The Behaviors of Humpback Whale

Introduction 

The humpback whale (Megaptera novaeangliae) belongs to the baleen whale species, which is one of the bigger rorqual species. Cholewiak et al. (328) explain that the adult humpback whales weigh approximately 25–30 metric tons and their lengths ranges from 12–16 meters. The humpback whale has a gestation period of 11 months and a lifespan of 45 to 50 years. The whale has a distinctive body shape where it has a knobbly head and long pectoral fins. The humpback whales are found in seas and oceans across the world and they migrate approximately 25,000km every year (Simon et al. 3788). This essay will explore the behaviors of the humpback whale, an animal that is popular among whale watchers due to its distinctive surface behaviors including breaching. 

Humpback whales are particularly adapted to gulping a large volume of concentrated water and food through their wide open mouth with a huge area. Whales are relatively found in water where they illustrate ranging remarkable surfacing behaviors. Scholars argue that some of these surfacing behaviors are a way for the whales to relate to land. Others argue that surfacing behaviors are a form of communication among whales. Wild about Whales (n.p) explains that humpback whales may flap their wings as a form of warning in case of nearby dangers. Other scholars argue that the movement of whales in water through a splash is a form of eliminating any skin parasites. Accordingly, the movements and behaviors may be for fun. 

Breaching

One surfacing behavior is breaching where the whale’s body leaves the water surface. Hawaiian Islands Humpback Whale National Marine Sanctuary (n.p) defines humpback breach as a powerful acrobatic display where the species launch itself out of the water surface. It pumps its tail severally to propel the whole body into the air and lands to the water surface with a resounding splash. Although all whales breach, humpback whales are known for their frequent breaching activity. The exact reason for the breaching activity among whales remains unknown. Many theorists argue that breaching is a form of communication, helps in warding off other males, helps the whale to dislodge barnacles and other parasites from the skin, or attract other whales. Generally, breaching is a form of recreational activities for people who love whale watching, it is entertaining, signifies cleanliness routine, territory marking, and sending a message.

Image 1: Humpback Breach

Simon et al. (3788) explain that whale watching is fun, as this species is the superstar of penchants for the puzzling and intriguing behavior. Rather than breaching, whale watchers admire how humpback whales hit the water with their fins, tails, or their heads. Another reason for breaching is looking around where they cautiously check the surroundings. Janik (62) argues that breaching is like an irksome ship where they breach if they hear a worrying or bothersome noise. Jumping around is always a fun activity for humans and particularly babies. Based on this, breaching can be a form of entertainment to reduce lonesome. Straley et al. (175) explain that as a form of entertainment, it may be a play game as they breach in small units of 2 or 3 humpback whales, as the whales are in a spirited session using a cetacean style. 

According to Janik (62), the breaching activity among whales may be a territorial action where they breach in case they sense an approaching menace or intrusion, as a way of intimidating the intruder. Other scholars believe that breaching behavior is a form of sending messages. For example, a whale may breach as a way to transmit a message to a fellow whale that they are changing their course. Another way is breaching as a form to seduce or woo a partner (Straley et al. 175). Another form of communication through breaching is to transmit messages in a noisy environment when others cannot make out their singing. 

Singing

The singing among the humpbacks depends on their locality, where there are varying songs and vocals between whales living in different ocean basins. Noad et al. (n.p) explain that male humpbacks sing when they are on the grounds and as they migrate from and to the breeding sites. Noel et al. (n.p) argue that humpbacks sing during sexual intercourse where it remains debatable if it is a form of attracting the females or repelling other males. According to Janik (64), the male humpback produces similar songs, which changes with time where each maintains the changes, an indication that singing is a cultural evolution and transmission. Straley et al. (175) argue that songs in similar ocean basins are similar with variations as the distance increases; while from different oceans, the songs are totally different.

Yirka (2018) argues that a new song among the humpback starts as a simple tune developing with time to a complex tune over time until it becomes ungainly. After this, a group of whales starts a new tune and abandons the other and they sing the complex new songs until they start another. It remains debatable why the whales change the songs over time. One of the theory is that the song tends to become complex and it is challenging to learn the developed song. Generally, the social singing of humpbacks whales is an example of animal culture and the unique aspect of the cultural aspect among the whales, which is only evident in humans and no other species. 

