Category: Biology

Spring Wildflowers at the Shaw Nature Reserve

Spring blooms (possibly of Royal Catchfly -- Silene regia) at the Shaw Nature Reserve

I took a half-day trip during spring break (somewhere around the 31st) to the Shaw Nature Reserve in Gray Summit. I was hoping to find some books on native, Missouri, flora and fauna, and see if the Reserve would be a good place for a field trip (they have sleeping facilities so even overnight trips are a possibility).

I found a number of books, including a nice one on mushrooms, and while I could have, I did not pick up one on wildflowers (of which there were several). Of course, spring is the perfect time to see wildflowers, especially since we ended up hiking the Wildflower Trail, so I’m probably going to have to go back sometime soon.

The lady at the main office (where you pay $5/adult) recommended we take the Wildflower Trail and then cut down south to the sandbar on the Meramec River, which is an excellent place for skipping rocks. She also recommended I take my two kids to their outdoor “classroom” for some real, unstructured play.


View Shaw Nature Reserve – Wildflower Trail in a larger map

Without a reference book, I’ve had to resort to the web for identifications, with only a little success, so I’ll post a few of my photographs here and update as I identify them.

The following two pictures are of a flower that was found covering the hillslope meadows; open areas with short grass.

Beautiful reddish-orange blooms on this small herb.
This picture better captures the growth form and leaves of this hillslope, meadow flower.
A yellow petalled variant.

Like little stars in the daylight, these small, white flowers meadow flowers almost sparkle.

Small, white, meadow flowers.

Pretty, small, yellow, meadow flowers.

Yellow, meadow flowers.

These bent-over flowers can be found on the lower, shadier edges of the hillslope meadows.

These guys like the shadier areas.
I love the texture of the charred wooden stump behind the flower. The meadow itself is possibly the result of a burn.

Iris’ were also in bloom.

Small iris.

Another herbaceous, yellow flower.

Pretty yellow flowers.

More, tiny, delicate flowers.

Found in the shadier, moister parts of of the slope.

Once you get under the canopy, you run into some broader leaved plants and their own, interesting flowers.

Bell-shaped flowers in broad-leaved herbs/shrubs.

We ended up spending a lot of time on the sandbar, learning to skip rocks and hunting for clams, but I save that for another post. And we never did get to the play area; that’ll have to wait for the next trip.

The Search for a New Earth

This NASA video updates us on the search for Earth-like planets around other stars. It overviews what’s been found, and outlines some upcoming missions.

The key to finding a planet hospitable to life (as we know it) is finding one with water at the surface. We’ve found large waterworlds that are too large and hot, with “thick, steamy atmosphere[s]”.

We’ve also found Earth-sized planets but they’re, mostly, too close to their stars to support liquid water, and it’s hard to tell what their atmospheres are like because they’re so far away. One of NASA’s upcoming missions, one will look at the light reflected off Earth-sized planets to determine the composition of atmospheres: the technique is called transit spectroscopy, and is based on detecting the emission spectra of the gasses in the atmosphere.

ᔥ Science@NASA ↬ Pale Blue Blog

Spring is Coming Earlier

The average change in the date of "first leaf" in the United States. Note that states farther to the north have seen greater change. Image from the interactive by Climate Central.

In Missouri, between 1981 and 2010 the average date at which trees first showed their leaves was two days earlier than the average between 1951 and 1980, according to this graphic by Climate Central.

You’ll also note the north-south trend, where change is greater as you go north. Most models predict that global warming/climate change due to increasing carbon dioxide will result in bigger changes as you get toward the poles.

The map is based on data from the National Phenology Network. The National Phenology Network has a good educational resource page, as well as access to their datasets.

Spring has been coming two days earlier (on average) in Missouri. Image from Climate Central.

Daffodil Pollen Under the Microscope

Fresh daffodil pollen grains seen under 1000x magnification.

For the record: Daffodil flowers have both male and female parts, which make them good subjects for dissection. And, it’s pretty easy to collect daffodil pollen samples to look at under the microscope. 1000 times magnification seems necessary to be able to make out structures.

Since prehistoric pollen, collected from places like the bottom of lakes, are one of the easiest ways of finding past climates, a study of more recent samples might make for a good student research project in biology or environmental science. They’d need to design the study so they could avoid having to use nasty acids (hydrochloric or hydrofluoric) to concentrate the pollen grains, but that should be possible. Perhaps an ongoing survey using pollen traps, akin to the European Pollen Monitoring Program.

