further discussion on monitor diet & feeding habits

[Ophiuchus]

Apparently, the mods deemed the last thread unfit to progress further. This is regrettable, since I made a promise and as a result of the thread closing, I couldn't deliver.

In the previous thread, I claimed that savannah monitors sometimes exhibit a "gorging" behavior; specifically, in lieu of their opportunistic feeding strategies, they will gorge themselves whenever finding prey because they prepare for the likley scenario of a fast before they come across another substantial meal.

Other members of this forum called BS and wanted proof/sources that backed my claim, so here they are. Sorry for the delay (I actually do have a life beyond this board).

Below is an excerpt from an interview with Michael Balsai:

Kaplan: As with many animals, food availability varies seasonally, especially in areas subject to regular flooding or droughts. It has been my impression, knowing what I do about the areas in which savannahs live as well as learning about them in captivity, that they are gorge feeders. That is, gorge when food is available to build up energy stores to get them through periods of decreased food availability.

Balsai: Many species of monitors do this, and this is why I mentioned that examining how diet varies seasonally for various monitor species could be important. In addition, some species have periods of inactivity (essentially hibernation of sorts), so they may gorge in anticipation of such activity (or inactivity, if you will). Savannah monitors and white-throats (V. albigularis) are two such species where at least some populations may show such behavior.

Kaplan: Obesity in savannahs seems to be caused by the same behavior that causes much of the obesity in other captive animals: overfeeding by the keeper. This seems to be a particular problem when the animal in question acts like it is still hungry even though it has taken in sufficient amounts for its age, health and physical status. This appears to be what happens with savannahs in captivity - their gorge behavior is interpreted as actual hunger, and so the animal is fed based on this behavior, rather than overall physical appearance.

Balsai: I think it is important to make more keepers aware of this "phenomenon" in many monitor species. Another species that shows this gorge behavior is V. gouldii horni (the argus monitors appearing in many pet shops of late). I am considering how to work a discussion of this gorge behavior into another column, at present.

Here is the entire interview: http://www.anapsid.org/balsai.html They go on to talk about obesity and lack of exercise with monitors as well. According to Balsai, I was partially correct. Savs do engage in gorging behavior, but its only observed prior to periods of drought and famine, not necessarily a permanent occurence yearround.

Next is an excerpt from a chatweek with Daniel Bennet on kingsnake.com. Not really about gorging but since there's so much debate about the "uselessness of feeding inverts to savs...:

AskDaniel: what is the best diet for a captive savannah monitor

daniel_bennett: whole animals, no processed meat, in the wild they only really eat invertebrates, but a mixture of insects and mice seem to work fine
.in fact its probably the most specialised of the African monitor lizards as far as its diet is concerned

AskDaniel: Please comment on foods other then Rodents adult Sav. would benefit from having.

daniel_bennett: crickets
daniel_bennett: and they also like lots of crickets
daniel_bennett: and a few orthopterans
daniel_bennett: in the wild the babies eat crickets
daniel_bennett: and the adults eat huge millipedes
daniel_bennett: and all ages take scorpions and snails and slugs
daniel_bennett: and beetles
daniel_bennett: but for captivity it should be simple
daniel_bennett: because they need plenty of of food
daniel_bennett: so crickets are ideal
daniel_bennett: maybe roaches
daniel_bennett: of coures animals that are used to mice will just laugh at crickets
daniel_bennett: so they might need reminding
daniel_bennett: but crickets are very good for savannah monitors
daniel_bennett: not just the nutrition, also the thrill of the cahse
daniel_bennett: chase

Not about savs, but it does indicate other large varanids do this as well:

Water monitors will gorge themselves when given the opportunity, and become so bloated they are unable to offer much resistance to predators (Smith 1931).

Whole page:http://www.mampam.com/index.php?option=com_content&task=view&id=60&Itemid=41

More:

During periods of drought or cool weather, it becomes dormant. For this reason, its feeding pattern is that of feast and famine. During the typical eight month wet season of the Savannah, when food is most plentiful, the Monitor will consume an enormous amount of food which will create the fat reserves necessary to sustain life during the dry season. It is estimated that in a typical wet season day, Varanus exanthematicus can consume one tenth of its body weight.

http://www.honoluluzoo.org/savannah_monitor_lizard.htm

More on invertebrates in the diet by Daniel Bennet:
http://mampam.50megs.com/monitors/advice6.htm

Okay....so they apparently only gorge during the "feast" period, the times of plenty when prey is abundant. But here's the thing: most keepers keep their monitors in "feast" mode all year long [just to clarify, I'm not including Frank Retes, or "Varanios" in this generalization; far be it from me to question someone more experienced than myself.] Now I'm definitely a noob when to comes to breeding varanids, but in most cases, it may not be feasible to put captive monitors in a "drought" period and not feed them anything. So we got to regulate and balance the diet out.

