Great question and for me, it points up one of the major confusions evidenced by the typical conservationist assertion that somehow, nature as we observe it in the recent centuries is in some type of 'balance', that is, before human intercession interrupts this 'natural' ecological normalcy. Species have come and gone in their multi-thousands upon thousands since life began. And so when I look out in my yard and see squirrels and chipmunks and robins and blue jays and crows and raccoons am I observing an ecological balance of some sort? Sorry for the sour humor!
But, seriously this question also attempts to bring into question another important issue; why are humans viewed as 'outside' of the natural system? For the zealous conservationist nearly everything we do is wrong. Having lived in Africa for 7 years and working for the Government of Botswana in Sothern Africa which boasts some of the most abundant 'wild' animal populations in the world, I experienced first hand the negative side of these NGOs that come into Africa and purport to understand a situation that they have never inhabited better than the people who live there. They go so far as to claim to be 'educating' the indigenous people on how to co-exist with animals that they have existed beside for millennium.
To push for balancing the needs of humans and animals and attempting to reach some sort of consensus is not anti-conservation. It is pro common sense with a touch of reality inserted into this emotionally charged issue.
To ensure that this answer incorporates a philosophical component, let me draw your attention to Spinoza's take on the proper interaction between humanity and the other lifeforms on the planet. This excerpt is from; Ethics Part Four- On Human Bondage- Appendix- VIII.
Whatsoever in nature we deem to be evil, or to be capable of injuring our faculty for existing and enjoying the rational life, we may endeavour to remove in whatever way seems safest to us; on the other hand, whatsoever we deem to be good or useful for preserving our being, and enabling us to enjoy the rational life, we may appropriate to our use and employ as we think best. Everyone without exception may, by sovereign right of nature, do whatsoever he thinks will advance his own interest.
This does not paint Spinoza as an opponent of animal rights. It simply lays out human choice coupled with a responsibility to manage wisely the resources on this planet. Sapere Aude, CS