80. r-selected species have
    (1) Long generation time (2) Large clutch size
    (3) More parental care (4) Specialized niche

Introduction

In ecology, species are often categorized based on their reproductive strategies and life-history traits. Two ends of this spectrum are r-selected and K-selected species. Understanding the unique features of r-selected species helps explain how they thrive in unpredictable environments and what sets them apart from their K-selected counterparts.

What Are r-Selected Species?

r-Selected species are those that maximize their reproductive rate (r) to take advantage of transient or unstable environments. They are typically found in habitats where conditions change rapidly, resources are abundant for short periods, and competition is low.

Key Characteristics of r-Selected Species

Let’s look at the options given and identify the correct trait:

(1) Long Generation Time

• Incorrect for r-selected species.

• r-selected species usually have short generation times, allowing them to reproduce quickly and exploit temporary opportunities.

(2) Large Clutch Size

• Correct!

• r-selected species are known for producing large numbers of offspring (large clutch size) in each reproductive event.

• This strategy increases the likelihood that some offspring will survive, even if many perish due to environmental unpredictability.

(3) More Parental Care

• Incorrect.

• r-selected species typically provide little to no parental care. They invest energy in producing many offspring rather than nurturing a few.

(4) Specialized Niche

• Incorrect.

• r-selected species often occupy generalist niches, thriving in a wide range of environments rather than specializing.

Examples of r-Selected Species

• Insects: Houseflies, mosquitoes, and aphids produce hundreds of eggs with minimal parental investment.

• Annual plants: Many weeds and grasses rapidly colonize disturbed soils, producing numerous seeds.

• Small rodents: Mice and rats breed quickly and in large numbers.

Why Large Clutch Size Matters

Producing many offspring increases the chances that at least some will survive unpredictable conditions such as drought, predation, or competition. This is a classic adaptation for species living in environments where mortality is high and unpredictable.

r-Selected vs. K-Selected Species: A Quick Comparison

Conclusion

r-Selected species are characterized by a large clutch size, enabling them to rapidly exploit changing environments. This reproductive strategy is the opposite of K-selected species, which invest heavily in fewer offspring and provide more parental care. Recognizing these traits is essential for understanding population dynamics, ecosystem resilience, and species responses to environmental change.

Correct answer:
(2) Large clutch size