Beings that have not developed enough to fully understand rights do not have access to their full set of rights. This is why parents have jurisdiction over their children until they become independent. Organisms that do not have the lifetime potential to understand rights, however, do not deserve to be given rights, because to do so would jeopardize ours. You cannot reason with a leopard to not attack you if it's hungry. To give the leopard rights would be absurd because it will not respect yours.
Rights are a responsibility that the individual holds to the community and other holders of rights.
Animals that do not have the capacity to understand rights or responsibilities cannot be given rights or that would destroy the whole concept of rights altogether. The crucial reason why animals do not deserve rights is not because they cannot reciprocate them, but because the rights that we give them must be taken from ones that humans have. There is not an infinite pool of rights to be given. Rights are balanced between parties involved. To give rights to individuals who do not deserve rights means taking them away from people who deserve them.