Researchers won't take dead orca calf away from mother as she carries it into a 17th day

orca
Credit: CC0 Public Domain

As Tahlequah carries her deceased calf for a 17th straight day, and concerns mount about her health, taking the calf away is not an option because of the tight bond between Tahlequah and the rest of the pod to her baby—dead or alive, experts say.

"These are very intelligent animals, and the loss of this animal is quite profound for the matriline and everyone who witnesses it," said Sheila Thornton, lead killer-whale scientist for Fisheries and Oceans Canada. She saw Tahlequah continuing to carry the Tuesday as J pod traveled south to the outer coast of Cape Flattery, Wash.

Ken Balcomb of the Center for Whale Research on Thursday saw Tahlequah still continuing to carry the calf, born July 24, for the 17th straight day. He estimated she has carried the calf more than 1,000 miles. The carcass is starting to come apart; the calf's insides were visible atop Tahlequah's head Thursday morning. Yet still she clings to the body of her baby.

"I certainly think the length of the situation is unprecedented," Thornton said. "There are many species who do undertake this sort of behavior if a young animal has failed to survive, they will carry the carcass, you can look at that as mourning behavior."

Several recent scientific papers and publications have documented grieving behavior in whales and dolphins, and scientists working in the Salish Sea have themselves witnessed similar sad sights of mothers carrying deceased calves.

Because of the tight bond between Tahlequah and her calf as well as the bond shared by the rest of the pod there is no plan to take the calf away. "That is not on the table," said Brad Hanson, wildlife biologist with the National Oceanic and Atmospheric Administration's Northwest Fisheries Science Center in Seattle.

Scientists are worried that Tahlequah, or J35, is not getting adequate food because she has been carrying her baby for so long.

"We have obvious concerns about the displacement of her behavior away from foraging and feeding, to carrying the calf, and concerns over the length of time of this behavior as it continues, and the possibility of decreasing her ability to forage effectively," Thornton said.

It is not known if her family is foraging for her and feeding her, Thornton said, and she could not get a good enough look at her from the water Wednesday to assess her condition.

Because Tahlequah was pregnant, it is possible she began carrying her deceased calf with an extra boost of lipids in her blubber that could be helping her now, said Dawn Noren, research fishery biologist at NOAA's Northwest Center in Seattle.

Dolphins she has studied have an extra-rich layer of blubber at pregnancy, to prepare for the tremendous energetic cost of lactation.

"The assumption is she could be fortified like a dolphin," Noren said. "The other concern is that she might be food-limited."

An adult female orca of Tahlequah's size could typically go for a month without eating and survive, Noren said. But what is unknown is her condition going into her pregnancy, and after the loss of it.

One thing that is certain, Noren said, is that the work of pushing the calf day after day through the water adds physical effort to her burden of loss.

Meanwhile, biologists and veterinarians mobilized Thursday in an attempt to prevent more losses in the imperiled J Pod family, with J50, age 3{, feared to be near death from starvation. The orca may also have an infection.

The plan on Thursday was to provide emergency assistance for the whale, with a visual medical assessment, as well as a shot of broad-spectrum antibiotics.

A medical team was speeding to Race Rocks, across the Strait of Juan de Fuca from Port Angeles, as of 1 p.m., to see if the conditions are right to attempt to help her.

The Lummi Nation is also standing by to provide live chinook salmon for the young whale. The fish could be a vehicle to deliver medication to her that can't be administered any other way.

The fish are being delivered by truck from a Washington Department of Fish and Wildlife hatchery in Marblemount, Skagit County, for loading into a tote on the Lummi Nation's boat.

The initial plan was to take the fish from seiners or reef netters, a maneuver the Lummi practiced Monday with success. But catches of chinook are too unreliable for people and whales to get enough fish for J50; at least 15 hatchery fish will be transported for the whale, with more in reserve.

Effort may also be made to collect a sample of her breath using a petri dish on a pole. However, Hanson said, conditions have to be just right to do so. The blow of a young whale is only about a foot and a half high, so winds must be calm and the whales close in order to collect a sample.

It's also not only a matter of weather; the whales themselves have to be in the right position and behavior to attempt a medical intervention. If they are busy traveling, biologists can't just push into the pod. However, if J50 is off by herself, quietly resting or foraging, that could present an opportunity.

With high winds predicted to be moving into the Strait of Juan de Fuca over the next several days, there was little time to waste to come to the whale's aid—if they come into range, and the conditions are right.

"We are ready to go," Hanson said.

People from around the world are following the trials of the southern resident orca clan, down to only 75 animals.

More than 1,000 readers responded to an invitation by The Seattle Times to share their thoughts on J35 and the other orcas.

Many have expressed surprise at just how powerfully watching Tahlequah has affected them. But Roxanne Sperry, a cancer researcher and theology student beginning a ministry as a veterinary chaplain, said such feelings are common—as is the sense there is no place to take them.

"This type of grief in people often goes underground, it's, 'It's just a dog, an animal, move on.' People go underground with these feelings, they are delegitimized. But it is it very, very, real," she said.

She was following Tahlequah's story from Lawrencetown, Nova Scotia, and like many around the world, is moved by the whale's plight.

In people, witnessing such distress in an animal can also be a portal that opens to deep, unresolved grief over losses of their own children and other loved ones, Sperry said. That includes pets, a bond that continues after an animal's death, just as with the loss of a person.

"Yet a lot of times in society that type of grief goes unrecognized," she said.

©2018 The Seattle Times
Distributed by Tribune Content Agency, LLC.

Citation: Researchers won't take dead orca calf away from mother as she carries it into a 17th day (2018, August 10) retrieved 19 April 2024 from https://phys.org/news/2018-08-wont-dead-orca-calf-mother.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Grieving orca highlights plight of endangered whales

3653 shares

Feedback to editors