The "Time-Compensated Sun Compass"

We left Mission this morning at 9:15 AM, drove 340 miles and decided to stop in Sugar Land (3 to 4 hours south of Nacogdoches).  We will finish our 10-week trip tomorrow.  It will be nice to get home.

We found a nice big Walmart with a Sam's Club next door, both sharing the same parking lot.  The place was busy and it was hard finding a section of parking space on the fringe of the lot into which I could maneuver the motorhome with toad. I drove around the entire parking lot twice without running over anything or looking any of the people staring at me in the eye.  I'm only taking up about 10 parking spaces but there are 2 other motorhomes with toads close by and taking up almost as much space (they aren't as long).  As a matter of boon-docking ("dry camping") etiquette we will not extend the slide outs.  It will be a little cramped but we are only here for the night.

The temperature here is Sugar Land is a very pleasant 71 degrees and a soft cool breeze is flowing in through our open windows.  Since our only power source is the generator it's good that we don't need A/C or heat (at the moment, anyway).  We are parked on the Sam's Club side of the lot, which is good, as they have free wi-fi for their customers and with my USB amplified antenna I am able to write this note and surf the web while sitting in the comfort of my motorhome.

Now we can finish the butterfly lessons by discussing the Monarch's navigation system.

How does the migrating Monarch butterfly find its way?  It’s not easy, that’s for sure.  You will need a clear head to follow my explanation.  So, pay attention!  There will be a test.

An airplane requires several different navigational instruments and aids to follow a defined flight path.  Especially for a flight of 2,000 to 3,000 miles.  The Monarchs have none of these devices, not even a map or a compass.  At least not a physical map or compass, as we would use.  They do utilize a very complex navigational system that is built into their genetic code, which uses their pin-head sized brain and their antennae to give them direction.  It’s like having a built-in GPS in your car.

Scientists call the Monarch’s genetic navigational system a “time-compensated sun compass” with time being measured by “circadian clocks” located in their antennae.  The “sun compass” uses the sun’s position during the day with timing information from the “circadian clocks” to maintain a constant heading.  A “circadian clock” is basically a 24-hour rhythm that repeats daily without the presence of any known external cues.    The rhythms can be adjusted to match the local time.  That just means that they can adjust themselves as the days lengthen or shorten during the year. 

The Monarch has 2 of these clocks.   One is incorporated into each of the Monarch’s two light-sensitive antennae.  Scientist refer to this as a “dual timing system”.  Only one antenna is required for the system to work sufficiently.  Therefore, if an antenna is damaged or lost the Monarch just keeps right on trucking without skipping a beat.  It is therefore a “redundant” system. 

The Monarch’s navigation system works by computing its position relative to the sun to keep it on course.  Timing is required for the Monarch to adjust his course for the position of the sun at any time of the day (think of it as a moving target as it moves across the sky).  The sun’s movement means that the angle of the sun relative to the Monarch is continually changing and therefore is continually being recomputed during the day.  The sunlight is processed through the Monarch’s eyes and antennae to adjust the “sun compass” so that the Monarch knows his position relative to the sun at any time during the day. 

I realize that I may have over simplified the explanation.  But at least you didn’t have to read science-speak such as; “the core mechanism relies on a negative transcriptional feedback loop, which drives self-sustaining rhythms in the mRNA and protein levels of a distinctive set of core clock components.”

By the way, I never did find out if they taste like chicken.  It takes about 400 to 500 Monarchs to make a pound and I never even found one.

A 3,000 Mile Rountrip

This morning was very cool and overcast.  The temperature at 10:00 AM was only 55 degrees, which is not good for Monarch hunting as they will not be moving.  The sun did come out about mid afternoon and during the half time of the Georgia vs. Florida football game (which my Bulldogs won, by the way.  Go Dawgs!) I went out and continued my search for Monarchs.  I saw plenty of its cousins but no Monarchs.  It seems as though I will be leaving Mission tomorrow morning without any Monarch photographs.  I did see one that was new to me.  Its photo is included here but I have not even tried to identify it. 

