[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: ora speeds

>> A couple things: 
>> 1) Auffenberg's observations agree with those of another study: 
>> Lederer, G. 1942. Der Drachenwaren (_Varanus komodoensis Ouwens). Zool. 
>> Gart. (Leipzig)(n.s.) 14(5/6): 227-244 
>> If I remember HP David Marjanovic correctly, these measurements were 
>> taken from animals at a zoo. 
>No idea, all I know is that Zoologischer Garten Leipzig is a zoo. And you 
>did not remember that I told you it's -waran, not -waren. :-) 


My bad there. These observations might be off of wild individuals after all. 
The researchers might just work for the zoo. I'll see if I can ILL myself a 
copy and maybe send you a copy as well, if you're up to it.

>> Yet, they still represent an independent account of  
>> these animals moving at these speeds. If one doesn't mind translating  
>> German (better if one already knows German), then one might find a data  
>> set there.  
>Well, if you can send the paper in some form, then I could try. Not that I 
>knew when, though. :-( 
>> 2) Oras, and varanids in general, DO NOT possess low aerobic abilities.  
>> They are highly aerobic lizards [...] 
>Yes, varanids cheat, they have an extra complicated lung, as detailed in a 
>chapter in the Ostrom Symposium volume, plus the famous gular pump. Allows 
>them to be pretty tachyaerobic without being tachymetabolic, apparently. 
>> Later work (Hopkins et al, 1995/Frappell et al, 2002) showed that,  
>> not only do monitors show gas exchange abilities on par with mammals,  
>> but their aerobic 
>> limitations are exactly the same as the ones found in mammals.  
>Wow. Really? 


Yeah, full refs will be coming in an upcoming posts

>> Furthermore, studies on other monitors (Bennett 1972) show reliance on  
>> anaerobiosis only at very high temperatures. 
>Why does temperature matter? 


I'm not entirely sure. Bennett's study just mentioned that exhaustion of 
non-glycolytic, anaerobic, pathways was only occuring in the high (38-40 
degrees C) temperatures, while lower temps showed very little reliance on 
anaerobiosis. I don't think it involved metabolism increasing beyond scope 
either, especially since Bennett mentions that metabolic rate became 
independent of body temp at the activity range. He does mention that oxygen 
saturation of certain physiological systems at higher body temps might be doing 
it (though he was mostly referring to the iguanid). At any rate, it is 


"I am impressed by the fact that we know less about many modern [reptile] types 
than we do of many fossil groups." 
- Alfred S. Romer  Osteology of the Reptiles