Fertility

Definition

The realized production of viable offspring by an individual, population, or colony over a given period; distinguished from fecundity, which denotes the physiological potential for reproduction regardless of whether offspring are actually produced. In arthropod biology, fertility reflects the intersection of egg production, mating success, fertilization rates, embryo viability, and early survival—making it a key parameter in life-history analysis, pest management models, and conservation assessments.

Etymology

From Latin fertilis, 'fruitful, productive,' from ferre, 'to bear'

Example

A queen honey bee (Apis mellifera) may lay 2,000 eggs per day at peak fecundity, but colony fertility—the number of eggs that develop into surviving workers—is often lower due to seasonal resource limitation, disease, or inadequate drone availability for mating.

Related Terms

• Fecundity
• reproductive success
• Fitness
• oviposition
• sterility
• infertility
• Life history
• r-selection
• net reproductive rate

Usage Notes

In strict demographic and ecological usage, fertility refers to actual offspring produced, while fecundity refers to reproductive capacity or potential egg production. This distinction is critical when comparing laboratory fecundity assays (potential egg output) with field fertility estimates (surviving progeny). Some medical and lay sources conflate the terms; entomological literature generally preserves the distinction. Fertility can be measured at individual, cohort, or population levels and is often expressed as age-specific fertility or total fertility rate in demographic models.