On a June night in 2006, amidst the rain-drenched evergreen trees of Kathalekan swamp, a scene never before witnessed unfolded before Dr KV Gururaja. The researcher watched keenly as a palm-sized acrobat performed – with her mate on her back – a headstand in a little stream along the roots of a wild nutmeg tree.
While in this position, she laid eggs on a twig of her choice. Their goal achieved, the mates descended, parted ways, and left their progeny at the hands of fate. But moments later:
“The male returned, dug some mud with his forelimbs, and plastered the eggs for some 20 minutes. Here was a supposedly-primitive creature indulging in intricate craftsmanship. And that’s how it got its name,” says Gururaja, about the Kumbara Night Frog.
‘Kumbara’, you see, is Kannada for potter.
Over the course of eight monsoons, the batrachologist (amphibian expert) with Gubbi Labs, a private research collective, returned to this biodiversity hotspot near Karnataka’s Jog Falls as part of a four-member team. Kathalekan (‘dark forest’ in Kannada), is considered a sacred grove by local tribes. And it is as hallowed for Gururaja, who not only discovered the Kumbara Night Frog, but also that this species endemic to the Western Ghats has a courtship ritual like none other.
“It starts when the female approaches a male’s territory. She inspects the area and ‘identifies’ a twig on which she’ll lay eggs. Once done, she and the male observe another ritual seen in no other frogs,” explains Gururaja. “They stand on their hind legs, face one another and feel each other out with their forelimbs. Only then do they get into amplexus (mating position).”
In 2014, 14 new dancing frog species were identified in the Western Ghats. One of these, the Kottigehara Dancing Frog, finds special mention by Gururaja.
“It indulges in foot-flagging, where males in close proximity extend their hind legs and expand their webbing in a display of bravado. If this doesn’t work, they kick one another,” he says.
“The ‘winner’ determined by a female is carried on her back to shallow water, where they mate. She then makes a cavity in the stream bed and ‘dances’ over her eggs, covering them with pebbles so they don’t go adrift.”
Research is still ongoing on these frogs, but Gururaja notes that even species we take for granted aren’t bereft of wonderment. Such as the male Indian bullfrog, which goes from brown to magnificent yellow in the mating season.
“That’s a visual cue to help males identify each another. This way, they conserve energy by not approaching another male. They also have group chorus calls, where 50-60 males croak simultaneously. It’s then harder for females to identify who’s who, which is what they intend,” he laughs. “Thereon, the victor is whoever gets to her first.”
Bitten by the love bug
Animal orchestras aren’t limited to frogs. Between stridulating grasshoppers and chirping crickets, it’s the tymbal (abdominal membrane)-beating cicada that bags the honour of loudest insect.
“Even in a booming chorus of male cicadas, females can identify prospective mates based on whose call is louder, deeper, more frequent, or for a longer duration. Calling is an energetic, intensive activity,” says Krushnamegh Kunte, a naturalist with the National Center for Biological Sciences (NCBS) of the Tata Institute of Fundamental Research. “Larger or more energetically-endowed cicadas produce deeper sounds and are more attractive to females.” (Think the cicada equivalent of the human female preference for deeper baritones).
Insect and arachnid courtship is assumed to be primeval or cannibalistic, what with dramatic clips on male-consuming mantises and spiders etched in collective memory. But some bugs prove otherwise. Take mosquitoes, whose buzz is annoying to everyone but them.
“Mosquitoes produce sound at varied frequencies at different stages of courtship. In many species, courting males and females modulate flight tones to converge toward a common frequency. If their frequencies are too different, they converge on a shared harmonic instead,” says Dr Geetha Bali, president of the Ethological Society of India, an organisation that studies animal behaviour.
Come-hithers in the six-legged world run the gamut from communal sounds to bug versions of Morse code. Fireflies, for instance, flash their lights in specific signals to initiate courtship. “Details within flash signals are different among firefly species, which helps a female identify her own kind. Non-luminescent fireflies use pheromones to signal to one another,” she adds.
Pheromones, not money, make the world go round. Nearly every animal on the planet, including humans, produces these chemical substances that affect the behaviour – both sexual or non-sexual – of its species. If a tiger moth could speak, it would probably tell us to never underestimate the power of a good perfume.
“Male tiger moths in the UK have been known to find their way to a female over distances of 5km. In some Lepidopteran (butterfly and moth) species, a female can attract males as far as 10km away,” says Peter Smetacek, who heads the Butterfly Research Centre in Bhimtal, Uttarakhand.