With wings open

With wings closed

This year may turn out to be one of the worst, if not THE worst, Monarch butterfly migrations in history!  A 20% to 30% decline in the Monarch population is expected this year in Texas.  It seems that many of the nectar sources used by the Monarchs as fuel along the migration routes did not reach their full blooming potential this summer due to the existing drought that is plaguing  much of the US (beginning its third straight year in Texas).  Drought and heat stress have significant influence on a plants developmental processes resulting in stunted growth and delays in or absence of flowering.  High heat can even melt the butterfly larvae.

The Monarch population began its decline long before the current drought began.  It has been in decline for the past 8 years according to researchers at Texas A&M University.  The reason is thought to be the increasing destruction of their environment as millions of acres of land are cleared and converted to crop use each year.

I should also mention that not only the drought is killing the plants upon which the Monarchs feed.  Monsanto’s weed filler, Roundup, kills many of the plants relied on by the Monarchs.  The milkweed is one of these plants killed by Roundup.  The larval stage in the Monarch’s life cycle requires milkweed for the larvae to survive.  No milkweed, no Monarch butterflies.

Now, about the migration itself.  First of all, the Monarch butterfly is the only butterfly known to make a two-way migration as birds do.  So, why does a Monarch butterfly migrate up to 3,000 miles from Canada to Mexico and back again?  Is it because they don’t like cold weather?  That is partially true.  The fact is that they are not able to survive the cold winters of most of the United States.  In a previous post I mentioned that the Monarch is cold-blooded.  They are unable to fly if their body temperature drops below 55 degrees.  So why don’t they stay in Mexico?  Because the milkweed plant that the butterfly larvae feed on does not grow in Mexico.  As a result, for the species to survive, it must move back and forth between Canada and Mexico.

Let me try and explain how this migration works.  Since it is a continuous cycle I will start in Canada in the spring.  Female Monarchs arrive in Canada during March and April and lay their eggs on milkweed plants.  It takes about a month after the eggs hatch to produce an adult butterfly.  Call these new adults the “First Generation”.  These new adults will live only 2 to 6 weeks so they waste no time in mating and a “Second Generation” is born in May and June and a “Third Generation” is born in July and August. 

The “Fourth Generation” is born in September and October and is very, very special.  These little guys don’t die in 2 to 6 weeks, as did the previous generations.  Although they look the same as the other generations they are biologically and behaviorally different from those earlier generations.  They are not sexually mature for one thing, so they don’t mate right away.  These changes are triggered by the cooler temperatures and shorter days.  They will live 6 to 9 months and fly all the way to Mexico and spend the winter in the mountain reserves of Michoacán (southbound Monarchs begin crossing the Red River into Texas by the first week in October). 

The Monarchs that return to Mexico each fall are the great-great-grandchildren of the Monarchs that left Mexico the previous spring.  Not one butterfly lives long enough to complete the entire 2-way migration.  So how do any of these butterflies know where to go?  It can’t be a learned trait.  Who would teach them?  Therefore, it must be some innate sense they possess.  No one really knows.  What makes it so weird is the fact that they even go to the same trees in Mexico every year.

When spring arrives, these special Monarchs leave Mexico and fly through Texas, mating and laying their eggs in milkweed plants along the way.  These special Monarchs then die, letting their offspring continue the northward migration to the northern US and Canada.  

Next, what kind of navigation system enables the Monarch to migrate to the same trees, as did their great-great-grandparents?  That’s for tomorrow!  Meanwhile, here are a couple of new photos of one of the guys from yesterday (Soldier or Queen?).

Sipping nectar

Twins

Good Butterfly Hunting

I actually went out looking for butterflies today about midmorning.  I was able to find some sipping nectar from various flowering plants around the RV park.  However, it was difficult to get them to sit still long enough to get a good shot (with the camera).  They are cold-blooded and much more active under a hot sun than in cooler weather.  A cold front is rumored to roll through tonight and drop the temperatures 20 degrees (it has already dropped from 86 degrees at noon to 76 degrees as of 2:30 PM), making tomorrow much cooler and the butterflies a little slower.  If so, then I will visit the National Butterfly Center and Butterfly Park tomorrow and try to get some better photos than I did today.

