A Trick or a Treat?

In less than a week, people all over the country, including right here at our museum, will be celebrating Halloween. Perhaps your workplaces and schools are already festooned with ghosts, skeletons, graveyards, and the like.  If you stop and think about it, you may wonder just how it is that we came to celebrate by trying to disguise ourselves or by trying to frighten people.  Is this a trick or a treat?

Picket fence and yellow trees
Creative Commons License photo credit: joiseyshowaa

The short answer as to why we celebrate this time of year with images of death is that we are in the middle of autumn, the season when nature itself is dying.  To fully understand why we celebrate Halloween when we do, we must fully understand the seasons.

Earth orbits the Sun with its axis pointed at the North Star, Polaris. As a result, its axis is tilted by about 23.5 degrees with respect to its orbital plane.  This tilt, combined with Earth’s revolution around the Sun, causes the seasons.  If the North Pole leans towards the Sun, the Sun is higher in our sky and we get more direct sunlight.  Also, daytime is longer than nighttime.  As the North Pole begins to tilt away fron the Sun, the Sun appears lower and lower across the sky, and daytime gets shorter and shorter.  Eventually, the slanted-in solar rays and short days bring about winter.  Very cold air masses form in the darkened Arctic and begin to move south, some of which can even reach Houston.

Keep in mind that the Earth’s axis does not tilt back and forth; it points at Polaris the whole time.  In June, the North Pole is leaning towards the Sun, but by December, the Earth’s motion has carried it to the other side of the Sun.  The North Pole, still tilting the same way, now leans away from the Sun.

A common misconception is that the Earth is closer to the Sun in summer and more distant in winter, and that is what causes our seasons.  In fact, Earth’s perihelion (closest approach to the Sun) occurs just after the new year (January 1-4), while aphelion (greatest distance from the Sun) occurs around the 4th of July.  Earth’s orbit is an ellipse, but the Earth-Sun distance does not change by enough to affect our seasons.

where are you?
Creative Commons License photo credit: shioshvili

In the cycle of seasons, there are four points of note.  At the March equinox, neither pole is tilted toward the Sun and the Sun is directly overhead at the equator.  The is the vernal (spring) equinox for us and the autumnal (fall) equinox for folks south of the equator.  At the June solstice, the North Pole is tilted as much as possible towards the Sun, and the Sun is overhead at 23.5 degrees North (the Tropic of Cancer).  This is the summer solstice for us and the winter solstice in the Southern Hemisphere.  At the September equinox, once again neither pole tilts toward the Sun, and the Sun is again overhead at the equator.  This is our fall equinox and their spring equinox.  At the December solstice, the North Pole is tilted as much as possible away from the Sun, and the Sun is overhead at 23.5 degrees South (the Tropic of Capricorn).  This is the winter solstice for us and the summer solstice below the equator. 

We generally think of these points as the beginning of spring, summer, fall, and winter, but it doesn’t have to be that way.  After all, nothing magically happens with our weather on these dates.  We could just as well consider these points the midpoints of each season.  In that case, the seasons would begin and end at points roughly halfway between the equinoxes and solstices, in early February, May, August, and November.  If the equinoxes and solstices are ‘quarter days,’ the points halfway between them become the ‘cross-quarter days.’

The ancient Celts of Europe appear to have divided their year in precisely that way.  Gauls living in what is now France used a calendar of twelve lunar months with a 13th month added every 2.5 years (similar to the Hebrew calendar today).  Their two most significant months were Gamonios (lunar month corresponding to April/May ), which began the summer half of the year, and Samonios (lunar month corresponding to October/November) which began the winter half of the year.  Julius Caesar noted that daytime followed nighttime in Celtic days.  By extension, the dark (winter) half of the Celtic year preceded the light (summer) half, making Samonios the start of their new year.

The Celts in the British Isles (Irish and Scots) also had festivals aligned with the cross-quarter days.  In early February was Imbolc (or St. Brigid’s day).  Weather predicting traditions of this day are preserved in our current Groundhog Day.  Traditional May Day celebrations are similar to those of the Celtic BeltaneLughnasadh, in early August, marked the start of the harvest. 

'' The Sentiment of Light''
Creative Commons License photo credit: jdl_deleon

The most important, though, was Samhain (pronounced ’sah win’, not ‘Sam Hane’, due to rules of Gaelic spelling), in early November.  This three-day festival marked the beginning of the winter half of the year and the start of the whole year, like Gaulish Samonios.  It was the close of the harvest opened at Lughnasagh, and the time for culling excess livestock.  At this time, the veil between the living and the world of the dead was considered thinner than usual, and people looked forward to meeting and communing with ancestors and relatives who had died.  A ‘dumb supper‘ was set aside for departed relatives.  To scare away unwanted spirits, people dressed in frightening garb.  Note that these spirits were considered unpredictable and possibly mischievous because they were not the familiar ancestors–not because they were particularly evil.  Divination was also practiced at this time, as people sought to predict whom they would marry or how many children they would have. 

