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Re: [CALBIRDS] LIfe and Death at KMHRP.

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  • redhead457@aol.com
    The most likely cause would be a bacterial infection in warm water -- from a combination of overly heated water, bacteria from sewage, animal waste and
    Message 1 of 5 , Jul 7, 2002
      The most likely cause would be a bacterial infection in warm water -- from a
      combination of overly heated water, bacteria from sewage, animal waste and
      stagnated water. The water should be tested immediately when this kind of
      die off happens.

      Linda Corey
      Stockton, CA


      [Non-text portions of this message have been removed]
    • Bruce Deuel
      The Department of Fish and Game has been plagued for years by die-offs of domestic ducks at parks where people feed them. The usual cause is duck viral
      Message 2 of 5 , Jul 8, 2002
        The Department of Fish and Game has been plagued for years by die-offs
        of domestic ducks at parks where people feed them. The usual cause is
        duck viral enteritis. It is especially hard on muscovies. It doesn't
        often kill the wild ducks present, but does sometimes and that's been
        the concern - that the disease would get into the wild populations. I
        have never heard of it killing fish, though, so in this case it could be
        something else, or there could be multiple causes. If it does turn out
        to be DVE, there will probably be a public relations nightmare, since
        the only thing that stops the outbreak is to remove all the domestic
        ducks!

        Bruce Deuel
        Red Bluff

        >>> <mjbbirds@...> 07/06/02 11:12PM >>>
        Dear Calbirders,
        I am hoping that you might be able to answer some specific questions
        that
        might help us determine why we are having a continuing bird and fish
        die-off
        at Ken Malloy/ Harbor Regional Park in Harbor City/Wilmington, Los
        Angeles,
        CA.
        First I should note that the park is open, the birding is good and the
        kill
        has to date mostly affected feral and abundant scavenging species.
        There
        have been somewhat sensationalized reports on television and radio, but
        the
        local paper, The Daily Breeze, published a fairly accurate article on
        July 4.
        We are hoping to determine the cause of mortality before/in case it
        spreads
        to include sensitive species or takes any more of our more common
        regular
        species.
        To date, virtually all feral ducks (approximately 260 mallards,
        Muscovies and
        Pekings) have died, as have a large number of coots, most of the gulls
        that
        were feeding at the lake, and most of the larger (all non-native and
        formerly
        stocked) species of fish. Virtually unaffected are feral geese, rock
        doves,
        gadwalls (which are present with juveniles), large numbers of ruddy
        ducks,
        pied-billed grebes (with juveniles), Ardeids, and so on. Today, least
        terns
        were present feeding on Gambusia, swallows of 5 species were flying
        over the
        lake (all but the bank swallow were accompanied by juveniles) and there
        were
        numerous tricolored blackbirds in the Icterid/starling flocks.
        Aside from the rock doves and geese, the affected birds are the ones
        most
        often fed lakeside by park visitors. Huge volumes of bread are brought
        to
        the lake daily, and we believe that bakeries may be dumping their "day
        old"
        bread at the lake as well.
        My specific question is, is there any evidence that toxic molds or
        bacteria
        on bread could be responsible? Perhaps the fish are dying because
        they are
        eating the bread, too, or are scavenging poisoned birds who die on/in
        the
        water?
        We have narrowed the field somewhat, and if another possibility seems
        plausible please let me know.
        The lake is certainly a candidate for eutrophication and the consequent

        mortality, and precedents for this have certainly been set in the
        past.
        Botulism poisoning, chemical poisoning by a toxic substance, and viral
        or
        bacterial pathogens are other possibilities we are considering.
        However, several points argue against any one of these being the
        primary
        cause of mortality (although in combination, they could certainly be
        contributing factors)
        1. the kill has been selective, not affecting fish eaters, species that
        avoid
        humans or even the smaller fish (Gambusia).
        2. The County (LA), Fish and Game and USFWS have taken samples, with
        inconclusive results. However, limited dissolved oxygen and pH testing

