I went to Hanalei this morning to see about some birds. This was official business, green-lighted as essential, because I was checking on the well-being of wildlife at Hanalei National Wildlife Refuge. More than 900 acres, and I may have been the only person out there. But there were plenty of birds.
Hanalei National Wildlife Refuge makes up less than one percent of the island but provides wetland and riverine habitat for 25 to 50 percent of Kauai’s endangered waterbird populations, and today, it was sunny and clear. So clear, the mountains looked like cardboard cutouts.
Unknown to many, the wetlands of Hanalei are home to five endangered waterbirds. All five are endemic to Hawaii, found here and nowhere else in the world. One species, in particular, could easily be called the County of Kauai bird, because it is the only extant native bird I can think of found only in the County of Kauai.
It’s also the species I was most concerned about today.
I’m talking about the Koloa Maoli, also known as the Hawaiian duck, once common throughout the Islands. One threat to the recovery of Koloa Maoli is hybrdization—with the non-native domestic mallard.
A few Koloa-Mallard hybrids can be found on other Hawaiian Islands, but the County of Kauai is known as the home of the last remaining genetically-pure population.
On Kauai, the biggest threat to Koloa Maoli is avian botulism.
Basically, botulism is food poisoning. Technically, avian botulism type C is a naturally occurring soil bacterium, Clostridium botulinum, which produces a powerful neurotoxin during warm, wet, and stagnant conditions—just the kind that can occur year-round in Hawaii. Since 2011, more than 1,300 waterbirds have been killed or sickened by the disease at the Hanalei refuge, with over 90% of the mortalities among five federally endangered species. Koloa Maoli are the most susceptible to botulism, because they are dabblers. They slurp up insects in mud.
When most people think of Hanalei valley, they think of taro. Approximately 180 acres of the refuge are farmed for taro in patches that from a viewpoint above look as geometric as a quilt.
I walked the circumference of a couple dozen taro patches today, and I’m happy to say I didn’t find a single dead or sick Koloa Maoli. But I saw plenty of healthy birds. It was sunny. It was clear. It was a lovely walk in the valley.
We’re up to 499 COVID-19 cases in Hawaii and 21 on Kauai.