Humpback Whales Feeding Behaviors

According to Janik (64), humpback whales survive on a diet of tiny fish like sand lance and herring. They take their prey by opening their mouth wide where they gulp a large volume of fish-laced water. The water is filtered through their bristly baleen plates inside their mouths and water squirted back through their mouth. The process is undertaken through lunge feeding where the whale makes a number of powerful strokes using the tail to increase their swiftness and when it opens the mouth, it reduces the speed. Straley et al. (175) argue that some humpback whales adapt another form of feeding termed “bottom side-rolling,” where the whale performs slow repetitive rolls at the rate of 30 per hour. 

Mating and Breeding of Humpback Whales

The sexual maturity among humpbacks is 6 to 10years of age or when females attain a length of 40 feet and males 35 feet (Parks et al. n.p). The humpback whales have a gestation period of 12 months and the female’s bears a calf every 2 to 3 years. At birth, the humpback has a length of 10-15 feet and weighs approximately 1 ton, which is equivalent to 907 kg. During the first year after birth, the calf relies on the mother’s breast milk, which is rich in content and contains 45% to 60% fat content. The calf weans on solid food at one year (Driel-Vis, 2018). 

Driel-Vis (2018) explains that the mating period among humpbacks starts from the end of August onwards. During this peak mating period, there are a lot of antics and interactions among the species. Driel-Vis (2018) adds that during the breeding period, the humpbacks do not eat anything. In addition, the species is not monogamous but rather their males have multiple partners during the breeding season. Accordingly, it is hard to see the whales mating but they have been seen engaging in seductive and affectionate behaviors. The males blow bubbles, which rise beneath the female’s genitalia. 

Nonetheless, getting female partner results in fights among the males and this is evident through battle scars among the males. Driel-Vis argues that battle scars are as a result of fierce competition among males for ovulating females. The females become pregnant while in warm water and during birth-time, they return to the same water for birthing to ensure their calves survive as they die if born in freezing waters. Lactating mothers are escorted by the males for a time but the males are not actively involved in raising the young ones, as they are busy looking for other mates as lactating females are not mating potentials. Another interesting behavior is that during the breeding period, females rarely interact with one another and each female chooses a specific male, though the attributes used by the females remain unknown.

Migration of Humpback Whales

The migration of whale is either to feed or to breed. For example, humpback whales feed particularly on krill that lives in freezing water, an environment that is not suitable for giving birth. Straley et al. (n.p) explain that newborn calves do not have the protective blubber layer under their skin, an element that makes them prone to death due to freezing. The species have an annual migratory route particularly in the autumn to their breeding and calving grounds in the winter in search of warm waters.

Straley et al (n.p) explain that the humpback migrates on approximately 5000km, which is the longest migratory journey of mammals on Earth. However, not all whales migrate, as the immature remains in the feeding ground and the mature travel for mating and others for calving. Therefore, humpback travels or migrates to other areas for suitable calving and in search of food where they travel from freezing cold water where they source for food to warm shallower waters for mating and calving. This is the reason why the humpback whales do not eat during the breeding period, as they are in warm waters and their prey lives in very cold waters. 

Spy hopping among Humpback Whales

Spy hopping is a behavior common among the cetaceans like sharks, humpback whales, and gray whales. The process involves poking the head out of the water to have a better view of the activities near the water surface (Cholewiak et al. 329). The spy-hop can either be with eyes just below the water surface or above the water surface as seen in image 2 below.

Image 2: A Photo Illustrating a Humpback Spy-Hopping 

Based on the aspect some eyes remains below the water surface, which means the spy-hopping aspect of whales may be more on hearing rather than vision. Parks et al. (n.p) explain that humpback whales may remain with their head poking for 30 seconds. During this time, the whale does not move the flukes or the tail to retain the upright posture. Rather they apply the pectoral flippers to remain afloat in a similar posture to individuals treading on the water with their arms. Another reason for this behavior is to view the prey. An interesting aspect discussed by Cholewiak et al. (330) is that humpback whales may spy-hop near whale-watching boats, which illustrates their curiosity similar to the humans watching them.

Blow

Humpbacks are known to blow mucus, water vapor, and air as they surface to take a breath. Mirjalili et al. (n.p) explain that whales blow air differently, where humpbacks blow small and bushy blows. The whales are different from humans, where humans breathe involuntarily; the humpback breathes consciously where they think of surfacing to breathe. This behavior makes the humpbacks to never sleep completely. Parks et al (n.p) explain that whales sleep with one half of their mind active to ensure they focus on breathing. 

