Crows

[avenus]

..

[DanaJ]

I'd go for E on this one. There's just this sort of contradiction between numbers:
- the crows hunt even 130 km away from the roost
- when they move, the new roost will be at around 8 km from the old one.

Well, if the area had been depleted of food, then they'd have to move really, really far away, like more than 130 km from the original site. If they only move 8 km, then the area clearly has food left.

[avenus]

anyone else?

[Gopi]

anyone else?

E

Crows range is 100 to 130 kms, where as the change in roosting site is only 8kms, which means they will be still hunting in the same area, implying that depletion of food resources can't be a reason for shifting their roost.

[rainmaker]

Another vote for E.

[pandeyvineet24]

One more for E

[sk8ternite]

Another for E

[avenus]

OA E

[joseph32]

I think E is the best in this case.