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Introduction
 

I have 2.2 Rhino Ratsnakes in my collection which are on breeding loan from Dave Cooke. 2.1 are LTC (6 years) and the other female is a CB03/4 from Russia. I received the animals at the beginning of 2007. That year I was unsuccessful in breeding them. The LTC female reabsorbed her eggs as she partly did this year. She laid 3 infertile eggs then went into slough and on completion 10 days later appeared thinner and no eggs could be felt inside her. The CB female in 2007 laid a clutch of infertile eggs. The LTC female had reabsorbed her eggs also in 2006 with Dave, the CB female however did have a healthy clutch of 8 eggs. This article is about the successful breeding of the captive bred female in 2008.

Brumation.

At the end of October 2007 I stopped feeding them and maintained the temperature for another three weeks before gradually lowering it over the course of two weeks. They were then moved on the 26th December in to 9L containers with a substrate of hemp core bedding, flowerpot hide and a water bowl that was changed approx every 4-5 days. The average temperature throughout brumation was 54°F (12.2°C) with some nights dropping to 48°F (8.8°C) and highs of 58°F (14.4°C). The average relative humidity was 65%.

All of the Rhino's liked to soak throughout brumation, especially so the females. This did worry me a little. Once when I went to change the water bowl, I had to lift the snake out, it was so cold and stiff I was sure it was dead. It remained in the same shape even when I put her down on the substrate, I had to prod her several times to get any reaction out of her, which was a big mistake as I awoke a monster, and she went into defensive mode with mouth gaping.

After approx 6 weeks in brumation, on the 10th February I began warming them up. They were moved onto my unheated landing which was a few degrees warmer than the brumation room for 24 hours then moved into the reptile room where they were placed on the floor at 74°F (23.3°C) for a further day. I then put a thermostatically controlled heat mat under them and gradually turned the heat up over a few days til it was at 80°F (26.6°C). They were then moved into there vivariums at full temperature where they have access to a basking spot of 84°F (28.8°C).

 

Mating

On the 21st March after the females pre brumation slough I introduced the male into her enclosure. I know this isn't the normal way round when introducing breeding pairs, but it is the most logical in my mind. Males at this time of year are actively seeking the females and will often cruise there vivs, so moving him doesn't upset him so much. For females I feel it is less stressful for them to have familiar surroundings during the breeding season. Your also not handling her unnecessarily when she could already be gravid and I often find that they are more receptive in there own enclosure.

There was alot of head jerking and swaying between the two when first introduced. I got distracted for approx thirty minutes and on my return they were hooked up. They parted within an hour and I returned the male to his enclosure. I paired them several times over the next few weeks with 4 day breaks in between in which time I would feed the female, she would normally take 4 medium mice each meal this is twice as much as I feed her out side of the breeding season. I witnessed several copulations and also the head jerking and swaying of the first introduction. Copulation was always preceded by the usual courtship rituals seen in other species. The male would mount the female and then inch forward on her, stimulating her with twitches from his body. When there heads were aligned they would gently sway them from side to side, which was rather sweet to watch. This behaviour ceased when intromission occured and the two would lay motionless except for the occasional twitch from the male. Courtship usually lasted about 5 minutes and almost always occurred within 15 minutes of them being introduced to one another. Intromission lasted between 15 minutes and 1 hour


Notes: I as well as other breeders have noted that males of this species will fight if housed together. My largest male made quite a mess of the smaller ones back when I inadvertently housed them together thinking that it was a true pair. I hadn't checked the sexes when I picked up 2.2 and was only told which ones were which, even though I then marked the containers they were in, there must of been some mix up in identifying them. Other breeders have put 2.1 together to initiate a breeding response which resulted in the males being aggressive towards one another, unlike ritual combat seen in other snakes, male Rhino Ratsnakes actually bite one another and will wrap coils around one another.

 

 

Was she gravid or wasn't she ?

It soon became apparent by looking at her that she was beginning to swell with eggs. When I run her through my hands I could clearly feel several eggs inside her. Normally I would be excited at this, but was a little apprehensive because of the results from last year. The Rhino Ratsnakes had a permanent feature of a humid hide in there enclosure which she could of used for laying, but I made her up an additional one which was slightly smaller so she had a choice. She almost immediately entered the new moss box and would spend alot of time between that and her dry warm hide. This was very encouraging for me as last year she didn't use the moss box at all preferring the dry hide or soaking in the water bowl. On the 17th May she refused her first meal and shortly after this went into her prelaying slough. When she sloughed I discovered an infertile egg wrapped up in the skin. My heart sank, as I thought this was an indication of what was to come. I checked her daily and she seemed content coiled up in the moss box as the days passed I got less concerned and more excited at the possibility of a good clutch.


