Pond Boss Forums INTRO Questions & Observations Bird leg fish transport

Kerry, welcome to pond boss, this is a fun topic cause there are so many theories on fish migration.
Interesting story, and probably happens often.
I personally think otters transport fish eggs in their wet fur as they travel streams and ponds.

Neat story, Kerry.

I like to think the bird-transport theory is possible, but maybe I'm just a dreamer.

The tornado transport certainly makes sense.

Kerry, where in VA are you located?

This may very well have been mentioned in this topic, but I would think muskrats could carry fish eggs between BOW's. I know the one that lives near our pond will carry Duckweed from the wetlands into our pond. I would imagine fish eggs could do the same...

I recently pumped out a new pond that was partly dug last summer, and it has a levee around it. Although no fish were stocked, there were minnows, bull heads, and 2 or 3 types of sunfish in that little pond. I won't speculate on how they got in there, but just say that nature finds a way.

This reported just this year. This report suggests that there has never been a study about the transport of fish eggs by water birds.

https://www.sciencedaily.com/releases/2018/02/180219103258.htm

The report also claims that fish egg dispersal is a commonly held opinion of researchers stating that :

"For their study, the Basel researchers also reviewed online forums and surveyed around 40 experts from research, private institutions, and enviromental NGOs. Their aim was to determine the prevalence of the theory of fish dispersal by water birds both inside and outside the research community. The majority of experts that took part in the survey found the theory so plausible that they deemed the mystery to have been solved. However, none of them could draw on any empirical evidence."

The hypothesis is certainly not well tested nor well examined employing science.

A couple of fairly recent links where researchers discuss the hypothesis:

https://www.researchgate.net/post/Does_a...o_pond_by_birds

https://www.researchgate.net/post/Is_the...ody_to_an_other

Evidently the first reference missed this paper?

http://faunaofindia.nic.in/PDFVolumes/records/107/01/0019-0031.pdf

If you read through the researcher's forum, you will find other references where research has attempted to invalidate the waterbird transport of fish eggs hypothesis. The research doesn't provide evidence of transport but rather tests whether evidence may contradict the plausibility of hypothesis. Research found that the eggs of some species of fish are resistant to dessication while another found that the eggs of some species of fish can be ingested by ducks and remain viable after being deposited in the faeces.

The summary from your link:

"Summary:
How do fish end up in isolated bodies of water when they can't swim there themselves? For centuries, researchers have assumed that water birds transfer fish eggs into these waters -- however, a systematic literature review by researchers at the University of Basel has shown that there is no evidence of this to date."

jpsdad, thanks for the links! I have been reading through the discussion by the various scientists and researchers around the world. It was remarkable to read about a couple things. One dutch researcher had done an experiment with ducks and fish eggs, including actually force feeding one group viable eggs and mixing eggs with food for the other, and found live/viable eggs in the duck feces! Hmmmm...
Another discussion I thought was remarkable I'll directly quote: "...story from Wikipedia about the Leucaspius delineatus, the Sunbleak, which as a telling german name..."The common German name Moderlieschen. Literally meaning "the little motherless one", this ultimately refers to the fact that the sticky eggs of the moderlieschen can withstand exposure to air for a remarkably long time. Deposited on water plants, they sometimes stick to the feet of ducks and similar birds and are carried by these to ephemeral ponds. Large numbers of young moderlieschens are thus sometimes encountered when such ponds dry up, and with no adult fish being present this gave rise to the belief that they were "motherless".

So, while not proving the theory, it does provide increased plausibility. Perhaps some of the eggs or gravid members of our North American pond species are also able to tolerate, in some minute quantity, dispersal in this way? And if even a few eggs can survive a trip through a bird's GI tract, then long distance transfer becomes much more feasible.

to be fair minded please do not forget they said this :

"We propose research directions for how to close this gap of knowledge and suggest that future empirical studies on passive fish egg dispersal may be inspired by existing work on passive dispersal in aquatic invertebrates. "

you are most welcome!

OK, I give up. I too am a true believer... This discussion and the one shut down by moderators is an example for all to contemplate.

I would think fish egg dispersal by birds would normally fail when transferred to waters where fish already exist. Survival of fry is generally very low in waters where fish are already present. But in BOWs with no fish, it only requires that a pair survive to reproduce. In most cases, it requires a year for fry to mature and reproduce in significant quantity so as to inhibit the introduction of new species by small quantity of fertilized eggs. So there might be a time window of opportunity where multiple species could be introduced to a newly built BOW where small numbers of viable eggs are deposited by birds.

Folks reading this should look up the term "confirmation bias".

So the question is how can experiments be arranged to test the hypothesis? Is it really like winning the lottery? Or perhaps it is natural process we have yet to really apply science to? Consider a BOW which is deliberately constructed to prevent interconnection with other sources of water. Consider the BOW is fenced to prevent human introductions of fish. Construct the BOW so that its proximity to other BOWs with fish would facilitate birds in transporting viable fertile eggs. Then observe what happens.

I would think that a zoo aviary would be a good place to set up two garden ponds, one with fish and the other without, turn some herons loose or king fishers and see if the transfer takes place. Video surveillance the ponds and wait to see. Sounds cool at any rate.

People are free to believe what they want - proof , no-proof or some proof. Truth is in many cases we really don't know.

What people here are not allowed to do is break the rules. See link below. Thanks for your understanding.

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92424#Post92424

RAH, looking back I think they should have shut it down. Look, I thought your references to bigfoot, elvis, and comments about two different kinds of people were offensive and an abuse. I also thought you misrepresented the "facts" that the issue is well evaluated by science and has been dismissed. Even so, I wish I had found better more influential way to address your comments. For my part the matter is addressed as far as I am concerned. We can only hope that funding might be available to actually conduct some science. Whatever the outcome of bona fide research, I am eager to understand the findings.

We can certainly agree and welcome more research. Best Regards, rod

If I see "my" heron drop a fish while flying away, I will attempt to retrieve said fish and determine its viability.

Thank you guys. There is never a reason to make a post personal.

Tomorrow's data may change everything. My apologies if my posts offended anyone. Beer awaits anyone wanting a debate on my dock.

Glad that�s over, no likey that kind of stuff.we want the family to get along

Agreed.

I've really enjoyed the experiences that are shared in this and other threads.

OK, I can't keep quite anymore! I KNOW for a fact that part of the reason Big Bird was created was to transfer the eggs of Aligator gar so as to help them from becoming extint. If Gar king would'nt have discovered girls and still frequented this site, he would surely verify my correctness.
Rod, how much beer?

Surely more than is good for a body to drink:)