In this flock of 20,000 flamingos, a father and his chick must find each other — before it's too late

In a sea of bright pink feathers, soft trills emerge. A male flamingo rubs its beak against the grey-tufted head of its newly hatched offspring. But the clock is ticking, and the chick and its father must listen closely and learn each other's voices quickly. 

Within 10 days of a flamingo chick hatching, its parents will fly off to find food, while the chick stays behind with the other juveniles under the supervision of a few adults. 

When the parents return, babies and parents must find each other among their flock. Flamingo chicks must recognize the voices of their parents, and the parents must recognize their chick's. Fortunately, the call of each flamingo is unique, like a vocal fingerprint.

In this clip from Finding a Voice, the third episode of Secret World of Sound, a series from The Nature of Things, we witness the incredible ability of parents and chicks to identify each other's sounds amongst the din of chirps and squawks. 

Colonies of wild flamingos can number in the tens of thousands to over one million. In this flock off Mexico's Yucatan Peninsula, 20,000 breeding flamingos are all trying to hear the cries of their baby in a cacophony that rivals a stadium crowd. 

Following the parents' departure, the chicks have congregated together. After all, it's safer to gather as a group when danger is lurking nearby.

A crocodile is stalking the colony. Winding its way through the mounds of mud nests, the predator hopes to separate one of the young flamingos from its peers. Launching itself forward, the crocodile's jaws just miss the mark — this time. But the commotion has created dangerous confusion within the flock, leaving one youngster out on its own.

Its desperate calls are drowned out by others. Even though the chick and its father have learned to recognize each other's voices, distinguishing individual calls in this deafening chorus is difficult. The chick is hungry and weak. It reaches out to nearby adults, hoping for a morsel of food. 

Sadly, this is how many baby flamingos meet their death. But fortunately for this plucky chick and its father, this is not the end. Finally, after picking up on each other's call, father and chick spot each other and race through the muddy water to meet. 

Watch the video above for the full story.