After we had been working with green sea turtles for three days, we turned our attention from marine reptiles towards studying and observing marine mammals for a day. Several dolphin and whale species live in the waters off the coast of Los Organos in northern Peru. The months of spring in the southern hemisphere, August – November, mark the mating season of Humpback whales (Megaptera novaeangliae). As a result, the abundance of whales during these months is especially high in the tropical waters off the coast of Peru. We left out hotel early in the morning and headed down to the pier. There, we were greeted by Santiago, one of the biologists and tour guides from Pacifico Adventures, the whale watching company that was going to take us out to sea.
Santiago gave us a short safety briefing and introduced us to our second tour guide, Romina. They took us down the pier where we waited for a few minutes before boarding a small, two-engine vessel. Similar to a bus, the vessel had two rows of seats on either side. Once everyone got settled on board and put their life vests on, we headed towards the open sea. After a few minutes, we drove past an old oil platform in the ocean that had been reclaimed by South American sea lions (Otaria flavescens), Peruvian pelicans (Pelecanus thagus), and neo-tropical cormorants (Phalacrocorx brasilianus). Our guides wanted to illustrate the difficulties of biological surveying and asked us to divide into two groups; one group was to count the number of neo-tropical cormorants, and the other group was to count the number of Peruvian pelicans as the boat slowly circled the platform.
Unfortunately, our tour guides did not account for the field work we had been doing in Lima, Paracas, and Los Organos prior to our whale watching tour. As a result, our counts were significantly more accurate than they expected; roughly 115 neo-tropical cormorants and 70 Peruvian pelicans. Pleased with our work, we continued our journey along the coast in search for marine mammals. During the first half hour, we did not see any whales. Everyone was eagerly scanning the water with their eyes, watching for blows (the fountain of water droplets generated when a whale exhales), dorsal fins (the back fin of a whale), flukes (the tail fins of a whale), and breaching (a whale jumping out of the water).
Finally, we spotted our first whales. Far in the distance at the right side of the boat, we spotted several humpback whales swimming along the surface of the water. At first, we saw blows from the whales exhaling as their heads broke through the water surface. Then, their entire bodies slowly scratched along the surface as the whales dove again. This highlighted the dramatic size of the humpback whales; female whales are usually larger than and normally grow up to 16 meters in length, even though individuals up to 18 meters have been recorded. Finally, the fluke of the wales would come out of the water for a brief moment before the whale dove. Whales lift their fluke in the air before diving to gain additional momentum going downwards.
The fluke of every individual humpback whale is unique, similar to a human finger print. Fluke Identification (Fluke ID) allows scientists to identify whales and track their movements all around the world. Humpback whale flukes range from being all white to being all black, with various colorations in between. Additionally, each fluke may have a slightly distinct shape, scars, or other distinct markers. Generally, flukes are classified on a scale of 1 to 5, from 1 being an all-white fluke and 5 being an all-black fluke.
We followed the group of roughly 5 humpback whales for about 20 minutes as they kept resurfacing. One student got particularly lucky; while all other students were looking for whales on one site of the boat, she looked towards the other side and got to witness a whale breach in close proximity of the boat. All other students only got to hear a giant splash and feel a few water droplets on their skin. Such groups as the one we observed are common in humpback whale breeding grounds, which the warm, tropical waters of northern Peru are a part of. These groups are referred to as competitive breeding groups, which usually consist of one female and several males in pursuit of the female. The males will show off to each other and fight each other. Eventually, the strongest and most dominant male will get to mate with the female. Sometimes, a competitive breeding group solely contains male humpback whales showing off to each other while searching for a female to mate with.
The first group we followed was a competitive breeding group, which became evident by the whales’ behavior. The whales were swimming fast along the surface of the water and slapped their flukes on the surface of the water as they were diving down, a demonstration of their strength addressed at other male whales. Eventually, we lost track of this group and continued searching for whales along the coast of Los Organos.
Before we encountered more humpback whales, we encountered a group of dusky dolphins (Lagenorhynchus obscurus). This was a special occasion, because this species had not previously been documented in the waters around Los Organos. As a result, our tour guides got extremely excited, a sentiment that was shared by a majority of the students on board. Dusky dolphins, like all dolphins, are highly social animals that live and travel in groups of several dozen animals. These groups of dolphins are referred to as a pod.
