Ticks are parasitic organisms that survive off the nourishment provided by the blood of a host organism. Although most people regard them as pests, ticks play an important role in keeping balance in the ecosystem. So even though they are regarded as one of the nastiest, most unappealing insects on earth, their role in the ecosystem is an important one.
Parasites
Parasites are organisms that feed and acquire energy from a host organism, usually to the detriment of the host. Parasites such as ticks, mosquitoes, intestinal worms and lice are commonly thought of as useless bloodsucking organisms, but parasites have an important role in the ecosystem.
Indicators of an Ecosystem's Health
Ecologists often use ticks and other parasites as an indicator of an ecosystem's health. Because ticks rely on a variety of host animals (mice, rats, deer, etc.) to thrive and reproduce, ecologists study tick population, distribution and health to understand ecological trends better. For example, if an ecologist finds that tick populations have dropped considerably in a specific area for more than the past 10 years, he would also expect to find a drop in the population or health of available host species, indicating a deteriorating ecosystem. In contrast, when an ecologist finds tick populations on the rise, it would suggest that healthier host species are available, indicating a healthy ecosystem.
Indicators of Animal Health
Just as ticks are used as an indicator of an ecosystem's health, they are also used as an indicator of individual animal's health. Ticks are opportunistic and will feed on any host available; however, ticks are quick to exploit sick, weak and old animals. When ticks infest an animal in a weakened or debilitated state, they take energy from the host, weakening it even further. In turn, when ticks infest the host, it creates a downward spiral and eventually leads to the death of the host either by the ticks themselves or by other natural predators.
Vectors
Ticks act as vectors, or temporary hosts for a number of infectious pathogens. Ticks are an ideal mode of transportation for microscopic pathogens because every time a tick feeds, it gains intravenous access to its prey. The most well-known example of ticks serving as vectors for infectious pathogens is the case of the American deer tick (Ixodes scapularis) and its association with the spread of Lyme disease. Other examples of ticks as vectors include the western American deer tick (Ixodes pacificus) which spreads Rocky Mountain Spotted Fever and the Australian paralysis tick (Ixodes holocyclus), which spreads tick typhus. Other diseases spread by ticks include tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis and tick-borne meningoencephalitis.
The Food Chain
Ticks also play an important role in the food chain of an ecosystem. Ticks and other small parasitic insects are a favorite food of birds which will often pick engorged ticks right off the body of host animals. Ticks also fall as prey to a number of predatory insects like spiders and parasitic wasps and are often infected by predatory species of nematode and fungus. Ticks are a strong and important link in the food chain as they take nourishment from large host animals high in the food chain and transfer that energy down the chain to lesser organisms.
Tags: host animals, important role, tick Ixodes, American deer, American deer tick