Scientists eventually figured out that the warm spring that year started the chain that led to the death of the foals. The unusual weather encouraged the early emergence of Eastern tent caterpillars before the arrival of the migratory birds that normally eat them.
"The caterpillars fell on the ground and they were ingested by mares," Weltzin said. "They contained a chemical that caused the mares to abort. ... There are interesting, nonintuitive processes that can occur due to changes in the timing of spring."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500