Doing the math, you’ve probably figured out that Halloween is not quite halfway from the equinox (September 22) to the solstice (December 21).  But remember, the Celts used a lunar calendar.  They celebrated their festivals on a certain phase of the Moon, possibly full moon, occurring nearest the cross-quarter day.  Upon the adoption of the Julian calendar, which was not strictly lunar, the festivals were moved to the beginning of February, May, August, and November, although this meant they were no longer exactly on the cross-quarter days. 

Saint
Creative Commons License photo credit:
The Wandering Angel

In the eighth century AD, Pope Gregory III moved the church’s commemoration of the souls in heaven (All Saints’ Day) from May 13 to November 1.  Another name for All Saints’ Day is All Hallows Day.  (’Hallow’ is an older term for ’sanctify’ or ‘make holy.’  Think of ‘…hallowed be thy name’ from the Lord’s Prayer).  The next day became All Souls’ Day.  The day before All Hallows Day or All Saints’ Day is All Hallows Eve, or Halloween.  The traditions of Samhain, with its similar focus on honoring the dearly departed, were a natural fit for All Hallows Day and All Hallows Eve.

Halloween, then, is ultimately just one expression of the human need to come to terms with death as a natural occurence and to honor those who have gone before.  In the season of the fall of the leaf, with the Sun taking a slightly lower path across the sky each day, the natural world is going through its own ‘death,’ providing a perfect context for our own activities.  We can therefore think of Halloween itself as a treat, not a trick.

I wish everyone a Happy Halloween, with many more treats than tricks.

Summer Encounters – Brazos Bend State Park

Oak tree

Welcoming Oak Tree

Last summer I was introduced to Brazos Bend State Park. I found many amazing animals living amongst the tall swamp reeds and old oak trees. Recently, I spent a weekend down there camping with my family. I’d like to share some of the beautiful animals we encountered on this visit.

Now, like many people, I’m not particularly fond of certain small, creepy-crawlies, including my least favorite: ticks! Unfortunately (and much to my dismay) I was feasted upon by one tiny tick. However, when I was given an opportunity to watch a spider feast upon its own meal, I didn’t feel the same distress. Near our campsite, there were plenty of enormous spiders for us to observe. I was astounded by the size and beauty of the Golden Silk Spider, Nephila clavipes, often called the Banana Spider.

Golden Silk Spider

Golden Silk Spider

She is relatively harmless to humans, but has an impressive web and can take down dragonflies. This species are also a cannibalistic species, preying upon their own kind. The males live on the backside of the web from the female, risking their lives to mate when the time is right. I witnessed a large female dining on a smaller female early one morning. Apparently, it is not such a good idea to build your web directly in front of a larger, hungrier silk spider! If you look closely at the photo to the right, you may be able to see the much smaller male sitting a couple of inches to the left of the female.

As a side note, I learned that another spider, the Brazilian Wandering Spider, Phoneutria nigriventer, is also often called a Banana Spider. This spider can be fatal to humans and should not be taken lightly.

Another favorite invertebrate that I was able to find at Brazos Bend State Park is the firefly (not to be confused with the excellent, but short TV series Firefly), also known as lightning bugs. Last summer was the first time I had ever seen them and I was still very excited when I saw them again this summer. I also managed to catch one and study it up close, watching as the abdomen slowly glowed on and off. These beetles use their bioluminescence to communicate with each other. Each species of firefly has their own, distinct pattern they flash to attract a mate. The male flashes his pattern while flying around, hoping to find a female responding to his light with her own light show. However, some females will mimic the pattern of another species in order to catch their dinner!

Lightning Bug

Lightning Bug

While walking around Elm lake, you can’t help but notice all of the beautiful water birds. They share the lake with the alligators, seemingly unaware of the dark eyes resting at the edge of the water’s surface. During the summer, you can easily spot pairs of white ibises, egrets & herons, common moorhens, black-bellied whistling ducks, and on occasion you may spot an osprey or wood stork. Below, I’ve posted a photo of a Green Heron, Butorides virescens, looking for his lunch amongst all of the duckweed. Green Herons typically hunt small aquatic animals including invertebrates, small fish, & frogs. It has been known to “bait” for fish, dropping a small item on the surface of the water and waiting to catch the fish attracted to the lure.

