What do cows mean when they moo?
Scientists in England have been eavesdropping on "conversations" between cows and their calves to answer that question--and they've discovered that moos convey a lot more meaning than you ever imagined.
“This is the first time that complex cattle calls have been analyzed using the latest and best techniques," Dr. Alan McElligott, a senior lecturer at Queen Mary University of London and the co-author of a new study about moos, said in a written statement. "Our results provide an excellent foundation for investigating vocal indicators of cattle welfare."
The scientists spent 10 months digitally recording call sounds from two herds of free-range cattle on a farm in Radcliffe-on-Trent, Nottinghamshire. The researchers then spent several months performing the acoustic and statistical analysis of the data. They determined that mother cows use two types of contact calls with their calves: a quiet low-frequency call when the calf is nearby and a loud high-frequency call when the calf is far away. Calves produce one type of contact call when they're separated from their mothers and they want to nurse.
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A mother cow's low-frequency call.
A mother cow's high-frequency call.
But that's not the only news about moos the researchers are offering up.
“The research shows for the first time that mother-offspring cattle 'calls' are individualized--each calf and cow have a characteristic and exclusive call of their own," Dr. Mónica Padilla de la Torre, who led the study while at The University of Nottingham’s School of Life Sciences in England, said in the statement.
The idea that cow-calf pairs have their own distinctive call isn't news to some farmers.
As James Bourne, a cattle farmer in Lincolnshire, told the BBC, "A calf certainly knows its mother from other cows. If they are not distressed and they are calm they will moo fairly low to the calf, almost talking to their calf. If they are distressed, in other words they have lost their calf or are separated from their calf, it's a much higher pitched moo."
The study was published online Dec. 8, 2014 in the journal Applied Animal Behaviour Science.