Reptile Forum, Reptile Classifieds - CaptiveBred

[Central Scotland Reptiles]

I seen an article the other week on culling offspring. As it is the breeding season, i just wondered what everyones opinion is on this subject.

For example, say you have two really poor feeders that needed to be force fed, would you then breed these together. The thinking is would the babies be poor feeders also?

Human intervention has taken this natural selection away, maybe looking at the bigger picture, these animals were never meant to survive to adult hood and to procreate???
_________________
Fraser Gilchrist
Central Scotland Reptiles - "Finding Beauty in the Beasts"

[Tea]

I'm not a breeder but my view on this subject is a simple one really...

First of all, as much as I advocate natural selection and letting evolution take its course, the line between what is acceptable and what isn't has become blurry over the years of humans playing god with both its own species and the animals it interferes with. With this in mind, we have halted our own natural selection process and that of other animals by providing healthcare and veterinary services therefore, why should we not apply this theory to the herps we keep within this hobby as well? I believe, if we're going to screw around with nature so much and produce animals that are for our own pleasure, aesthetically, the whole natural selection excuse for culling is a bit of a weak one.

Secondly, I would have thought that, as a responsible breeder, anyone expecting clutches of eggs will have made sure they have adequate space and resources to support the resulting babies. With this in mind, the only real reason for culling, in my opinion, would be if babies are born with debilitating birth defects. If the welfare of the snakes is as high a priority as it should be then breeders should be willing to give the weaker babies a chance too.

Like I said though, I am not a breeder so I don't know the ins and outs of how these things turn out. All I know is that, by nature, I could never cull anything and so, if I were to breed, which hopefully I will one day in the not too distant future, I'll make damned sure I can support whatever babies may result. The above is just the way I see things
_________________
http://www.iherp.com/tea

0.1.1 Elaphe guttata guttata
1.0 Python regius
1.0 Xenopus laevis
4.0 Hyla cinerea
0.0.4 Litoria cearulea
0.0.1 Varanus exanthematicus
1.1 Chameleo calyptratus

[Scott W]

Interesting post.

I'd be suprised if two poor feeding hatchlings that eventually feed fine that then go on to breed will automatically equal poor feeding young.

There are of course a few strains that do consistantly hatch out as poor feeders, normally due to a smaller size but a lot of these lines seem to of been improved by more selective breeding to increase offspring size.
_________________

Please DO NOT pm orders for reptiles, send email instead scott@captivebred.co.uk

[Central Scotland Reptiles]

You make some very valid points Tea. I am just curious as to peoples views.
_________________
Fraser Gilchrist
Central Scotland Reptiles - "Finding Beauty in the Beasts"

[Tea]

Thank you. Yes, I have to admit, this kind of thing always piques my curiosity as well. It'll be interesting to see what people have to say.

Going back to another aspect of your question, I would tend to agree with Scott's point about it being unlikely that poor feeding adults would produce poor feeding offspring as, with the exceptions of hereditary diseases which are obviously highly undesirable anyway, I'm not aware of many other prominent and commonly encountered genetic traits that would cause this sort of behaviour bar the exceptions Scott made which refer to size etc. I think this behaviour is usually attributed to environmental stimuli and overall health... which could be as a result of complications during development within the egg or similar factors that may have occurred post conception.

Forgive me if that didn't make much sense... I'm at work and my brain is frazzled
_________________
http://www.iherp.com/tea

0.1.1 Elaphe guttata guttata
1.0 Python regius
1.0 Xenopus laevis
4.0 Hyla cinerea
0.0.4 Litoria cearulea
0.0.1 Varanus exanthematicus
1.1 Chameleo calyptratus

[Mook]

If you are breeding animals in captivity natural selection and evolution are not applicable terms. They are replaced with selective breeding.

I think the obvious point is that it is a our responsibility to only breed healthy animals.

Does this mean that any animals that are not fit for reproduction are worthless and should be killed?

Good question: I guess that depends on your own personal morality.

[Tea]

Yes, personal morality would be one of the things it would depend on.... as well as your reasons for getting into breeding these animals and your balance between welfare and money.

