Friday, January 13, 2012

Urushiol - Sap of the Poison Ivy

I’ve told people to roll in Poison Ivy. To be fair, I’ve only asked people who insist they can roll in it but never develop a rash from it. So far no one has taken me up on my challenge.
Flowing through the vascular tissue of Poison Ivy (Toxicodendron radicans) and its relatives are liquid resins called urushiols that are contained in the sap. If exposed to skin, these oils can cause rashes varying in severity depending on the person. Generally speaking, only primate species are allergic. That includes us humans. I’ve never seen a monkey with a poison ivy rash nor have I seen one rolling in it. So far no monkey has taken me up on my challenge.
Deer browse on it. Turkeys, grouse and other ground grazers feed on the fruit to no ill effect. In fact, the seeds come out the other end with sufficient natural fertilizer, a bonus for the ivy.
Top left: Poison Ivy covering a hickory in Ipswich, MA
Top right: Poison Ivy reaches for the sky through the top of a Cabbage Palm
Bottom left: The glossy, dark green, lobed variety in ht Everglades

Bottom right: Jungle Pete collapses in the Poison Ivy after a 6 hour hike in the swamp

Identifying Poison Ivy is so tough for some, they wouldn’t know it if they had rolled in it. It can grow as ground cover, a small shrub or a climbing vine. In the swamps of the Everglades I’ve seenPoison Ivy winding 60 feet up the trunk of a cypress. Leaves can be dull to glossy, light to dark green and rounded to lobed based on location and time of year. Each leaf has three leaflets, but occasionally they do fall off and in the winter the leaves will turn color and fall off completely, even in Florida. Urushiol still flows through the plant at this time so beware.
There are some people that insist they are allergic if they just look at Poison Ivy. Were they looking at the plant as they held it? Some say they have never gotten it and others say they have developed or lost immunity to the oils. All of these are possible. But if you’ve developed immunity don’t tempt fate. Or do. Go roll in it. I think you’d be a complete sap.

Thursday, January 5, 2012

Baby New Year – The Gray Squirrel

Half of the Gray Squirrels (Sciurus carolinensis) alive today will not survive to 2013. This does not ease my mind regarding the predicament I find myself in on the day when a small, slightly-furred and sightless creature was found on a boardwalk deep in the heart of the Everglades. What to do?The lifespan of a Gray Squirrel averages 11 to 12 months which means half of them can live longer and some as long as ten years of age in the wild. It also means that from birth through adolescence there are plenty of hardships that lead to their demise. Poor nut crops and cone production can lead to insufficient food supply, and diseases combine as the two greatest causes of Gray Squirrel mortality. Predators including hawks, bobcats, raccoons and the tree climbing snakes also reduce the population size.
In the cypress forests of the Western Everglades, Gray Squirrels are relatively abundant and more frequently seen than their larger and more colorful cousin, the Big Cypress Fox Squirrel (Sciurus niger avicinnia). Mating season begins earlier in the south with courtship involving routine male competition, chasing of the female and a one-minute mating affair that results in 2-6 pups being born 44-46 days later.
Doe squirrels will build a secluded nest in the cavity or fork of a tree but still must protect their young from nest predators and cannibalistic squirrels. Pups are blind and naked with only the vibrissae whiskers to help them locate their mother in the nest. Within a few weeks they begin to grow fur and by week four they can open their eyes.
After only a week they have doubled their size from half an ounce to an ounce and as the pups grow, space in the nest dwindles. Occasionally they are accidentally pushed from the nest or dropped by the mother while transporting them.
This pup was found in the middle of the Fakahatchee Strand State Park boardwalk. It was seemingly unharmed and breathing fine. My choice was to find a rehabilitator to care for it or delicately move it from harms way and leave it for mama to come and get it. Having seen a squirrel close by, I left the pup and wished it well in 2012, hoping to see it in 2013.