P1:Tortoises is declined.
-Illegal law is inefficient.
P2:原因1:low reproductive potential.
-breed only fifteen
-lay a few aggs.
-babies are vunerable
P3:原因2:predators:
-delicate shells
-dig their burrow
P4:措施:-limited habitat
-raven population increasing
-disease can be passes
P5:措施:rely on vegetation ,protect plants.
284---说明问题---解释----寻找进一步解决方案(和影响因素
生词:moisture水分 captive被俘虏的
The desert tortoise---as a threatened species in 1989----decline in number by 90% since 1980s
Illegal to harm them----insufficient, and further intervention is required
Recovery is slow<----desert tortoise low reproductive potential (female breed only after reaching full size at 15-20 years old, and only lay eggs when adequate forage is available----average produce only a few eggs annually---->young are neglected by adult and only 5% reach adulthood) ---hatchlings will slowly into protective armor over the next 5 years
Predators-->most death
--->Tortoise burrow into the earth, but larger predators may dig tortoise out
Additional measures must be taken
1. limited habitat must be protected
2. aggressive measures to control the birds are necessary
3. stop releasing captive tortoise (perish and pass disease
4. They rely heavily on moisture in the vegetation<------loss of native plants
(Although, they can dig precipitation basins when rain is impending)