January 28, 2013

Don't Eat That Bean!

After writing recent posts about Poison Sumac and White Snakeroot, I got to thinking more about poisonous plants. Plants can have wondrous healing properties, of course, but there sure are some to be avoided out there. And some can be both good and bad for humans, depending on which part is used and/or how it is prepared. I was reminded about all this on our trip to Florida when we walked by a big thriving stand of one of the most poisonous plants on the planet, Castor Bean (Ricinus communis), at Loxahatchee National Wildlife Refuge:

Those big, palmately-veined leaves are unmistakable.  I remember seeing this plant growing as a weed when I lived in San Diego, and a botanist friend with whom I was birding filled me in on its potent properties. 

Plants, which can't fly, scream or run out of the way of something attacking them, have to have some defense against hungry critters. Chemicals, thorns, leathery texture and other obstacles fill that bill. Often those defenses are inconvenient or even hazardous to humans, but for me they add a lot of interest to the botanical world and Castor Bean is way up there on my list of fascinating plants.

Native to Ethiopia, Castor Bean grows well in many tropical areas and has become a weed in southern parts of the United States. It can be grown in Ohio and other temperate areas from seed as an ornamental annual, although as you'll see that doesn't seem like a great idea even though Amazon, eBay and other sources can fix you right up with seeds. Cultivars are available with purple and red leaves, but the seeds should definitely be kept away from children.

Castor Bean flowers are rather unusual:

They are not very conspicuous, lack petals and are pollinated by wind. Male and female flowers are separate, but the plant has both on a stalk called a raceme. The male flowers are below the female flowers. Here is a closeup of the flowers:

Once pollinated, the female flowers develop spiny capsules which each contain 3 half-inch long speckled seeds. The seeds (which, despite their name, are not really beans; Castor Bean is in the spurge family or Euphorbiaceae, along with poinsettias) can be seen here.

While intact seeds can pass through the digestive tract without causing a problem, if the outer shell is broken or chewed they can cause extremely severe gastrointestinal reactions and can be fatal. These effects are due to a chemical called ricin, which prevents cells from making proteins. Ricin is also present in lesser concentration throughout the plant. In addition, allergenic compounds can be found on the plant's surfaces which can cause nerve damage, making castor bean harvesting a hazardous profession.

Why harvest castor beans? Well, the flip side of the toxicity of these plants is the fact that if you mash up the beans and extract the oil, you have the familiar component of traditional and alternative medicines, castor oil. The process separates the ricin from the oil, since ricin is water soluble and not soluble in oil. The ricin can then be destroyed by heating while processing the leftover mash into fertilizer.

Here are some facts about uses (and misuses) of castor beans, ricin and castor oil--references are at the end.

  • One castor bean seed can kill a child, four seeds will kill a rabbit, 5 a sheep, 6 an ox or horse, 7 a pig, 11 a dog, but it takes 80 to kill a duck (statistics which mainly prove that human curiosity has no boundaries...).
  • In addition to potentially fatal gastroenteritis, castor beans can also cause neurological and ophthalmological lesions
  • According to the Centers for Disease Control, in 1978, Georgi Markov, a Bulgarian writer and journalist who was living in London, died after a man stabbed him with an umbrella, which injected a ricin pellet.
  • Castor oil is a good motor lubricant and has been used in internal combustion engines, including those of World War 1 airplanes, some racing cars and some model airplanes. It does not, however, mix with petroleum products. It has been largely replaced by synthetic oils that are more stable and less toxic.
  • Castor oil is used in the food industry as food additives, flavorings, and as a mold inhibitor.
  • The United States Food and Drug Administration has categorized castor oil as a "generally recognized safe and effective" laxative but it can cause painful cramps and can, shall we say, be a much more powerful laxative than is usually needed or desired.
  • In traditional medicine, castor oil has been used for just about everything, from skin problems to birth control, to headaches, muscle aches, and sinusitis. It has been used to induce labor, but the accompanying awful vomiting and diarrhea render it inadvisable for that application.
Here are some interesting links for more information:

The chemical properties of plants continue to be mind-boggling to us humans, who try so hard to understand and explain the world around us. Here is one last photo of a Castor Bean plant, and notice that in all of these photos of mature plants you don't see any insect damage on the leaves--likely for a very good reason! 

January 20, 2013

Florida Scrub Jay

The predicted "arctic blast" of cold air that I mentioned in my last post has indeed materialized here in Ohio, so I'm going to think about warm Florida today! As I mentioned in a previous post, a handful of birds occur in Florida and nowhere else in the U.S. The Snail Kite and Limpkin from that post do, however, also occur in Central America. One bird, the Florida Scrub Jay, can ONLY be found in Florida.

