LONDON, June 30 (UPI) — A British study says harbor sears are giving birth to their pups earlier every year as a result of changes in the marine ecosystem.
The mammals, also known as common seals, are being born 25 days earlier in the year compared with 35 years ago, the BBC reported Wednesday.
Scientists suspect depletion of species of large fish by fishing has allowed populations of smaller fish species favored by the seals to thrive, the BBC said.
This, in turn, means abundant food supplies for the seals, which could effect their mating and birth cycles.
Females undergo rapid weight loss during the weaning and mating seasons, leading the researchers to suggest that the animals needed to “acquire a fatness threshold” before they can mate again.
“In other words, the better the food acquisition during and after lactation, the earlier they regain the mass needed” for mating, the study said.
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