producing more offspring. Iteroparity is when a species reproduces multiple times over its lifetime. This species' strategy is to protect against the unpredictable survivability of their offspring, in which if their first litter of offspring dies, they can reproduce again and replace the dead offspring. It also allows the organism to care for its offspring, as they will be alive during their development. Factors affecting fecundity There are a multitude of factors that potentially affect the rates of fecundity. For example: ontogeny, population density and latitude. Ontogeny Fecundity in iteroparous organisms often increases with age but can decline at older ages. Several hypotheses have been proposed to explain this relationship. For species with declining growth rates after maturity, the suggestion is that as the organism's growth rate decreases, more resources can be allocated to reproduction. Other possible explanations exist for this pattern for organisms that do not grow after maturity. These explanations include: increased competence of older individuals; less fit individuals have already died off; or since life expectancy decreases with age, older individuals may allocate more resources to reproduction at the expense of survival. In semelparous species, age is frequently a poor predictor of fecundity. In these cases, size is likely a better predictor. Population density Population density is often observed to negatively affect fecundity, making fecundity density-dependent. The reasoning behind this observation is that once an area is overcrowded, fewer resources are available for each individual. Thus there may be insufficient energy to reproduce in high numbers when offspring survival is low. Occasionally high density can stimulate the production of offspring, particularly in plant species, because if there are more plants, there is food to lure pollinators, who will then spread that plant's pollen and allow for more reproduction. Latitude There are many different hypotheses to explain the relationship between latitude and fecundity. One claimed that fecundity increases predictably with increasing latitude. Reginald Morean proposed this hypothesis, the explanation being that there is higher mortality in seasonal environments. A different hypothesis by David Lack attributed the positive relationship to the change in daylight hours found with changing latitudes. These differing daylight hours, in turn, change the hours in which a parent can collect food. He also accounts for a drop in fecundity at the poles due to their extreme amounts of day lengths, which can exhaust the parent. Fecundity intensity due to seasonality is a hypothesis proposed by