Beauty, the Sublime and Darwin: Exploring the “sheer poetry” of field biology with Dr. Harry Greene

The diversity of life on Earth is under serious threats from multiple human-related causes. Science plays well-known roles in addressing management aspects of this problem. 

Dr. Harry W. Greene, professor of ecology and evolutionary biology at Cornell University, wants us all to know that natural history also plays a vital role in Earth’s health.

Ecology Lecture 1

Natural history enhances our appreciation for organisms and environments, thereby influencing value judgments that ultimately underlie all conservation. Wow, that is huge! This is why we should all care about nature — our planet and all life on Earth depends on it!

While Greene is in Houston for the East Texas Herpetological Society Annual Conference and Reptile Expo September 19 – 21, he will give a special presentation at the Houston Museum of Natural Science on Monday, September 22 at 6:30 p.m.

Greene will explain how an 18th century philosopher’s distinction between “beauty” and “sublime” can be used in the context of Darwin’s notion of “descent with modification.” As a good biologist, he will illustrate this approach with frogs, snakes, African megafauna, Texas longhorns, and California condors.

Dr. Harry Greene is a popular author and will be signing copies of his latest book Tracks and Shadows: Field Biology as Art following the lecture. The book explores multiple themes including the nuts and bolts of field research and teaching, the destruction of habitat and loss of biodiversity, the “sheer poetry” of field biology, and the role of natural historians in saving species from extinction.

Ecology Lecture 2

“Natural History and Aesthetics – Why Should We Care About Nature?”
Harry Greene, Ph.D., Cornell
Monday, September 22, 6:30 pm 
Houston Museum of Natural Science
Public $18, HMNS members $12
To register in advance, click here or call 713.639.4629. 

Harry W. Greene’s primary interests are behavioral evolution, community ecology, and conservation biology, and is especially interested in mammals, lizards, and snakes, particularly vipers. Greene is the Stephen Weiss Presidential Fellow and Professor of Ecology and Evolutionary Biology at Cornell University and a recipient of the E.O. Wilson Award from the American Society of Naturalists. His book Snakes: The Evolution of Mystery in Nature (UC Press), won a PEN Literary Award and was a New York Times Notable Book.

Love our lectures? Save the date for these upcoming nature lectures at HMNS!
More info at www.hmns.org/lectures

Plant Conservation in a Rapidly Changing World
Thursday, September 25, 6:30 p.m.
Habitat destruction will drive to extinction more than half the kinds of plants and animals that exist now on Earth within the next 75 years or so. Dr. Peter Raven will share how plant species can be saved through high-tech genetic seed banks, the establishment of protected areas, and botanic garden collections. Cosponsored by the Mercer Society.
Click here for tickets.

Monarchs: Is the Migration Moribund?
Monday, September 29, 6:30 p.m.
The monarch butterfly is known for its annual roundtrip journey to and from overwintering sanctuaries in central Mexico. Yet today this marathon migration is under great threat. Dr. Nancy Grieg will discuss what, if anything, can we do, followed by a screening of the 3D film Flight of the Butterflies.
Click here for tickets.

Gulf of Mexico Biodiversity and Oil Spill Resilience
Monday, October 13, 6:30 p.m.
The Gulf of Mexico appears quite resilient in the face of many environmental insults, such as overfishing, habitat loss and destruction, degraded water quality, extensive coastal development, and climate change. Dr. Wes Tunnel will explain what a tipping point of too many problems might eventually cause.
Click here for tickets.

“Bats: The Night Shift”
Monday, October 27, 6:30 p.m.
Bats have radiated into almost every habitat on Earth, bringing with them their important ecological responsibilities. Their great diversity of feeding strategies is a testament to the adaptability of these nocturnal animals and reveals their important roles they play within ecosystems. Bat researcher Dr. Cullen Geiselman will discuss the great variety of bats, including the 38 species in Texas of which eight call Houston home.
Click here for tickets.

Growing an Ark: The Expanding Role of Gardens in Plant Conservation
Thursday, November 6, 6:30 p.m.
Journey around the world and learn of the significant successes and contributions by botanic gardens in the efforts to rescue plants from extinction through expanded research, conservation programs, and environmental education with Dr. Peter Wyse Jackson of the Missouri Botanical Garden. Cosponsored with The Mercer Society. 
Click here for tickets.

Mean green flying machines: the hummingbirds are here!

