For the first time ever, researchers have compiled evidence on how coyotes rapidly spread throughout North America. Although scientists have long been aware that the dog-like mammals moved quickly throughout North America over the past century, little is known about where they came from or how they spread so fast.
To shed light on that, scientists from the North Carolina Museum of Natural Sciences analyzed a combination of museum specimens and fossil records to track coyote distribution over the years.
Such research revealed that, while many mammal species declined since 1900, coyote populations exploded. That trend is well documented at a local and state level, but it has never been analyzed on a continent-wide scale before now.
“We began by mapping the original range of coyotes using archaeological and fossil records,” said study co-author Roland Kays, head of the Biodiversity Lab at the North Carolina Museum of Natural Sciences, according to Earth. “We then plotted their range expansion across North America from 1900 to 2016 using museum specimens, peer-reviewed reports, and game department records.”
To gather the new data, researchers reviewed over 12,500 records that spanned the last 10,000 years. That revealed coyotes once occupied a larger area of North America than previously believed. In fact, while past research speculated that ancient coyotes only lived on grasslands and central deserts, the fossil evidence revealed that they had a much broader range.
Coyotes began to expand across North America around 1920, a shift that likely occurred as a result of farming, forest fragmentation, and species hybridization. As people began to move west, it cause the animals to migrate on to new areas.
Since the first move, the animals have permeated many parts of the continent and are currently moving down into Central America past the Panama Canal. This new evidence is important because it answers many questions about why coyotes spread so quickly. It also sheds light on their evolution, as well as their role in ecological systems. Further research on the animals could also give more insight into their connection with wolves and dogs.
The study was published in the journal ZooKeys.