Each Autumn, cave-goers cannot help but notice large groups  of bats roosting in caves throughout the winter months, or at least they used to. For the past decade, bat populations in the Eastern United States have plummeted in the presence of an invasive fungus responsible for what has been coined “white-nose syndrome.” Last month, officials from the US Fish and Wildlife services stunned biologists by announcing the first observed bats with white-nose syndrome on the West Coast. The current threats facing American bats are unprecedented in recent history, and unless human intervention succeeds, many once-common bat species may vanish altogether.

A Little Brown Bat (Myotis lucifugus) with White-Nose Syndrome (Source: Bloomberg via Getty Images, 2009)

Around October and November of every year, North American bats like the little brown bat (Myotis lucifugus) flutter into caves called hibernacula where they wait out the winter. During this period, they enter a state known as torpor; their heartbeat slows to a near stop, and their body temperature drops to just above freezing. In March 2007, biologists from Albany, New York, set out to do a routine census of the local hibernating bats. Upon reaching the first hibernaculum, they were floored at the site before them: they found  dead bats everywhere. Peculiarly, the bats looked as if they had dunked their faces in a white powder. When spring arrived, the surviving bats left the hibernacula, and the pandemic seemed to have ended. However, by the next winter, it became clear that this disease did not just go away.

The spread of White-nose syndrome (Source: Lindsey Heffernan, PA Game Commission, 2016)

In 2008, white-nose syndrome was reported in 33 caves in four states. By 2009, five more states started experiencing massive bat die-offs. Spreading in an ever-expanding bullseye, 25 states and five Canadian provinces were losing bats to white-nose syndrome by 2015. Only last month, officials in Washington have confirmed that the disease has made the  leap across the great plains. It is unknown whether or not this fungus was carried west by human cave-goers, or if infected Eastern bats made rare forays to the region.

The condition has since been linked to a cold-loving fungus dubbed Pseudogymnoascus destructans. It is not known exactly how this fungus kills the bats, but it has been shown to disrupt their torpor during hibernation. The bats, perhaps irritated by the fungus, fly out of the hibernacula during the Winter months. There are no insects for them to eat during this time and so these flights turn out to be costly, depleting vital energy stores, leaving the bats likely to succumb to starvation and respiratory complications caused by the fungus. Similar fungi have been found on European bats, although they do not experience adverse symptoms. These bats likely coevolved with the fungus, and so gained resistance. P. destructans was likely introduced from Europe by way of human activity. Unlike in Europe, North American bats exposed to P. destructans experience mortality rates approaching 100%.

Bats from the Tetrapod Collection, Museum of Biological Diversity © Stephanie Malinich, 2015

Many affected areas have experienced declines in bat populations by more than 90%. In some places, there just are no more  bats to kill off. In what were populous hibernacula, there are now bodies of dead bats, piling up like snow drifts. Often, biologists conducting a bat census find it impossible to navigate the caves without stepping on carcasses. In 50 years from now, if populations have not recovered, the only place to study North American bat populations may be in natural history collections. Museum collections, such as the one at the Ohio State’s Museum of Biological Diversity, contain physical records (specimens) that continue to yield valuable information about biogeography, and serve as a template against which modern populations may be compared. It is through using such records, that changes within species can be detected. Museums are a natural starting place in the attempt to solve issues such as those currently threatening North American bats.

Grant is one of our Research Assistants and focuses on birds.

About the Author: Grant Terrell is a 1st year majoring in Evolution & Ecology at The Ohio State University and works as a Research Assistant at the Museum of Biological Diversity in the Tetrapod Collection.

Afroduck swimming in Mirror Lake at OSU
(©Abigail Smith)

Afroduck was Ohio State’s beloved unofficial mascot because of a unique trait that set him apart from the other ducks, a crest of feathers on his head that looked like an afro. Many have wondered if this is a kind of rare genetic mutation never before seen in ducks. As it turns out, his fluffy little afro is a genetic mutation, but it is far from rare.

Many duck varieties can have the crested trait, like this Mallard Duck. (©Heather Paul, 2011)

Afroduck was a breed of domestic Crested Duck. This means that he was specifically bred to have a fluffy crest atop his head. The crest trait has been selected for by breeders in many different duck species. These ducks are considered ‘fancy breeds’ and are bred for show, not for their eggs or meat.

Breeders have been selecting for this trait for centuries. Crested ducks even appear in 17th century Dutch paintings.

Melchior d’ Hondecoeter. A Hunter’s Bag near a Tree Stump with a Magpie, 1678. Rijksmuseum, Amsterdam, www.rijksmuseum.nl

When humans breed animals for a specific trait we call this  artificial selection. Artificial selection has allowed us to domesticate wild animals into livestock like pigs, cows, and sheep. Unfortunately, selecting for a certain trait and attempting to exaggerate that trait as much as possible can have unintended consequences. For example, dog breeds with smashed-in faces, like bulldogs and pugs, have respiratory problems because of their small nostrils, elongated soft palate, and narrow trachea. Selectively breeding for a crest in ducks also comes with negative consequences.

The crest forms on the head of the duck because of a malformation in the skull. These ducks develop with a gap in their skull which is filled in with a mass of fatty tissue. The feathers growing from this area of the head are fluffy and create the crest. Studies have found that the fat bodies cause motor incoordination in some ducks. A 2009 study conducted by J. Mehlhorn and G. Rehkämper tested coordination in crested ducks by placing them on their backs and timing how long it took for them to right themselves. Ducks with larger fat bodies were more likely to have bad coordination

This diagram shows where the fat body develops inside the skull. (Julia Mehlhorn and G. Rehkämper, Brain alterations, their impact on behavior and breeding strategy in Crested Ducks (Anas platyrhynchos f. d.), 2010)

The crested gene is potentially a lethal gene as well. If two ducks with the crested trait are bred there is a 25% mortality rate for the ducklings. Ducklings who receive the crested gene from both parents are likely to die in the shell. The gap in the skull will cause the duckling’s brain to develop outside of the skull.

Humans have used artificial selection for hundreds of years to genetically modify and domesticate plants and animals. In the case of Afroduck and other fancy ducks, humans have selected unusual genetic mutations that they find visually pleasing. Breeding animals in order to exaggerate a single trait often creates unintended and detrimental side-effects. While we might consider Afroduck’s best phyiscal trait to be his fully afro, he might not agree.

Chelsea is one of our student workers and does general collection work

About the Author: Chelsea Hothem is a 3rd year majoring in Evolution & Ecology at The Ohio State University and works as a Research Assistant at the Museum of Biological Diversity in the Tetrapod Collection.