Photo by JC Donaho. http://jcdonaho.com/

Photo by JC Donaho. http://jcdonaho.com/

What was that high pitched chirping and flash of iridescent green that just whizzed past at lightning speed? You just got buzzed by a hummingbird! The fall migration is passing through Houston, and these feisty little birds seem to be particularly abundant this year. Houston does not have (for the most part) any resident hummingbirds, but a few species pass through in spring and fall as they fly between their nesting grounds in the northern states and Canada, and their wintering ground in Central America.

The northward spring migration is much more diffuse than the fall event – you may hear a hummingbird or two in February or March, but they don’t linger. However, in late August through September and into early October, hummingbirds can be very evident in Houston. These marathon travellers will pass through our area for about 4 to 6 weeks, stocking up on fuel to take them over the Gulf of Mexico to their winter abode. They are particularly abundant on the Gulf Coast, where inclement weather can force them to stay put until a more opportune time comes to complete the migration. Rockport, Texas hosts a huge “Hummerbird Festival” every mid-September, with lots of talks on hummingbirds and other birds, butterflies, etc., and home tours to see gardens that are particularly full of hummingbirds. It’s over for this year, but put it on your calendar for future years and check it out!

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Most hummers you see in Houston (and in Rockport) are Ruby-throated Hummingbirds. Males are a metallic green with white bellies, and are named for the patch of dark feathers on their throat that glows a brilliant, iridescent ruby red when the sun hits it just right. Females and immature males do not have the spectacular throat coloring, and are white underneath. Some young males may have a fleck or two of red on their throat.

Two other species are sometimes seen here – the Rufous Hummingbird and the Black-chinned Hummingbird. Juveniles and females of these species are a little hard to distinguish from Ruby-throated females and youngsters, but the males are distinctive. Rufous males are a bright bronze color, with an orangey red throat. Black-chinned males are green with a black throat, below which, in the right light, a brilliant violet band will flash.

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Farther west, in the Big Bend area and west into New Mexico, Arizona, and California, hummingbird diversity is much higher. About 15 or so species are known from the USA, and most of these occur in the western states. For the apex of hummingbird diversity, head to the highlands of South America (e.g., Colombia, with about 140 species), where dozens of different species can be seen, some of them truly spectacular. Most of these are residents in the tropics and do not migrate.

 

Male and Female Ruby-Throated Hummingbirds, slow motion, August 2010 from Hummer Lover on Vimeo.

All hummingbirds behave similarly. Masters of speedy, controlled flight, they can hover in place, move backwards and forwards, dive and soar with incredible speed and precision. They can reach speeds of up to 60 mph, their wings whirring at 80 beats per second. Males in particular are territorial and aggressive, cheeping furiously as they drive off rivals from a good food source.

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Ruby-throated Hummingbird. Photo by JC Donaho http://jcdonaho.com/

Hummingbirds’ main food is flower nectar, so they are important pollinators of certain species of plants. They especially seem to gravitate to red flowers, although other colors are visited. Their long thin beaks and even longer tongues allow them to reach inside floral tubes that are much too deep for most butterflies and bees. Since birds in general have a poorly developed sense of smell, flowers pollinated by hummingbirds typically have no scent.

Hummingbirds also eat small insects such as fruit flies and gnats, catching them on the wing or finding them inside the flowers they probe for nectar.

Bottle feeder with ant-guard

Bottle feeder with ant-guard

Because they love sweet fluids, it is easy to provide feeders for hummingbirds, and several designs are available. Hummingbird food is simple to make; you just need sugar and clean water. DO NOT use any other sweetener – including honey or other types of sugar –just your standard white table sugar. Use four parts water to one part sugar. Bring the water to a rolling boil, add in sugar and stir until it dissolves, then turn off the heat. Do not cook it too long or it will start to caramelize. Let the solution cool and you are ready to fill your feeders. Keep extra sugar solution in the refrigerator.

IMPORTANT! If you want to feed hummingbirds you must commit to regularly changing their sugar water food! Sugar water ferments and/or grows mold quickly, and when spoiled it can make hummingbirds sick. Since you will need to clean the feeders about every three days, do not fill them too full or you will waste a lot of sugar solution. Fill them from between ¼ to ½ full, at least until you see how fast the hummers empty them.

DO NOT add red food coloring, and avoid commercial solutions with food coloring. Coloring is not necessary, as most feeders have red parts built in to attract the hummers’ attention. Like spoiled sugar water, food coloring is bad for the hummingbirds’ health.

Every three days, even if your feeders are not empty, clean them thoroughly with hot water and refill them with fresh solution. At the end of the season you should sterilize the feeders either in the dishwasher or using a dilute bleach solution before drying and storing them until next year. I prefer to use glass feeders as these are easier to sterilize.

