Press-Enterprise: A breeze stirs the silence at Joshua Tree National Park as a red-tailed hawk takes flight from the spiky arm of one of the namesake plants in search of breakfast. It’s a scene that national parks protector Mike Cipra has witnessed many times. Still, he can’t contain his enthusiasm on this early morning outing, despite the gloomy topic he’s discussing with a visitor — the probable extinction of the Joshua tree in the park that bears its name. The ancient plants are dying in the …