divendres, 29 de juny del 2012

She carries more eggs

Last Monday, 15 days after the female laid, I palpated her inguinal and I felt eggs again. I haven't noticed behavioral changes, such as stop feeding or visiting the land area. As I always do when I palpate she carries eggs, I have a look at the land area in the evening, in case she is making the nest. Also,  every few days I palpate her.

These days we are having a heat wave and the maximum temperatures in the shadow are very close to 40ºC. Yesterday evening, at 21:00, we were 29ºC. This is more typical of the "canicula" (dog days) than June.  Fortunately the vegetation covers half of the pond creating shadow. I also have the measurement of last summer water temperatures in the hottest days, so, I don't think the terrapins are in danger. Every two days I add some water as the evaporation looses are important.

It is curious to see the behavior of some animals in these hot days. The terrapins are very inactive. On the other hand, Paper Wasps  (Polistes dominulus) are extremely active. They visit the pond in great numbers, looking for the water. They use it to thermo regulate their nests, cooling it through evaporation. They often stop on rocks or vegetation, but sometimes they land on the water taking advantage of the surface tension, the same way as pond skaters do. In the beginning I was concerned that the terrapins tried to eat them. Over time I have seen that they completely ignore them. I guess the aposematic coloration of wasps reminds them other wasp species native to their habitat and they "know" it is better not to disturb them.



divendres, 15 de juny del 2012

She laid during "La Patum"

It had to be that day. I wanted to go on Sunday night with some friends to "La Patum de Berga", the village festival,  and the terrapin started digging the hole at 19:00.
The day before, on Saturday, more or less at the same time, she tried to make a nest. I saw her digging, hidden among the vegetation. In a couple of hours she stopped. Where she was trying to dig a hole there was a stone and the earth in the area was very hard. 


Trying to dig a hole



She was just starting, I didn't try to make more pictures


She left it like that 


As I was saying, she tried again on Sunday. Like she did on Saturday, she chose to do it under the grass.


I saw she was digging for the regular movements of the grass


At 21:00  I realized she would be there for a long time, so, I went to the festival.  To the " Patum de Berga", proclaimed "Masterpiece of Oral and Immaterial Patrimony of Humanity" by the UNESCO in 2005. 

http://www.youtube.com/watch?v=pCPHOT41Boc

http://www.youtube.com/watch?v=3D8Rc5ruGmg&feature=related

http://www.youtube.com/watch?v=SaOnPQ5HEPM

http://www.jordicohen.com/category/patum/















When I came back home, around 3 o'clock in the morning, the terrapin was still in the same place, working in the nest. I went to sleep. Next morning, at 9:00, I saw her underwater and, in the place she had been most of the night, to my surprise, the eggs uncovered.

The upper one has part of the shell collapsed

She laid four eggs. The hole was not very deep, I think this is why the last one collapsed. The earth was very hard and it looks as she had problems to dig the hole. Some species sometimes lay the eggs in places with vegetal debris and do not bury them. I don't know if Clemmys sometimes does it. But last year she made a proper hole and covered the eggs, in a place with sand mixed with the earth.
I talked about it with a friend with a lot of experience breeding turtles. What he does is dig the earth and water it some days before the females starts trying to nest. That way it is easier for them. If she wants to make a second clutch, I will do it. Also next winter, I will soften that earth with some sand and garden earth.
Regarding the incubation I wanted to try  Lucky Reptile incubators. Some time before I programmed one at 25ºC and another one at  30ºC. I already realized that there was more than 2ºC of difference between the real temperature and the one you read. But the worst is that they failed when I needed them. When the terrapin started digging I connected the incubators, but the temperature didn't pass the 25ºC. At the 12 hours anything had changed. I tried to put them both at 34ºC and the temperature didn't rise up. One of them was new.
I put two eggs in my old Jaeger. I checked the temperature with signatrol data loggers. I programmed it at 29,5ºC.  The humidity higher than last year.
I put the other two eggs, even the collapsed one (which I don't think that survives) as described in some prehistoric books. A bowl with water heated by a aquarium heater. All closed with some inclination to avoid condensation water drops falling on the eggs. The eggs in vermiculite, in an open box. The temperature about 26ºC.
There is a signatrol data logger in both incubators, measuring the temperature and the humidity every hour. Now I have to wait.

dijous, 7 de juny del 2012

Ready to lay eggs

This spring is being hot, with thunderstorms in the afternoons. This rain stimulates the Clemmys.  They use to move to shallower areas and even the shore. This also happens when I water the pond. During last thunderstorm, I noticed something. One terrapin was walking underwater, near the shore,  with the top of the carapace almost touching the water surface, with the neck outstretched and the nose on the substrate. Moving slowly as if seeking something. At one point it even removed the sand of the bottom with the leg, pulling the dirt on its carapace. It really looked as though it was looking for food.
I remembered that once before, also after a rain, they were doing something similar and one of them swam quickly  away with an earthworm. I thought she had been lucky to find an earthworm, but I now wonder if the thunderstorms might have some relation with food availability.

The pond has completely changed in appearance


April


June


June

I often pass a net to clean the water of fallen leaves or to control filamentous algae. In these cleanups I have found several invertebrates: ditiscus sp, water striders and recently, dragonfly larvae.



In fact, I have assumed they are dragonfly larvae because of their face, quite similar to the mother's. She visited the pond in autumn 2011. She touched the wood with the abdomen in different places for several minutes. I thought she was laying eggs.



Both Clemmys spend most of their lives in the water.  Only the male in spring has some terrestrial activity for a brief period, when it walks up and down the land area, specially in the early morning. This year he has done it in late March. I wonder if this corresponds to those migrations described in some articles. They also occupy different type of ponds in different seasons.  I have only seen the female going to land to nest. And this is what she is doing now. Last mating I saw was in April. Now she is carrying eggs. About 15 days ago I felt something on palpation but I wasn't sure. One week ago I palpated the eggs very easily. The female has also changed the behavior. She has stopped eating (even earthworms!). And she goes to the land area, specially in the early morning (and maybe during the night, I am not there to check). Every day since last week I have a look at the land area when a come from work in the evening, around 21:00 and again before going to bed, between 23:00-24:00.  Today it has been a very hot day. If there in not an afternoon thunderstorm, I suspect that she will lay tonight. This is also what I  thought yesterday. And two days ago.