Zealous frog fathers guard eggs against cannibals 

Zealous frog fathers guard eggs against cannibals 

Context

Bush frogs breeding in bamboo stems don’t mind pulling off an all-nighter on protection duty

What

Male white-spotted bush frogs zealously watch over their eggs for 37 days, leaving only once tiny froglets emerge

Why the protection?

If the adults lower their guard even for a day, other males ‘cannibalise’ the eggs, scientists say.

Breeding Pattern

The observations of the bush frogs’ parental care and novel records of cannibalism, published on December 14 in Behavioural Ecology and Sociobiology(a journal dedicated to animal behaviour), add details to a breeding pattern that scientists first recorded in 2014: that of the white-spotted bush frog Raorchesteschalazodes (rediscovered in 2011 after 125 years and found only in the Western Ghats’ Agastya Hills in Kerala and Tamil Nadu) breeding inside hollow bamboo stems.

How was it observed

Inserting an endoscope into these bamboo stems, herpetologist Seshadri K.S., who is with the National University of Singapore, observed the breeding behaviour of the critically endangered bush frogs in Tamil Nadu’s KalakkadMundanthurai Tiger Reserve for his recent work.

Loud alarm calls

The males both attended to the eggs by sitting on them [possibly to keep them hydrated], and physically guarded them by standing between the eggs and the entry hole, scaring away intruders by producing loud alarm calls and even lunging at themThe frogs deterred katydids (a kind of cricket) and even cockroaches this way.

First known instance of cannibalism in tree frogs

• However, when these protective fathers were removed from their egg clutches, Mr.Seshadri found that a majority (more than 70%) of the eggs perished: some were eaten by ants or infected by fungi.
• However, the main reason was that other male bush frogs entered the stem and ate unattended eggs.
• This is the first known instance of cannibalism among tree frogs of the Rhacophoridae family.

Why the cannibalism?

• This could be because eggs are a source of nutrition
• But it could be a territorial display which also frees up available nesting sites.
• Egg-laying sites within bamboo stems are highly prized because ideal cavities (which have to be cracked open by other animals) are few.