The glorious bluespotted sunfish & the "gaudy male syndrome"

While dip-netting in a FL canal I came across one of the most interesting and beautiful fish in freshwater, the bluespotted sunfish, Enneacanthus glorious (see photo). This fish is well named since the adult males are covered with brilliant blue spots that shine intensely. It is a wide-spread species occurring in the coastal plain from Florida to New York, especially in heavily vegetated, slow-moving waters. Note that the tail-fin is rounded and not forked as in most sunfish; this may be an adaptation for a life in thick vegetation. This gorgeous fish is also unusually tolerant to low pH's down to about 4.5, a very useful attribute for a fish living in dark, acidic waters.

The striking coloration of the male appears to be designed for attracting females and likely advertises the health and vigor of the male, in a way much like the mane of male lions. We have a fish (the mountain redbelly dace- see photo below) in the creeks of our Blue Ridge mountain farm which has a similar characteristic, namely a very bright coloration of adult males. It is likely that the purpose of this "gaudy male syndrome" is similar wherever it occurs. One of the amusing aspects of this trait is that females get to choose the males, and are probably anxious to choose the best genetic stock to fertilize their eggs.

If this all seems strange to humans it is because we have a somewhat different mating system in which the male is not gaudy but is larger and stronger than the female and engages in male combat for territory and females. However this is not to say that the female does not make a choice of her mate!

The variety of color and form in Nature is remarkable and a continuous source of wonder, speculation and study.

Bill Dunson Englewood,

FL & Galax, VA

The tranquility of Nature- NOT!

A story from Bill Dunson of three species that frequent the woods and river valleys of the Blue Ridge highlands. Have you ever considered these types of interactions?

There can sometimes be great drama in the lives of birds as well as humans, as we have been observing a pair of ospreys and their tormentors, a pair of great horned owls.

We have not directly observed all the specific interactions of these two wonderful species, but can surmise what must be happening. It appears that the owls drove a pair of ospreys from their nest and occupied it (see photo of owl's head just above the edge of the nest). Then the ospreys moved further down the island at Stump Pass State Park and built another nest (see photo) and seemed to be happily engaged in domestic bliss. But just yesterday it appeared that the osprey pair had left the nest and were flying around somewhat distraught. The male was carrying a stick and chasing the female and no one was minding the nest. We are afraid that something may have happened to the baby ospreys or the eggs; perhaps the owls are involved or not- we do not know.

A pair of bald eagles also moved from a nearby nest site occupied last year and built a new nest in a tall Norfolk Island pine just north of the owls, where all seems to be well, except that here we can see in a great photo by Paula Kaye that an immature eagle is harassing the adult on the nest! Eagles also have quite a lot of trouble from owls themselves but in this case junior may want to inherit Mom's territory or maybe is just curious about what married life is like.

So when we might think sometimes about how wonderful and stress-free the lives of animals wild and free in nature must be- think again! Life is a struggle, perhaps for creatures great and small?

Bill Dunson

Englewood, FL

The bagworm- it builds a house and comes to eat your plants

I came across an old acquaintance today while walking near Arcadia,FL, the bagworm. This curious caterpillar of a moth with an unpronounceable name, Thyridopteryx ephemeraeformis, has a very strange habit that makes it very distinctive and easy to identify. As its name implies it makes a case or bag out of silk and bits of plant material and crawls around with only its head and front end exposed. The bag is an ingenious contraption of small pieces of stems and leaves of the plant that the caterpillar is feeding on. In this case the plant was a hog plum, but this moth feeds on a wide variety of plants, causing it to be a serious pest in some situations. Clearly the bag serves to protect the caterpillar in two ways; it is both a camouflage and a physical protection against attack by predators such as birds. However the caterpillar must come at least partly out to feed and can be attacked then.

For some amazing photographs of the Bagworm check out Victor Engel's work: http://bugguide.net/node/view/135982/bgimage

The breeding habits of the bagworm are quite peculiar- the female is flightless and remains in the case for her entire adult life. The adult male must fly to her location and fertilize her eggs, which are laid in the bag where they remain all Winter. They hatch in the Spring and the young larvae disperse and make their first bags. Although this species is named for a mayfly (which the adult male slightly resembles), there is a greater resemblance to the caddisfly larvae which lives in water but also constructs a case out of sticks, sand or small pebbles. Now although caddisflies and bagworms are somewhat related, they are in separate groups and it seems unlikely that a common ancestor had the habit of constructing larval cases. So we may conclude that their shared habit of constructing cases for their larvae is probably an example of separate but convergent evolution.