Different strokes for different folks and all that.. but I can imagine there are some people out there whose answers to this question would be slightly more than just inflammatory

That's all I can really say on the matter now really as I don't have the experience that a lot of the guys that post on here have and i fear that my responses my come off as ignorant to those with a more intimate understanding of the genetics and practices involved. My knowledge is purely theory and I don't want to step on any toes if I get a bit mixed up!!
_________________
http://www.iherp.com/tea

0.1.1 Elaphe guttata guttata
1.0 Python regius
1.0 Xenopus laevis
4.0 Hyla cinerea
0.0.4 Litoria cearulea
0.0.1 Varanus exanthematicus
1.1 Chameleo calyptratus

[SteveL]

The only time i would euthanize would be if the animal was in obvious discomfort ..Although Snakes tend to heal rather fast if theres any accidents etc .
I was reading on a U.S board about certain big breeders who freeze there jag siblings rather than put them into circulation ,For me that is wrong !why breed them if your going to select them for looks alone then kill off healthy snakes ?!?.

Some snakes are Poor feeders due to being small sized to begin with then the are only picky because you tend to have to offer then bits of prey when they are probably programmed to take live full items ..

there all good to breed from as long as theres no other obvious problems IMO

so for me it has to be try to preserve life !
_________________

[Scott W]

[Central Scotland Reptiles]

I suppose it would be helpful / beneficial if i post the actual article i seen!!!

Here you go -

Culling Offspring
A much overlooked and underused practice

The voluntary culling of offspring is a practice all too few people participate in. In reality this is a disservice to the hobby as a whole on several levels, and has amounted to a disturbing trend.
In today's world of information, knowledge, and availability of animals, the number of people breeding reptiles increases every year.
All these things are indeed assets to the hobby, but the relative ease of reproducing many species has resulted in virtually every person in possesion of a pair of leopard geckos or cornsnakes to feel they have to breed them.
The problem lies in the fact that this results in nothing more than more animals being produced without rhyme or reason and very little progress being made.
In part, the reason behind this lies in the desire for monetary gain. If an egg hatches, the baby will be sold regardless of whatever characteristics that baby might or might not bear. This includes behavioral traits as well.
The simple truth is this is irresponsible and not every hatchling produced needs to be added to the gene pool.

What we have today is a multitude of small time breeders with one pair of this and one pair of that just hatching eggs for the sake of producing more animals and selling everything produced with no regard for the betterment of the captive lineages. This often results in the sale of sibling pairs, which promotes inbreeding for no purpose, and the sale of mediocre animals which will go on to produce more mediocre animals and so on.
The entire attitude of breeding for the sake of producing more animals to sell needs to be corrected.

I have seen estimates that in excess of 150,000 leopard geckos were produced this year(2002). My point is why should you or I put together a group of leos for breeding? What purpose would it serve? None whatsoever beyond the generation of a small amount of additional income.
The current effort put into the reproduction of many common species must be shifted to the area of refinement, and this is dependant on culling.

So what is culling anyway? Contrary to the belief of some, culling is not keeping the best one or two offspring for your group and selling the rest. Many large scale professional breeders refer to this as culling, but it is just a facet of selective breeding, since they would have just sold them all if none met their personal standards to merit keeping.
Culling is the destruction of any offspring bearing any undesirable, or less desirable traits. By traits, I do not mean only color and pattern.

I realize that the intentional killing of certain offspring is distasteful to some, and will be considered cruel by many. I am not writing this however to cater to the warm and fuzzy opinions of many today who claim the title of "herper" just because they keep a few reptilian pets.
Many people hold an inherent sympathy for the weak, or just the lives of the less desireable. There is little room for this shortsighted approach.
Nature itself is harsh and unforgiving in its methods and in what individuals are allowed to reproduce. We too must become strict in our standards, but we have to use different criteria.

That brings us to the question of how will the culling of offspring be accomplished? The answer will vary depending on the species involved. The degree of culling must be based on the relative abundance of a species as captive born. The more common a species, the more strict the criteria should be. Species which remain rarely bred may be limited to the culling of only deformed or otherwise defective offspring, while the most common species should be culled using much broader standards.

First and foremost, any offspring with physical deformities should be culled. Snakes born with one eye, or a spinal kink etc should not be sold. Likewise, lizards born with turned feet or deformed limbs should never leave your possesion.
Even though in many cases these conditions are not genetic, there is simply no reason to add less than perfect specimens to an already saturated market. It is all the more applicable if the condition is genetic, or suspected to be so. These animals should never be allowed to reproduce.
The only time that this standard could be relaxed would be when it concerns a species which is very limited in availability, and the specimen only has a minor nongenetic blemish but is still capable of needed reproduction.
Note I said species, not morph. Just because a morph is rare (and thereby commanding the coveted higher price tag), is no excuse to sell deformed specimens. Case in point, one eyed albino boas. There exists the possibility that this condition is a genetic defect resulting from inbreeding. When these snakes were still bringing several thousand dollars, a grand or two was deducted from the price of the one eyed individuals and they were sold regardless. This was greed, no more, no less.

