Photo Caption: Bur oak trees are known for their large acorns as well as their thick and fire-resistant bark that helps protect them during prairie and savanna fires. The oaks pictured, from the savanna behind Hickory Knollls, are all over 100 years old and still going strong.
Bur Oak Trees
October 20, 2017
Maybe, as an alert observer of natural phenomena, you’ve noticed what’s up with bur oak trees this year. Or maybe you’ve been an unfortunate victim, twisting an ankle or suffering a knock on the head as the big trees drop their jumbo-sized, shaggy fruits. Either way, it’s hard to deny: 2017 is a big year for bur oak acorns.
Oaks in general are referred to as “mighty,” but I’d wager that bur oaks are among the mightiest. They grow tall and spread wide, and their bark is thick and corky-an asset that was particularly handy back when prairie fires were common.
Then there are the bur oak acorns. The largest of any native oak, these fruits can measure more than 1 1/2 in. in length and feature a cap that looks like something grandma might have knitted. It’s knobby and deep and encircled with a bushy, bristly fringe; I swear I wore something just like it back in the ’70s.
The bur oak acorn is so notable, in fact, that it accounts for the species’ common and scientific names. “Bur” refers to the acorn’s resemblance to the burs produced by the burdock plant-you know, the ones that stick on clothing and pet fur like glue this time of year. Another name for the bur oak, mossycup oak, also underscores the acorn’s shaggy appearance. Meanwhile, the species’s scientific name, Quercus macrocarpa, literally means “beautiful tree with really big fruit.”
This year, like the hickories we wrote about a few weeks ago, the really big fruit is present in really big quantities. We’re in the midst of a natural event scientists refer to as a “mast year,” a year in which particular species of trees produce prodigious quantities of fruit. The occurrence is synchronous, meaning just about all trees of those species do it at the same time, but also irregular, happening at intervals that may range from as few as two to as many as 12 years. Oaks, hickories and walnuts are some of the main mast producing trees in our area.
While they all know what to call it, those same scientists aren’t all in agreement as to why it occurs. One leading theory proposes that masting is a reproductive strategy meant to help the tree gain an advantage over seed eaters like mammals and birds. If the trees can produce so much fruit that every animal that eats those seeds has more than enough, then certainly some seeds will survive to sprout and grow and pass along that all-important genetic material.
But just as the trees giveth, they sometimes taketh away. Low mast years are also part of the picture, and help keep seed predator populations in check. I remember year not too long ago where virtually all nut-producing trees in our area were at a low ebb; there was not a walnut or acorn to be found. Squirrels were scavenging wildflower seeds and leftover berries-and birdfeeders– instead of nuts in October. And come spring, there were noticeably fewer squirrels in the woods.
To further sort out the puzzle, scientists also are exploring whether mast years occur in response to environmental cues, like the abundant rain we had this year. Other theories focus on mast years being the result of some internal, biological mechanism. Research on the subject is ongoing and results are mixed.
We can be sure of this, though: 2017 is a big year for bur oak acorns. Enjoy the bounty, but watch your step!
Pam Erickson Otto is the manager of nature programs and interpretive services at the Hickory Knolls Discovery Center, a facility of the St. Charles Park District. She can be reached at 630-513-4346 or firstname.lastname@example.org.Good Natured, Nature, Trees
Photo Caption: Midland brown snakes are quite common throughout the TriCities but rarely seen due to their small size and secretive nature.
October 13, 2017
I would guess that pretty much all of us have heard the cautionary tale of the Itsy Bitsy Spider. But how many people have heard about the Itsy Bitsy Snakes?
Back in August, the staff here at Hickory Knolls was in full-on nature camp mode, hosting dozens of kids in a variety of outdoor-themed programs. I was lucky enough to lead my tenth year of Reptile and Amphibian camp, known in shorthand as Herp (for Herpetology) Camp.
It was a Wednesday-a very warm Wednesday-as we headed out with our merry band in search of the group of animals targeted for that day: snakes. (Other days had aimed for other critters also classified as herps-frogs, toads and salamanders. Funny thing. These amphibians are in no way related to reptiles. But they are creepy and crawly and, back in the day, they were lumped in with snakes and lizards due to their squiggly nature.)
At any rate, there we were, hiking along with eyes peeled for garter snakes, the most likely quarry for the habitat we were in. Which is kind of funny, because we were poking around in an old quarry.
The hot summer sun blazed down on us, and it wasn’t too long before one of the campers started to display some adverse reactions to the heat. Not a fan of hot temperatures myself, I offered to walk him back to the picnic pavilion where a nice, ice cold drinking fountain was located.
So off we went, the sweaty camper and I, through the cloud of mosquitoes and around the patches of poison ivy, making our way back to the pavilion. I was still in snake mode though, so our progress could be rated as somewhere between slow and downright pokey.
About halfway up the trail to the woods, I noticed an odd, wavy motion among the crushed gravel. The creature making it was small, tiny even. Or, to reference the above comparison, itsy bitsy. I was about to write it off as a worm, except for the fact that no self-respecting worm squiggles across dry, rough crushed gravel on a 90-degree day.
I told my friend the sweaty camper to hold up a moment. I reached down and picked up the teensy creature, and was delighted to see that it was in fact a snake. An Itsy Bitsy Storeria dekayi wrightorum, or midland brown snake.
Now, in the Illinois snake world, we have some pretty large contenders, like Pituophis catenifer sayi, the bullsnake, which regularly reaches a length of eight feet or more. And the black ratsnake, Pantherophis spiloides, that measures out around six feet. (For all you snake fans out there, you can see both of these magnificent species at Hickory Knolls.)
Anyway, Illinois is also home to some very small species , that top out at a length of less than two feet. We have the ringneck snake, Diadophis punctatua, which can grow to 15 inches; the red-bellied snake, Storeria occipitomaculata, which tops out at 10 inches; and our featured species, the midland brown snake, which averages 13 inches in length.
The brown snake is actually quite abundant in our area, although it is rarely seen. Its habit is to hang out in leaf litter, which is brown, and in moist soil, which in our area is mostly brown too. So it’s of no surprise that the species is easily overlooked.
I found my first brown snake about 20 years ago when I was raking my fingers through leaf litter looking for butternuts. Imagine my surprise to find a small brown snake intertwined amid my fingers! The snake, I’m sure, was as surprised as I was.
Since then I’ve seen adult brown snakes basking on the paved Fox River Trail as well as on the bluffs along the Fox River in Batavia and North Aurora. But never until August did I see a teensy juvenile. At that time it was probably recently birthed, as brown snakes produce live young instead of eggs.
The diet for this secretive species is mainly earthworms and slugs-two other groups of animals that prefer moist habitats. The wee beastie we found was nearly as large as its prey!
As you go about your walks and hikes this fall, keep the midland brown snake in mind. You might not actually see one, but can trust that one or more Itsy Bitsy individual is likely nearby.
Pam Erickson Otto is the manager of nature programs and interpretive services at the Hickory Knolls Discovery Center, a facility of the St. Charles Park District. She can be reached at 630-513-4346 or email@example.com.Good Natured, Reptile