Laying

On 6th June 2008 at 7pm I looked in the moss box and caught her laying, she lay coiled around three eggs, and it was obvious that there were more to come. I gently put the lid back on the box, ran down the stairs giggling like a demented teenager and excitedly told anyone who was in ear shot... She's laying .. there white, there perfect ... whoooaaa. Checking on her three hours later she had finished laying and 6 pearly white eggs in a perfect 3.2.1 pyramid shape where visible within her coils. The top egg was only loosely adhered to the bottom two so I gently removed that. The female was very alert whilst removing the eggs and didn't look tired out, like some females do after laying. I had defrosted a mouse for her earlier which she took with relish, changed her water which I added some reptoboost to, and then left her to recover. The female went into a prelaying slough and was blue for about 2 weeks, she eventually shed her skin but refused all food. At first I thought perhaps she was going to lay a second clutch. She hadn't lost any condition by laying so I wasn't overly worried about her. As the weeks went on though and she didn't look to be gravid again, I did start to worry about her lack of eating. She then developed a skin complaint which could of been the underlying cause of her not eating, as soon as that was treated she began eating again. I took it slowly at first only offering small mice, but after a few feeds she was back to her usual 2 medium mice and even managed to chomp down a day old chick.

Notes: Details of her skin complaint and treatment will be in a forth coming article.


Incubation

The eggs were half buried in a 2.1 vermiculite to water mix and moved to the incubator. Although there was a little artistic creativity with the vermiculite to make sure that all were buried but not completely. I have a Herp Nursery 11 incubator which was set to 83.3°F (28.5°C) for the duration of incubation. I occasionally lifted the lid of the container to exchange air throughout incubation, more so towards the end. Humidity was 95-100%.

 


Hatching
 

The first egg pipped on day 54 of incubation followed 33 hours by the second. 48 hours after the first one pipping the third poked it's head into the world. On the advise of Rob Stone (hph) from High Plains Herpetoculture the three remaining eggs were manually pipped. A few hours after this a head was seen poking out of one of them. The other two eggs looked to have a while to go yet judging by the network of veins surrounding the hatchling. One thing I did notice was that the fluid in the egg was very thick and gelatinous, unlike any egg content that I've seen before and over the years I've hatched thousands of eggs from a wide array of species. This might be a reason for some breeders reporting full term egg deaths, the consistency of the albumin fluid making oxygen transfer more difficult unlike some other species such as Gonyosoma & Orthriophis where it's the shells that give the hatchlings trouble in emerging.

On day 59 of incubation the remaining hatchlings had their noses poking out the eggs and several hours later had emerged.

 

 

One thing worthy of mentioning here is about the horns, they are floppy when when they hatch. I guess this is to allow the hatchling to be able to use it's egg tooth to exit the egg. Although the horn is not hard and inflexible in adults it is fixed at the base. With hatchlings its very pliable. Some look very silly when they hatch, I had one whose horn had adhered to the top of it's head, presumably from the thick goo it had been sitting in, in the egg. The horn becomes fixed by the first slough which generally occurs about a week after hatching.

 


Hatchlings
 

The average weight and length of the hatchlings was 0.25 ounces (7g ) and 10 inches (25.4cm)

The hatchlings of this species are notoriously difficult to get started and with some guidance from the article by Rob Stone on feeding baby rhino's I got all six of them feeding on pinky heads. They continued to strike feed on pinky heads for several feeds and then progressed onto whole pinks. As my feeding methods are similar to Rob's it seems pointless in relaying it all here, so I'll just point you in the direction of his article for further reading.

 

This site has information on the following genera of Ratsnakes ... Spilotes, Spalerosophis, Ptyas, Zamenis, Elaphe, Rhinechis, Senticolis, Pseudelaphe, Pantherophis, Bogertophis, Orthriophis, Gonyosoma, Oreocryptophis, Oocatochus, Euprepiophis, Coelognathus, Archelaphe