        showed no problems. Also arguing against eutrophication is the fact
        that
        there have been no visible signs of an algae bloom, water clarity has
        not
        diminished substantially, there has been no noticeable odor, etc. We
        believe
        that the extensive Ludwigia mats growing along the shoreline do a
        fairly good
        job of removing dissolved nutrients from the water. Water level has
        dropped,
        and no water has been entering the lake for quite a while. With the
        nutrient
        load from the bread, potentially anaerobic conditions would seem to set
        the
        stage for mortality due to lack of dissolved oxygen and/or botulism.
        But it
        seems a eutrophic event would not be nearly as selective and would be
        much
        more evident.
        3. Necropsy results have not been returned to us, and we are not sure
        if and
        when we will get them, but we are told (on the basis of chemical
        tests??)
        that botulism is not involved. My initial suspicion was botulism,
        because a
        park garden supervisor described symptoms of dying birds that were
        consistent with the neurotoxic effects (inability to walk or fly,
        "rubber
        neck" posture, etc.)
        The County Hazmat guys immediately ruled out accidental or intentional
        toxic
        chemical loading of the Lake, on the basis of some of the preceding.
        Intentional poisoning of the bread cannot be ruled out, however.
        Bacterial or viral pathogens that crossed such taxonomic gaps (e.g.,
        ducks,
        coots, gulls and even fish) yet did not affect closely related species

        (gadwalls, ruddy ducks, terns) seem unlikely.
        In any case, any insights, preferably documented rather than anecdotal,
        would
        be appreciated.
        As an end note, I know that individuals in the humane community may be
        upset
        at me for saying this, but without the huge contingent of feral and
        scavenging species, the lake has a quiet and serene beauty that
        provides a
        long-absent sense of wildness there. It is nevertheless important
        that we
        determine the cause of mortality so as to determine how to cope with
        the
        regulatory agencies and public park users regarding park management
        methods,
        and of course, determine whether it will run its course before killing
        other
        species at the park.
        The park is open to the public, and if you desire, please visit on your
        own
        or come to my next public walk there (Sunday July 14, 8 AM, meet in the
        lot
        between Anaheim St. and Vermont) In addition to the surviving species

        mentioned above, there is at least one chat south of the dam and
        hopefully,
        our least Bell's vireos are still present and nesting. Our nesting
        least
        bitterns become more visible in July and August.
        Martin Byhower
        __ /\ __ Martin Byhower, Lomita, CA
        / ___\/ \/___\ Director, BIRDING SOUTHERN CALIFORNIA
        \| |/ Private guiding, & more
        /\ Email: mbinrbc@...
        ///\\\ WEBSITE: http://www.qi-whiz.com/birds


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      • Charles Bragg
        ... Anyone wanting to read about DVE can see our March 1994 newsletter at http://home.att.net/~cgbraggjr/v17n7.htm The duck symptoms are close to what
        Message 3 of 5 , Jul 8, 2002
          At 08:34 AM 7/8/2002 -0700, Bruce Deuel wrote:
          >The Department of Fish and Game has been plagued for years by die-offs
          >of domestic ducks at parks where people feed them. The usual cause is
          >duck viral enteritis.

          <snip>

          Anyone wanting to read about DVE can see our March 1994 newsletter at http://home.att.net/~cgbraggjr/v17n7.htm The duck symptoms are close to what is happening at Harbor Park, but the species dying and living are mystifying.

          The articles in the newsletter cover all sides of the enormous controversy over analysis and treatment in the Venice Canals in Spring 1993. It was nasty.
          Here is the clinical description of DVE:

          DUCK PLAGUE (DUCK VIRUS ENTERITIS)
          Cause: A herpes virus.
          Host: Only ducks, geese, and swans. There is variation in species susceptibility to this virus. For example, blue-winged teal are most susceptible, while pintails are least.
          Transmission: Direct contact with affected birds or contaminated surfaces, ingestion of food or water contaminated with infected feces or oral discharges, inhalation of viral particles and vertical transmission from female to forming egg.
          Clinical Signs/Field Signs: Rapid death in previously healthy appearing birds. Sick birds are seldom seen but may seek cover and have ruffled feathers, extreme thirst, loss of awareness, droopy head and wing, inability to fly, sensitivity to light, blood around the vent or bill, and prolapsed penis.
          Lesions: Bands or disk shaped areas of hemorrhagic or yellow/tan tissue distributed in or on the esophagus, intestinal wall and cloaca. Blood in the digestive tract. Small white spots on the liver and hemorrhages on the heart.


          -- Chuck


          ========
          Chuck Bragg, Pacific Palisades, CA
          Santa Monica Bay Audubon Society:
          http://smbas.cjb.net
          ========
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