They may not be as popular as more charismatic animals such as mammals and birds, but spiders are just as vulnerable to human impacts, according to a new study.
Spiders in decline
The study, published in the journal Biological Conservation, looked at whether spiders are more tolerant of human actions than other species. It concluded that spiders suffer the same consequences of changes to their habitats as any other animal. However, compared to other animal groups, few spiders appear on the IUCN Red List as being in danger of extinction.
The researchers focused mainly on three ecosystems: agricultural land, pasture and forest. By combining the results of studies undertaken since the 1980s, they showed that human actions have had damaging impacts on spider numbers in farmland and pastures. The results for forests were less clear.
Spiders face a range of threats, including changes in vegetation structure due to fire, grazing and crop-growing. In forests, habitat fragmentation may be a problem, and the use of insecticides can also have an impact on spider populations. These threats may also affect the availability of the spiders’ prey.
The researchers proposed a number of solutions to protect spider populations, including a reduction in mechanical alterations to the land from activities such as ploughing, cutting and grazing. They also recommended that habitat fragmentation should be avoided and the use of insecticides controlled, and concluded that organic farming was likely to be of benefit to spiders.
Spiders vital to ecosystems
Although spiders do not generally attract much public sympathy or attention, they play an important role as predators within terrestrial ecosystems. Spiders are also important to humans in controlling pest species.
Unfortunately, spider conservation has not been a high priority and the status of most species has not yet been formally assessed. Declining spider populations are a reminder of the importance of conserving less popular and less well-known animals, which are just as vital to natural ecosystems as their more charismatic counterparts.
Liz Shaw, ARKive Species Text Author