You are absolutely correct. Less than 10% will make it under ideal conditions. However, from what I've read that's how some of the successful releases were made here in the USA. Pen birds from England were planted here and survived. Farming conditions have changed considerably over 200 years. Instead of wasting the money on put n take why not use it for research to find out why the birds are down across the country? Once we have science proving the cause/s we can better address the issue. Right now as far as I know, there are few if any experiments being conducted. Someone mentioned earlier that the DNR is concerned about bird flu in pats. How about pheasants? I don't know the answer, but planting birds to be shot is a political move, not a scientific one. It is a doomed program just like the last one.
Less than 1% will live 6 months.Average life of a wild pheasant is 1.5 to 3 years of age.
The game birds that were established years ago (pheasants,chukars,Hungarians) for example had the genetics and diversity and were wild.The new science is genomics,(genomes,genetics) for endangered species.
Today's pheasants are genetically devoid and have been breed for so long they have become domesticated.There survival would be equal to a farm chicken which have to be cared for,immunized,medicated.
The science seems to show that if a pen raised pheasant actually does survive to breed which we used to think is a plus actually is possibly not beneficial.This can actually enter the gene pool and have long term effects on wilds.
Once a population gets low restablishment of endangered species even with restored habitat has been a problem.Genomics seems to have the clues to why.Here is a article from USFWS.
Species of management concern often have small population sizes and are subject to threats such as loss and fragmentation of habitat, and disturbance. We conduct genetic and genomic studies to identify populations with low genetic diversity and small sizes, and populations that are isolated because natural dispersal and migration patterns are inhibited. These populations may be more vulnerable to local extinction without management action. Work focuses on animal and plant species in California and the desert southwest and spans seven ecoregions. Science objectives include describing metapopulation structure and function, estimating gene flow and dispersal rates, effective population size, and the number of breeders, and testing hypotheses on the impacts of fragmentation and disturbance on population structure and the maintenance of genetic diversity within populations. Another objective is often defining evolutionary relationships among cryptic species or lineages (phylogeography and systematics). These studies typically represent the first genetic surveys for these species, and significantly add to existing system knowledge. Results guide species management actions such as habitat restoration, translocations and re-establishment programs and developing long-term genetic monitoring plans.