Ecuador: Part II

One group of birds Ecuador has in abundance are the hummingbirds (family: Trochilidae). If you live in the Eastern United States you typically can only see one species of hummingbird, the Ruby-throated Hummingbird (Archilochus colubris). Rarely one may encounter a second species, the Rufous Hummingbird (Selaphorus rufus) or one of a handful of other rare vagrants from the Western US. However, Northwestern South America is the world hotspot for hummingbird diversity. Hummingbirds are confined to the Americas and of the more than 300 hummingbird species over 120 species can be found in Ecuador.

During our trip to Ecuador we saw more than 30 species of hummingbirds. These included large showy species such as the Collared Inca (Coeligena torquata) to species in which males sport spectacular, long tail feathers like the Long-tailed Sylph (Aglaiocerus kingi) to smaller iridescent green hummingbirds like the Andean Emerald (Agytria franciae) and the Rufous-tailed Hummingbird (Amazilia tzacatl, see photo left). The Andes accounts for much of the diversity in hummingbird species, and diversity in other organisms. One can encounter different assemblages of hummingbirds at different altitudes. One can encounter 10 species at a site at 1,000 meters and then a completely different 10 species when one moves to 2,000 meters. Also, the eastern and western slopes of the Andes will be home to different hummingbird species.

This amazing diversity draws hummingbird enthusiasts from around the globe. Hummingbird feeding stations are common in Ecuador, particularly in tourist areas, making for some very relaxed birding ticking off species from the comfort of a deck while sipping Ecuadorian coffee, or in my case a cold Coca-Cola. Cincinnati Museum Center, with the help of the Jocotoco Foundation and the Neblina Forest birding tour company, is currently planning future museum led ecotours to Ecuador where museum patrons can see the amazing biodiversity Ecuador has to offer. Until then check out the video below of a hummingbird feeder at the Jocotoco Foundation's Tapichalaca Reserve. Enjoy!



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Cincinnati Museum Center enters the genomic age...

The beginnings of a working molecular genetics laboratory has been built in the zoology department at Cincinnati Museum Center. Frozen tissue collections are central to a modern natural history collection and typically the most active collection in terms of loans and exchanges between museums. This weekend we extracted our first DNA samples for the new lab. This should be the first ever DNA extractions at Cincinnati Museum Center.

The first step in converting a frozen piece of tissue into genetic data is the extraction of DNA from the tissue cells. DNA (short for DeoxyriboNucleic Acid) is the primary stuff of heredity. Within living cells are long stretches of DNA passed from parent to offspring that provides the information used in the development of the organism. Analysis of DNA can provide researchers with many things, from the action of genes to the evolutionary history of species. Removing the DNA from the cell involves bursting the cell open with soaps (known as cell lysis) and then separating the DNA from the myriad of proteins and other biological compounds that make up the cell. This is done by mixing the soup of cellular compounds from cell lysis with an organic solvent (phenol) and spinning it in a centrifuge. A tube with this cellular soup that has been mixed with phenol when spun down in a centrifuge separates into two layers; the bottom layer and the interface between the two layers contains all the proteins that you want to remove and the top layer is essentially water with the stuff you do want, namely nucleic acids like DNA. Remove the top layer and you have DNA cleaned of all the other cellular material you don't want. Repeating this process gets the sample cleaner and cleaner with each spin.

After a few rounds of these phenol extractions one takes the top layer containing the DNA, moves it to a new tube and adds ethanol. At this stage a neat thing happens. The DNA is not soluble in ethanol and together with salts that also are removed in the top layer of a DNA extraction, it becomes visible to the naked eye as a white, cottony mass. The photo to the right is the genomic DNA from a House Finch (Carpodacus mexicanus) extracted here at Cincinnati Museum Center. These samples will be part of a collaborative research project between Auburn University, University of Minnesota and Cincinnati Museum Center to understand the relationships among populations and the genetic history of both native and introduced house finches in North America.