Green Heron

Green Heron

The last animal I want to bring up from my encounters at Brazos Bend State Park is the Nine-Banded Armadillo, Dasypus novemcinctus. We were hiking on a path near the George Observatory while we waited to buy tickets to look through the telescopes later that evening. My well-trained ears told me there was an animal moving about in the underbrush nearby. I turned to look and couldn’t believe my eyes when I saw my first armadillo! The novelty of this new mammal had me snapping pictures left and right, spending a good 20 minutes observing its search for food.

Nine Banded Armadillo

Nine-Banded Armadillo

Eventually, my dogs noticed this new creature and started barking. By this time, the armadillo had meandered right near the path and upon being frightened by the dogs, he did an about-face and nearly ran straight into my friend’s legs! He eventually found his way back to the denser foliage and continued foraging for lunch. After this first encounter, we later came across 4 more juveniles, these were much quicker to run away from us than the first adult we observed.

The nine-banded armadillo may be opportunistic, eating whatever food they come across, but mostly they eat a wide variety of invertebrates: caterpillars, scarab beetles, grubs, termites, & worms. They will also eat carrion and occasionally crustaceans, fruit, reptiles & amphibians. Armadillos are excellent diggers but have poor vision. When frightened, they may jump straight into the air!

Armadillos are capable of crossing water in two interesting ways. In order to get around the problem of their heavy armor, the armadillo can hold its breath and simply walk across the bottom of a body of water. However, they are able to swim by inflating their stomach to offer some bouyancy. Nine-banded armadillos have identical quadruplets around March, the young staying with the mother for several months.

If you would like to see more photos from Brazos Bend State Park, please visit the BBSP Flickr group webpage. You can also find a wide variety of photos from HMNS at their Flickr group page as well. I am still working on updating my own Flickr page with Museum-related photos, but in the meantime, enjoy this one last photo of the largest alligator I’ve seen at Brazos Bend. I was standing directly above him on a dock at Hale lake. My best guess at his length: 12-14 feet long!

Large Alligator

American Alligator

Summer Encounters – Around the House

Green Anole on ti plant
Creative Commons License photo credit: mannyh808

Summertime in Houston has been very exciting for me. This is my second summer living here and each year I discover new animals.  Last year, I was thrilled to learn about Anoles, Mediterranean House Geckos, and of course, American Alligators. My first job at the Museum was to assist in teaching field camp during the summer for our Xplorations program.  I quickly became familiar with the wildlife of Houston’s surrounding areas along with learning how to survive the heat and humidity while hiking.  My previous experiences with animals in Oregon and New Mexico did not prepare me for the entirely different array of wildlife here in the South.

Tersa Sphinx caterpillar
Tersa Sphinx caterpillar

My first encounter with a new animal this summer happened in my own back yard. On my small butterfly bush, I happened accross a very large, brown, spotted caterpillar.  Since childhood I have had a fascination with these lovely little insects and so I promptly ran inside to get my camera to document my find.  I later had the caterpillar identified by one of the Museum’s entomologists, Laurie.  She quickly ID’d my caterpillar to be a Tersa Sphinx, Xylophanes tersa.  I was amazed at the size of this butterfly larva.  After enduring the bites of the huge zebra-striped mosquitoes and now seeing this large caterpillar, I was once again reminded that everything’s bigger in Texas.

On the other hand, last month we were asked to identify a tiny, writhing, worm-like creature.  It was found near our office which added to the curiosity of this animal.  It was only about 2 inches long, very smooth, not slimy, and appeared to have scales with a pointy tip for a tail.  Was it a type of worm?  The diminutive size and shape suggested worm, but it was somewhat hard to the touch, a bit shiny, and without any of the mucous normally occuring with worms.  Could it be a caecilian?  No, those don’t live in Texas and would definitely be slimy.  Could it be a very tiny snake baby?  Aha! Perhaps we were getting somewhere.

Texas Blind Snake
Texas Blind Snake, Leptotyphlops dulcis

After consulting with my friend who’s an herpatologist by hobby (thanks, Ira!), we discovered that we did indeed have our hands on a tiny snake.   Judging by its size & character, this itty-bitty critter was a juvenile Texas Blind Snake, Leptotyphlops dulcis.  I was reassured of this animal being a snake when I noticed it would occasionally stick out its tongue.  This small serpent would only grow to be about 8 inches in length, by far the smallest snake I have ever had the pleasure of meeting.  Many Texans may come across this snake in their gardens under logs or bushes, mistaking it for a worm.   It emerges from its hiding place in the soil to feed on termite and ant larvae, making it a welcome hunter to any gardener.  Like many other native species, it has been adversely affected by the red imported fire ant

Update. The BBC has published an article on 8/4/08 about the world’s smallest snake, Leptotyphlops carlae, found in Barbados.  This smaller relative to the Texas Blind Snake will only reach 4 inches at maturity, half the size of our native Leptotyphlops dulcis.

