In the past two months of a cetacean pregnancy, he says, you can start to see signs that mama's feeling a little blah : decrease in appetite, discomfortand possiblebacterial infections like bursella that cause late-term miscarriages in other cetacean species. But compared witheverything that can go wrong at or following conception or birth, the odds that something will go wrong with these two pregnant animals in the next few months is more limited, he says.
But if the mother does lose her calf, she and the entire orca community must overcome the emotional loss. Whales are highly family bonded, and the UW's Giles says their family members may know of a pregnancy through echolocation. Its like living with moving and breathing ultrasound [machines] all around you, called your mom and brother and sister, she says. It's physically taxing, It's medically taxing and dangerous, And then it's emotionally taxing for these individuals to continuously get pregnant, Giles says.
In some pregnancies, late-term calves can become ticking time bombs in their mothers bodies. If a grown calf dies, gets stuck and releases bacteria in the birth canal, the mother can die.
Calves that do make it through the birth canal need to swim to the surface and take their first breath immediately. The calves flukes and dorsal fins are floppy in utero, but calves come out tails first over one to two hours so their fins have time to harden in the cold water. Calves can be successful when they're born head first, but they don't have that functional paddle, Nollens says, noting calves usually get assistance from other females.
Throughout this process, theres another threat on the perimeter: male orcas, which can become aroused during childbirth and act aggressively toward the calf if females dont keep them away. Nollens says hes heard reports of newborns with rake marks, and thinks its likely theyre from males thattried to get access to a mom or calf during birth.
Of all the stress points in a whales pregnancy, lactation and weaning require the most work. Pregnancy is cheap it's lactation that is hard, NOAAs Noren says.
When orcas give birth, their caloric needs skyrocket, Nollens says, which means they must work harder to feed themselves and provide 40% fat whale milk to help their newborn grow quickly. If a killer whale has unlimited access to food, the food intake within days will go up 50%, Nollens says.
This responsibility can be overwhelming. Most of these females already have other offspring that they also need to support, so it is a huge demand to support themselves, nurse their young calf and help support other offspring and family members, Fearnbach says.
It can take two to three years, depending on whom you ask, to gradually wean a calf, which is entirely dependent upon its mother until it learns to forage. Dr. Astrid van Ginneken of the Center for Whale Research notes that where fish are scarce, weaning takes longer because calves have fewer fish to supplement their nutrition.
Dozens of researchers, policymakers and stakeholders have spent the past few years coordinating a $1.1 billion plan to save Puget Sounds orcas from low food availability, as well as ocean disturbance and pollution. While all southern residents suffer from the effects of these factors, its especially pronounced for mothers and their newborns.
All of those threats compound each other, and researchers are split on which ones are worse. I know some people are really about, 'It's only the prey, only the prey,' and other people are, you know, anti-boats, I think it's not that simple, Noren says.
In my opinion, to save these whales, we have to be laser focused on the food issue, and then secondarily the toxicants issue, Giles counters.
More:
Here's what pregnant orcas are up against in Puget Sound - Crosscut