 

Perky Pet feeder

Perky Pet feeder

A few guidelines on feeder placement – hummingbirds are not at all shy, so you can put feeders near your house where you can enjoy watching their activity. I put one right outside my kitchen window, and hang others around my back yard, especially near trees or bushes where hummingbirds can perch between bouts at the feeder. If you put out more than one feeder (I recommend this!), don’t put them too close, and ideally place them out of sight of each other to avoid their being monopolized by one dominant male.

Salvia leucantha, aka Mexican Sage

Salvia leucantha, aka Mexican Sage

In a good season, you will have dozens of hummingbirds – and the more feeders, the more hummingbirds! I usually put out from 3 to 9 feeders, depending on activity. Of course, hummingbirds also visit flowers for nectar. The classic hummingbird flower is red with a long floral tube, but many others also bring them in. Some good choices are salvias (many varieties), hummingbird bush, coral vine, trumpet creeper, and russelia.

Salvia guaranitica, or Purple Majesty Sage

Salvia guaranitica, or Purple Majesty Sage

Of course, if you have outdoor cats, you should not put out hummingbird feeders or any other kind of bird feeder!

Did you know?

  • Hummingbirds are only found in the Western Hemisphere.
  • Hummingbirds’ jewel-like, glittering colors do not come from pigments, but result from the refraction of light hitting special structures on their feathers.
  • The Bee Hummingbird from Cuba, less than 2.5 inches long, is the world’s smallest bird.
  • The largest hummingbird is the Giant Hummingbird, from Patagonia, Chile. It is about the size of a cardinal, but only weighs half as much (about .65 ounces, or about 1/20th of a pound).
  • The longest hummingbird is the Black-tailed Trainbearer from Colombia. The male’s total length is about 10 inches, including its 6.5 inch tail!
  • The Sword-billed Hummingbird from Ecuador has a 4 inch long beak, almost as long as its body!
  • Check out the PBS Nature special on hummingbirds, “Magic in the Air,” for some amazing footage of these incredible creatures!

Gamers Unite: See how you’d fare in battle with Battleship Texas at HMNS 9/20 and 11/11

This post was written by guest blogger Andy Bouffard, Wargame Facilitator.

“To a wargamer, wargames are not abstract, time-wasting pastimes, like other games, but representative of the real… You can learn something from wargames; indeed, in some ways you can learn more from wargames than from reading history.” Greg Costikyan in the collection Tabletop: Analog Game Design.

The Battleship Texas exhibit, now showing at the Houston Museum of Natural Science, provides visitors with plenty of history to read, videos to watch and lots of fascinating artifacts to admire. On September 20 and November 11, 2014, 9 a.m. – 5 p.m., another dimension to the Battleship Texas exhibit can be experienced — wargaming

Museum visitors will be able to do more than read about naval warfare, via the written history of USS Texas. On these days you will be encouraged to interact with two simulated battles, each illustrating a different age of maritime warfare and each using representative model ships from their respective age.

Simulation 1
Throughout much of WWII, the German battleship Tirpitz, sister to the famed Bismarck, was a threat in the icy waters of the Norwegian and Barents Sea — threatening to leave the protection of Norwegian ports and attack Russian-bound Allied convoys out of Great Britain or to break out through the Denmark Straits as Bismarck once had. Meanwhile, throughout much of 1942, USS Texas escorted convoys and patrolled the seas, protecting against the likes of a raiding Tirpitz. While Tirpitz and Texas never met, historically, we’ll explore what might-have-been had Tirpitz attacked an Allied convoy and Texas was there to stop her.

Could Texas and her escorts have been a match for Tirpitz?  Help us find out!

Simulation 2
On September 5, 1781, the British army at Yorktown, Virginia, was surrounded by the Continental Army on land and the French navy at sea. Unexpectedly, a British fleet commanded by Sir Thomas Graves arrived to challenge the French blockade of Lord Cornwallis’ army. Although caught by surprise, the French fleet under Admiral De Grasse was able to form a line of battle and prevent the British from breaking the siege of Yorktown. The battle itself could be called a draw, but it did force the British fleet to return to New York for reinforcements and refitting. It is not an understatement to say that this seemingly inconclusive battle led to the formation of the United States of America. 

Can YOU do as well as De Grasse, or maybe even better than Thomas Graves? Find out!

