Why is stop and start codon signals necessary for protein synthesis ?

Start codons is necessary for the start of protein at accurate site on mRNA sequence, while stop codon is necessary for termination of protein synthesis. if any of them either start or stop codon attach at inappropriate place in mRNA sequence it will lead to abnormal protein synthesis.

The hawk receives 0.1% energy from the caterpillar although the caterpillar gets eaten by another bird smaller than the hawk first