Sunday, August 10, 2014

Keeping Astronomers Hours!

As I prophesied a week ago when we returned from the Midwest, our Cereus repandus on the east side of the house has been a busy plant lately.  Past observations have revealed that a pinky-fingernail sized bud transforms to a nearly 14cm (5") diameter flower in 8 days!  Last night was the 3rd consecutive night of blossoms, but nearby storms and gusty winds made any images difficult, but I had a setup out the 2 preceding nights.  I've done the time-lapse thing before, and documented the transformation from bud to flower to pollinators, so what to do this time with the abundance of riches before me this time?

My decision was to take a detailed census of the night-time visitors that came by the flowers during the night.  Shooting a frame every 3 minutes (used on the time-lapse above), makes it likely that some will be missed, so the frame rate was moved up 6X to 30 seconds between frames.  The flowers don't open fully till about 10pm, so started about then, going to nearly sunrise at 5:30.  Yes, that is a lot of pictures (1672!), and most just show the lonely blossom, but some show more, and that is the purpose of the exercise!  At left is shown the "standard", mostly repeated 730 times the first (Thursday) night.  Of the two flower open that night, this one was about 50cm (20") off the ground - the other option was about 200cm (7 feet) off the ground!  My Canon XSi was used with the kit 17-85 lens shot at 55mm focal length, F/9 with the on-camera flash.  A third party intervalometer was used to trip the shutter every 30 seconds.

While was watching TV inside, I didn't have long to wait!  Ten minutes after starting the series, the first moth came by.  And it didn't mind the flash, hanging around for at least 90 seconds (three frames).  They are assembled together here at left.  This one didn't mind digging deep for a taste of nectar!  Click on the frame and you will note the little slit visible near the tip of the wing.  As shown at right, this same moth Note the wing slit!) returned 30 minutes later for a single frame.  While not visible in the left images, this shot shows the yellow side spots, identifying it as Manduca rustica, the rustic sphinx moth.

It was then quiet for a long time...  Some 3+ hours later elapsed until the next visitor came by at 3:15.  Another Sphinx moth, this one showing off his proboscis and head details.  Note the absence of a wing slit, so this one is a different moth.  Hard to say if the flash frightened him off or if they can feed in under 30 seconds.  Certainly the 3-frame set above, with its head buried in the flower might not have  been as distracted by the flash of light. 

Photos were taken until 5:15 am Friday morning, when the intervalometer stopped - nothing else was shown...

The following night (Friday), the flower opening was at eye level, about 180cm off the ground.  I decided to look face-on into the flower for a different perspective.  I started the sequence a little earlier, right at 10pm, and had to wait a little longer till Midnight for some action.  Thhis reveal is another rustic sphinx moth, with wings on full display, showing his large size.  I measured the flower later at 14cm (5.5"), so the wingspan is a good 12cm (5").  In order to get it all in I downsampled the image, so resolution is lost in the left frame.  The right image is shown at full resolution for maximum detail.  Antennae are folded down, and it sports what look like rabbit ears, also folded down, but might be an artifact of the coloration pattern.

A minute later another spotting, likely the
same moth was seen hovering over the flower inserting its proboscis.  It is slightly out of focus as it is too close to the camera, but if you look at the frontward of the orange-yellow abdomen spots, the upper edge is whitish as the above shot.

Fifteen minutes later, another spotting, but much more out-of-focus, so more difficult to do an identification.  for what it is worth, the proboscis, which is nearly in focus, shows a kink about at the end of its front leg.  Interestingly, in the left image, the is a kink in about the same place, so there I a chance that all three of these images are likely the same sphinx moth...

Well, that was the end of the moth appearances, but no the end of the activity.  At 5am, suddenly a spider is seen working on a web off the edge of the flower.  It has some resemblance to a huntsman spider, but I read they generally don't spin webs...  While the spider itself only appeared in one frame, the web was there the rest of the night, the flower petal it was attached to slowly bending as the above section of the web was finished and tensioned...  The web extends up 120 cm (4 feet) to the eave of the house, where it still stands.  Hmm, what might it have been trying to catch???

At 5:15 (interestingly the time I stopped taking frames the night before), it is like an alarm went off and the blossom was attacked by honeybees!  It was rare for a frame to catch less than 3 or 4 bees in the picture, often many more!  This effect is visible in the time lapse referenced in the first paragraphs time-lapse link.  From 5:15 to sunrise the bees fed hungrily.  It is interesting to note their full pollen baskets on their rear legs, even those who first appear at 5:15.  One of the frames, shown at right, looks to show a couple of intoxicated bees taking a break as they lie on their backs taking a rest before resuming work...  I never spotted any of the bees struggling with the spider web, but the location of the web might have been chosen for that purpose!

And as the twilight grew and the sun came up, the bees halted their visit too and the flower closed up and the night was over.  Very few other pollinators were spotted - I saw what looked to be an iridescent green bee of some sort, very tiny and out of focus, but mostly bees and sphinx moths, but it was fun to do the census and see what all came by during the night.  There appear to be an abundance of these night time bloomers around, and while the absolute number of these moths are small, hopefully the food source will increase as more plant these cereus.

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