Metamorphosis – Tale of a Wetland (Bryan Maltais 2012)

Nature reveals its ability to heal when amphibians, reptiles, birds and plants repopulate a recently abandoned rock quarry to create a flourishing wetland in Fort Collins, Colorado. However, the scarred earth of this healing quarry causes salamanders to undergo a rare and peculiar shift in their morphology. Time-lapse sequences show seasonal changes of the wetland over one year accompanied by underwater footage of amphibians breeding and undergoing metamorphosis. Everybody is familiar with the metamorphosis of butterflies and moths. The following video is an outstanding computer tomography scan demonstration of a butterfly chrysalis metamorphosizing over 16 day period:

Winner of TriMedia Film Festival and Denver Indie Fest, herpetologist and filmmaker Bryan Maltais tells the story of a freshwater wetland community centered around two amphibian species: The barred tiger salamander (Ambystoma mavortium) and the Woodhouse’s toad (Anaxyrus woodhousii). The biology of the tiger salamander is quite interesting because it provides a textbook example of an important biological concept called neoteny (aka Paedomorphosis). Briefly, neoteny is retention of juvenile characteristics in adulhood. The concept is very useful in explaining evolution of many organisms. In 2012 for example, based on a quite detailed analysis of skulls a group of scientists concluded that birds living today are neotenized version of dinosaurs. The concept also extends into human evolution. Biologists are now accumulating more evidence that human evolution is shaped for quite a bit based on retention of juvenile characteristics such as ability to digest milk (lactose tolerance) in adulthood or having larger brains by prolonged childhood period (leaving more time for brain to develop). You can watch an articulated video on this subject by a Scientific American blogger Karen Straughan.

In Maltais’s documentary microscopic filming reveals tiny zooplankton and how they power the wetland, while above water, amphibians contend with predators and impending drought. Among the zooplankton Daphnia (waterflea) is a keystone species for freshwater communities and its genome has been sequenced by an international consortium in 2011.

The mating of Woodhouse’s toad is another focal subject. Males of this species compete frantically for females advertizing themselves by energetically costly calls. Females live anywhere within a few miles to just a few dozen meters from the wetland, but they are not stimulated to move to the wetland and enter breeding pools until it rains heavily. After arriving at the wetland they hone in on the most attractive male call. In the arid west, it presumably requires a certain volume/intensity of rain to stimulate female migration because only then will breeding pools become deep enough to support tadpoles for at least 4 weeks before drying up again.

At the end, Maltais draws attention to worldwide decline of Amphibians and emphasizes the Chytrid problem. He also lists some of the species covered in his documentary but the list is not exhaustive. A few of other species mentioned at the recovering community of abandoned quarry include Killdeer (Charadrius vociferus), Bank swallow (Riparia riparia), Red-winged blackbird (Agelaius phoeniceus). In addition to birds a few plants are also mentioned such as the Purple pasque flower (Pulsatilla vulgaris), Cattail (Typha spp.).

 

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