This is a passover-themed question:
How long would it take a pound of gefilte fish to disintegrate? This is assuming that it’s left out, at the current time, on a street corner, and that it is not touched, and no foreign substances (other than pavement and the occaisional bit of cigarette smoke or exhaust fumes) are introduced.
What, Gefilte fish? Fishloaf? I’m thinking not that long, the flys get to it, lays some eggs, maggots, probably a cat would get to it first.
I remember a web site where a guy put out a pound of hamburger to see how long it would last and after the third day an animal ate it.
SWAG, 7 days it’s pretty much gone, 10 days it’s just a whitish stain.
This site has the life cycle of a fly, eggs to maggots in just 2 days!
Well, I can tell you how long it takes my husband’s aunt’s gefilte fish to disintegrate when it’s in my stomach: almost immediately. Thank Og for Imodium. 
It would depend greatly on climate and omnivora. I’d say if you are in a temperate climate, 48 hours or less. Cooler climes and beginning of spring, maybe twice that.
Of course, by the guidelines of your OP (unrealistic), maybe a week or longer. Realistically, seagulls or pigeons would finish it off in a couple hours…a day at most.
Gefilte fish in the rain?
Walrus and matzoh?
You trying to come up with new contemporary versions of the Four Questions?
No. Actually, Four Questions is a misnomer. There’s really only one question, with a four-part answer.
Can I still get partial credit?
As for the OP, you have to clarify it. Does “foreign substances” include rain water, bacteria and larvae? “Not touched” implies no predation. That pretty much leaves wind erosion, and evaporation, neither of which are rapid processes. Although the tensile strength and resistance to wear of a gefilte fish are pretty low.
I think given the many variables, this question should probably be solved by a “Body Farm” sort of experiment. Maybe you could apply for a grant.
I taking only gefilte fish into consideration is too narrow; for even if we knew the answer to your question, any duration would fail to convey a deeper meaning without other standards with which to compare.
I propose, in the interest of science, I propose the “How fast does nature nosh? challenge”, where various staples of your nearest kosher deli are subjected to environmental exposure, and relative maintainance of integrity recorded over time.
Imagine the expansion of human knowledge when we know not only the half-life of gefilte, in, say, tropical, temperate, and polar climes, but also, potato and meat knish, gehakte leber, cholent, knaidlach, latkes, sundry blintzes, etc. One needn’t stretch their imagination to appreciate the utility of such food durability data. Even more fascinating would be a broader comparison of the rates of degredation of kosher vs. trayf fare. Needless to say, if some intrinsic difference could be found, the scientific and theological implications would be staggering.
I think my friend’s Aunt Doris still has a kugel from 1964.
I believe you are referring to The StinkyMeat Project on thespark.com