The Urban Pantheist (urbpan) wrote,
The Urban Pantheist
urbpan

Blue Rabbit Urine

At my work, there is a recurring report from people tracking animals in the snow; a bizarre and lurid claim of blue rabbit urine. After six winters there, I have finally witnessed this first hand. Before seeing the blue stain on the snow myself, I was frankly skeptical, and assumed that people were seeing something else, and mistaking it for blue rabbit urine.

A quick search turns up one article on the phenomenon--posted by an "urban field ecologist," no less--from the previous winter. You can read it here: http://nuthatch.typepad.com/ba/2005/12/blue_smurf_pee_.html Another reference to this, with anecdotal experimental information is here: http://www.ont-woodlot-assoc.org/sw_nonfibre_redskies.html

The gist of it, is this: Our native rabbits (the eastern cottontail) have been browsing on an alien shrub (European buckthorn). The buckthorn contains a chemical that passes out with the urine, which comes out yellowish to brownish, but after exposure to sunlight, turns a lovely blue color. This effect is visible, of course, because the urine in question is suspended in snow. You would think that the cottontails are eating the berries of the buckthorn, because they are purplish, but according to the second reference above, the effect occurs after the rabbits eat other parts of the plant. Buckthorn holds its leaves long after most native deciduous plants, and in winter cottontails subsist largely on bark and twigs. The second reference also emphasizes that buckthorn is not a favored browse plant of North American herbivores, and that they have to be driven to feed on it out of desperation. I'm not sure about that; my workplace has enough Norway maple saplings to sustain a cottontail factory farm.

So, without further ado (okay, one doo) here is some blue rabbit urine:

Tags: blue rabbit urine, buckthorn, eastern cottontail, photos, snow, tracking
Subscribe

  • Weird happenings on a elm tree in a behind the scenes part of the zoo

    I was called up to see a tree up in a non-public part of the zoo, which (the thought was) might have a hornet's nest in it. A hornet's nest in a…

  • (no subject)

    I stood with another naturalist (actually a bona fide scientist who I admire and feel honored to hang out with sometimes) waiting for a third to…

  • 280 days of Urbpandemonium #227

    Looking like a wasp is an adaptation assumed by many different species of flies. Looking like a really huge wasp is more rare, but this Mydas fly…

  • Post a new comment

    Error

    Anonymous comments are disabled in this journal

    default userpic

    Your reply will be screened

    Your IP address will be recorded 

  • 20 comments

  • Weird happenings on a elm tree in a behind the scenes part of the zoo

    I was called up to see a tree up in a non-public part of the zoo, which (the thought was) might have a hornet's nest in it. A hornet's nest in a…

  • (no subject)

    I stood with another naturalist (actually a bona fide scientist who I admire and feel honored to hang out with sometimes) waiting for a third to…

  • 280 days of Urbpandemonium #227

    Looking like a wasp is an adaptation assumed by many different species of flies. Looking like a really huge wasp is more rare, but this Mydas fly…