The pollen grains come from the anthers.

The Physics of Flight: World Bird Sanctuary in St. Louis

Bird of Prey -- at the World Bird Sanctuary.

A discussion of the physics of flight, interspersed with birds of prey swooping just centimeters from the tops of your head, made for a captivating presentation on avian aerodynamics by the people at the World Bird Sanctuary that’s just west of St. Louis.

Lift

The presentation started with the forces involved in flight (thrust, lift, drag and gravity). In particular, they focused on lift, talking about the shape of the wings and how airfoils work: the air moves faster over the top of the wind, reducing the air pressure at the top, generating lift.

The shape of a bird's wing, and its angle to the horizontal, generates lift. Image adapted from Wikipedia User:Kraaiennest.

Then we had a demonstration of wings in flight.

Terror from the air.

We met a kestrel, one of the fastest birds, and one of the few birds of prey that can hover.

Kestrel.

Next was a barn owl. They’re getting pretty rare in the mid-continent because we’re losing all the barns.

Barn owl.

Interestingly, barn owls’ excellent night vision comes from very good optics of their eyes, but does not extend into the infrared wavelenghts.

Barn owl in flight.

Finally, we met a vulture, and learned: why they have no feathers on their heads (internal organs, like hearts and livers, are tasty); about their ability to projectile vomit (for defense); and their use of thermal convection for flying.

The ground warms when it absorbs sunlight (e.g. parking lots in summer) and in turn warm the air near the ground. Hot air rises, creating a convection current, or thermal, that the vultures use to gain height.

The Sanctuary does a great presentation, that really worth the visit.

Humans Beings, Super-Predators

Usually, when new, more powerful predators evolve or come in from elsewhere, the local species can often adapt by themselves becoming better defended through a variety of means [larger sizes, thicker shells for example]; but this option seems to be closed when it comes to the evolution of humans as super-predators.

— Geerat Vermeij (2012), quoted in Walker (2012): Super-predatory humans on the BBC website.

Humans, using ingenuity and tools, have become an uniquely, irresistible predator species that the world has never seen before, and to which other species are finding it very difficult to adapt. That’s the premise of a paper by Geerat Vermeij that’s nicely summarized by Matt Walker on the BBC website.

Normally, predators and prey evolve and adapt to each other. Lions are better able to attack and kill smaller buffalo, which means the larger buffalo are more likely to survive, which results, over time, in the average size of the buffalo herds getting larger.

Humans, on the other hand, like to target the larger buffalo, creating a selective pressure the other way. Unfortunately, once the larger specimens are gone, humans will go after the smaller ones, and the intensity of the attacks have often been enough to drive entire species into extinction.

Though humans have been around for a couple hundred thousand years, we still have not seen our full impact on the environment. Which is somewhat interesting to consider.

Human Evolution: A Family Tree

The Smithsonian has an excellent, interactive, family tree for humanity that goes back 6 million years.

io9 has a neat image of key primate and homonid skulls that show the story of human evolution, and how we know about it.

Image via io9. (The skulls come from the collection of the University of Leiden and were labeled by Roosje de Vries.

Beyond Interstellar Space: Finding Earth-Like Planets

Artist's rendering of Keppler 22b, a planet 600 light years away that is in the habitable zone of its solar system. Image credit: NASA/Ames/JPL-Caltech.

The Voyager 1 spacecraft is rapidly approaching the space between the stars, where the Sun’s solar wind is pushed back by the interstellar magnetic cloud.

Voyager approaches interstellar space -- an artist's rendition. Image credit: NASA/Ames/JPL-Caltech

How far will it go? The spacecraft have enough power to last until 2020, when it will be about 20 billion kilometers from the Sun (it’s now about 17.8 billion km away). In 40,000 years it will drift “within 1.6 light years … of AC+79 3888, a star in the constellation of Camelopardalis” that’s about 17.6 light years away.

Consider the 40,000 years it will take Voyager to travel 17.6 light years, and the distance to Keppler 22-b, a recently discovered “Earth-like” planet that’s about 600 light years away.

Keppler 22b's orbit and size compared to Earth's. Image via NASA/Ames/JPL-Caltech.

Keppler 22-b is in the liquid water zone of it’s solar system: far enough away from its sun that water on its surface will not just boil away from the heat, yet close enough that the water does not just freeze solid instead. Liquid water is a key necessity for all life as we know it.