breathing hard (panting, so to speak) from what one can only imagine is a very long, slow-motion wrestling match.

Renee

DFR,
That is an interesting observation. Did the period of mating associated with the lack of a sperm plug result in the production of young? In some boids it has been found that when sperm plugs are not formed it is indicative of little or no sperm production. I was curious if what you experienced with this breeding correlated with these findings. In both of our breedings with greens that resulted in young, the single male left several sperm plugs during the roughly 2 month period he was in with the females. Thanks,

Kelly

` The large male was with the female for 10 weeks. During that time, he mated with her constantly. I introduced two other males, several times, for a short time only. I only left the multiple males together, with the female, when I could constantly observe. This was done five times, eight to twelve hours each time. I never observed the smaller males getting together with the female, the large male kept them at bay. He left many sperm plugs, but only when the other males were present.
` The mating was fruitful, but the gestation was very unusual. The female was 4 1/2 years old, her first time. She fed, on very small items, for the first 3 months, then refused food. Her gestation went for six months! Then she started giving birth to large ( 15 to 21 inch ), fully formed babies, all dead. Some were delivered along with their shed skins! This process went on for 2 months!! At the end of the process she delivered 4 unfertilized eggs. Eight weeks after the birthing started, I fed her, and she gave birth to two more large, perfect, dead babies, with their shed skins beside them. Total of 29 fully formed, dead babies, 4 unfertilized eggs. Also, she never attempted to eat the eggs, or the dead babies. I left some in with her for several hours, to give her the chance.
` She did not seem to suffer physically from this ordeal. Loss of body mass was minimal. Today, she is active, and hungry, and totally tame. She is also pushing 14 feet!
` The mating began in October, 2002. Today, she is waving her tail, and driving the males crazy with her pheromones. The males are climbing the walls, attempting to mate with each other, and with a large B.c.i. male. In the last few weeks, as the female has become receptive, the males are leaving sperm, and plugs constantly. The sperm is almost exclusively left in the water. If I do allow them to mate again, it will be after at least one year off.
` I would be happy to hear everyone's opinion on what caused the babies to die, before birth.

` Incidentally, I took scores of flash pictures during the mating. None of them seemed to mind, and went on about their business. The large male exibited his normal curiousity about the camera, and investigated, but did not cease mating!
`

` Rich
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Rich,
That was definitely a very unusual gestation and birth. It actually went very typical until the stillbirths. The 6 month gestation was average for yellows, as was the feeding for the first half of this period. Newborn yellows are usually in the 20 to 26 inch range so these were slightly small, but I think that was due to the exceptionally large litter, which tends to cause the individual young to be smaller. A small percentage of stillborns is not overly unusual, but it is noteworthy that the entire litter was fullterm and stillborn. I don't know exactly what caused the stillbirths or the extremely protracted birthing period, but it is possible that the initial birth was delayed for a few days, for some unknown reason, causing the young to suffocate. Especially in light of the fact that shed skins were found along with the young when they were born. After the young had died, the rest were just expelled over an extended period. Even for her size, that was a very large litter. Thanks for the information.

Kelly

Interesting. A friend of mine had a pair of yellows do the same last year. Unfortunately I do not know all the details off hand, but I will enquire further on this subject. Sadly he bought a new house and had to liquidate his collection quickly, including the yellows before I could put funds and caging together.

GD
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I don't believe in luck. Luck is God covering your a** when you screw up.

` I would appreciate hearing anything you can find out about the circumstances of the breeding and gestation of your friend's Anacondas.
` Sorry you missed them. Anacondas are very satisfying pets.

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She was 4.52 m, 168 lbs. She was in an area next to a larger, deeper body of water than our primary research focus area (which was ~ 2 hours away), and it is in this same area we found the largest males; we have caught a couple larger females here, too. This modulo leads to a tributary where they've released crocs, so it leads to deeper water (in wet season).

Renee

Thanks for the information, she looked like she had some fair size to her. At that weight, she was definitely in breeding condition.

Kelly