I did get a few photos on my morning safari and they are on a separate page (see “Butterflies” in right-hand menu).  I was somewhat disappointed not to have seen a Monarch after using it in the leading role of my recent butterfly posts.  Perhaps I will see one tomorrow.   I have attempted to identify the butterflies in today’s photos by using the internet and believe that I have managed to do so for all but one.  When I go to the Butterfly Center tomorrow I will show them the photos and get positive identification.  Perhaps then I will be able to let you know if they actually taste like chicken.

Lost and Found

I wasted most of the day doing nothing before we went to dinner with 5 of the other couples who are with us in Mission.  The chosen restaurant was an Italian one, Milano's, in Weslaco, about 30 minutes away.   We rode with Gary and Sonia but somehow got separated from the pack.  We had never been to Milano's but we had the address and I had the Tom Tom USA GPS app on my iPhone.  We followed its directions and became completely lost.  We double checked and confirmed that the address was entered correctly, however when the "you have reached your destination on the left" was announced we were no where near anything resembling a restaurant.  As a matter we were in a rather seedy looking area.  The restaurant was on West Pike Boulevard but the GPS had put us on East Pike Boulevard and was directing us to drive further east.  I pulled up Google Maps on the iPhone and entered the address but that only seemed to confuse us more.  Gary stopped and tried to enter the address into the truck's built-in GPS but the GPS wouldn't cooperate.  It said something like we were in an unmapped area and thus couldn't get to the restaurant from where we were.  We were literally driving in circles while trying to make sense of 3 different navigation programs.  During this time Gary received two calls from the main group, already at the restaurant and wondering where we were.  A few minutes later I received a call on my phone from the group and they helped with the directions so that we finally found the restaurant.  It turned out that East Pike Boulevard was north of and parallel to US 83 while West Pike Boulevard was south of and parallel to US 83.  It would have made more sense to name them North and South Pike Boulevard instead of East and West.   Better yet, one of them shouldn't have been any kind of Pike Boulevard as they weren't even connected to one another.  It didn't make any sense and even confused all 3 GPS's.

On the way back to the RV park we also took a wrong turn and ended up on the end of a dead end street with 2 Chihuahuas staring us down in the middle of the road.  Gary blinked first and backed up.  By the time we made it back to the RV park it was too late and I was too tired to post another butterfly lesson.  I'll do better tomorrow.

Where Are the Butterflies?

The Big Day is tomorrow.  The official start of the 17^th Annual Butterfly Festival of Mission, TX.  This is why we came.  It is what we have been anxiously awaiting.  There is only one problem.  The severe Texas drought means fewer flowers, fewer flowers means less nectar, and less nectar means fewer butterflies!  The butterflies aren’t picky about which plants the nectar comes from as long as they can find the plants.  They use their vision to find a bloom, but once they are on the plant they “taste” with receptors on their feet to find the nectar.   

Monarchs have a few other “super” powers also.  They can see polarized ultraviolet light (humans cannot) and they can hear ultrasound (humans cannot).  Butterflies can also touch and feel with hairs that cover their “skin”.  Monarchs also have ears and can hear both high-pitch and low-pitch sounds.  However, their ears are not on their heads where you might expect, they have a “hearing” membrane located at the base of each wing.  Their antennae perform double duty.  They are used for both touch and smell.  The male Monarch can smell a female from over a mile away! (refer to yesterday’s post to find out what happens once he gets her scent!)

Due to the drought, I have seen only a few around the RV park.  The butterflies won’t change their migration route in order to find areas less affected by the drought.  The route is hardwired into their DNA somehow.  As a result, there will be fewer Monarchs making it all the way to Mexico.  To make matters worse, the trees in which they roost over the winter in Mexico are being cut down by illegal logging operations, which the Mexican government is attempting to stop.  Unfortunately, until the drought ends and the logging is stopped there will be fewer and fewer Monarchs each year.

Now, when you do see one, how do you know whether it is a male of female?  Do you even care whether it is a male or female?  I don’t especially care but since I found out I’m going to tell you anyway.

The male Monarch Butterfly is easily distinguished from the female by two highly visible black spots (pouches of "love" chemicals) on the male's hind wings and the thinner black webbing within the wings.  The female's webbing is thicker and she has no identifying wing spots as does the male.  Now, go out and find a Monarch and determine its sex.  If you can do that, fee free to call yourself a lepidopterist.

