Need Advice- Frog Necrophilia

[jaelen]

Help... not sure what on earth to do about this one!

I went out to check on things in the garden yesterday, and saw a large bloated frog lying belly-up on the floor of the pond. I got the net and gently fished it out, and discovered a smaller frog clasped to her back, (am presuming it's a 'her').

The smaller frog feebly kicked it's hind legs a few times but refused to let go- and I'm pretty sure the larger one is definitely dead- the eyes are open but milky and fogged-looking... quite bloated, too- and pale in colour.

I carefully returned them both to the pond, in the hopes that the smaller live one would let go, but nope- this morning, there they both still are.... with the big one still belly-up.

Should I fish them both out of the pond and just hope the live one attempts to return to the pond on his own? I know it's still pretty cool out, but that dead one is going to start to decay sooner or later, and contaminate the water,

and I don't fancy trying to separate them by hand....

(I'm in the process of recovering from a bad cold virus, and even little things still make me queasy- don't think sicking up in the pond would do it any good! )

This is the third dead one now- there's been one other since the one I posted about several weeks ago.

[Dogghound]

What you describe is a pair of frogs in amplexus, where the male (smaller frog) has either grabbed a dead female or grabbed a live female which has subsequently died whilst he was attached. Early arriving females are at an increased risk of complications when in amplexus as they are not always ready to spawn when they reach the pond, particularly if a cold spell starts up. The males usually grab the females quickly after they enter the pond, this embrace can last for weeks and occasionally months. The male can greatly increase the females energy needs and cause breathing complications. Females commonly drown in these cases or at least get injured, due to such a tight embrace.

Without seeing the frogs its quite hard to comment on what killed the others. Winterkill is one of the most common causes of common frog deaths during the winter, this is usually a byproduct of prolonged freezing of the ponds surface. This is a result of oxygen levels dropping to a critically low levels, this is usually due to decaying plant material using up oxygen and oxygen failing to break the pond frozen surface, similarly ponds which are heavily shaded or have a thick layer of snow on top can result in plants failing the photosynthesis resulting in a further lack of oxygen. These ponds often have high levels of hydrogen sulphide in the water.

So could your pond be shaded? lack aquatic vegetation? have too much decaying vegetation? too many dead leaves? fish? inputs of nitrates?

This winter will result in low amounts of winterkill due to the mild temperatures and lack of ice, however it is known for it to occur in ponds which have not froze, especially if other factors are involved.

Alternatively the same male or other males could have caused these deaths in the pond by clasping onto other frogs and going into prolonged amplexus. Females in particular are often quite weak going into the breeding period and are even weaker after it. The breeding season often results in a lot of deaths as it takes so much out of the frogs, and remember they do not feed until they have mated.

The final cause would be disease, but the way you describe the frogs as pale, bloated with milky eyes usually is suggestive of winter kill but not always. Any obvious damage to these frogs such as ulcers (these can be quite small and often form around the hind limbs) or irregular swelling of body parts (particularly the hind limbs)?

[Kayleigh]

I would fish them both out and the live one will crawl off hopefully but if there is a frost its best if they are not left in the open.

[jaelen]

Dogghound-

the pond was in a sorry and neglected state when we moved in last December- from a neighbour we learned it hadn't been cleaned out in about 15 to maybe even 20 years.

We decided to wait until all the tadpoles, (and there were hundreds of them!) grew into froglets and left- so the pond was completely dredged and cleaned late last August... frogs reappeared almost immediately, sometimes three or four at a time, and I saw them almost daily up until it was quite cold, (I remember there were several out there bonfire night, looking very concerned at the fireworks! )

I did put in some oxygenating plants once it was refilled, but those won't have had much time to establish themselves, although the watercress seems to be flourishing, (I thought the freeze last week killed it, but it's revived amazingly well!) The elodea densa is also still alive.

It does have small overhanging fruit trees, but I try and keep the leaves cleaned off of the surface- what did sink to the bottom I decided to let stay until spring, since I thought any frogs wintering there might appreciate the cover provided. In winter, it is in continuous shade due to the dividing fence and neighbour's house.

If I were to follow Elaine's advice and fish them out, do you both think it ok to do it tomorrow? I've just checked the weather, and even though it's not meant to be sunny, it's still supposed to be warmer, (10c) than it is on Monday.

Here's a photo of the pond, to give you some idea of how it's situated- this was taken not long after it was cleaned, so it's not this clear any more!

[Dogghound]

Originally Posted by jaelen

If I were to follow Elaine's advice and fish them out, do you both think it ok to do it tomorrow? I've just checked the weather, and even though it's not meant to be sunny, it's still supposed to be warmer, (10c) than it is on Monday.

Yes I would remove the dead frogs as they will only have a further negative impact on the pond. Since the male is active it might also be worth seperating him from the dead frog and putting him back into the pond. A word of warning the amplexus grip is very strong and he wont be in any rush to let go, so if you dont feel comportable seperating them or feel you may end up hurting him, I would probably just leave them in the pond.There is no point putting him outside of the pond as he will just head straight back in. I would avoid disturbing any other frogs within the pond as some of them may still be torpid and disturbance is best avoided when in this state.

[King Edward]

Are there areas around the edge of the pond where the frogs can rest supported while they breathe at the surface (e.g. on gently sloping sides, or on plants/stones/submerged wood etc. near the surface)? I often see frogs resting like this, at or just under the surface, especially where there are emergent or overhanging plants to provide cover.

I'd think such areas would be especially important for females in amplexus, which would be more easily tired out by having to force their way up for air, and would benefit from being able to rest safely near the surface.

How about if you were to lay some cut branches or something overhanging the pond edge (or trailing into the water), to give them something to hide under and rest on until you have more plant growth in/around the pond?

[jaelen]

Originally Posted by King Edward

Are there areas around the edge of the pond where the frogs can rest supported while they breathe at the surface (e.g. on gently sloping sides, or on plants/stones/submerged wood etc. near the surface)?

I've put a few things like that in for them... stones at one end, hanging pond baskets and a construction made from old clay tiles and bricks that forms both steps and hiding places, (called the Frog Hotel, )

They can use the pond baskets to get in and out- or sometimes they just sit in them... I took this photo back last September or October I think. (The baskets are more submerged now- the rain has topped it up to the brim.)

[Billabong Karen]

Very interesteing thread, though sorry it's a bit gruesome for you Jaelen. Keep us updated on your lovelorn male frog.

[jaelen]

Well, how embarrassing... I could see the female still on her back yesterday morning, so reluctantly decided to remove her... and him, if he was still there, too, (because of the leaves she was lying on, I couldn't be sure.)

So got the net and carefully lifted her out; seeing that the male was still clasped around her, and tipped them both out onto the ground- and was horrified to then see both of them feebly start kicking, and moving their legs sluggishly about!

I put them both back into the pond as quick as I could- the female was probably relieved to be able to finally turn over, but I daresay the male wasn't happy with me at ALL (and as to the defamation of his character- necrophilia, indeed! )

Still- I just so pleased they were both still alive, and I've learned my lesson... henceforth, I will leave the dead frogs in the pond alone.

[Kayleigh]

Ha ha, that's so funny..bless 'em!..

I had one last year clutching tightly to something that turned out to be a black dead fish..
It was a very alive dark green tench that lived to see another day in my neighbors fish pond.
Not to mention the Toad clutching the frog..

Roll on spring...