Relevance: GS III (Environment – Biodiversity & Climate Change) | Source: The Hindu / Oxford University Study

1. The Context: A Race Against Time

A decade-long study in the Western Antarctic Peninsula (one of the fastest-warming regions on Earth) has revealed a startling trend.

• The Shift: Three major penguin species—Gentoo, Adelie, and Chinstrap—are now breeding approximately two weeks earlier than they did ten years ago.1
• The Driver: This behavior is a response to a 3°C rise in local temperatures. The penguins are frantically trying to synchronize their breeding with the availability of food.

2. Winners and Losers (Generalists vs. Specialists)

Climate change is not affecting all penguins equally. It has created a stark divide based on ecological resilience:

• The Winners (Gentoo Penguins):
  • Why: They are “Generalists.” They have a flexible diet (don’t rely just on krill) and do not migrate.
  • Outcome: They adapted quickly, moving into new nesting grounds and displacing other species. Their population is stable or growing.
• The Losers (Adelie & Chinstrap Penguins):
  • Why: They are “Specialists.” They rely almost exclusively on Krill (a tiny crustacean) and are migratory (returning to specific spots).2
  • Outcome: They cannot adapt their diet or habitat fast enough. They face a high risk of local extinction as their traditional nesting sites are taken over by Gentoos.

3. The “Timing Trap” (Trophic Mismatch)

The core problem is a broken chain reaction known as a Phenological Mismatch:

1. Melting Ice: Warmer seas melt ice earlier.
2. Plankton Bloom: Sunlight hits the water sooner, causing microscopic plants (phytoplankton) to bloom early.
3. Krill Crisis: Krill feed on this plankton.3 If the bloom happens too early, the krill population peaks and crashes before the penguin chicks are born.
4. Starvation: Even if penguins breed 2 weeks early, they often still miss the “peak food window,” leading to chick starvation.

UPSC Value Box

Q. With reference to ecological adaptations, the terms “Generalist” and “Specialist” species are frequently used. Consider the following statements regarding the impact of climate change on Antarctic penguins:

1. Gentoo penguins are considered “Generalists” because of their flexible diet and non-migratory nature.4
2. Specialist species like Adelie penguins are generally more resilient to rapid climate fluctuations than generalist species.
3. A “Phenological Shift” refers to the change in the physical features of a species due to evolution.

Which of the statements given above is/are correct?

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3