Sex and the Single Butterfly

The only kind of butterfly with which I am the least bit knowledgeable is the Monarch.  In fact it is the only butterfly that I might be able to identify.  It also appears to be the star of the soon to begin Butterfly Festival here in Mission, TX.   So what is so special about this insect?  They each weigh less than 1 gram (0.035 oz.) and they fly from Canada to Mexico, up to 3,000 miles in 2 to 4 weeks.

Before we begin to unravel the mysteries of the butterfly migration it seems appropriate that everyone should be familiar with the life cycle of the Monarch butterfly.  This will be the subject of today’s lesson.  Now, listen carefully, class.

First of all, the Monarch’s life cycle is composed of 4 separate stages.  These are the egg, the larvae (caterpillar), the pupa (chrysalis), and the adult butterfly.

The beginning of this 4-stage life cycle begins as it does with most other insects and animals.  With the male and female fooling around.  The Monarch males are real macho, caveman-type studs.  When the mating seasons begins the male will grab any female he can find, latch onto her and carry her up into a tree where they may go at it for hours, even throughout the entire night!  Once the male has had enough of the female he quickly drops (literally) her and goes on the prowl for another.  This goes on until the females decide they’ve had enough (and are full of sperm) and the migration begins.

The egg stage begins with the female laying eggs.  She can only lay one at a time but she can lay 200 to 400 or so a day.  As she lays the eggs she fertilizes them with the sperm she has stored.  However, she must find a milkweed plant on which to lay the eggs.  If the female lays the eggs on any other plant the caterpillars will die after being hatched.  It takes about 4 days for the eggs to hatch.  The females do not live much longer after laying their eggs.

Milkweed is toxic to most birds and other insects, which helps protect the eggs from predators.   The female doesn’t lay all of her eggs in one place.  She scatters them around as much as possible.  Again, this helps to protect them, not only from predator birds and insects but also from other Monarchs, even the mom herself!  Yes, they are cannibals.  Monarchs will eat their own eggs.  Once hatched, the larvae will also eat other nearby eggs. 

The caterpillar larvae that hatch from the sesame seed-sized egg will feed exclusively on milkweed (with the exception of possibly eating their un-hatched brothers and sisters).   All they do is stuff themselves with as much milkweed as they can.  As they fatten up they outgrow their exterior skin and shed it (molt), EAT it, and continue growing.  The butterfly caterpillar will repeat this process 4 times.  From larvae to pupa takes about a month.

A pupa (chrysalis) is revealed and when the skin is shed the fourth and last time. The pupa then attaches itself to the underside of a leaf and forms a chrysalis.  This is not to be confused with a cocoon.  The outside of the chrysalis is the skin of the pupa.  After about 10 days the front of the chrysalis splits open and the adult butterfly emerges. 

The adult butterfly cannot fly until its wings are unfolded and dry.  The wings have veins through which a fluid is pumped to inflate the wings to their proper size and shape.

Let’s review what we have learned today:

1.      .     Monarch butterflies like sex.  A lot of sex. 
2.           They are promiscuous and have great stamina. 
3.           The female saves the male’s sperm for later use. 
4.           Once the male has tired of a female he tosses her aside and finds another.
5.           Once the females have had it with the males they leave town, have their babies, and die. 

If only life was that simple.

Smugglers, Margaritas, and The Presidential Debate

No news regarding butterflies today.  In fact, not much news at all.  It was a lazy day, most of which was spent inside the air conditioned coach.  Did I mention that it is very hot and humid in Mission, TX?  The "season" doesn't begin until November when the "Winter Texans" overrun every RV park in the area.  Hopefully, it will have cooled off some by then.

We did go out to a grocery store today because we were running out of food.  On the way to the supermarket we decided to take a look at the Bentsen State Park, a very popular "birding" location, and the National Butterfly Center, both within a mile of the RV Park.  We were surprised to find that the State Park does not allow vehicles, except for bicycles.  There is a parking lot at the gate from which you walk to the visitor center.  In this sticky weather we will have to think hard about visiting.

