Pygmy whale and her calf put down after beaching themselves in Delaware

Moved by the plight of a stranded pygmy sperm whale and her nursing calf, bystanders at Woodland Beach in Kent County, Del., this morning struggled in vain to rescue the mammals by heaving them back into Delaware Bay.

But the 9-foot, 750-pound mother washed ashore again, followed by her 5-foot-long calf. The mammals ended up being recovered by researchers, and later were euthanized.

"Usually if they strand, something's wrong," said Suzanne Thurman, the executive director of the Marine Education, Research and Rehabilitation Institute, which will conduct a necropsy of the animals on Wednesday at its offices in Lewes.

The post-mortem will determine if the mother was ill, infected with parasites or had ingested plastics, Thurman said. The adult whale had no outward signs of injury, but appeared to be emaciated, which Thurman said "is probably indicative of an underlying illness."

The calf, which was less than a year old, had not yet weaned and would not have survived without its mother.

Pygmy sperm whales, which resemble dolphins, are not uncommon in Delaware Bay and sometimes mysteriously swim ashore.

The attention of bystanders and hovering news helicopters added to the animals' stress, Thurman said. Even so, the chance of a successful rescue of any beached marine mammal is "minimal," she said.