Sunday, 22 January 2012

Rat Snake (Ptyas mucosa) Egg Incubation




            It all started with a call from some residents of the Chikhloli Village, Badlpur (W) [ 19°10'59"N   73°12'48"E ] regarding some eggs they had found which they supposed were of a reptile. They asked for our help in relocating the Eggs as some burrowing work was to be done on the site where the eggs were laid. We reached at the spot as soon as possible and found 12 eggs laid around 2 feet below ground level in a tunnel. The size, number, position and period of the eggs made us believe that they belonged to either Rat Snake or a Spectacled Cobra.
The 12 Eggs

           It was not possible to convince the villagers to let the eggs remain where they were till hatching as the plans to make some stairs there was in urgent progression. So we found it inevitable to move the eggs from there. The orientation was left unchanged and utmost care was taken to move the eggs in a clean box which we had carried with us. Thus the responsibility of the eggs came on us and it was also a nice opportunity to study the incubation. It was impossible to judge the date of hatching as we were not knowing the date of laying the eggs. All the eggs were in a perfect condition till 02-09-2011. On that day the first egg started to suffer a dent. A couple of days later we observed similar dents on 3 more eggs. All those eggs were separated from the rest as we found a possibility that the other eggs would also start deteriorating. Now we had a 1/2 ratio of eggs, four sick eggs and 8 healthy ones. The first egg which had dented was in the worst condition with the dent growing bigger and the egg getting compressed more and more. On 09-09-2011 we noticed that the dent has caused a crack in the egg and the inside portion can be seen through. There was no possibility of saving the under-developed baby so we broke open the egg and got the first sign of our guess being accurate.
The under-developed baby found in the spoiled egg
                The Big eye as compared to the Head, The supralabial and infralabial position and the length pointed to towards it being Ptyas mucosa i.e. Rat Snake. Later the remaining three eggs also suffered the same as the first egg had and were out of the race one by one. Luckily our 8 healthy eggs continued to be so and showed the first sign of nearing hatching on 27-09-2011 as they started to become softer and darker in colour. On 29-09-2011 we noticed the first opening to the first egg and the first baby poked it's snout out of the egg.
The first baby poking it's Head out

                     Our guess had proved to be accurate it was the Snout of a Rat Snake. The first baby took almost 2 to3 hours to completely free itself from the Egg and was active enough to strike at me just as I was shifting it to a small Box. Later one by one all the Neonates came out and glimpsed at the Big world giving us some excellent pictures in the process. All the babies were healthy and we were more than happy to release them about 200 meters away from the place were we had found the eggs. Even the villagers were happy to leave them there as they knew that their mother must have chosen the best suitable place for them and they were non venomous, harmless reptiles who were going to grow at a huge length of 11 feet to become Adult Rat Snakes and control the mice population in the Rice fields eventually helping the Farmer-Villagers.


One of the Neonates in the process of hatching