In fact, its very specific habitat requirements have limited its range to sandy scrublands in central Florida, which look like this:

Plants which are characteristic of this habitat include a variety of small, evergreen oaks, taller slash pines and sand pines, and an understory which includes saw palmetto and sand palmetto. This habitat has been vastly reduced, probably since the mid-1800s, for development of towns, citrus groves and pastures, and more recently for military installations, phosphate mining, tourist attractions, shopping malls, the space center...and on and on. 

The habitat is dependent on periodic fires, and fire suppression has further reduced scrub jay habitat. All of these factors have severely reduced the bird's population, but they can be reliably seen at Merritt Island National Wildlife Refuge, just north of the Kennedy Space Center.

Florida Scrub Jays are about the same size and shape as the Blue Jays here in Ohio, but they lack the crest and bold black and white markings. They look similar to the Western Scrub Jays that we had in our backyard in San Diego, but the Florida birds have distinctly different DNA and are therefore considered to be a separate species. They eat almost anything they can find, with insects being their main food; acorns are also an important part of their diet. Here is a picture of one out looking for food:

Success! This bird may eat this item, but they also bury acorns and other seeds which in turn helps to regenerate their habitat:

A couple of interesting behavioral characteristics are quite different from those of the look-alike western population, and, in fact, from most birds. Florida Scrub Jays use what is called "cooperative breeding" in which juvenile birds help to raise their parents' later offspring. They live in family groups of between two (a mated pair) to larger groups of up to 8 adults and one to 4 juvenile helpers. Breeding success is significantly higher when helpers are present than when they are not. 

Another interesting characteristic of these birds is that they often station a "sentinel bird" on a high perch to watch for predators while the rest of the family looks for food, often in open areas on the ground:

If a hawk or other predator is spotted, the sentinel gives an alarm call and all find cover.

Florida Scrub Jays have been extensively studied (note the bands on these birds' legs) and since their population has been severely reduced they are considered "threatened" by the federal government. Because they live in family groups, if birders are lucky enough to find one bird they might see at least a couple more. 

Here is one more picture of this unusual bird:

January 13, 2013

January Thaw

Saturday, January 12, 2012

What a contrast! Last Saturday we were bundled up hiking in snow, and today we removed several layers as the temperature climbed to 65 degrees. This warm southern air is bringing lots of moisture with it, and will be followed by what the weather forecasters like to call an “arctic blast”. Sunday looks very wet, so today we headed with a friend to Dawes Arboretum in Newark.

We have hiked the trails through the prairie and wetland areas at Dawes but we had never walked through the more central areas, so today we took the loop trail from the visitor’s center to the lake, and back to our car. It went through both the formal gardens and the woodland. This was anything but a dismal winter hike! Right by the visitor's center we found this lovely Lenten Rose or Hellebore just about to bloom:

Despite its name, it is not closely related to roses, and the Hellebores are native to Europe. They certainly add a lot of beauty to gardens very early in the year, when little else is in bloom. 

The arboretum has an amazing array of woody plants from all over the world, roughly organized by botanical family. My favorite area was the holly collection, one of the largest in the world. A large flock of American Robins was feasting on the berries. The familiar American Holly was featured prominently:

The deciduous Winterberry Holly was gorgeous:

Here is a black-berried holly called Inkberry, which is native to much of eastern North America:

This yellow-berried holly cultivar was also stunning:

As we walked the trail we were surprised to see a few dandelions in bloom, taking advantage of the warm day and a bit of sunshine. These cheery yellow flowers are excellent nectar sources for insects:

We were in for a couple of surprises as we hiked through the woodland, which is dominated by beech trees both large and small:

The friend that we were hiking with showed us a tent caterpillar egg case on a cherry tree, a preview of things to come in the spring. Soon our friend noticed this moth cocoon hanging on a spicebush twig, and immediately identified it as a Promethea Moth, which is also known as Spicebush Silkmoth: 

How cool is that? This moth caterpillar has surrounded itself with leaves, and cemented the capsule to the spicebush twig. The round buds that are visible are the spicebush's flower buds; in the fall this small tree will have bright red fruits that are eagerly consumed by a variety of birds. Spicebush is one of the Promethea Moth's preferred caterpillar food plants. Take a look at the gorgeous adult Promethea Moth at this link

A little further on we had our biggest surprise for a January hike: a butterfly! A  mourning cloak, a bit tattered but still readily identifiable, flew past us twice and we were pretty speechless! Mourning cloaks are one of the few butterflies that overwinter as adults in Ohio; they find crevices to shelter themselves and their physiology keeps them from freezing. They basically hibernate, but it is not unusual for them to fly on a warm day. January is certainly too early to expect them though!

Robins were active in the woods, turning over leaves looking for insects. At this time of year their diet is mostly berries, but on a warm day like this a few invertebrates are active and provide some protein:

Notice how well this robin blends into its surroundings!

Speaking of active insects, here is a mid-day look at the beehive at the Dawes visitor center:

I can't imagine that they were getting much nectar, but maybe they visited some dandelions!

