HUMPBACK WHALES

Copyright infringement not intended

Picture Courtesy: https://www.prideofmaui.com/blog/maui/maui-whale-watching-faq

Context: Homosexuality in the animal kingdom is not uncommon, as evidenced by the recent sighting of two male humpback whales engaging in sexual activity. 

Details

• The recent observation of male humpback whales engaging in sexual behaviour underscores the widespread occurrence of homosexuality in the animal kingdom. This behaviour has been documented in over 1,500 species, ranging from insects to mammals, and is observed in both sexes, both in captivity and in the wild.

The "Darwinian Paradox"

• Charles Darwin's theory of evolution posits that all living things strive to reproduce and pass on their genes. However, homosexuality seemingly contradicts this principle, as it doesn't directly contribute to reproduction. This apparent discrepancy is often referred to as the "Darwinian paradox."

Explaining Homosexuality

• "Indiscriminate Mating" Hypothesis: This hypothesis proposes that early ancestors may have reproduced with any available individual, regardless of their sex. This indiscriminate approach could have been beneficial for several reasons:
  • Reduced complexity: It would have eliminated the need for complex mechanisms to identify compatible mates based on specific traits like size, colour, or odour.
  • Increased mating opportunities: Individuals wouldn't risk missing out on potential reproductive opportunities due to excessive pickiness in mate selection.
• Evolutionary biologists suggest that homosexual behaviour can offer social advantages: Same-sex interactions can foster positive social relationships and promote cooperation within groups. This is supported by evidence showing a correlation between sociality and the prevalence of homosexual behaviour.
• Reducing conflict: Homosexual interactions may help establish dominance hierarchies and mitigate aggressive tendencies between individuals, particularly in species with high levels of intrasexual aggression.

Homosexuality as an Adaptation

• Recent studies suggest that rather than being a disadvantage, homosexuality can be a "convergent adaptation", meaning it has evolved independently in multiple species due to its social and potentially even survival benefits. For example, research suggests it might mitigate "adulticide" (killing of other adults of the same species) in some mammals, particularly among males where intrasexual conflicts are more common.

Humpback Whales
Key Points	Details
Scientific Name	Megaptera novaeangliae
Size	Adults typically range from 40 to 50 feet (12 to 16 meters) in length.
Weight	Adult humpback whales can weigh between 25 to 40 tons.
Lifespan	Estimated to be around 50 years, though some individuals have been known to live beyond 80 years.
Diet	Primarily filter feeders, they consume small fish and plankton by lunging through groups of prey.
Feeding Mechanism	Baleen plates in their mouths allow them to filter food from the water.
Migration	Humpback whales are known for their long-distance migration, travelling between feeding and breeding grounds.
Breeding Grounds	Common breeding grounds include tropical and subtropical waters.
Mating Behavior	Mating behaviours involve complex vocalizations, breaching, and other acrobatic displays. Male humpbacks may also compete for female attention.
Gestation Period	Approximately 11 months
Calves	Typically, a single calf is born, and the mother provides care and protection.
Communication	Humpback whales are known for their intricate songs, which can last up to 20 minutes or more.
Conservation Status	Generally considered a species of "Least Concern," but some populations face threats from entanglement in fishing gear, ship strikes, and habitat degradation.
Notable Features	Long pectoral fins, distinctive hump in front of the dorsal fin, knobbly head, and unique tail markings (flukes) are used for individual identification.
Social Structure	Generally, humpback whales are social animals and can be seen in groups, though they may also exhibit solitary behaviour.
Notable Behaviors	Breaching (leaping out of the water), tail slapping, flipper slapping, spyhopping (raising head vertically out of the water to observe surroundings).

Conclusion

• The observation of homosexual behaviour in humpback whales is a reminder of the diversity and complexity of sexual behaviour in the animal kingdom. While it may seem to contradict traditional evolutionary principles, various compelling hypotheses suggest that it can offer significant social and potentially even survival benefits, explaining its persistence across various species.

PRACTICE QUESTION Q. What is the primary feeding mechanism of Humpback Whales? A) Suction feeding B) Filter feeding C) Jaw snapping D) Predatory lunging Explanation: Humpback whales have baleen plates in their mouths that act as a filter to capture small fish and plankton. During feeding, the whale opens its mouth, takes in a large volume of water, and then pushes the water out through the baleen plates, trapping prey inside for consumption.