What Are Viruses?

You are hearing a lot about viruses as the world deals with its first pandemic in a century. By the time the Spanish flu reached its final peak in 1919, the virus that caused it was still an unknown. By that time, the germ theory was well established and accepted. While bacteria had been observed and were understood to be agents of disease, the concept of a virus hadn't entered anyone's thoughts yet.
A virus differs from bacteria in many ways, the most striking difference being that we can't really classify a virus as a living thing. In all living things, the DNA and RNA in each cell is active. A virus has either DNA or RNA, which is inert. It does not active until the virus enters a host cell. The virus is now a living thing, and now it is feeding off the energy produced by the cell it has infected.
Other differences between a virus and bacteria is that a virus has a protein coat, has only DNA or RNA rather than both, and can transfer its DNA or RNA into other cells. A virus is much smaller than bacteria. Bacteria can be seen with the aid of a light microscope. Viruses are even tinier. They have to be, in order to fit inside a cell.
Most viruses infect only a certain species. Some, like our current coronavirus and the swine and bird flus, are able to make the jump to another species. In the case of the swine flu, it jumped from pigs to people. Because they are structured and behave differently than bacteria, antibiotics used to treat a bacterial infection are no good against viruses. How do we stop viruses then?
Antiviral medications exist, but are difficult to develop. Because a virus uses a host cell to replicate, an effective antiviral has to target only the virus and not the host cell. The most common treatment is to let the virus run its course. Eventually, it is hoped, the immune system will be able to overcome the virus. In the meantime, you're likely to experience some discomfort.
Prevention is your best bet. Vaccinations work to train your immune system to kill a virus by giving it a dead one to work on. Good hygiene like washing your hands (you hear that a lot these days) and avoiding close contact with others help reduce the spread of viruses.
Note: every virus is unique. For information on the current COVID-19 coronovirus, visit the CDC or WHO.
This week's information comes from "Microbiology, an Introduction (8th edition)" by Gerard J. Tortora, Berdell R. Funke, and Christine L. Case; the dreaded Wikipedia antiviral drug entry; and the CDC. 

Species of the Month

Introduction: One of the surest signs of spring is the return of the American robin, March’s Species of
the Month. From their cheerful morning song to the way they hop about your lawn, what’s not to love
about this little harbinger of better weather?

American robin (Missouri Department of Conservation)

Scientific name: Turdus migratorius

Kingdom: Animalia (animals)

Class: Aves (birds)

Order: Passeriformes (perching birds)

Range: Southern Canada to southern Mexico

Habitat: Open grassy areas and open woodlands with dense shrubs

Lifespan: Average age 2 years

Diet: Berries, worms, insects

Predators: Snakes, squirrels, blue jays, crows, ravens: eggs only; snakes, hawks, house cats: adults only 

Conservation Status: Not listed as threatened or endangered, but protected under the Migratory Bird
Act.

Other Information: The gregarious, ubiquitous American robin is one of the first birds to begin nesting
in the spring. They start shortly after arrival, and may lay as many as three clutches of eggs. Each
clutch gets its own nest. The parents won’t start a new family until the old one has fledged the nest,
about two weeks after hatching. The young won’t become expert fliers for another two weeks after and
will be somewhat reliant on the parents until then.

American robin nest with eggs (Missouri Department of Conservation)

Male robins are slightly larger than females. Unlike many other birds, male and female robins look
nearly identical. Females are slightly lighter in color. Juveniles have a speckled breast, rather than the
familiar reddish coloring.

Juvenile American robin (Hal and Kirsten Snyder)

Outside of breeding and nesting season, American robins typically feed and roost in large flocks. They
roost overnight in trees in dense woods or secluded areas. During spring and summer they are more
solitary. Watch them in your yard. When grounded, their motion is hop hop hop hop or run run run run
run stop run run run run run stop. When stopped they frequently cock their heads. They do this because
they are looking for worms or any danger. They must move the entire head because their eyes don’t
move like ours.

American robin wrestling a worm (Cornell University)

This week's information comes from the Animal Diversity Web at University if Michigan again.

Amazing Okavango

Ever hear of the Okavango River in Africa? You probably haven't. It's a rare river that flows into an inland delta rather than the ocean. During the winter, it floods the glassland and creates a seasonal wetland that attracts wildlife from all over Africa in one of the world's greatest migrations. It is an amazing oasis in the Kalahari Desert.

Flooded Okavango (Natural World Safaris)

The annual flood occurs at the height of Botswana's dry season, so it offers welcome relief to the plants and animals in the area, in addition to welcoming migratory animals of all shapes and sizes. The abundance of water boosts the growth of plants, drawing in herbivores. The herbivores attract large predators.

Elephants (Royist)

Safari cruise through the grasslands (National Geographic)

Among the many different animals who take advantage of the situation are elephants, lions, cheetahs, zebras, rhinos, 89 fish species, and 24 globally threatened birds. Not only is the Okavango key to survival of individual animals, it is crucial habitat for entire species.

Lion and buffalo (National Geographic)

A safari in the Okavango is like watching "The Lion King" live and in person. This weeks information comes from UNESCO World Heritage.