Until recently, the harbour town of Oamaru on New Zealand's South Island had a bit of a penguin problem: the birds were blocking roads and causing daily traffic delays.

The trouble started when the penguins began traversing the same busy stretch of road every day and night as they travelled out to sea in the mornings and returned to their underground burrows at dusk. The town's officials responded by trying to reroute the birds to less obstructive and less dangerous paths – unfortunately, the little waddlers proved "very habitual" in their ways, according to marine biologist Dr Philippa Agnew.

So, faced with a continuing bird-based impasse, the town changed tack: a 25-metre-long (82ft) penguin tunnel was built under the road instead.

Despite their rather dramatic disruption to the local flow of traffic, the little or "little blue" penguins (Eudyptula minor) are aptly named: they stand just over 25 centimetres (about ten inches) tall and weigh only one kilogram (2.2 pounds) on average. Less diminutive were the curious human fans who flocked after them, causing just as much disruption to traffic as the penguins themselves, according to local mayor Gary Kircher.

"It's not a safe situation," he told local media earlier this year. "Primarily my concerns are around safety, both of the visitors and the welfare of the penguins."

A "penguins crossing" sign in Oamaru. Image: Wikimedia Commons

The new tunnel is the first wildlife underpass in New Zealand, and the month-long construction presented its own share of technical challenges. Existing waterways and power lines had to be moved out of the way so that well-worn penguin paths would not be interrupted. Despite the hassle, the project received plenty of support from the local community, with several businesses donating both materials and time to the effort.

Though new to New Zealand, dedicated wildlife crossings have proved their worth for species all across the globe. Railroad tracks in Kobe, Japan received special tunnels to help usher its resident turtles across the tracks without risk to either turtles or trains in 2015, for example. Canada constructed both overpasses and underpasses in Banff National Park in 1996 for some of its larger animals. Meanwhile, Washington in the United States is currently building an overpass over the very busy Interstate-90 highway in an effort to not only protect animals and drivers from collision, but also to help species expand their range and genetic diversity, especially as climate change forces animals to relocate from their traditional territories.

New Zealand's blue penguins are not currently considered endangered, but populations are in decline, so helping penguins and people coexist is crucial for conservation. And Oamaru's avian residents seem to have taken the new route in their stride. "With a little light at the end of the tunnel to guide the way, the little blues just waddle on through!" says the Oamaru & Waitaki District team.


Top header image: Scott Henderson, Flickr