Ovulating but not getting gravid

[Imperial Geckos]

I have a gecko that has been ovulating for over a month and has had various copulation's with different males but she is not becoming gravid. Has this happened to anyone?

Thanks,
Alex

 

[JordanAng420]

Yes and it is one of the most frusterating things to ever happen, I know.

Are you leaving the males and females together or are you just doing "sessions?" Its much more effective to leave them together for a month or two.

 

[Imperial Geckos]

I have been doing sessions...Im going to just leave her in with the male then.

Thanks for the quick response!

-Alex

P.S..Yes it is VERYYY FRUSTRATING! lol

 

[JordanAng420]

No problem. I've come to find that it takes a little while for the male to really romance the female...LOL

 

[snared99]

This has happened to us this year, as well as some other fattie breeders i have spoke with. And atr first it seemed to be a male issue with not having interest in breeding, but to be honest im not 100% sure what is going on. But im sure temps have something to do with it. Here is can be 1 degree one day and 55 the next. Im guessing it is mother nature playing a role. If the females do not think it is a optimal environment for their young they will not reproduce, just instinct tking over. Well atleast thats my theory.
We have tried 'session' breeding and group breeding with the same results. We just hatched out our first amel of the season today and we are 3 months behind. Frustrating is not the word for it. Our amel females have been ovualting since mid september.

 

[SFgeckos]

Awesome, another physiology discussion!

In my experience, not all fattail females will lay eggs every year. The majority of them do, but some will take a year or two off every few seasons. I have some females that are 6+ years old that have never “missed” a season, while others regularly take every other year off. I believe that there are many factors that can attribute (I'm referring to females), including unnaturally fast growth in captivity, genetics (natural locality genetic differences), nutrition, body condition (I’m not talking about too skinny, I mean too obese! I maintain all my female geckos in a body condition of 3.5/4.5 out of 5, males 3/3.5 out of 5. Obese animals= poor breeders, higher percentage rate of reproductive issues), environmental stress, and probably most importantly, temperature, humidity, and photoperiod.

Since fattailed geckos fall under the cyclicity category of “seasonally polyestrous” they display “clusters” of estrous cycles that occur during a certain season of the year- normally in the spring/summer. There are two subtypes of seasonally polyestrous animals, short-day breeders and long-day breeders and as you can guess, geckos fall under the long-day breeders because increased day length initiates estrous cyclicity. For most animals studied, photoperiod is what controls the transition for animals that exhibit anestrus (when the ovaries are relatively inactive and neither ovulatory follicles or a functional corpus lutea are present) to the onset of estrous cyclicity. Some animals can exhibit a “silent ovulation” which is an ovulation that is not accompanied by behavioral estrus. In order for a successful ovulation, progesterone must be present for a certain period of time prior to exposure to estrogen. Often times, this means that the first corpus lutem formed after the first ovulation after seasonal anestrus helps to make the brain more sensitive to estrogen. This may explain why some geckos appear physically to be ovulating, but do not become successfully gravid when bred.

My experiences match up with what is mentioned in several books (if you want a list of references/articles to check out, please email me) which all say that photoperiod is the most important. This goes into neurobiology, but basically light stimulates the retina of the eye (many basking lizards have a “third eye” that monitors photoperiod) and triggers the suprachiasmatic nucleus located in the hypothalamus. The postsynaptic neurons make contact with specialized cells in the pineal gland, called pinealocytes that secrete a hormone called melatonin. Melatonin is synthesized and released only during the periods of darkness or night, which in long-day breeders represses reproduction (longer light photoperiod= less melatonin production= less reproduction repression) For short-day breeders, it is the opposite with melatonin stimulating GnRH hormone to promote estrous cyclicity. I would recommend increasing the daylight exposure to all your females, at least 12-14 hours per day or more. You can probably even leave all the lights on 24 hours a day without any ill effects.

I hope this information has been somewhat helpful! I’m surprised I can eat dinner while typing/thinking at the same time!

Jon

 

[snared99]

Jon,
Great info! Dont know if i would leave the lights on for 24 hours though...lol

 

[SFgeckos]

Haha, yea it's a great way to increase your electricity bill! =)

This might be a bit off topic...

I remember in the 1990's I was reading an interview/article from the very successful monitor breeder Frank Retes in AZ and he talked about how he left the lights on 24 hours a day. At the time I thought to myself, why would he do that? I think it was because he understand reproductive/animal physiology, studied natural habitats and tried many methods "outside the box" which is one of the reasons why he was a successful pioneer. Not only that, but he openly shared his information to other hobbyists and keepers- which can't be said for all "pioneers" in herpetoculture. Back then, other keepers were not having success breeding monitors, yet he was able to consistently produce multiple clutches that were above the average number. Of course, nutrition and a high temperature gradient were important, but I believe the increased photoperiod helped the females maintain longer or more regular ovulation cycles that ensured multiple clutches!

Jon

 

[snared99]

I do agree with the photoperiod theory, and think the longer photoperiod the better results. But there is now where in the world where lizards/geckos live where it is light 24 hours a day.(atleast im pretty sure there is no lizards in alaska..lol)

 

[BSM]

Thats exactly what i did when i had all my monitor species and they were all breeding, Frank is a great guy to learn from but he doesnt answer emails or phone calls , there definately in a league of there own. Monitors just take up so much space and so much food + the ecltricity for 24/7 lights all year (4 big cages 16 lights), wish i could bring them when i moved but not enough room in the new place.

 

[SFgeckos]

"But there is now where in the world where lizards/geckos live where it is light 24 hours a day.(atleast im pretty sure there is no lizards in alaska..lol)"

Of course, the answer to your question is nowhere! Their natural habitats have different seasonally changes- usually "long and short photoperiods" or "high humidity/low humidity" or "high day temperatures/low day temperatures" etc. However, stop and think about what happens after several generations in captivity. The natural "built in" physiological changes in correlation to environmental changes are still there, but they may have become diffused or diluted. For example, African fattailed geckos are from different localities in Africa. Wild caught imports (adults/subadults) may have already experienced several seasons of changes, and thus their bodies are accustomed to those exact changes- which is why sometimes imported animals can take years to "cycle" to North America's photoperiods or seasons because we are in the Northwestern hemisphere and they may be from the Southwestern hemisphere. It would be similar to someone living in the tropics for years with lots of sunshine and heat, then moving to the South Pole! After several generations in captivity, some animals may "lose" the same cycle of their previous wild ancestors and need more extensive or extreme "triggers" of environment changes, while others retain their natural genetic instincts. This may explain why some "lines" of reptiles breed or cycle at a specific time/trigger, while others are more variable. This could also be why some males are "ready" when females of the same species are not, because their cycles don't overlap? Although, usually males seem like they are always ready =)

Extreme examples are domesticated house pets or farm animals, they have different hormone levels (and cycles) than their wild cousins. In fact, even within the same domesticated species, such as beef cattle and dairy cattle which are genetically exactly the same, they have so many physical and physiological differences! Just my observations and opinions.

Jon

 

[Imperial Geckos]

wow, this is all very interesting..thank you guy for all the extra info

 

[chansbrow]

Excellent discussion!

 

[chadbandman]

If the lights on in your house do you know it's dark outside? Monitors view the light as a heat source not the sun. Monitor and geckos are way different in there Psyche and breeding.