After lunch we headed to Lobdell Reserve, a park near Alexandria, and did another loop hike. Most of the snow was melted here, but there were a few patches remaining:

This made me think of Jim McCormac's post a few days ago about "snow fleas" over at Ohio Birds and Biodiversity. These are tiny critters called springtails or Collembola, which are now classified as "hexapods" although they used to be considered insects. They occur in tremendous numbers in the soil, and especially on sunny days they come out on top of the snow and look like little specks of pepper. They are just a few millimeters long at the most, but they can travel several inches in one jump.

I was wishing that I had known about these critters last week when we had so much snow, but I decided it was worth looking at the small snow patches that remained today. I looked at lots of patches, and saw lots of little black specks but they didn't move and were probably just dirt! Finally, down on my hands and knees, I checked out a patch that did indeed have springtails! They weren't present in huge numbers, maybe because it wasn't very sunny, but they were pretty cool nonetheless:

Now that picture might not generate much excitement, and this guy was only about 2 millimeters long, but boy could it ever jump! And it is pretty cool that this animal would be so active on the snow in January. There are hundreds of species of springtails in North America, and this looks quite different from the ones that Jim photographed--and I won't hazard a guess as to which one it might be.

We also saw a fairly fresh crayfish burrow:

These crustaceans bring up balls of dirt and deposit them on the surface. Burrowing crayfish are semi-aquatic and their burrows can be quite deep, eventually reaching water-saturated soil where their gills can stay moist.

Just as we were pulling out of the parking lot Bill heard something (other than road noise and the target practice taking place nearby) and we all got out to listen right by this small, partially frozen wetland:

It was a chorus frog! Their call sounds like a finger being drawn across a comb. 

We have learned to expect the unexpected on these winter walks! 

January 6, 2013

Winter at its Best

Most of the time I barely tolerate winter. Here in central Ohio, the weather is often gray and downright depressing after the holidays. I think I was spoiled by living in San Diego for 8 years, when we could go to the beach, mountains, desert, or anywhere in between within an hour or so any day of the year and see flowers blooming and usually, sunshine. (Oh yes, there were those pesky jobs that took up 5 days a week, but we sure took advantage of the weekends!) 

Today, though, was a glorious winter day, with bright sunshine highlighting a covering of clean snow, relatively mild temperatures with no wind, and lots of interesting avian winter visitors to check out. We started at Pickerington Ponds Metro Park, where a Harris's Sparrow has been reported for the last several days. This is a rare bird for this area, and one we had never seen in Ohio. 

On the way to the park we passed a flock of Horned Larks in a farm field:

These hardy birds are resident in central Ohio year round, and feed on seeds leftover in fields. I don't think I've ever seen one at a feeder, though.

We also passed this beautiful farm:

The Harris's Sparrow has been coming to a feeder at the park, and when we got to the parking lot several birders were already there, bundled up and armed with spotting scopes. Of course, we found out that the bird had been seen before we got there, and then had flown off. We know that patience is necessary in these situations, so we settled in with our scope and enjoyed great views of Red-Bellied Woodpecker, a common bird but always fun to see:

American Tree Sparrows were quite numerous at the feeder:

American Tree Sparrows are among my favorite birds. They are fairly common in rural areas in central Ohio in the winter but they breed far to the north at the edge of the tundra. I always enjoy seeing them!

After 45 minutes of waiting and watching and chatting with the other birders, someone said "There it is, in the tree to the right of the feeder, and now it is underneath the feeder!" Excitement--there was the Harris's Sparrow, and we got good but very brief looks at it with the scope as well as our binoculars. I didn't get a picture, but there is a photo in this link. Winter plumage is paler than the bird in the picture. Harris's Sparrow only breeds in Canada but does winter in the U.S., generally west of Ohio so this is a fun bird to see here.

Then it was off to Blacklick Woods Metro Park. All week there were reports of an Ovenbird there, a warbler which typically winters far to the south. Unfortunately, a Cooper's Hawk made a meal of it a few days ago, so we knew we had missed that rarity! We did a good hike though, enjoying lots of snowy scenery. The snow last week "stuck" to the trees and shrubs and very little has melted:

From Blacklick Woods we went to Blendon Woods Metro Park and walked the Lake Trail. First, though, we stopped at the visitor center to check out the feeders and saw the Oregon Junco that has been there recently. As is obvious from its name, this is a western cousin (actually a subspecies) of our Dark-eyed Junco, a common winter bird here in Ohio. Junco taxonomy is complicated and many think that the Oregon Junco should be a separate species. I'll stay out of that argument!

The birds were pretty cooperative along the Lake Trail. Here is an Eastern Towhee:

and an American Tree Sparrow:

It was fun to watch the Red-breasted Nuthatch foraging upside down on a tree:

A Fox Squirrel, beside its nest, watched us as we hiked back to our car:

All in all, getting out today was a great way to chase the post-holiday winter blues!