Ornithocoprophily, A Bacterial Surprise, and Hungry Bunnies

16 Jun

Silvilagus palustris



After serial thwarts the last couple Fridays, John and George finally hit the muddy road today, mostly to think big— to shoot broad-perspective video of a marsh in the Kiplinger Nature Preserve for a project evolving under John’s  video genius.    (We’ll return to that in due course.)  Thinking big shifts the focus from wildflowers to the forest.

In a Florida marsh, an obvious fact from a distance is that our feathered friends prefer certain trees for roosting and more.    And if birds occupy an individual tree or clump much of the time,  guano showers below.    Fertilizer!  On Florida’s otherwise awful, nutrient-poor, sandy soil.  That’s gotta matter!

To go to the extreme case, consider “tree islands” with rookeries.   Biologist Paul Wetzel and collaborators in 2005 reviewed the relationship between rookeries and Florida tree islands, with points to ponder.   Although bird manure is not the only source of phosphorus enrichment in a “tree island,”  it can account for 20 times that from other sources, and 3000 times that from atmospheric fallout.  Such super-fertilization can generate “luxuriant” growth persisting up to 50 years thereafter, although the overall effects on species composition need attention.  In smaller venues with lower levels of deposition the floristic effects need study.  What I really want to know if the main broadleaf tree of the Everglades and a beloved roosting tree,  Pond-Apple, which is prominent in Kiplinger,  practices ornithocoprophily (love for bird dung).

tree island

What bird dung does.  (From Wetzel et al.  Front. Ecol. Enviro. 2005.)


Tree fertilization technicians at work:  PECK HERE

While still up in those well fed trees, look at one of the commonest pants there, Ball-Moss.    Not really a moss, this species is Tillandsia recurvata, an epiphytic Bromeliad and relative of similar Spanish-Moss.

Tillandsia recurvata 2

Ball-Moss in a tree, by John Bradford

To see Ball-Moss go peek up any oak tree, or even a telephone wire.   This little airplant thrives up high clinging to twigs where soil nutrients are not.   The species captures rainwater under beautiful microscopic leaf scales.  All good, but is that enough for “fertilizer”?

Spanish moss (Tillandsia usneoides) 4

Scale from Spanish-Moss, close relative of Ball-Moss. (Courtesy of Dr. Robert Wise, UW Oshkosh)

Back in 1994 ecologists M.E. Puente and Y. Bashan didn’t think so, and uncovered a surprise:  nitrogen-fixing bacteria haunting the tissues of Ball-Moss.  Nitrogen fixation is the process of converting inert nitrogen gas from the air into ammonium a plant can use.    This is most famously the domain of legumes with their own bacteria, but more and more non-legumes with nitrogen-fixing powers are turning up.   The bacterium in the Ball-Moss is Pseudomonas stutzeri, which would be nothing but anther boring Latin name except for two things:

Thing 1. The same bacterium has surfaced as a nitrogen fixer in a grass.

Thing 2. The same germ is a minor human pathogen. CLICK FOR DETAILS

Oh no, does that mean handling Ball-Moss exposes a person to potentially deadly bacteria?    Technically, yes.  In practice, I have no idea.  But in any case it underscores the little hobgoblins lurking in the weeds around us.

The bacteria feed the Ball-Moss, and the Ball-Moss helps this rascal with dietary fiber. ONE FINAL CLICK




Posted by on June 16, 2017 in Uncategorized


3 responses to “Ornithocoprophily, A Bacterial Surprise, and Hungry Bunnies

  1. theshrubqueen

    June 17, 2017 at 8:58 am

    Cool, a great read. it amazes me the bird borne plants in my garden, mostly native Firebush.

    • George Rogers

      June 17, 2017 at 8:54 pm

      Yes, firebush sure gets around…glad it is so nice to have around!

  2. FTLjeff

    October 6, 2017 at 11:50 pm

    My Fort Lauderdale yard is overrun with live oak and laurel oak seedlings…. in every bed, stray pots, even hanging baskets. It’s those nasty little blue dinosaur descendants that some call “blue jays”.

    I’ve caught ’em in the act. Well, that is when they’re not involved in the daily cacophony of name-calling and territory disputes that usually occupies their attention!


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