Author Archives: John Bradford

Evening-Primroses, lovely members of the big genus Oenothera with almost 100 species in North America, are well represented as mostly bright yellow wildflowers in Florida,  some in  open sandy habitats. One cosmopolitan beach species, arguably native to Florida, Beach Evening-Primrose (O. drummondii), found itself called out recently as listening for  pollinators.  Yes, listening.

Photo courtesy of Harry Rose.

Biologist Marine Veits and a group of collaborators in 2019 reported honeybee buzz and similar vibes, but not other tones, to induce increased sugar concentration in the nectar.   In their interpretation, this ability sweetens the pot  upon demand, promoting bee pollination yet conserving sugar when there are no customers.   What’s more, the petals resemble one of those parabolic microphones they use to focus birdsongs, to capture frog calls, and to eavesdrop on conversations.

It may all be just as reported and interpreted, but questions come to mind:

1. Are bees meaningful pollinators for evening-primroses?   The flowers are (actually) textbook examples of moth-pollinated blossoms, having long tubes producing nectar way down deep exclusively reached by a moth’s long proboscis.   But bees are known to visit the flowers, perhaps merely gathering pollen, as bees do.   That could result in pollination without nectar consumption.   Then again, who is to say the long tube can’t fill with sweet nectar, allowing an occasional bee sip.  

Nectar is produced at the bottom of the long skinny tube. Bee can’t reach there.

• Would a small increase in sugar content boost pollination?  Not if the bees are there just for pollen. And even if they are obtaining some nectar, it’s not been shown (pretty hard to accomplish!) that marginally raising sugar concentration leads to more pollen deposited by more bees on more stigmas.  

• In 2017 botanist Sebastian Anton and collaborators studied the floral dynamics of several evening-primrose species in Europe and found the flowers to not just release nectar into the tube, but also to suck it back in dynamically, depending on circumstances.  The nectar level waxes and wanes.  As the flowers reduce the nectar volume, the sugar concentration increases.  That is, sugar concentration increases when the flower is stashing away nectar, not dishing it out.   Does buzzing set off a flower alarm:  “Hey, non-moth invaders detected, hide the goodies!”   After all, some types of bees drill into flowers and steal nectar like mosquitoes stealing blood from my elbow.

• Yet another concern is that the flowers don’t have any identified “nervous tissue,” whatever that could be in a plant.   Absence of detection does not prove absence of some subtle signal, duh, but it doesn’t help either.  Plant cells live within extremely thin delicate membranes with their own innate molecular movements and unimaginably delicate processes.  Whether or not buzz detection is usefully adaptive, vibrating cell membranes could conceivably change cross-membrane transfer dynamics, maybe even make membranes “leaky.”   That is, could vibrational sugar leakage take place with no purpose?

Who knows?   The idea is new and fascinating and plausible, and that is how science works.  Taking another look at the same question with additional bee and flower species is joyous future grist for the mill.   The original research was in the Mediterranean. Now somebody should try in Florida.

to see more:

DOI 10.1007/s00425-017-2748-y

DOI 10.1111/ele.13331

Until today I thought the blog was defunct due to technical reasons. But through a stroke of record-keeping genius, John found the key to salvation so here we are, bullett dodged.

Today I did something I enjoy excessively—walked through a mostly dry Bald Cypress Swamp. Met an otter ‘long the way, also to my surprise hog scat deep in the swampy shadows, and an apple snail mobile home.

But entirely absent were young Bald Cypress, seedlings of saplings. None, not one, in a swamp spanning acres. Bald Cypress does make seeds, and they germinate in wet places where they blow….but not where the older trees drop their needles.

Something a crowded Bald Cypress swamp generally does not need is more trees . Those roots are already competing fiercely in awful waterlogged soil. Making competing youngsters underfoot would be suicidal, not a plus. Arboreal family planning, in fact, is well known among conifers, although I have not seen seed-o-cide reported for Bald Cypress itself. But I sure saw it in practice today.

Poisoning your own seedlings is called autotoxicity. And if you can do, you might as well knock off other species’ seedlings as well, known as allelopathy. And of course Cypresses get extra help via annual flooding.
If a Bald Cypress topples is the swamp, who fills the void? This is one of the few conifers able to regrow from basal stump sprouts. It can begin anew, but only when regrowth is necessary.

Think how many species of woody wetland plants most have their seeds blow, float, or ride inside animals or birds into a swamp. You do see some “outside” woody youngsters growing on cypress trunks, on knees, on stumps and logs, and on various other humps and hummocks. Wax Myrtle and Buttonbush do that. But not on the fallen needle carpet.

