Why are haggards typically not chosen for falconry?

In falconry, haggards refer to adult birds that have already gone through their first breeding season. The reason they are typically not chosen is that they often have already established their role in the ecosystem, particularly in breeding. Retaining haggards for breeding purposes helps maintain and enhance the population of raptors. If these birds are taken out for falconry, it could negatively impact the gene pool and overall wildlife management efforts.

The other options touch on various aspects associated with choosing a bird for falconry. While an aged bird may have different training needs or habits (as implied in the first option), and certain birds may have specific prey they hunt (as mentioned in the last choice), the overarching concern remains their role in breeding and ecological balance. Training difficulties could arise with haggards due to their established behaviors, but the primary reason for not selecting them is their value to breeding programs. Thus, the focus on their contribution to breeding is the most compelling reason for their limited use in falconry.