Now there's plenty of sites that emphasize the risk of overfeeding and obesity. I could cite links all night long and take up an entire page of this thread if no one believes me on that issue. Regardless of whatever you're feeding them, savs can get obese very easily without exercise.

 

[davo]

I can hardly remember the original "discussion" topic this has been so longwinded.
Was it not to do with how bad mice are for feeding monitors? All I can see is that they do no harm as a staple diet when supplemented with others such as crickets.
That and the discovery that they gorge themselves before all the food goes/lean times. Well theres possibly only a few thousand examples of that in all species then.

 

[jason longboard]

an old freind of mine hade a large enclosure for a 4 foot monit that i cant remember what type but he fed it a fish as he did always along with rodents and he came out later to find it swallowed it whole,choked and croaked.he loved this thing.just thought it was interesting.i have not falowed your last thread and know this may be off topic,just thought ppl like to know things and learn from others mistakes,again this does not pertain to your real topic i think.

 

[Ophiuchus]

Well, thats kind of how it started. I don't think its bad to feed to varanids mice. I think its bad to feed them mice excessively and exclusively. As long as one supplements the diet with other things and doesn't feed them rodents every single day, I don't have a problem with it.

But what spawned this thread was that I had mentioned the behavior that some monitors have of gorging themselves. Someone in that thread essentially told me that this was baloney, and then accused me of stating that it was a "disease" which I never said that. Interestingly enough, the thread was closed before I could respond, so now, here I am, trying to back up my claims so people won't blatantly assume I'm full of it.

 

[jason longboard]

i didnt read that thread but you seem very involved and helpfull on the threads i am on with you so i can back you up on those and say thanks for helping keep this site interesting.i try hard to make sure ppl know i wont argue to much unless i have hands on with what the topic is but once i let some stuff realy get to me and acted like a kid.i dont know why your thred got closed but usualy they do if its starting to seem like a cat fight and not coming together for resolve.like you i have a life too and somehow get to make time to get on here now and then to hopefully make someone laugh or help them with something,or just to show them someone cares about their pet other than them.House is your avatar so i have to like you.

 

[Ophiuchus]

Yeah, I'll admit I get pretty hot-headed sometimes. Its one thing just to disagree with someone, but I gotta tell ya; I really get pissed when someone tells me I'm lying when I'm not. Like this monitor-gorging business...I know I'm an arrogant jerk sometimes (hence the avatar), but I don't lie and I don't make stuff up. I back up what I say when humanly possible. Now if someone looks at this thread, and still say the whole gorging thing is bull, then they can go take it up with Bennet and Balsai. If they want to go prove two reputable experts in the realm of varanids, then thats their battle, not mine. I delivered my end of the bargain, so to speak.

Like you, I usually don't comment on something unless I know a thing or two about it. Thats why you don't see me in the amphibians or turtle/tortoise threads too often.

 

[davo]

Well originally it was said they have gorging attitudes... as in all the time. And fair enough you pointed out that that is wrong and it was only under specific conditions.

Also your original post was how feeding a diet of mice might be a factor of agressive monitors, which is not the case, and also that it will lead to poor health if you feed the monitors more than 1 once a week or 2 weeks.
"Now I'm not going to tell anyone not to feed their savs rodents (although I never fed mine any and he turned out great). However, I do suggest feeding them rodents in much moderation, perhaps one once a week or even every other week."

I'm sorry but there is no reason that is true.
And of course feeding excessive amounts of mice or rodents leads to monitor obesity... because they are excessive to the amount of prey they should consume, not because of the food items themselves.
No one is arguing that there are lots of unhealthy obese monitors out there, with owners that are feeding too much and everyday, but to say the prey items are not good for them isn't true.

 

[Ophiuchus]

Well, about the gorging thing...I specifically mentioned it and Varanios specifically stated that it was untrue. I proved him wrong.

And in the other thread, I believe we established that the aggression is more of a matter of caging issues, and not simply diet...something I acknowledged. I still believe a sav can be raised with minimal rodent quantities in its diet; after all, I did it once, I can do it again.

But oh well...I don't have the space or the finances to house another sav just prove my theory right again. And its not like you guys believe me anyway. And you would just call me cruel.

 

[davo]

Again it's not the fact that it can be done... you could feed them 100% crickets if you wanted. It's the fact that you stated that rodents are detrimental to a monitors overall health, when there is no proof of this, and every other source points the other way. Rodents are a good food and in some cases important food source.

Don't take this personally btw, this is what it is - a discussion about Varanids.

 

[Ophiuchus]

It's the fact that you stated that rodents are detrimental to a monitors overall health

If fed in excess, they can be detrimental...even if the cage is the size of an average bedroom. Of course, at which point it reaches that state is still a grey area, I suppose. How much is too much? When the monitor finally gets his fill? 2 rats a week? 4 mice a week? a rat everyday? 4 mice every 2 days?

I suppose I could just to resort to the invincible argument that everyone makes that "if it works and my animal is alive, I'm doing okay."