Those carpets can be several inches thick, and the material visibly resembles expensive potting soil from a garden store, it stifles seed growth like a natural preemergent herbicide, with two exceptions.
One is Cocoplum which has ecological tolerances so broad it loves to be pruned into a hedge. Its hard floating Cocoplum seedpit feeds and apparently protects the embryo from drying, flooding, and needle poisons. Nothing stops Cocoplum. It could sprout on Mars.
The second needleproof tolerator is Pond Apple, which, like Cocoplum, also has large, hard-shelled, protective, nutrient-rich floating seeds. These have an extra trick (called epigeal germination) where, once the root hits the carpet, the rest of the seed lifts safely above the poison carpet, and ready for “next year’s” flooding.

Its roots spread horizontally trouble-free into the needle duff Pond Apple can remain as small understory tree, or eventually become substantial.

Being able to invade a light gap by floating seeds faster than a Cypress’s basal sprouting, Pond Apples can crowd into Cypress Swamp gaps, although given a few centuries, the enormous Cypress will have the last word.

You may hope that the Florida legislature provides the funds to buy land for water storage but I know that when I buy a duck stamp the 98 cents of every dollar is mandated to buy wetlands.

Duck stamps are the greatest federal program in existence. 98 cents out of every dollar goes to buy wetlands. That is a Federal mandate. Since 1934, when the program began, it has purchased or leased over 6 million acres of wetland – an area nearly the size of Maryland. Much of this area is now part of the National Wildlife Refuge system. It’s the envy of the world.

Stamps have enabled the purchase of over 2500 acres at the Arthur Marshall refuge and almost 86,000 acres in 6 other refuges in Florida.

And here is the backstory:

In 1934, our country suffered in severe economic depression. Real needs were many; financial resources were slim to non-existent.  At the same time, our abundant natural resources were rapidly disappearing. In an era when hunting still provided the meat on many tables, it seemed there were more hunters than ducks.

As chief of the U.S. Biological Survey, forerunner of today’s U.S. Fish and Wildlife Service, J. N. “Ding” Darling devised a program wherein hunters became stewards of the wildlife they hunted.

“Ding” Darling was most widely known for his editorial cartoons, which appeared in nearly 150 newspapers nationwide and earned him two Pulitzer Prizes.

Although “Ding” earned his living as an editorial cartoonist, his passion was teaching the wise use of the world’s natural resources. Skilled in public speaking, articulate in writing, Darling devoted his special talents to conservation education and to developing programs and institutions which would benefit wildlife.

One of “Ding’s” cartoons

Darling’s Design for the First Federal Duck Stamp~1934 is especially significant to conservation. After he had guided the funding for the Migratory Bird Hunting Stamp Act through Congress, Darling sketched his concept of a suitable image for the First Federal Duck Stamp. With its enthusiastic adoption, a remarkable program of stewardship was born that endures today, more than a half-century later. Here is an image of “Ding” Darlings original stamp:

Not only does the stamp provide the funds to buy and maintain the wetlands it provides a beautiful piece of artwork. Every fall hundreds of painters across the country compete in the Federal Duck Stamp contest, which gives participants a chance to have their paintings featured on the duck stamp of the year. So when you buy the stamp not only are you saving wetlands but you are buying a wonderful piece of art. Here is an image of the current stamp depicting Trumpeter Swans

If you want a great read about the peculiar world of competitive duck painting then pick up a copy of The Wild Chase by Martin J. Smith. This book follows the Federal Duck stamp contest of 2010. If you saw and liked the movie “Best In Show” you will really enjoy this book. Some of the descriptions of the ducks and geese in the 2010 duck stamp contest were hilarious. The Brant, a smallish goose is like a feathered Martha Stuart – they put more down in their nests (for insulation) than any other waterfowl. The Northern Shoveler is Lady Gaga of the wetlands – iridescent green head and neck and really showy plumage. The Ruddy duck is an oddball – a skyblue bill that is just ridiculous. The Ruddy Duck appeared on the stamp in 2016

Another interesting duck is the Red-breasted Merganser who looks like he had his hair styled by Woody Woodpecker.  The bird appeared on the 1994 stamp.

I hope you will consider the purchase of a stamp as part of your conservation effort. Here is a link to the Federal website that contains a lot of duck stamp information: https://www.fws.gov/birds/get-involved/duck-stamp.php

I buy my stamps from the US Post Office and here is that link: https://store.usps.com/store/browse/subcategory.jsp?categoryId=duck-stamps&categoryNavIds=stamp-collectors%3Acollectibles-by-type%3Aduck-stamps