We found the Butterfly Center and saw an arrowed sign that said "Butterfly Park" and pointed down a small road next to the Center.  The road ran straight for about half a mile to the US/Mexico border.  We didn't see anything that looked like a butterfly park (although we had no idea what one should look) but we did find the Border Patrol at the end of the road.  When the agent asked where we were going (we were at the end of a road that dead-ended at the Rio Grande) we replied that we were looking for a butterfly park.  Then he asked where we were from.  I then asked him if the Rio Grande was on the other side of the berm that was in front of us.  He replied in the affirmative and told us that it was a popular crossing for drug smugglers.  The road we were on ended at the berm where there was a cut, or drive, through the berm that allowed vehicles to drive up and onto the berm.  The Border Patrol agent told us that many times when they were chasing a drug smuggler that the smuggler would race down this road, go through the cut in the berm, become airborne, and land in the river.  The smugglers would then exit the vehicle and run (the river is very shallow) to the Mexican side.  All the Border Patrol could then do was seize the vehicle and any drugs it was carrying.  There is now a new and very sturdy barrier at the end of this road to prevent smugglers form using this escape tactic.  I would really like to be there the first night one of the smugglers tries this tactic!  Apparently we didn't look like drug smugglers and after enjoying a friendly chat we turned around and left.

This evening we sat around enjoying frozen Margaritas before having a catered dinner.  Now we are getting set to watch tonight's Presidential debate.  I'm not sure I could watch if I were completely sober.

Butterflies Are NOT Free!

All of the RV’s in our group left the RV park beside the Rio Frio this morning at 8:30.  Carol Ann and I waited and left about 45 minutes later.  Not that we are anti-social, it’s just that since our Mexico adventure we can no longer travel in a caravan.  It’s more stressful than traveling alone.  The “rubberband” effect makes it impossible to drive on cruise control because of a constant speeding up and slowing down. 

Upon leaving the RV park this morning we had a choice of turning right or left, either way would require traveling on a narrow county road for a few miles but either way would put us on US 83, our route to Mission.  The GPS told us to turn right, which we did.  After only a couple of mile we were quite surprised when we came upon a section of the road with water running over it.  It was where the Rio Frio crossed the road.  The road and shoulders were made of concrete to prevent the river from washing away or eroding the road.  It was only a few inches deep but it was still somewhat unnerving.  I can’t believe in this day and age that we actually had to FORD the river!

What we saw through the windshield

Looking out the driver's side window

After that exciting start the remainder of the trip proved to be a relatively eventless drive of about 300 miles to Mission, TX and the Bentsen Palms Village RV Resort.   I did take some other photos on the drive:

It's Texas, for God's sake!

From the Rio Frio to the Rio Grande

Helping the Border Patrol watch for illegals

We will be in Mission for 7 nights, departing next Sunday morning for home and the end of our 10-week trek throughout the Southwestern US.  It has been a good trip but we will be glad to get home.

The 17^th Annual Butterfly Festival begins in Mission begins this Thursday and runs through Sunday.  Having never attended a butterfly festival I wasn’t sure what to expect so I did a little research.  It turns out that these people are really serious about their butterflies!  The festival is not about drinking beer, eating, and having fun.  It is more of an educational experience and includes seminars that will be presented by highly respected lepidopterists (someone who studies butterflies and has a lot of time on his or her hands).   There is still time for you to get to Mission and attend one of these seminars.  I have listed 3 of them below:

1.          Functions of Butterfly Coloration
2.          Searching for Blues in Western North America
3.          What Butterflies Want and Need

I won’t be attending any of these seminars as each one requires a registration fee of $30 to $40.  Like I said, these people are serious about their flying bugs.

I have already discovered some very interesting facts about butterflies from Google, which cost me nothing.  While we are here in Mission I will be learning more about these fascinating creatures and hopefully getting some good photos.  Think of me as “your man in Mission with a mission”, reporting to you from the actual site of the Butterfly Festival.  I will be answering such fascinating questions as:

•       How does one determine the sex of a butterfly?
•       Where are the butterfly’s ears located?
•       How many miles are traveled in the Monarch migration?
•      At what altitude and speed do they fly when migrating?
•       How does one tag a butterfly?
•       Why do some butterflies live only about 4 weeks while others live up to 9 months?
•       Do they actually taste like chicken?

Make sure to check this blog every day in order to keep up with the fast-paced happenings at the Butterfly Festival.