The study, which focuses on a population of 200 living around the Moray Firth and the east coast of Scotland, allows researchers to isolate expectant mothers by examining aerial photographs taken from remotely operated vehicles.
Previously, the breeding success of dolphins was assessed based on the detection of live young, so there were no records of unsuccessful pregnancies.
The pioneering project is being carried out by researchers at the University of Aberdeen in collaboration with Duke University’s Marine Robotics and Remote Sensing Laboratory in the US.
This will help specialists understand the health status of dolphins and help pinpoint the causes of any changes in the population, such as lack of food.
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Dr Barbara Cheney, a Research Fellow in the School of Biosciences at the University of Aberdeen, works at the Lighthouse Field Station in Cromarty.
She said: “The main goal of the study was to see if we can remotely determine pregnancy status from aerial photographs taken with an unoccupied aerial system or drone.
“Similar studies have been done for larger whales, but to the best of our knowledge, this is the first time this has been done for small cetaceans.
“This is important because reproductive success is key to population growth, but it is especially difficult to measure in wild populations.
“The use of aerial photographs will allow us to regularly track changes in the reproductive success of this conservation-supporting protected population of bottlenose dolphins.”
The researchers conducted five boat surveys in July and August 2017, and a total of 64 dolphins were identified.
Only one of 15 dolphins whose pregnancy status was known was misidentified as not pregnant.
“We know that reproductive failure has been associated with harsh environmental conditions, pollution and natural toxins, but previously we could only assess the impact on populations where animals are easily captured or remotely sampled,” added Dr. Cheney.
“This study will provide us with a wealth of new data to further improve our knowledge and understanding of bottlenose dolphin reproductive success.”