Friday, August 29, 2008

Bowdoin NWR

Marbled Godwit

After too many days of too much work and not enough time for myself, I was finally able to spend a few hours at Bowdoin National Wildlife Refuge just east of Malta, MT. I dropped Benton off at school and had until I needed to pick him up from school to get away.
I have been visiting this refuge for over 3o years. I used to visit a bit more regularly when I was younger. Dad and I would drive the hour long trip at least a few times a year. We often visited the refuge alone but I do remember also spending time there with P.D. Skaar and one time I remember meeting Helen Cruickshank there too.

Yesterday was a wonderful day to be out. The seemingly ever-present prairie winds had diminished for the day and the temperature was in the relatively mild mid-80's range not the 100 plus we had experienced earlier in the week. Despite the nice weather viewing conditions were not the best as most of the places I was finding birds to look at were located south of the access roads so I was looking into the sun much of the time.

Red-necked Phalarope

Red-necked and Wilson Phalaropes were common throughout the refuge.

Stilt Sandpipers

White-faced Ibis

White-faced Ibis

White-faced Ibis



Olive-sided Flycatcher

Olive-sided Flycatchers are rare migrants from boreal forests to the north. I found two catching insects near the refuge headquarters.

Baird's Sandpiper

Lesser Yellowlegs

Least Sandpiper

This last photo is a dead Red-necked Phalarope. This was one of the shorebird casualties I found. There appears to be an ongoing outbreak of avian botulism at the refuge and I found quite a few dead and dying waterfowl along the south end of the refuge. Green-winged and Blue-winged Teal seemed to be the most common duck species affected but I found at least one representative of all the duck species commonly found on the refuge this time of year dead on the beach during the casual quarter mile survey I conducted. There were a few shorebird carcasses scattered along the beach as well including the phalarope above and Least Sandpiper, Bairds Sandpiper, and a few other unidentified shorebird carcasses. Vultures are apparently immune to the effects of avian botulism and one was found gorging itself along the shoreline.

Avian botulism is a common disease infecting migratory waterfowl and shorebirds throughout the west and is can also be knows as Western Duck Disease or Alkali Sickness. The bacteria Clostridim botulinum produces a toxin that is lethal to birds and induce death through paralysis, hence the other common name - limberneck. These bacteria are commonly present in these environment but outbreaks of bird deaths generally occur when temperatures are high in August and September. Outbreaks are propagated when flies lay their eggs on infected birds. The resulting maggots concentrate the botulism toxins and when other birds feed on the maggots they get infected, causing an exponential growth in bird deaths. Outbreaks generally last until cold weather breaks the chain of infection, but the extent of the outbreak can be lessened by removing the carcasses of the dead birds. I spent a few weeks in the late 1980's at Bowdoin doing just that - picking up waterfowl carcasses during a botulism outbreak. I suspect that budget cuts at the USFWS have limited their ability to mobilize enough personnel to deal with these problems and hopefully cooler weather will interrupt this deadly cycle before it grows too much larger.

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