While Oceans Unlimited SCUBA divers discovered the colorful marine life among the coral reefs of Manuel Antonia National Park, Captain Eddy spotted the telltale white puffs of water vapor. As our divers surfaced, Captain Eddy pointed out the whales and identified them as a mother humpback and her calf. Everyone watched in awe as the mother helped her newborn calf to the surface, exhaled another puff of vapor, and submerged below the blue waters. Suddenly, everyone aboard heard an eerie, beautiful sound and we recognized it as humpback communication! Everyone dove in and listened to the humpback melody. A clip of the song is below, and our divers heard these incredible animals throughout the second dive of the day.

Generally, only male humpbacks “sing” and can be heard for miles underwater. The website www.whalesong.net broadcasts songs recorded in Hawaii, and you can hear the footage from yesterday here. The two whales we saw yesterday were a female and her newborn calf. The sounds heard underwater could be her communicating with her calf, perhaps directing it toward her or teaching it to sing. We are unsure why the whale made these sounds, but we do know it was an incredible experience! Humpbacks are amazing animals, and we have the pleasure of having them in Costa Rican waters from August to April.

Humpback whales make one the most remarkable journeys of any animal. Their annual migration can be upwards of 5,000 miles; they leave cold nutrient-rich polar waters for the warm water of the tropics to breed. In Costa Rica we are fortunate to be the target destination for humpback whales from both the Arctic and Antarctic! The female humpback spotted yesterday was probably a Northern hemisphere humpback, because the season for humpbacks from the Southern hemisphere is August to November when they return to Antarctica for the summer feeding season.

The humpback currently in Manuel Antonio National Park likely left Alaska sometime in September as ice closes in on the sea, and travelled the nearly 5,000 mile just in time to give birth in the warm waters. Her calf appeared to be about 6ft long, indicating that it was born recently. The gestation period is 11-12 months, and calves will stay with their mothers for a year or longer after birth. Calves drink up to 45kg per day of thick, nutritious milk from their mothers; however, the mothers will not be able to eat until they return to polar waters. She will survive on a thick layer of fat called blubber until her calf is strong enough to start the long migration north.

In polar seas, these gentle giants will strain krill and small fish from the water with their 270-400 baleen plates. Mysticetes (baleen whales) will take in a large mouthful of water and then use the bristles of their baleen as strainers as they push water out of their mouths. Their prey remains on the inside of the baleen, and they use their tongue to gulp down krill and small fish. Humpbacks can grow to be 52ft (16m) long on a diet of small creatures. They feed almost constantly when in cold waters, but the concentration of prey is much lower in the tropics and humpbacks will eat almost nothing until they return.

These incredible creatures can be found in Costa Rica between August and April, but worldwide they are on the endangered species list. They were decimated by hunting, with a 90% drop in population until a moratorium on hunting in 1966. The population is recovering at around 3% increase per year, and there are an estimated 80,000 humpbacks worldwide. We are incredibly fortunate to have heard and seen humpbacks on our dives! In Costa Rica you can also find pilot whales, beaked whales, and bottlenose, common, spotted and spinner dolphins so why not come and enjoy their beauty with us!