Gift-giving, meanwhile, is not exclusive to humans. As Dr Bali points out, “snails, squid, crickets, ladybirds, bedbugs, butterflies, fireflies, and humans all deliver gifts to prospective mates in attempts to improve mating success.” Why, some cheeky male balloon flies even present empty gifts – encased in silk bubbles – to females and trick them into mating for virtually nothing.
“Other than visual cues, which are significant in Lepidopteran courtship (hence the brightly-coloured wings) some species collect nutrients from wet patches of soil or animal scat and package it along with sperm as a capsule. This is presented to the female as a spermatophore,” explains Krushnamegh Kunte. “Mate choice can hinge on how big or nutritious a spermatophore is, since females can produce more eggs with bigger, better spermatophores.”
Wind beneath their wings
If you watched Sir David Attenborough’s path breaking Life series, you’d know that perhaps no animal order outclasses birds for their smorgasbord of dramatic wooing techniques. Think superb lyrebirds, bowerbirds, peafowl, flamingos, birds of paradise, red-capped manakins… the list is exhaustive.
“Even house sparrow, common crow, and common pigeon males flirt, show off, and go loopy at the onset of mating season,” says naturalist and photographer Sunjoy Monga. “And there’s the baya weaver, which acquires a vivid yellow and choco-brown hue by May and hysterically toils on its nest for weeks to impress females.”
While the male Indian roller – with its distinct Prussian blue, purplish, and sky-blue primary feathers – performs aerial gymnastics to reel in the ladies, the male skylark, points out Monga, is so melodious, it inspired a generation of English Romantic poets.
“But if I were to pick an Indian bird for its spectacular courtship display, it’d be the Sarus Crane,” he says. “Mostly monogamous, these birds with loud, trumpeting calls duet, prance, leap, and even yank off grass and other vegetation in the air in a frenzied, lovesick display.”
The Sarus Crane is one of few animals that metaphorically puts a ring on it. But even albatrosses, wolves, and gibbons, leave alone humans, will wander if given an opportunity.
Bittu Sahgal, one of India’s most eminent naturalists, cites the male elephant as an exemplar of mammalian courtship – not because it is monogamous (it isn’t), but because of its reserve of patience.
“When females are in estrous, they exude pheromones to indicate willingness. Males can only approach them then. In some cases, they have courted love interests for up to three years before being ‘greenlit’,” Sahgal says. “Males also share food sources and use their trunks to caress, nudge, and reassure females during courtship.”
The gharial, like its imposing crocodilian cousins, may not feature on amorous animal listicles. But the distinctive snout of this critically-endangered reptile plays a pivotal role in its courtship, says Nikhil Whitaker, curator at the Madras Crocodile Bank and Centre for Herpetology.
“The ghara (snout) in mature males is thought to double as a signalling device. Air forced through them may signal to females and (male) competition that a male is nearby,” he explains. “Courtship in other crocodilians consists of (low-frequency) bellowing and ‘jaw slaps’ by males. Their chin musk glands exude a pheromone that informs females in the nearby vicinity of his presence.”
The gular (throat) flap of the male common garden lizard – found in and around Chennai – develops into a cream white to pale yellow colour. During breeding season, it begins courtship with dewlap extensions. When a female responds, the male starts encircling her and performs foreleg push-ups! –Nikhil Whitaker
Of all zoological examples, however, there are none as enigmatic as courtship in the high seas.
“Species like the blue whale and right whale have been known to ‘date’ or escort non-receptive females weeks before mating season,” says Ketki Jog, a marine biologist and member of Marine Mammal Conservation of India. “Male humpback whales ‘sing’ in season, but exactly how their songs function is not known. One study showed that males sing to attract females when there are few or no other males around.”
As for the bad rep male dolphins often get for ‘gangraping’ a female: Jog stresses that such behaviour is not a given, especially in solitary cetaceans.
Sadly, very little is known about cetacean (aquatic mammal) mating. “It takes years to collect data that is substantial for relevant conclusions. A lot remains unexplained, but that’s the beauty of it,” she feels.
Nearly every species has a courtship practice that has been fine-tuned by humans, says Dr KV Gururaja. Whether dancing, territorial guarding, offering gifts, or zoological versions of breakfast in bed, it’s a case of been there, done that.
“The first amphibian came some 360 million years ago. Humans have been around for two million years. If you join the dots, you will see that most behaviours we think to be exclusive were shaped by these tiny, beautiful creatures,” he concludes. “Think about it.”
- The New Mexico whiptail lizard is a female-only species that reproduces asexually. But that doesn’t stop them from mounting and simulating sex with one another.
- French angelfish are monogamous. They live, hunt, and even defend their territories against other neighbouring pairs.
- In some termite species, mates have been known to stick with each other for up to 20 years.