This is the first of several issues of Museum Notes that will discuss Nebraska's Endangered and Threatened species. Future issues will deal with fish, birds, amphibians, reptiles, mammals, and plants. As a prelude to this series of Museum Notes, we might ask "what does it mean to be Endangered or Threatened?" As defined by the Endangered Species Act of 1973, the term 'endangered species' means any species that is in danger of extinction throughout all or a significant portion of its range. Excluded from this definition would be any insect species determined to constitute a pest whose protection under the provisions of this Act would present an overwhelming and overriding risk to man. A 'threatened species' is any species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. Before a plant or animal species can receive protection under the Endangered Species Act, it must first be placed on the Federal list of endangered and threatened wildlife and plants. This listing program follows a strict legal process to determine whether to list a species depending on the degree of threat facing it.

Problem pollen almost always comes from plants that use wind to transport their pollen to another plant. The chance of an individual grain finding the flower of another plant of the same species is much smaller with wind pollination than it is with animal pollination. Wind-pollinated plants compensate for the lack of precision by producing millions of extra pollen grains, some of which land in noses. Pollen from animal-pollinated plants is sticky, usually forming clumps that are too large to remain in the air very long. However, Nebraska's strong winds occasionally strip these sticky grains from flowers and carry them to noses or pollen samplers. Air-borne pollen has a more restricted size range than that carried by animals. Pollen grains are measured in microns, a unit that is one millionth of a meter. The largest pollen grains, produced by plants that use animals for pollination, are barely visible to the naked eye at about 250 microns (one fourth of a millimeter). The size range for pollen that is transported by wind is an order of magnitude smaller. Unless it has air bladders like pine pollen, grains that are much larger than 100 microns (the size of corn pollen) usually fall out of the air before traveling more than a few meters. At the other end of the scale, a pollen grain smaller than ten microns (the size of ragweed pollen) cannot be caught efficiently by plant stigmas, the part of the flower that leads to the ovule for fertilization.

To understand the evidence of chipped stone tools, we must understand something about their manufacture and use. Not any kind of stone will do. A homogeneous, fine-trained stone with good fracturing properties is required. Cornman names for such stone include flint, chert, jasper, and chalcedony. Even fine-grained quartzites were used. Often people had to travel hundreds of miles to find the stone they required. Sometimes they traded for special varieties.

Jewel Scarabs are found only in the New World, mainly in the mountains of Mexico and Central America. Four species, including the very fancy Chrysina gloriosa which has silver and green striped wing covers (elytra), occur in the mountains of western Texas, New Mexico and Arizona. Only a couple species are known from the Andes Mountains of northwestern South America. Many species are found in the incredibly beautiful and diverse cloud forests of Central America. It's a real treat to study Jewel Scarabs (or anything else) that live in these cloud forests because of the endless variety of strange, wonderful, and very colorful animals and plants that surround you.

Vigorous and diverse colonies of aquatic plants are usually a sign of healthy and stable aquatic environments. In fact, the plants themselves stabilize the shorelines, underwater soils, and water chemistry. Waters rich with aquatic plants are rich with aquatic animals and waterfowl, which find cover, breeding habitat, and abundant food. Non-alkaline waters have more aquatic plants than alkaline waters but, in the absence of pollution, both waters have stable communities. However, excessive nutrients from pollution by sewage and runoff from cropfields stimulate rampant growth by a few species that overwhelm the others, leading to decreases in aquatic plant and animal species. Most Sandhills waters are unpolluted and their aquatic floras are stable, but that is not the case for many streams and reservoirs elsewhere in the state.

Projectile points can be made from just about anything that can be sharpened, including stone, glass, wood, bone, and metal. Flaked stone points are most common in Nebraska, although metal points and occasionally bone points have been found.

It seems to stretch and confound our imagination, our reason, our whole thought process, to conceive of visitors from outer space hovering in our skies and perhaps even landing on our planet. But the ideas have gained popularity even with some knowledgeable scientists. So we must discuss a very broad field, about which little is known and of which much is speculation. To proceed we must assume the possibility of life elsewhere in the universe.

The University of Nebraska State Museum has recently acquired fossil evidence regarding the evolutionary history of these common Great Plains reptiles. We can now trace the record of the hognose snakes back to a time long before the arrival of man, the bison, or even the mammoth on the North American Continent.

The University of Nebraska State Museum is essentially a natural history museum composed of nine divisions. Exhibits are designed to introduce visitors to the vast scope of knowledge encompassed by such disciplines as anthropology, geology, paleontology, and zoology. The Museum staff members (curators, educators, exhibit designers, technicians, and preparators) who develop these exhibits must consider the wide range of age, interest, and educational levels, as well ~s the cultural background of the museum visitor. The intellectual appetite of the eager little first grader, whose attention span can be brief indeed, must be satisfied, while the interests and needs of the University student must also be met. Exhibits vary from the simplest presentation of an artifact, piece of taxidermy, or fossil, to highly complex displays. The more complex displays include miniature dioramas; life-size ecological dioramas, like those in the Hall of Nebraska Wildlife; and elaborate mechanical and electronic presentations such as Ceres the transparent woman. The techniques, media, and ideas used in the creation of museum exhibits are so varied that museum artists need to be people of considerable versatility since they never know what they will be called upon to do next.