AVIAN BOTULISM

Summer 2013

 I spent 5 weeks this summer assisting the refuge guys surveying Hanalei Valley.  Botulism among the birds is ugly business (see post last year) with the bacteria lying dormant in soil until a little understood combination of factors turns it on and birds die.  The response is understood; get the sick and dying birds out so it does not spread.  So, volunteers are recruited and I was assigned an area to survey twice a week.

            Because I carry a camera my route took three hours most days.  It was an opportunity to observe everything around me while I carefully scrutinized for downed birds.  Hanalei Valley is gorgeous and has a long agricultural history.  Uniquely, Kauai has the greatest populations of rare endemic birds, some of which hover on the turning point of extinction.  The waterbirds that co-exist with the culturally rich activity of taro farming are amazing: Hawaiian Stilts, Hawaiian Moorhens, Hawaiian Coots, the Nene or Hawaiian goose, and most rare, the Hawaiian or Koloa duck, all have a presence in the valley.

            On my first day out I found a sick juvenile moorhen (I thought it was dead), inert in the corner in mud.  When I lifted it out with rubber gloves to place it in a plastic bag it blinked and moved slightly.  Since botulism attacks the nervous system I thought the symptoms were evident of the condition.  It turned out to have been dying from some other cause – sad but thankfully it wasn’t the disease that spreads easily throughout the valley.  For the next five weeks I found several dead animals, mostly very young, all casualties of predation, not the disease.  In the meantime, I was more than rewarded with the antics of the healthy population of feathered critters.

From the lookout you can see the section east of the river and my surveys covered the back half.  I started at different times but the afternoon was too hot; I really preferred early morning.  Any time could quickly change from sunny to moody to outright downpour; lots of personality out there. 

East of Hanalei River from overlook

Some days were sunny, some moody - rain jacket necessary gear 

Roads dissect some of the plots, others have wide dikes, but a few have extremely narrow dikes.

The majority of botulism victims were in one area on the other side of the river and it was decided to transect the whole area.  I volunteered to help survey the “hot spot” one day in addition to my sector surveys.  We lined up and walked across one field at a time so no sick or dying bird will be missed.  Easy enough in fallow or flooded fields without taro, but crossing a farmed plot requires careful checking while not damaging the plants.  Luckily we found no cases and the problem seemed to be ebbing.           

Transect survey of hotspot

            By checking my area twice a week we were confident that the botulism had not reached that section of the valley.  I got to observe wildlife behavior and to capture some of the beauty I experienced.

Stilts

Wetland field not planted in taro

Favorite nesting area for stilts who get very noisy and even dive bomb anyone who approaches

 Daily business of eating is interspersed with sentinel watching and warning of danger

 Other daily business is controlling who lands and eats in any given plot

Hawaiian Stilt eggs 

This nest site was not good - there was not a trace of these beautiful eggs 5 days later,

probably a rat family had some good grinds

This is one of the characters that was trying to convince me to go in a different direction

Coots

 Hawaiian Coot

Harder to get a picture of than I would have thought.  I've watched them many times as they chase moorhens out of ponds they have claimed for themselves - not in the least shy.

 This pair may have had a nest in the plants - they didn't venture far from cover

On patrol

Note chicken on dike behind him - amazingly not many chickens in field area, too wet

Nene

Nene or Hawaiian goose

 Fun to watch these guys fly in formation over the valley and then land,  

sometimes right in front of me

 As grazers they are on land more than water - nice to see them swim, too

A snow goose has somehow gotten itself to Kauai, probably on a rogue wind.

The Nene have welcomed it surprisingly; 

last year they shunned a cackling goose that closely resembled them in size and color.

Moorhens

Hawaiian Moorhen or Gallinule

This loose group has mixed ages, adults, juveniles and little guys 

Three moorhen chicks just hatched/hatching with little semi-bald heads 

I peeked into this nest and by the next day they were swimming

I watched one family for the entire five weeks, fun to see their progression

Moorhen parents with four chicks - still slightly bald here

Always one adventurous one slower to join the round up

 Koloa Ducks

 Koloa Duck

endemic and rare even though we get to see them in Hanalei Valley

Early morning they were often seen on the dikes - they actually nest further up the valley

 Easily flushed, 

many times they would take off from fields where they had been totally camouflaged

Quite content in this tiny open area, it was great they weren't disturbed by my walking by

These are the critters most in danger from the avian botulsim because the tipping point 

for their continued existence is teetering.

Other critters

 Snail

Not everything living in the ponds is a bird.  

Someone at some point in history brought these in to eat but no one eats them

 This distinctive patch of bubble gum on the taro is actually the snail eggs

This tiny damsel fly is about an inch long

unlike the dragonfly - the wings fold back when it lands

 Two indigenous Night Herons (adult and juvenile) and the introduced cattle egret

            Both of these common birds can pose a threat to small birds but the night heron eats more fish in the pond and along the river. The egrets are opportunists that eat many things - bugs, centipedes, lizards and have also learned to follow large mowing equipment. 

Night Heron 

Egrets sporting russet stripes indicating mating colors

note snail eggs on taro stems

            The National Wildlife Refuge system has experimented in Hanalei by protecting not only the wetland habitat for endangered birds but by protecting the ancient culture in taro farming.

The taro itself is fascinating and Hanalei grows most of the crop for Hawaii.  Cultivating it is hard, continuous work.  Sam Andrade works for one of the farmers and his schedule was the same as mine so I crossed his path often.  There are many varieties and most of Hanalei’s taro is sent to Oahu for processing into poi – which then serves all of the islands.

Taro

 Sam working the front half of the plots east of the river 

 I worked the back half for my surveys

 The corm (in buckets) is the part used for making poi

The shoot coming off is trimmed of leaves and re-planted for the next crop

the leaves are sometimes used for food, but these are not kept

Three buckets is about 80 lbs, a unit of measure for sale

 Bins of shoots ready to be planted - this field is partially planted now

A newly planted field

The Fitzgerald and Quick homes in background

The leaves will grow quickly and get tall and thick, 

then they die back and the energy goes into the corm (not a root)

  l loved this field, the leaves have turned to the sun and appear corrugated

I also saw over the five weeks, koloa duck chicks, coot chicks and moorhen chicks

I

 Many varieties, this green leaf type was holding morning dew like jewels

Different day, different type, still jewel like in the early morning

One of the biggest treats of this work was discovering the taro flower

the smell is very subtle and slightly sweet - a whif on a breeze is like nothing else

            My last day on survey was very nostalgic as I was leaving for the mainland in a few days and would miss my stomping grounds.  Happily the botulism threat was subsiding and we will see what I can help with when I return.