Dolphins are extraordinarily skilled hunters, feeding on schooling fish, squid, and sometimes crustaceans. Dolphins belong to the toothed whales, a group of whales that, as the name indicates, have teeth. Other members of this group include killer whales and sperm whales, a species most famously represented by Moby Dick. Humpback whales on the other hand belong to the baleen whales. Instead of teeth, these whales possess baleens; long, broom like structures hanging from the top of the mouth that allow the whales to filter small planktonic lifeforms, such as crustaceans, out from the water column. Humpback whales are somewhat unique, as they are the only species of baleen whale that has been documented literally eating dirt from the bottom of the ocean and then filtering small lifeforms out of the dirt as the whale swims through the water column. It is fascinating to think about that humpback whales reach their massive weight of up to 36,000 kg solely by feeding on some of the smallest animal lifeforms in the ocean.
We continued our tour and slowly began heading back towards the port. On the way there, we encountered a special treat: a humpback whale with her newborn calf. Both animals were calmly floating at the surface and allowed three whale watching boats to slowly circle them. The animals were sitting completely still at the surface, which caused our tour guides to hypothesize that the mother whale was currently feeding her calf, or had been doing so shortly before we arrived. The fact that the whales were not concerned about the presence of the whale watching boats bears testimony to the great trust between humans and animals in the waters of northern Peru, and the responsibility of the touring companies in interacting with the whales.
Around the world, distinct populations of humpback whales exist, and all of them, except one population in the Arabian Sea, have one thing in common; they migrate. During the winter months, humpback whales live in the waters surrounding the Antarctic or Arctic. Here, they feed. When it is spring, during the months of August – November in the southern hemisphere, a part of the Antarctic humpback whale population migrates to the warm waters of Peru and Ecuador, while other parts migrate to Hawai’i, Australia, and other locations. Here, humpback whales reproduce and give birth. A pregnant female humpback whale will swim all the way from the Antarctic to Peru, give birth, nurse its calf, and then swim back; without feeding! The reasons for this migration are not exactly known, though it is assumed that calves benefit from beginning their lives in warm, tropical waters rather than in the freezing waters surrounding Antarctica.
Eventually, we left the mother and her calf in peace and headed back towards port. Shortly before we reached port, one of our tour guides believed to have spotted a moonfish swimming at the surface. However, as we got closer it turned out the “moonfish” was just the fin of a dead South American sea lion floating at the surface. While we headed for port, I started talking to one of the tour guides, Romina, about my brief experience working with humpback whales in the eastern Caribbean. Last spring break, I got to work with a researcher that was investigating how humpback whales use ocean bathymetry, the shape of the ocean floor, to amply their famous singing across large geographical areas throughout the ocean.
Every humpback whale population has a distinct song and all males that belong to a certain population sing that same song. Usually, males begin singing once they reach sexual maturity; immature male whales have been observed following mature, singing whales, potentially to learn the song of their population. Throughout a breeding season, the song of a population slowly evolves and changes. At the beginning of a breeding season, male whales sing the exact song that was sung towards the end of the previous breeding seasons. Distinct humpback whale populations have developed ‘accents’; similar to a Texan and an Australian, an Arctic and an Antarctic humpback whale will sound different.
Once we were back on shore, we got to visit the facilities of Pacifico Adventures, the tour company that had taken us whale watching. Pacifico Adventures was started to unite two seemingly separate worlds: tourism and research, a combination commonly referred to as ecotourism. The money that is generated from touristic activities is used to fund scientific research. All tour guides on board are scientists; as the tourists observe the whales, the guides take photos and other scientific data. This combination has proven highly successful in the case of Pacifico Adventures. The company proves to be profitable, has been able to develop its own museum, and funds extensive scientific research.
After a brief tour of the museum, we got to meet the founder of Pacifico Adventures who briefly talked to us about the story of her company. Afterwards, all students toured the gift shop extensively and obtained some souvenirs. It was good to know that our money would support future scientific research. Throughout the following days, many students returned to Pacifico Adventures on numerous occasions to enjoy the view of the ocean, learn more about whales, and, most importantly, purchase amazing brownies from Pacifico’s Café.