So if you see bagworms on one of your valued plants you might just want to move them someplace else since they can do some serious damage. The simplest time to do this is in Winter when the bags contain hundreds of eggs and can easily be picked off the plants. But in any event let us marvel once again at the remarkable diversity of nature.


Bill Dunson
Englewood, FL & Galax, VA

Snake plant flowers

It is hard to believe that anyone has not at some time had snake plants (Sansevieria) in their family households. The ability of this interesting but strange plant to survive almost any treatment made it popular around the world as a house plant. Unfortunately in warmer areas such as Florida they ended up planted outside and have caused considerable problems since they are highly invasive, especially in shaded forest locations where native plants are crowded out by the snake plant. Removing them is problematic since the roots break into small pieces and generate many new plants.

I have fought a running battle with snake plants in our Florida yard since a former owner got them started. So I always considered them a big pest with no redeeming qualities. However I have now recognized that the regular Winter-time blooms of these plants are actually quite interesting from an ecological perspective (see photo). A spike of white tubular flowers emits a powerful fragrance and is actually quite beautiful, if you can get past the bad-boy image of this species. I am always interested in predicting what might pollinate specific flowers, based on flower color, shape and smell. I found out that this plant originated most likely from Western Africa but have not yet found out what pollinates it in its native habitat. However the white tubular flowers with a strong odor indicate pollination by a night-flying moth with a long tongue, possibly a sphinx/hawk moth whose larvae are often called horn worms.

I did find one article that determined that the primary sugar in the nectar of the common snake plant is sucrose, and predicted that this in conjunction with the flower structure would attract mainly sphinx moths. Note also that the authors found extra-floral sources of nectar and surmised these might satisfy creatures such as ants that might otherwise steal the flower nectar and limit the plant's ability to reproduce:

http://aob.oxfordjournals.org/cgi/content/abstract/58/4/541

So look around you with a renewed interest in plants and animals that you might have dismissed as unworthy of notice, and you may find unsuspected beauty and interest among the "bad boys" of the natural world.

Bill DunsonEnglewood,

FL & Galax, VA

The Io moth & caterpillar- some amazing natural designs

On a nature walk this morning at Stump Pass State Park in Englewood, FL, our group came across two caterpillars of the Io moth (see photo). At this stage they are a striking light green, with a red and white stripe along their sides. The younger caterpillars are brown to orange-brown. Although we were tempted to pick this beautiful green caterpillar up, I knew that this species has poisonous spines that can cause a lot of pain. One might assume that the green coloration is for camouflage, although it is so bright that it might even be considered a warning coloration along with the red/white stripes. The branched, poison-bearing spines pack a powerful jolt to any potential predator.

Strangely enough it was about three years ago that I saw the adult of this strange moth at our farm in Galax, VA. The unusually colored adult moth appeared on a window screen one morning where it must have been drawn to the lights the night before (see photos). With the wings closed the moth is cryptic in the right background and would presumably escape detection by most predatory birds. If it is detected and is poked, it opens its wings and reveals a marvelous set of false eye spots (see photo). Many moths have eye spots on their hind-wings that mimic an owl's face or just provide something scary for a bird to think about. But the Io moth has what I consider the most impressive set of eye spots. But even so I am amused that a bird would find this intimidating.

One again we can be amazed by the evolutionary process that can lead to the development of such a remarkable pattern. The variety of animal coloration is a never ending source of wonder.

Bill Dunson

Englewood, FL & Galax, VA

The Value of Water as a Bird Attractant

Our Florida location is on a barrier island (Manasota Key) only a short distance from the mainland, but a very dry location in terms of freshwater for critters to drink. The "soil" is basically sand with a maximum elevation of about 11 feet, and there are no natural ponds, except of course for sea water in the mangroves and beach areas. Since no typical terrestrial birds can drink sea water (it is about three times the salt concentration of their blood), non-sea birds must find their drinking water elsewhere, and thus be limited in their occurrence here, or get it from their food (seeds are very dry, but animal prey or fruit contain more water- a help but not generally enough). There is brackish water below the soil surface of the island- depending on recent rainfall, available to trees but not to most animals. Thus we have found that putting out fresh water in bird baths is very attractive to a wide variety of birds, including some that you might not expect to visit. For example yesterday I looked

out the back window and saw a Cooper's hawk in one of our three bird baths (see photo)! This was a huge treat since these hawks are not generally that easy to study up close and personal.

So put out a water bath, preferably with a drip but OK if not, as long as you refill and clean it periodically, and watch for interesting visitors. Try putting out several baths in locations that differ in the amount of cover, and distance from your house.

Bill Dunson

Englewood, FL & Galax, VA