Why has the U. S. Fish and Wildlife Service said that no more captive-bred wolves will be used to bolster the population of red wolves in North Carolina?

This is to stop their killings as they are already an endangered specie.

Explanation:

the decision to either end the program or modify it has been expected. The US fish and wildlife service has it will continue to manage the program and it would lift restrictions on killing stray wolves that stray from their territory. There is a fear of the specie vanishing in less than a decade and currently landowners need permission before they can kill any of these animals that wander into their properties. Even though these landowners have referred to these animals a nuisance on their properties, the wildlife service in a report has said it would continue to recognize the species.

The US Fish and Wildlife Service stopped releasing captive-bred wolves into the wild because the landowners were killing an already endangered species for game

Explanation:

In an effort to save the already dwindled numbers of red wolves from going extinct, the US Fish and Wildlife service started capturing the red wolves from the wild and breeding them in a secure facility for a captive breeding program. They were then selectively introduced back to the wild to roam.

However the land owners in North Carolina started hunting them for game and many red wolves died from gun shot wounds. And out of about 42 red wolves that were bred and released, only about 11 are known to still exist.

Hence the US Fish and Wildlife service rescinded its decision and stopped releasing captive bred wolves into the wild