The final animal I’d like to share today is the first new mammal I’ve seen in Houston.  Much to my dismay, my dogs (Sasha & Dione) like to dig holes in our backyard.  Dione is quick enough to catch any unfortunate animals that may happen to find themselves in her territory.  As fas as I can tell, she is more interested in playing with the animals than eating them.  One evening, she finally managed to dig up an Eastern mole, Scalopus aquaticus.  I’m sure she’s been hunting them for a while, hence all the holes in our yard.  I rescued the poor mole from the dogs and brought it inside to investigate as I’ve never seen one until now.  It was covered in slobber so I wasn’t able to enjoy the silky smooth coat that is a normal characteristic of moles.

Mole
Eastern Mole, Scalopus aquaticus

The most amazing feature of this mole were its feet.  The front feet are very large, broad, paddle-shaped feet with webbing between the toes - perfect for digging.  In comparison, the hind feet were very small, similar to those of a mouse.  The mole’s eyes, ears, and nose also indicated a subterrestrial life.  We were unable to see any eyes or ears through its fur.  There really isn’t much to see underground and protruding ears would simply get in the way of digging. The nose was long and sensitive, great for smelling prey in the dark.  One type of mole, the Star-Nosed Mole, has an extremely sensitive sniffer.  It has even been found to sniff underwater.  Our Eastern Mole may not be able to smell underwater, but they do consume a great many invertebrates that can be potentially damaging to plants.

If you have crossed paths with an unfamiliar Texas animal, please share with us as we enjoy hearing about other people’s experiences.  Look for Summer Encounters – Brazos Bend State Park as my next blog post when I share some of my adventures in hiking around BBSP roasting alligators and hunting marshmallows….oops.  Well, you know what I mean.

Diary of a Summer Camp Shopaholic

Summer camp is here and the lower level of the Museum is full of summer campers of all ages. Those of us who work in the Education Collections area, where we house all of the supplies for Summer Camp, really know how to shop.

Xplorations Summer camp is made of 20 onsite classrooms at HMNS, each with about 20 children each week participating in 20 hours of hands on activities with materials ranging from flowerpots and fingerpaint to raw eggs and racecars – we need a LOT of materials.

My weekends are filled with trips to the more obscure places for the more specific items like 10lbs of bulk flat sided plastic, gemstones for Star Warrior’s sashes and as many mini aluminum pie tins as we can find (believe me, I’ve been to about 10 stores looking for them – they are hard to find) as well as the usual trips to grocery stores and Target for several shopping baskets worth of goodies.

We also order from lots of scientific supply companies, restaurant suppliers and educational suppliers each week. My fabulous ExxonMobil Community Summer Jobs Program intern, Julia, heads out to Fiesta or Randalls at least twice a week for more eggs, milk or baking soda. I thought I’d take a few photos of our supply stash so that you all could see what it takes to fill our camp classrooms with fun for everyone.

restaurant-supply.jpg

Cups and Deli Containers and Plates – oh my.

slant-blue-aisle.jpg

We try to keep some method to the madness in our supply
room – labeled blue bins help us stay as organized as possible
among the craziness of camp.

candyland.jpg

Our very own candyland. Candy is used in camp for DNA
models, construction materials and certain candies can even
trigger soda explosions.

kitchen2.jpg

The camp crew is very proud of our new “Kitchen Land” where
all things kitchen and food related have gone to live this
summer — allowing them a separate home from construction
paper and fingerprint powder.

We have two refrigerators for camp in our supply area. One contains various “staining items” for Test for the Best’s stain remover test, Wizard Science Academy’s squid and swamp eel for dissecting and many containers of “flobberworms” (earthworms for non-wizard shoppers); the other seems to contain lots and lots of eggs and milk.

Camp trips to the grocery store usually involve at least two or three full baskets and it is always fun to see how long it takes the checker to ask what you’re doing with 20 chicken legs with thighs attached, 40 tubs of vanilla icing, a bag of dog food, 25 boxes of sugar cubes, eight boxes of dinosaur fruit snacks, eight varieties of milk chocolate bars, six, 18-packs of eggs, 44 small oranges and all of the marshmallows that came in on yesterday’s marshmallow delivery. Sometimes people are too embarassed to ask, but when they do and we tell them that it’s for HMNS Summer camp - it explains a lot.

fridge.jpg

What’s the wierdest thing in your fridge today? We have a vacuum sealed swamp eel (from Nicole’s favorite stop – the Asian market).