Empathy
Human against self
The most important theme in the tale was empathy, or lack of it. Empathy is defined as the ability to share and relate to another's feelings. In the story, the hoopoe attempted to make the king feel empathy through the riddles it asked him, but didn't expect him to actually be lenient, as shown when "The hoopoe bowed its head... and it waited in silence to hear the harsh punishment of the king."
However, the hoopoe also showed great wisdom in its choice of riddles, as each inspired a new kind of empathy or understanding in the king. The first riddle reminded the king of a belief they both shared (that all creatures should be free), leaving him to conclude that what he was doing was enslaving his fellow beings. The second riddle told him of an emotion they both shared (sadness) and reminded him that he was causing sadness in the soon to be beak-less birds. The final riddle taught him of the importance of a birds beak - "something delicate enough to put food in a babies mouth yet strong enough to bore holes in the hardest wood."
Everyone has the ability to have empathy, however it is a survival trait still ingrained in many people to instinctively put themselves or someone they care about above other people or species. The king in the story was in example of this. His power and eagerness to use it to appease his wife blinded him, and it took the hoopoe's riddles to remind him to have empathy for the birds as well.
Survival of the Fittest
Human against human
The king, in a way, is a representative of people who believe themselves superior to other people based on differences of appearance or personality. He allowed himself to be inconsiderate of others in pursuit of his wife's request, to temporarily believe he was better then them, Many people are similarly inconsiderate of others when they're focused on themselves or people like them alone, and can believe they are superior to others. However, we are not genetically created to act a certain way towards others are personality only has a little basis in our genes (such as how certain genetic disorders cause behavioral issues like aggressiveness or shyness). However, the main force shaping personality is our environment. It is the influence of society and the people around us that encourage certain traits within us and suppress others.
Because of this, it would be incorrect to view our genes as racist. Racism is a social construct and racist people have learned their behaviors from society, not from their genes. Genes are what they are - and since the diversity of humans is part of why we are so successful as a species, genes cannot be biased towards one particular variety of humans.
Power In Nature
Human against nature
The king and his mistakes could not only represent how humans sometimes view other humans, but also how we as a race view nature and the rest of the world around us. Traditionally, our role in the environment has been one of imbalance and excess. We have always been a species that strives for expansion and innovation, something which is likely the reason we have such an advanced civilization today. However, what most believe sets us apart as a species from the rest of nature is our ability to understand and not by restricted by our place in nature.
Unfortunately, as with the king, the power and perspective we have has, in a way, blinded us to the impacts we have made on the environment and our fellow inhabitants of it. Like how the king intended to remove an essential part of an entire species, humankind have caused 322 species extinctions in the past 500 years. We have treated the environment we live in horribly in our quest for advancement, and only recently have we begun to realize the impacts of what we've done.
It is our job, as the species that created the damage, to use the influence of our power to have empathy and fix what we have damaged. We need to speak up for the species we have not protected like we have our own and stop using harmful environmental practices. There will be no helpful hoopoe for us, reminding us to have empathy whenever we act selfishly. It is up to us to recognize when we aren't having and empathy and up to us to do something about it.