A very important part of a breeding project that is often overlooked is to have a plan. Before you start to breed a species you need a goal, a result you are aiming for, a set of standards you want to meet.
The process begins of course with the careful selection of your founding stock. Do not be in a hurry to get your group together. Know what you are looking for and do not let the price figure in too heavily. Never settle for lower quality in order to save money. The founding stock is the basis of the entire project, and if you cut corners at the beginning, you are crippling your own efforts.
Do not buy siblings with the intention of breeding them to each other. There is nothing wrong with buying siblings, but also buy another pair form a seperate bloodline and cross the pairs.

Now the main issue, you've hatched eggs, what do you cull? This is where it gets subjective. With all the possible breeding programs, there is no one answer. Alot will depend on the goals you established earlier.
Generally speaking, any offspring which are not at least as high quality as the parents are subject to culling. There is no reason to step backward. Anything involving the color or pattern traits will largely depend on the tastes of the breeder and his level of dedication to the perfection of the blood line.

Other characteristics however, should be held to stricter standards. For instance if you are breeding mountain kingsnakes or gray bands you will have some problem feeders. If, after a reasonable amount of time, you have some specimens that refuse to eat mice devoid of any manipulation, they should be culled. Nonfeeders should not be sold in the first place, even at discounted prices, and those that remain so should be removed from the gene pool. This will strengthen the captive lineages.

Likewise, if a specimen just fails to thrive it should be culled. I spent several years keeping and breeding bearded dragons. One fact of breeding this and other species which produce fairly large numbers of offspring is that a small percentage of them just will not take off. Some people, out of a sense of sympathy, or obligation, will put great effort into nursing these individuals, coaxing them to eat etc. I allowed several dragons to die naturally from their refusal to hunt for themselves, it needs to be done. My wife took one dragon many years ago and hand fed it, spending an hour or so per day for 4 weeks convincing it to eat. While this is a noble act, these animals should be culled. The weak have no place in the gene pool, and saving such animals is not doing the species, or future keepers any favors. The dragon my wife spent so much time with grew into a healthy adult, but we kept her until her natural death nine years later, and she was never bred.

These are merely some examples meant to make you think about where you are going with your breeding projects. Producing an animal for no reason other than to have a few more babies to sell is no longer acceptable in this time of over saturation of many species.
Where many common species are concerned, there exists no reason for experienced hobbyists to produce them at all. Their efforts are much better spent working with other species that are in need of being produced.

Things like leopard geckos and cornsnakes, including the common morphs, are already produced by the tens of thousands. These species are ideal for the kids, and the less experienced to get their first taste of breeding, and this is great. However, if you are an experienced hobbyist producing yet more leopard geckos, you are accomplishing nothing outside of your own self serving interests. At least a portion of every breeders efforts should be aimed at the advancement of the hobby as a whole.

I myself have been guilty to a degree of several points I have mentioned here. I'm not trying to convince you to stop producing common species. I am only saying that with many species the numbers being produced are more than adequate. More focus should be placed on quality rather than the quantity of the common species, and alot of the effort put into pumping out even more of these would be of better service to the hobby if applied to less common species, especially those that are not bred due to the lack of potential for financial reward.
In the past I have worked toward producing abberantly patterned California kings. This project was just for the enjoyment of seeing the odd patterns. In the process though, I also produced many average, or even below average looking hatchlings. I sold them all, often wholesale, just to move them. This practice benefitted nothing, and many of those should have really been culled. The availability of average looking cal kings does not warrant my producing even more. It does nothing for the refinement of the species, nor is there a need for more of these in the pet trade.

The majority of people will refuse to take culling to that level. They would equate culling a healthy but imperfectly banded cal king to lighting a cigarette with a $20 bill. These people will ensure the over abundance of the most common species, and their status as disposable pets. They also make it easier for those of us less concerned with money, and more so with the betterment of these species and the hobby as a whole to practice more strict culling.
At the very least, poor feeders, and weak or deformed hatchlings should be destroyed. There is really no valid excuse for selling them and their culling will only improve the gene pool.
Culling is not easy, and I do not enjoy it any more than you. As responsible breeders though, we must practice it to some degree.
_________________
Fraser Gilchrist
Central Scotland Reptiles - "Finding Beauty in the Beasts"