A Rodent Like No Other – A New Indonesian Species


Just when you thought you had a grasp on mammalian diversity, nature throws you a curve. Scientists working in Indonesia have just discovered an extraordinary new species of rodent (Figure 1). It’s unlike any other rodent on Earth. Read More...

Ground Squirrel Hibernation Altered by Climate Change

Climate change is causing a late wake-up call from hibernation for a species of Rocky Mountain ground squirrel and the effect is deadly.

A University of Alberta-led international research team examined data on a population of Columbian ground squirrels (
Spermophilus columbianus) and found a trend of late spring snow falls has delayed the
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Ambushing the Predator: Squirrels and Rattlesnakes

As a young boy growing up in the Adirondack Mountains of Upstate New York, old-timers would often say that if you encounter a black bear in the woods you should shout and wave your arms in an effort to make yourself appear larger and more threatening. Read More...

Social Evolution in Mole-rats

Naked mole-rats (Heterocephalus glaber) have received a lot of scientific attention because they are the only mammals with a eusocial mating system. Like honey bees, naked mole-rats have colonies with a single breeding “queen,” a few breeding males, and numerous non-breeding “workers” who forage and maintain Read More...

Out of Africa: Caviomorph Origins

South America was isolated from Africa and the North American continent during most of the Cenozoic. As a result, early mammalian immigrants evolved in isolation resulting in a unique assemblage of terrestrial mammals. Approximately 34 million years ago (Eocene-Oligocene) global cooling and drying periods are believed to have spurred major faunal changes in South America terrestrial fauna,
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Continuous Tooth Replacement in a Mole-rat

Mammals are characterized by diphyodonty, only two generations of teeth, among other traits. However, a few mammals have evolved a form of continuous tooth replacement. For example, Manatees (Trichechus) add extra teeth Read More...

Pre-natal Hormones Shape Female Social Interactions

In many mammals the female uterus is divided into two horns, a right and a left. Several embryos develop along the length of each horn. For example, a pregnant dog might have four fetuses developing in the right uterine horn and three more developing in the left horn. Thus, each fetus has neighbors. However, the Read More...

Poisonous Rats!

Large, poisonous rats roam the Earth. It sounds like a post-apocalyptic scene from a B movie, but it’s not. Jonathan Kingdon, who mammalogists will know as the author Read More...

Singing Mice Top The Charts

Maybe singing mice (Scotinomys teguina) wouldn’t make it to Hollywood in America’s Got Talent, but they put on a good show. Males of these diminutive Neotropical rodents sing by producing a series of trills when attracting mates (Figure 1). Like some birds, singing mice Read More...

Who’s Your Daddy – Paternity in Ground Squirrels

Reproductive strategies are shaped by sexual selection, but selection pressures often differ between the sexes. When both sexes mate with multiple partners during the breeding season (polyandry or polygynandry) a conflict arises between the sexes. Females can be
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Remodeling Fever – Kangaroo Rat’s Reshape Burrow Systems Seasonally

Visit any home improvement store this time of year and you will see dozens of people purchasing materials to remodel or beautify their homes. We are not alone - banner-tailed kangaroo rats (Dipodomys spectabilis) also remodel their Read More...

Blast From The Past – Red-crested Tree Rat Rediscovered After 113 Years

It’s not everyday that an animal presumed extinct comes ambling into your lodge. But that’s just what happened at the El Dorado Nature Reserve Eco-lodge in the Sierra Nevada de Santa Marta region in Read More...

Sex is Costly for Males too

It is axiomatic that females invest heavily in each gamete (ova), producing few of them relative to males. Males, on the other hand, invest little in each sperm cell and therefore produce Read More...

Climate Change Makes Marmots Fat and Fit

Environmental change, including global warming, is altering the ecology and behavior of mammal species. For example, red squirrels in the Yukon are breeding 18 days earlier than they did only ten years ago (Reale et al., 2010). Likewise, climate change altered hibernation behavior in yellow-bellied marmots Read More...

A Whiter Shade of Pale

As it was with the peppered moth, so it is with the deer mice of Nebraska’s Sand Hills. Covering roughly a quarter of Nebraska, the Sand Hills are grassy dunes of light colored sands deposited Read More...

Red squirrels adopt orphans

When does it pay to adopt? The benefits to the adopted infant are obvious, but how does the adoptive parent benefit? Rearing offspring is costly, both in terms of time and energy. Why would a parent endure these costs if the offspring is not their own? Read More...