One factor which is not to be underestimated is that modern agriculture practices has destroyed wild game all over Europe.
Large fields (>200 Acres), the destruction of hedges, fungicide application, pesticide, mechanized harvest etc has played havoc on partridges, hares, etc.
The population collapsed from the 1970s on.
What's good for yield is not good for birds.
In essence, this has annihilated the traditional hunting market.
Best regards,
WC-