More on Battleship Texas, at HMNS through November 16:

The exhibition, organized by the Texas Parks and Wildlife Department, highlights the history of the Battleship Texas in service to the United States Navy through World War II. It showcases 60 artifacts of the only surviving U.S. Navy vessel to have seen action in both world wars. Objects on view include a never-before displayed flag from the ship and a shell that hit the vessel but did not explode, plus select pieces from the silver service presented to the battleship by the people of Texas, historical photographs and personal items from men who served aboard the Battleship. A special listening station shares crewmember memories of service aboard the Battleship during World War II.

More on Wargaming in Houston:

Inspired by the National WWII Museum’s “Heat of Battle” wargame convention, Texas BROADSIDE! is held annually aboard USS Texas and uses wargaming as a means to educate the visiting public about the history of US armed conflict.  The event features local-area gamers playing board and miniature wargames aboard the USS Texas.  These games simulate various battles on land, at sea, or in the air, from early American military history, through WWI and WWII, and on to more recent, modern day, battles.  Don’t miss Texas BROADSIDE! 2014 on USS Texas held October 10-12. All proceeds will be donated to the Battleship Texas Foundation. The event is hosted annually by the Houston Beer and Pretzel Wargaming club. Details can be found here.

Houston Beer and Pretzel Wargaming is a group for gamers who meet once a month to share in wargaming amongst friends with good food and drink and wargames camaraderie.  Details can be found at here.

 

It Takes a Village ….A Milkweed Village

monarch-2

As the obligate host plants for monarch caterpillars, milkweeds are a staple in any butterfly habitat garden. However, milkweed is not just for monarchs! Many other insects call the genus Asclepias home, giving rise to the concept of a “milkweed village.”

Milkweed plants produce bitter tasting toxins called cardiac glycocides, and insects that eat milkweeds have evolved to use these to their advantage, sequestering the toxins in their bodies to protect themselves from predators. Most, if not all milkweed-eating insects have markings of black and orange or yellow, a type of aposomatic coloration that warns predators of their horrible flavor. If a predator such as a bird, lizard, or spider were to eat one of these insects, it would spit it out. The next such insect would be avoided, as its coloration would remind the predator of its foul flavor.

Most butterfly gardeners have encountered the bright yellow oleander aphid, Aphis nerii, which congregates on the new growth, flowers, and developing seed pods of milkweed plants. Aphids are phloem feeders, meaning that they suck the sap, along with the toxins, out of the plant’s vascular tissue.

Ladybug larva

Ladybug larva

The presence of these aphids on milkweed attracts a number of predatory insects. Ladybug larvae and adults (Hippodamia spp. and others) are important predators of milkweed aphids. Other small beetles such as mealybug destroyers, Cryptolaemus montrouzieri, and scale destroyers, Lindorus lopanthae, eat aphids along with other small sap-feeding insects. These beetles are interesting creatures in that their larval stage looks just like their namesake (i.e., mealybugs and scale, respectively).

scale destroyer larva2

Scale destroyer larvae

The maggot-like larvae of syrphid flies also eat aphids, sucking their bodies dry. Syrphid pupae look like little brown or tan teardrops. If you notice these on your milkweed plants, leave them in place to ensure another generation of these beneficial flies.

Syphid fly pupa

Syrphid fly larva

Tiny parasitic wasps such as braconids lay their eggs in aphids’ bodies. The wasp larvae feed on the inside of the aphid until they pupate, then exit as an adult wasp through a tiny hole in the aphid’s exoskeleton. The leftover brown “shell” is called an aphid mummy. These mummies are a good sign that your aphids are being parasitized. Don’t worry, these wasps don’t harm monarch caterpillars.

aphid mummy

Aphid mummies

With all of these great beneficial insects around, I hardly had to spray our milkweed crop at the museum with any insecticidal soap this year. However, if the aphid population on your milkweeds gets to be overwhelming, the best way to knock them back is to spray them off the plants with a sharp stream of water. Try to avoid damaging or knocking off any beneficial insects in the process.

Other “pests” of milkweed plants include the milkweed leaf beetle, Labidomera clivicollis. These chunky, orange and black beetles and their larvae feed on milkweed leaves.

Milkweed Beetle (Wikipedia)

Milkweed Beetle (Wikipedia)

Large milkweed bugs, Oncopeltus fasciatus, are also common in the southern United States. These oblong-shaped, sap-sucking true bugs are orange and black and mostly feed on the developing seeds, flowers and nectar of milkweed plants. They don’t usually cause much damage.

