With the discovery of a fifth newborn orca calf off the west coast of Vancouver Island, researchers say they’re hopeful the endangered southern resident population is bouncing back.

The calf, which experts believe is just several days old, was spotted swimming with its mother near Sooke on Monday.

Before the births began in December 2014, a newborn calf had not stayed alive for the previous two-and-a-half years.

Things looked bleak late last year, when a pregnant 19-year-old orca belonging to J pod was found dead on the shores of Vancouver Island along with a full-term fetus it was carrying.

That death brought the southern resident population down to just 77 whales.

But researchers have since been given hope with five successful births bolstering the southern resident population.

Take a look at a timeline of this orca “baby boom.”

J50, born December 2014

jpod baby

(Photo: The Center for​ Whale Research)

This female calf’s mother, identified as J16, was one of the oldest to give birth in more than four decades, according to researchers.

The birth was the first of three in the last year for the 27-member J pod. It’s the same pod J50, the pregnant orca that died, belonged to.

J51, born February 2015

Baby orca discovery stuns researchers

(Photo: The Centre for Whale Research)

The J pod got its second new addition in less than two months with the birth of J51, a male orca calf.

The newborn was spotted swimming with its mother, 36-year-old J19, in the Juan de Fuca Strait on Feb. 12.

L121, born February 2015

Baby orca whale

(Photo: AP/ National Oceanic and Atmospheric Administration/ Candice Emmons)

The male calf was caught on camera Friday, Feb. 27, swimming with its mother in Puget Sound.

Biologists with the National Oceanic and Atmospheric Administration spotted it with other whales in the “L” pod, one of three pods that make up the southern resident population.

“The whales were very grouped up and within a few minutes we observed the new calf with its unique orange-ish color on the white areas,” said NOAA’s Dr. Bran Hanson. “The calf looked very energetic.”

J52, born March 2015

j pod orcas

(Jeanne Hyde/Maya Legacy Whale Watching/The Canadian Press)

Yet another newborn calf emerged in J pod in March, confirmed when whale watchers glimpsed the baby orca in Active Pass off Galiano Island.

That birth brought the total population of the endangered southern residents to 81.

Heavy creases, or fetal folds, spotted on the calf meant it was just a few days old, scientists said.

The fourth birth in under a year piqued biologists’ interest because only half of orcas born in the wild survive the first six months of life.

L122, born September 2015

5th new orca calf spotted off B.C. coast

(Photo: Dave Ellifrit/Centre for Whale Research)

The latest calf was born to the L pod sometime this month, according to the Centre for Whale Research.

The newborn was spotted frolicking in the water with its mother, 20-year-old L91, and other family members near Sooke.

“It was really exciting,” said Mark Malleson, a whale watching guide who photographed the calf. “You never know, you could see some more over the course of the fall here, because we’re getting into the time when we would typically have calves.”

The orca’s gender is unclear.