Green Flash

Green Flash on the western horizon of Madagascar

A green Flash occurs during a sunset (or sunrise), and i knew that they occurred off of the cost on the Kona side of the island. So i was wondering what causes them? and how can I find the right conditions to see one?

Green Flash off the coast of Hawaii

Causes of the Flash
The green flash is caused from the sun's light being bent in the atmosphere, (this also causes the sky to appear blue) only in the few seconds of maximum length between you and the sun as its mostly beyond the horizon causes the spectrum to be bent in a green hue (usually, it can also appear to be blue, yellow, and even violet) for anywhere from half a second to up to 15 seconds, which is why it's described as a flash.

Seeing the Flash has a few rules

1. Your apparent horizon must be lower than your eye level (which is why the ocean is the perfect requirement although not necessary)
2. The Air MUST be reasonably clean. If there is too much dust, smog, or haze than the light from the sun wont refract properly and you will just see a normal sunset.
3. Because the flash is quite small, (especially if you have never seen it before) some kind of aid will be necessary, such as binoculars, zoom camera lens, opera glasses, etc. But Remember: if the sun isn't comfortable to look at DON'T! you will hurt your eyes. so sunglasses are also a good idea, and they really don't diminish your chances of seeing it.

Sources:

Intro To Green Flashes

Wikipedia

Species Status Clasification

I am wondering, what classifies a species as endangered, threatened, vulnerable, or invasive? Quite a few of us have used these words in our Blogs before and i was wondering what makes that species what it is.

Wikipedia Says that species that have dwindling numbers are divided into 3 categories

• Critically Endangered (CR)-Extremely high Risk of Becoming Extinct (example. Florida panther, only occupies 5% of original range and only has 70 animals left capable of breeding)
  
  
• Endangered (EN)-A Species that is in danger of becoming extinct due to a range of reasons being: over hunting (from other animals and humans), changing environment, loss of environment, or just way to few numbers. (example. Nene which is suffering low numbers and loss of environment)
  
  
• Vulnerable (VU)-A species who's runs a risk of becoming extinct but has not been qualified as an endangered species because numbers may still be high despite other factors like loss of habitat. (example. Polar Bear which still has decent numbers but is loosing habitat to global warming)
  

• Invasive Species- a species that has been introduced to a non-native environment and has become harmful to the native environment and/or human health. (example. Coqui Frog which spreads fast due to high reproduction rate, and is hard to get rid of)

Spiny Back Spider

After researching, I have found no exact matches to my "little friends" here, but i have found a few good leads. In 1985 Thelacantha brevispina was found in Hilo, or at least that's what it was identified as at the time. Currently it's known as Gasteracantha mammosa. The other good lead is a spider called Gasteracantha cancriformis which has been in hawaii since the 1950's . Both Species are nicknamed "Spiny Back Spider."

I lean toward calling it Gasteracantha mammosa because Gasteracantha cancriformis tends to be more solitary, where as our spider builds webs off of other webs in quite elaborate structures which is more in line with the description of Gasteracantha mammosa which will do this in areas where prey is plentiful.

Now to tell you about the Spiny Back Spider,

It's length is anywhere between 1mm (when immature) and 6mm (full grown female) wide and it's only slightly wider than it is long. The females spin large webs in high places like between two trees , or on telephone poles (this is a problem for repairmen who want to work on that pole), males tend to spin webs lower and, if they can manage to attach it to the females, they will especially when their is plenty of food to go around. they decorate their webs with small tufts of silk to simulate certain flowers, and this attracts bugs like wasps which they will gladly consume for dinner. The immature spiders tend to build smaller versions of these webs much closer to the ground and further from the large group of adult spiders. Egg sacks are not found on the web but close by, and they are florescent green until the spiders hatch when it turns yellow, and each egg sack can hold up to 200 eggs.

This species is listed as a pest and an invasive species in the Hawaiian islands, both agriculturally and residentially. This spider is not known to come into residences, but it will built its web very close by. They wont bother you unless you bother them; unfortunately, when they build their webs on your front porch and you walk right through their web they will bite you, as is the case in the telephone poles and when they build their webs out in the fields that need to be picked. Their bite causes localized swelling on some people, but if you are sensitive to spider bites you should seek medical attention.

So finally getting rid of them:

the Organic way to get rid of them is to crush them and their egg sacks.
the not so organic way is to use Strike Roach Ender, Raid House and Garden, Johnson's No Roach, and Black Flag Ant and Roach spray.

Sources
Asian Spiny Back Spider
Urban Knowledge Master

Spiders

When I first met these little spiders i wasn't quite sure that they were actually the spiders, but rather i thought it was the prey, but then i noticed that on more and more huge webs (in comparison to the spider) were these little spiky arachnids. After noticing them more often I've also noticed that they seem to live in what looks like colonies. Well they can build webs off of each other which is shown in one pictures. so Ultimately I'm wondering what are they exactly, why do they live like this, especially since i thought that spiders were extremely territorial, and are they poisonous?

Pictures:
top: a close up of the spider
Bottom: The spiders on their webs that are built on top of each other.