Jewish tradition teaches us to care for our Earth -- to preserve that which God has created. The rabbis developed the principle of Bal Tashchit (do not destroy), which forbids needless destruction. Rather, we are encouraged "l'vadah ul'shamrah," to till and to tend, to become the Earth's stewards. In Genesis after the great flood (9:9), God declares that the Covenant established is one between God and all the creatures on the planet. These principles, among many others, highlight the Jewish concern toward creation and our mandate to preserve it, for our own sake and for the sake of the Covenant.
Specific concern about the destruction of a species was expressed centuries ago, as Nachmanides interpreted the following passage:
Scripture forbids a destructive act that will cause the extinction of a species even though it has permitted the ritual slaughtering of that species. And someone who kills mother and children in one day, or takes them while they are free to fly away, is considered as if having destroyed the species.