Image 3: A Photo of Humpback Blowing air

Lob-Tailing or Tail Slapping and Fin Slapping

Lob-tailing is termed as the method by which whales communicate with one another in water. Parks et al. (2014) define lob-tailing in humpback whale as a process by which the whale lifts its tail fin or fluke out of the water and forcefully slaps the water surface with a loud report and big splash. According to Mirjalili et al. (2016), lobtailing is non-verbal communication (social behavior) like pectoral fin slapping or breaching that is used to seduce or sexual advertise to intimidate a foe, impress a potential mate, or seek attention from an individual. 

The sound from the flap is heard from a great distance both below and above the surface of an ocean and is likely to result in a call-and-response reaction from other whales. A likely effect is that another whale may respond through lobtailing or find a group of whales’ lobtailing together. Straley et al. (175) explain that tail slapping may either be ventrally or dorsally (upside down or right side up) lasting for a few minutes in time, with rest breaks of a few minutes. The whale tail is likely 15′ (4.5m) across and slapping creates an impressive show (Parks et al., 2014). Each show is a form of communication where big splashes indicate long distance calls. 

Image 4: A Photo Illustrating a Humpback Whale Lob-tailing

Conclusion

Humpback whale is an interesting animal to study and watch. It travels to the surface to breathe, a reason that makes it sleep with half of the brain active. The gestational period for humpback whales is 11 months and the calf sucks for one year and solid food introduced after one year. The males are not monogamous and they fight for their mates. However, after calving, the male does not take care of the young calves, as they are busy looking for new mates. During the breeding and the calving period, the species travel from cold waters to warm waters. During this time, they do not eat, as their prey lives in very cold water (an environment that kills newborn calves). Some of the other interesting behaviors include breaching, blowing air, singing and lobtailing. All these behaviors make the humpback whale interesting due to its unique way of interacting socializing, communication, and culture.

Works Cited

Driel-Vis, Jerry van Driel-Vis. “Interesting mating habits of the humpback whale”. Sunshine Coast Afloat, 2018, Accessed 12 Apr 2019.

Hawaiian Islands Humpback Whale National Marine Sanctuary. “Humpback Whale Behaviors”. Hawaiian Islands Humpback Whale National Marine Sanctuary, https://nmshawaiihumpbackwhale.blob.core.windows.net/hawaiihumpbackwhale-prod/media/archive/documents/pdfs_info_facts/behavior_sheet.pdf. Accessed 12 Apr 2019.

Straley, Janice M. et al. “Seasonal Presence and Potential Influence of Humpback Whales On Wintering Pacific Herring Populations In The Gulf Of Alaska”. Deep Sea Research Part II: Topical Studies In Oceanography, vol 147, 2018, pp. 173-186. Elsevier BV, doi:10.1016/j.dsr2.2017.08.008. Accessed 12 Apr 2019.

Wild about Whales. “Whale Behaviour”. Wild About Whales, 2018, https://www.wildaboutwhales.com.au/whale-facts/about-whales/whale-behaviour. Accessed 12 Apr 2019.

Yirka, Bob. “Humpback Whales Found To Compose New Communal Song Every Few Years”. Physc.Org, 2018, https://www.sciencemag.org/news/2018/11/humpback-whale-songs-undergo-cultural-revolution-every-few-years. Accessed 12 Apr 2019.

Mirjalili, Seyedali, and Andrew Lewis. “The whale optimization algorithm.” Advances in engineering software 95 (2016): 51-67.

Cholewiak, Danielle M., Renata S. Sousa‐Lima, and Salvatore Cerchio. “Humpback whale song hierarchical structure: Historical context and discussion of current classification issues.” Marine Mammal Science 29.3 (2013): E312-E332. 

Janik, Vincent M. “Cetacean vocal learning and communication.” Current Opinion in Neurobiology 28 (2014): 60-65.

Parks, Susan E., et al. “Evidence for acoustic communication among bottom foraging humpback whales.” Scientific reports4 (2014): 7508.

Noad, M. J., Cato, D. H., Bryden, M. M., Jenner, M. N., & Jenner, K. C. S. (2000). Cultural revolution in whale songs. Nature, 408(6812), 537.

Simon, Malene, Mark Johnson, and Peter T. Madsen. “Keeping momentum with a mouthful of water: behavior and kinematics of humpback whale lunge feeding.” Journal of Experimental Biology 215.21 (2012): 3786-3798.