As humans take up ever more blank space and urbanise the untamed wild , the fauna that call these places home have a hard choice to make : move on to someplace else or conform to their new surroundings .
Staying put can be peculiarly tricky for animals that rely on sound to communicate with each other and steer clean of risk . Brick walls and human - madenoisecan change the acoustic landscape and drown out their union calls or disguise the sounds of approaching piranha . In Taiwan , gutsy little frogs are make the most of thing . Instead of permit human infrastructure get in their way , they ’re place it to habituate .
In suburban and rural arena of Taiwan , it ’s jolly easy to get hold open concrete waste pipe alongside roads and foot paths . Their bottoms are often coat in clay and covered in plant litter . This hit them attractive to small-scale animals as travelways , mating sites , and even hold out space . But the concrete paries can make conversation difficult by causing sounds to carom and reverberate . Animals listen for each other ’s calls “ will hear not just the direct sound waving , but also reflected waves arriving at different times , ” say a squad of researchers at National Taiwan University in Taipei .
But there ’s an top side to that , depending on who ’s doing the talking . “ In contrast , some signal ( e.g. , those with narrow relative frequency bandwidth ) can potentially benefit from echo , ” the researchers say in anew paper . “ The muse sound wave can make the signaling higher in amplitude and longer . ” Mientien tree frog seem to have figured this out , and the male person are often found perched in the drains letting out their gamy pitched mating calls to attract females .
When the team compared the shout of the frogs in the drains with those that sat next to them on the undercoat , they find out that the drain claim were louder and longer . The echo due to the concrete did n’t demean the call . Instead , the researchers say , the drainpipe play like “ miniature urban canon ” and really amplified the narrow - bandwidth calls .
While the research worker did n’t look at how female frog responded to the calls in this study , they suspect that the waste pipe - aid call are just what they want to find out . Other research has show that distaff frogs and other amphibians are more attracted to long , loud calls .
Hanging out in drains is n’t all fun and toad toying , though . It also presents some challenge . The first is that the shape of the drainpipe and the shelter they cater appeal snakes that can cover in the goo and ambush unwary prey . Many of the toad frog seem to get around this by rest on arm lean against the drain walls so they ’ve got a good view of their surroundings .
Another problem is that the steep concrete rampart can be difficult to maneuver . Mientien tree diagram Gaul coupling ask the female carrying the male person away from his vocation rod to a damp place to reproduce , and the females might have a hard time hauling the male person out of the drainage . Whether that leads a slew of female to vacate males in the drainage without mating or even ignore drain caller in the first place remains to be seen . For now , at least , the waste pipe - as - megaphone looks like a clever workaround for tree frogs looking for love .
