Passenger pigeon mite

Species extinctions trigger chain reactions

When animal or plant species go extinct, a chain reaction is set in motion. Often, at least one other organism dies out along with it. Thus, with the passenger pigeon, the passenger pigeon mite also went extinct in 1914. In a study published in 2004, researchers led by the biologist Lian Pin Koh of the University of Singapore found that the extinction of a single species can result in the loss of up to 100 other species.

If a keystone species goes extinct, dependent species disappear as well. Such dependencies can exist, for example, between prey and predator, host and parasite, or herbivores and plants.

According to Science magazine, which published the study, people have so far not taken into account that such dependencies even exist. This would therefore multiply the number of plants and animals threatened with extinction worldwide.

In an article in Neue Zürcher Zeitung from 2014, it is also said that parasites are poorly studied and that it is not possible to determine how many have already gone extinct along with their hosts.

Passenger pigeon mite – fact sheet

scientific name	Diplaegidia gladiator
original range	North America (USA, Canada)
time of extinction	1914
causes of extinction	extinction of the host (passenger pigeon)

Almost nothing is known about the passenger pigeon mite

Mites are a subclass of arachnids (Arachnida). The smallest representatives are 0.1 millimeters in size; the largest are ticks, which can reach a length of three centimeters when fully engorged.

Nothing is known so far about the size of the passenger pigeon mite. Today we know that this mite species specialized on only one host—namely the extinct passenger pigeon. A similar fate befell the nose mite Halarachne americana, which died out along with the Caribbean monk seal.

The passenger pigeon chewing louse was also considered extinct

In an investigation, Giovanni Strona of the University of Milan found in 2013 that parasites dependent on a single host generally prefer hosts that are very common and not endangered. Conversely, rare hosts are more likely to be colonized by parasites that are not particularly choosy in their selection of hosts.

In addition to the passenger pigeon mite, the passenger pigeon chewing louse (Columbicola extinctus), which also used passenger pigeons as hosts, was long considered extinct. Surprisingly, researchers later found that the pigeon louse has found a new host in at least one other pigeon species.