# Pumilio and UVB in the wild



## Dendrobait (May 29, 2005)

PLOS ONE: Ultraviolet Radiation Influences Perch Selection by a Neotropical Poison-Dart Frog

Can't open this to see what levels of UVB we are talking of here.


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## froggorf (Nov 22, 2008)

PloS ONE is an open access journal, anyone can download the PDF for free or you can just scroll down on your link and see the full text w/ figures


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## Dendrobait (May 29, 2005)

Huh-odd. Yes the graphs do show just fine! 

In my understanding UVB has to be the only source of Vit D3 for wild frogs, correct? Yet these frogs go out of their way to avoid what are very low UV levels.


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## nish07 (Mar 16, 2008)

Oddly, in my viv where there is a thin strip of UV-B bulb (does produce UV-A too), the male is vocalizing from an area away from it but the females are off and on jumping into it for a while instead of other areas of the viv at a fairly high point meaning more UV. It represents an area that is higher intensity, higher up and only about a 5 inch wide strip of a 20 inch deep vivarium. 

When you are referring to calling perches you're referring to areas where a male wants to lead a female to lay eggs. A male would likely call a female to an area where there is little UV because the female knows UV will damage her eggs. It's hard to say if this is a specific situation that occurs surrounding courtship (offspring) only or not.

-Nish


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## Briank (Oct 14, 2013)

Funny I read the article last night then find It here. What I got from it was it doesn't madder what level perch the male calls from because If it is up high they seek more cover to avoid uvb or high levels of it. what was more interesting is that they do not see uva but have receptors in the eye that are aware of its presents and use them to avoid the uvb rays. As for vitamin D the low levels must be enough or they get it from a food source. So it seems to me you don't need uva for them to be happy they don't really see it but it did mention they do see colors.


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## nish07 (Mar 16, 2008)

UVB is what converts D to D3. UVA doesn't but the paper says they can sense the higher levels of UVA and therefor stay away from it while perch calling.

The frogs can choose to be where UV gets to them or not. if you can see the sky then you are getting full UV which is quite high compared to the levels in this paper. If a frog ever goes into an area where there is full sky they are getting a ton of UV. They are likely not calling from those locations and UV is known to be harmful to eggs so they probably don't lay eggs in it.

-Nish


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## Dendrobait (May 29, 2005)

nish07: I don't think calling perches and laying sites are not related in this case. Assuming calling is territorial and as well as for attracting males you would expect them to be calling from sites where they are visible. Actual clutches of eggs are probably laid somewhere else (in leaf litter). Indeed...this would be somewhere with low UV. Since you supply UV-do you get clutches of eggs laid out in the open? I doubt this sort of behavior occurs in the wild-but in captivity people often find pumilio eggs laid in very conspicuous spots.

That is interesting about your females "basking" under the UV. Some simple preference studies with these guys would be interesting.


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## nish07 (Mar 16, 2008)

Generally it was my understanding that the male would call from an area and the female would come to him if she was ready to lay eggs and whatever other reasons (maybe similar colors etc.) From there the male leads the female to the laying site but I don't know that it's necessarily very far from the perch. The female picks the site by choosing whether to lay eggs or not wherever the male leads her.

The males will probably sit and call to both let other males know they're there and to attract females but it's to attract females. They also probably don't want to sit in the sun and get a sunburn like we don't either. The eggs are definitely laid in areas out of UV as UV is very harmful to eggs.

-Nish


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## chamfriend (Dec 8, 2011)

Excuse me if me english is not that good but I am from Germany, but there is at least paper that does cite the UVB Radiation Levels in the natural Habitat and in vitro (for pumilio and auratus):

http://people.oregonstate.edu/~blaustea/pdfs/HanBiotropica2007.pdf

Tihs one is publically avialable, interesting read

Best regards

Siegfried


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## nish07 (Mar 16, 2008)

That's true, hard to say. In direct sunlight, I'm sure the UV-B is somewhere in the 200 uw/cm^2 range. Where they are sitting most of the time it is a lot less but there is some. It may be that their skin does not block much of it... but eggs are probably nearly always laid outside of UV.