Now we come to the most familiar milkweed inhabitant – the monarch butterfly, Danaus plexippus. As we all know, monarch caterpillars eat voluminous quantities of milkweed leaves, and display the textbook aposomatic coloration of white, black and yellow stripes. Their chrysalids, or pupae, are a gorgeous jade green with gold lines and spots.

monarch

Here in Houston we sometimes encounter another milkweed visitor – the queen butterfly, Danaus gilippus. Queen caterpillars look very similar to the monarch, but they have three pairs of tentacles instead of the monarch’s two. Their chrysalids are also similar, but are a bit smaller and may sometimes be a pale pink rather than green.

Like everything else, monarchs are part of the food chain, and are preyed upon or parasitized by a number of different organisms. One of their most prevalent parasites is a tachinid fly, a gray, hairy species about the size of a house fly. An adult fly female will lay her eggs on a monarch caterpillar and when they hatch, the maggots burrow inside. The maggots live inside the caterpillar, eating its tissues, until they are ready to pupate. At that point they crawl out of the caterpillar and fall to the ground, where they pupate in the soil The maggots often leave the caterpillar after it has pupated, leaving a trail of slime that dries up and looks like white strings hanging from the chrysalis. These strings are tell-tale signs of a tachinid fly infestation.

Tachinid fly larva emerging from monarch caterpillar.

Tachinid fly larva emerging from monarch caterpillar.

Assassin bugs, Zelus sp., are frequent visitors to milkweed plants. This true bug will stab monarch caterpillars with its rostrum or beak, paralyzing the victim and liquefying its insides, making it easier to consume.

Vespid wasps are another important predator of monarchs. The familiar large red wasps, Polistes carolinus, and the smaller yellow and black European paper wasp, Polistes dominulus, both hunt caterpillars as food for their own hungry larvae. Once a wasp finds a host plant with caterpillars, she will come back regularly to check for more, especially in the summer months when wasps are the most active. This can be upsetting to butterfly gardeners. To protect your caterpillars from these all-too-efficient predators, place a screen such as a pop up or mesh laundry hamper between them and the wasps.

Polistes carolina  Photo by Val Bugh

Polistes carolina Photo by Val Bugh

 

Polistes dominulus

Polistes dominulus

Finally, a parasite of notable concern that specifically affects monarchs (and also queens) has emerged on the scene of butterfly gardening. This protozoan parasite, Ophryocystis elektroscirrha, commonly known as Oe, begins with a dormant spore, usually deposited by an infected female monarch as she lays her eggs on a milkweed. When the caterpillars hatch and begin to eat, they consume the Oe spores along with the leaf. Once inside a caterpillar’s gut, the spores become active and reproduce several times. When the butterfly emerges from its pupa, it is covered in dormant Oe. spores, giving rise to the next generation of infected monarchs. Mildly infected butterflies may show no sign of infection but as Oe levels build up, they eventually cause problems such as weakness, deformity, and even death.

OE Life Cycle (Monarchparasites.org)

OE Life Cycle (Monarchparasites.org)

The annual migration to Mexico each fall helps to weed out infected butterflies, which are usually too weak to make the long trip and die along the way. However, some monarchs don’t migrate and may stay in the Houston area all winter long. In the south, butterfly gardeners primarily grow tropical milkweed, Asclepias curassavica, which unlike the native milkweeds does not die back to the root in the fall. Oe spores can remain viable on the leaves of this perennial species for some time, infecting the next generation of caterpillars that eats them. As this situation repeats, it can cause populations of severely infested monarchs. We therefore encourage butterfly gardeners to cut back their tropical milkweed every spring after the first generation of monarchs arrive and eat the milkweed down, and then again in the fall before or during the migration, so that the butterflies will be encouraged to migrate and not overwinter here.

Spiny soldier bug nymph eating a monarch caterpillar. (Photo by Dan McBride)

Spiny soldier bug nymph eating a monarch caterpillar. (Photo by Dan McBride)

With all of these challenges, it’s no wonder that only five to ten percent of monarch eggs make it to adulthood. Keep in mind however, that monarchs are an important part of the food chain and without their survival and natural demise, our native ecosystem would not be as diverse as it is. In any case, human interactions with the environment have caused the most damage to monarch populations – huge amounts of monarch habitat has been lost due to the expansion of agricultural land and use of Roundup Ready crops. Planting butterfly-friendly gardens, especially if they include milkweed, can help mitigate this loss of habitat.

You can do your part by attending our fall plant sale at the Houston Museum of Natural Science. Stock up on the nectar plants that monarchs need to fuel their migration as well as host plants for native butterflies.

The sale will be held on Saturday, October 11th from 9:00 a.m. until noon (or until plants are gone), and will take place on the 7th level of the museum parking garage. Remember, the early bird gets the larva, so to speak, and don’t forget your wagon!