Water pollution.
A decrease in the birth rate will cause a decrease in population over time.
A low birth rate and environmental hazards are two things that can cause a population to decrease.
A low Birth Rate and environmental hazards are two things that can cause a population to decrease.
an increase in the spider population
Polluted water can cause a decrease in animal population. This is possible if the pollutant is toxic and harms creatures in the water or those that drink the water.
The shrimp population will increase which will cause an increase in the squid population.
it is an environmental factor that causes a population to decrease.
There are many contributing factors that could be the cause for a decrease in fox population. Over population, not enough food, disease, or over hunting or poaching any of these could be the reason for a decrease in the population.
A sudden decrease in the butterfly population would cause a corresponding decrease in the chameleon population since they no longer have enough food.
The aliens start attacking them more
What will cause a decline in the human population is loss of fish, dirty water, a whole in the ozone layer. These are just three causes that could decrease mankind.
probably because they are an easy meal for hunters (animal hunters not people)