That paper stated ambient UV-B was 5-15 uw/cm^2 so wherever they got that it was definitely not direct sunlight. The calling sites were lower in UV (especially for pumilio) but not completely outside of it. Eggs would probably be laid further outside of UV.

I think I am going to lower my UV exposure a bit but I won't remove it. I don't want to say how much but I'll continue to use it and calcium clay with eggfeeders.

-Nish


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## nish07 (Mar 16, 2008)

I am going to reduce the UV-B levels to approximately the range of pumilio calling sites in my egg feeders (where my solarmeter goes from 1-0 uw/cm^2) at the halfway height of my viv in a small strip of the viv somewhere in the center making up about 20 percent of the total area that UV-B hits at all. At halfway up the viv it will go from 0-1 uw/cm^2 and higher than that will get higher in that small area if they choose to go there. I may also turn that light on for only half of the day (6 hours.)

Ground level and most of the sides and top of the viv will have virtually none. They can either choose to be in none, be in a tiny amount or be in a decent amount (around 5-12 uw/cm^2 as that paper says.) Only about 5% of the total viv space will have that much and by far most of the viv will have less than 1 uw/cm2 or none. With the way my vivs are, this shouldn't be hard. It requires using fine mesh screen which I already do but I have to swap out my bulb for a different one (already did that.) Still using Arcadias. I will test it with my meter when the lights come on in an hour or so.

-Nish


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## Ed (Sep 19, 2004)

Dendrobait said:


> In my understanding UVB has to be the only source of Vit D3 for wild frogs, correct?


Correct. Frogs cannot use plant derived vitamin D (D2). 




Dendrobait said:


> Yet these frogs go out of their way to avoid what are very low UV levels.


Or an alternate view is not that the frogs go out of their way to avoid what are low levels but that the frogs behaviorally control their exposure to UVB. Behavioral control of exposure to UVB is nothing new in herps and it's been discussed on the forum before now.. 

As for the distinction between "low" and high, keep in mind that this is a comparison that doesn't take into account the ability the convert provitamin D3 to D3. It has been demonstrated in other taxa, that species even within a genus can have wide variations in their need for exposure to UVB. Species that are adapted to high levels of sunlight are not only are able to tolerate a greater level of exposure but require a higher intensity of UVB to be able to convert provitamin D3 to D3. 

People should also keep in mind that vitamin D3 and its metabolites actually function more like a hormone than a typical vitamin. What has been established in multiple taxa is that species (including species that are traditionally considered to not need UVB exposure and can get all they need from their diet like snakes) will if provided the ability to behaviorally regulate circulating levels of D3 and it's metabolites will have levels much higher than what can be achieved through simple oral supplementation. 

The key is to simply provide the frogs with shaded perches from which they can call and let them modulate their own behavior appropriately. The risk to the eggs is minimal at best as the frogs if provided with appropriate sites will deposit the eggs in shaded locations. 

The ability to regulate their own circulating levels of D3 should be considered important for froglets as this is one of the areas where there is the greatest risk of deficiency for species that are too small to ingest dusted fruit flies. 

The differences in reproductive success in calling perches is moot in captive enclosures unless you are allowing for competition for the sites and mate choice. If you are only housing a single male, then there isn't any reason to worry about it. 

Some comments 

Ed


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## Ed (Sep 19, 2004)

Dendrobait said:


> .this would be somewhere with low UV. Since you supply UV-do you get clutches of eggs laid out in the open? I doubt this sort of behavior occurs in the wild-but in captivity people often find pumilio eggs laid in very conspicuous spots.


I've never had pumilio eggs deposited out in the open. They have always been deposited in the leaf litter, or in the film canisters that are tilted on their side usually again buried in the leaf litter. 



Dendrobait said:


> That is interesting about your females "basking" under the UV. Some simple preference studies with these guys would be interesting .


In my 90 gallon cube, I've seen the frogs basking up closer to the top of the tank on multiple occasions. 

Some comments 

Ed


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