What is the difference between fecundity and fertility

On the other hand, fecundity is the potential to reproduce which is dependent upon many other factors such as fertilization of eggs by sperms and the ability to successfully carry the term of pregnancy, etc. So fecundity is the reproductive capacity of a single person or a population. Furthermore, fecundity is taken as a measure of fitness and is influenced by genetic factors and environmental factors.

So, this is the key difference between fertility and fecundity. In addition, lack of fertility is infertility while lack of the fecundity is sterility. Hence, it is another difference between fertility and fecundity.

Fertility and fecundity are two terms which go hand in hand. Fertility is a natural concept which determines the ability to reproduce. In contrast, fecundity is the concept which evaluates the potential of an organism to reproduce. Thus, fertility is measured by the number of offspring per mating couple, whereas fecundity is measured by the number of gametes or seeds produced by a mating couple.

If either one individual of the mating couple does not satisfy the two concepts; fertility and fecundity there can be complications during reproduction, fertilization and conceiving. Therefore, these two concepts are very important in population ecology. Thus, this summarizes the difference between fertility and fecundity. Smarr, et al. Fecundity is the physiological ability or the potential for reproduction.

It is closely related to fertility and is measured by the number of gametes, seed sets or asexual propagules produced by an individual or a population. In population demography, fecundity is the number of offspring produced per mating season. However, fecundity includes both the number of offspring produced and the survival of the young per mating period. Figure 2: Fecundity Variation. Fecundity is an important phenomenon in the regulation of the size of a population based on the requirements of the ecosystem.

The paper examines how fecundity affects the age pattern of natural marital fertility. A homogeneous fecundity model is developed to show the relationship between fecundity total and the distribution of fecund waits, a period between conceiving and conception with regular unprotected intercourse. However, in a heterogeneous model it may be assumed that apparent fecundability varies according to Henry's beta distribution, with human variation ranging from.

The day-specific probabilities of conception with respect to the day of ovulation along with the assessment of time to pregnancy are taken into account to measure fecundity in humans. In ecological terms, the net reproductive rate is an important parameter that takes into account fecundity. Net reproductive rate is the average number of offspring that a female can produce throughout its reproductive life span, with due consideration of fertility with respect to age and rate of death in a given period of time.

An estimate of population fecundity improves the ability to translate research in reproductive physiology into foreseen effects on fertility. Thus, fecundity is a very important parameter to study in ecology and animal biology. In ecology, fecundity is also an indication of the amount of energy that is spent on raising offspring.

As a general rule of thumb, fecundity is inversely proportional to the amount of energy spent. As per this rule, there are two possibilities: 1 a group of the population that can reproduce in higher numbers and 2 a group of the population that can reproduce a limited or few offspring in their lifetime. Thus, as per the inverse fecundity and energy rule:. This inverse fecundity and energy rule are similarly applicable to the Plant Kingdom as well.

Here, of course, the energy investment is not in terms of parental care, however, it is in terms of energy-rich quality seeds. Plants with low fecundity will produce a few or limited numbers of seeds with high energy which thereby have the higher or maximum possibility of survival, for example, coconuts. On the other hand, plants with higher fecundity will produce a large number of seeds e. Thus, the survival chances of these seeds would therefore be low.

Another important aspect of fecundity and ecology is the time of reproduction. Again, the population can be divided into two basic groups depending on the time when an organism starts to reproduce:. Parity is indicative of the number of any individual that can reproduce in its life span. Some organisms can reproduce their progeny only once in their lifetime while others can exhibit multiple reproductions. Thus, fecundity can follow two patterns:. In iteroparity, the fecundity increases with age and then eventually decreases.

Thus, the organism stops growing once they reach reproductive maturity and are ready for their first progeny production. This is to conserve all their energy to invest in the process of reproduction.

This is a kind of ecological pattern to increase fecundity. Both the parent as well as the progeny would not be physically competent to withstand the environmental pressure i. Thus, unfit or incompetent organisms or individuals would be eliminated from the system.

Some of the factors affecting fecundity are explained below. These factors include body size, environmental conditions, are choice of a mating partner. Metabolic rate, dispersal capacity, survival probability, and fecundity are some of the factors that cause the disparity in body mass among individuals or species. However, it is important to understand that in a species, the ratio of combined offspring mass to maternal mass tends to roughly remain constant.

This means that females with larger bodies tend to have higher fecundity and larger offspring. Thus, evolutionarily, a larger body gives a selective advantage to large-sized females and their offspring. The fecundity is affected by environmental conditions.

Environmental conditions can affect maternal body condition and survival.