Hopes are that genetic-based research will continue to grow in the zoology collection. Certainly this is a good start in bringing Cincinnati Museum Center into the age of modern, collection-based genetic research.

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DNA adds some 'mussel' to conservation efforts

The Southeastern United States is a center for biodiversity in North America. This is particularly true for freshwater mussels. The Ohio Valley is home to numerous species of freshwater mussels (family: Unionidae; class: Bivalvia) and the upper Coosa River basin in Tennessee, Georgia and Alabama was once home to over 40 species of freshwater mussels making it among the most biologically diverse freshwater habitats on Earth. Unfortunately, however, human activity in the great watersheds of the Southeast have had devastating effects on freshwater mussel diversity. The building of locks and dams, agricultural and industrial run-off and urbanization along rivers have all contributed to the extinction of many species of freshwater mussel. In the Ohio valley species like the Clubshell (Pleurobema clava, see photo left) exist in populations that are considered highly vulnerable to extinction and other species, like the Tubercled Blossum (Epioblasma torulosa, see photo bottom right, both specimens are from the Cincinnati Museum Center Zoology collection), are likely extinct already. For freshwater mollusks in general over 70% of the known species are extinct or in danger of extinction.

Identifying one mussel species from another can however be difficult. Mussels are typically identified on the basis of the size, shape and texture of their shells, however, within populations these traits can vary significantly and often vary in response to variation in the environment. The difficulty in identifying one species from another confounds conservation efforts to identify threatened populations and leaves open the possibility that species thought to be extinct may persist in populations with aberrant characteristics making them difficult to distinguish from more common species.

In a recent paper by University of Alabama researcher David Campbell and his colleagues, DNA barcoding was used as a tool in identifying freshwater mussel species in the Coosa basin. DNA barcoding involves sequencing a segment of DNA common to all organisms. In general, sequences should be unique to a species, although there is often some sequence variation within species as well. DNA barcodes can be used in addition to analysis of morphological characteristics as a tool in identifying species. Focusing on the freshwater mussel genus Pleurobema, DNA barcoding revealed the existence of four species thought to be extinct from the Coosa basin; Pleurobema chattanoogaese, P. hanleyianum, P. troschelianum, and P. stabile. The DNA evidence showed that all of the Coosa basin specimens previously identified as Peurobema perovatum were actually the supposedly extinct P. hanleyianum. Also, the Warrior Pigtoe (Pleurobema rubellum), a mussel species currently listed as extinct, was identified using DNA barcoding from the nearby Black Warrior River system.

This study shows the utility of DNA analyses in conservation efforts. With the growing emphasis on DNA techniques here at Cincinnati Museum Center plans are underway to adopt DNA barcoding protocols on threatened and difficult to identify groups, like freshwater mussels, in the Ohio Valley.

CAMPBELL, D.C., JOHNSON, P.D., WILLIAMS, J.D., RINDSBERG, A.K., SERB, J.M., SMALL, K.K., LYDEARD, C. (2008). Identification of ‘extinct’ freshwater mussel species using DNA barcoding. Molecular Ecology Resources DOI: 10.1111/j.1755-0998.2008.02108.x

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University of Cincinnati Drawing Class

Museum collections have many uses, and not all of these uses for museum specimens are scientific. The zoology collection at Cincinnati Museum Center is often used by local artists to create biologically accurate wildlife art. Field guides are an excellent example of the synergy between art and science in museum collections. Jim Day of Talon Wildlife Creations is one such local artist who regularly uses the collection to create life-like reproductions of birds from domestic bird feathers. Other well known artists such as John Ruthven and the late Charley Harper have used the zoology collection extensively as reference material for their artwork.

The next generation of artists are utilizing the zoology collection as well. Led by instructor Courtney Bennett students from the University of Cincinnati visited the collection in late February (see photo right). The students were sketching everything from mounted Ring-tailed Cats to primate skulls to Harpy Eagle study skins. Courtney recently sent us photos of some of the student work (see photo above left). We hope to host many other local artists, both professional and student, and provide them with many subjects for biological illustration and wildlife art.

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