Carl W. Rettenmeyer (February 10, 1931 – April 9, 2009) was an American biologist who specialised in army ants. He was born in

Meriden, Connecticut Meriden is a city in New Haven County, Connecticut, United States, located halfway between the regional cities of New Haven, Connecticut, New Haven and Hartford, Connecticut, Hartford. In 2020, the population of the city was 60,850.Swarthmore College Swarthmore College ( , ) is a Private college, private Liberal arts colleges in the United States, liberal arts college in Swarthmore, Pennsylvania. Founded in 1864, with its first classes held in 1869, Swarthmore is one of the earliest coeduca ...

in Pennsylvania. He first became interested in army ants when he visited Panama as an undergraduate and then returned there as a postgraduate. Although he studied many aspects of army ant biology, he particularly focused on the animals associated with the ants and especially mites which live on the ants. He was well known for his photography of army ants, with his photographs appearing in over 100 publications, and he used his video footage to create two DVDs. He taught at the University of Kansas from 1960 until 1971 and then at the University of Connecticut until his retirement in 1996, after being diagnosed with Waldenstrom’s macroglobulinemia. After his death in 2009, a set of papers on army ants were published in '' Insectes Sociaux'' in memory of his work.

Personal life

Rettenmeyer was born in

Meriden, Connecticut Meriden is a city in New Haven County, Connecticut, United States, located halfway between the regional cities of New Haven, Connecticut, New Haven and Hartford, Connecticut, Hartford. In 2020, the population of the city was 60,850. Together they had a son and a daughter. In 1996 he was diagnosed with Waldenstrom’s macroglobulinemia, a form of lymphoma and expected to die within a few years. Although he retired the same year, a new drug developed soon after his diagnosis kept the disease in check, allowing him to continue to work, despite often having to use a wheelchair due to his frailty. He continued to correspond with other army ant researchers with enthusiasm after retiring.

Education

Rettenmeyer attended

Swarthmore College Swarthmore College ( , ) is a Private college, private Liberal arts colleges in the United States, liberal arts college in Swarthmore, Pennsylvania. Founded in 1864, with its first classes held in 1869, Swarthmore is one of the earliest coeduca ...

as an undergraduate, majoring in Biology and graduated in 1953. Whilst in his junior year he was contacted by Theodore Schneirla, an acquaintance of his professor. Schneirla was studying the behaviour of army ants and needed an assistant to work for six months on Barro Colorado Island (BCI) in Panama, which Rettenmeyer accepted. Schneirla was interested in army ants behaviour as he thought that by studying it he could understand how it would be possible for humans to fight wars more effectively. They spent many nights observing army ant trails and it was at this time that Rettenmeyer first noticed that other animals lived on the ants. a subject that continued to fascinate him throughout his life. After graduating he studied a PhD in

entomology Entomology () is the science, scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such ...

at the University of Kansas under the supervision of Charles Duncan Michener, which he completed in 1962. During his PhD '' Life'' magazine approached him asking him to accompany a photographer to BCI to photograph army ants. Rettenmeyer says that this was his "lucky break" and during nine weeks spent on BCI he collected thousands of specimens, including 147 species of mite found living on the ants. Upon his return to Kansas he was encouraged by faculty members to apply for funding so he could return to study army ants in the rainforest. Through his career he went on over 20 expeditions to Panama, Ecuador and Costa Rica.

Research

Rettenmeyer studied a broad range of topics related to army ants, publishing on general army ant biology, chemical communication and foraging behaviour. His work also inspired other researchers to investigate such diverse areas as avian ecology, social insect symbioses, tropical

phenology Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonality, seasonal and interannual variations in climate, as well as environmental factor, habitat factors (such as elevation). Examples includ ...

and conservation biology. He presented at many conferences and published over 50 papers during his career. In 1963, Rettenmeyer rediscovered the army ant ''

Neivamyrmex sumichrasti ''Neivamyrmex'' is a genus of army ants in the subfamily Dorylinae. Range ''Neivamyrmex'' species can be found from the central United States to southern Argentina. Taxonomy As of 2021, 129 ''Neivamyrmex'' species have been identified. ...

'', which was first described by François Sumichrast in the 1860s but then not studied further. In 2003, he helped another expedition find the species again, and also tried to find a species of beetle associated with it. However, '' Ecitosius robustus'', the robust army ant beetle, is almost impossible to distinguish physically from the host ant, and Rettenmeyer was unable to find it among the samples collected. He was one of the first biologists to visit

Monteverde Cloud Forest Reserve The Monteverde Cloud Forest Reserve ( es, Reserva Biológica Bosque Nuboso Monteverde) is a Costa Rican reserve located along the Cordillera de Tilarán within the Puntarenas and Alajuela provinces. Named after the nearby town of Monteverde and fo ...

in Costa Rica, which is now a major center for Neotropical research. In 1975 he reported in '' Science'' the first recorded case of mass recruitment in army ants. He found that when worker ants encountered a food source that was too large for them to kill or carry themselves, they can communicate with other workers via chemical and physical signals to recruit them to assist. Working with his wife, Rettenmeyer identified 557 species of animals associated with ''

Eciton burchellii ''Eciton burchellii'' is a species of New World army ant in the genus ''Eciton''. This species performs expansive, organized swarm raids that give it the informal name, ''Eciton'' army ant. This species displays a high degree of worker polymorph ...

'', the greatest number of animals known to associate with any single animal species. Although many of the associations are likely to be opportunistic, over 300 species are thought to be reliant on the ant to survive. As well as these species, Rettenmeyer collected many thousands of specimens that have not been identified. He spent his later years examining samples from 1600 army ant colonies he had collected and in total found 45,000 mites. Of these mites, only 3% have been studied and whilst doing so, three new mite families were identified as well as over 100 new species. Those identified often have inconceivably strange lifestyles. One species ('' Macrocheles rettenmeyeri'') only lives on the feet of one particular species of ant ('' Eciton dulcius'') acting like an extension to the foot, whilst sucking the blood of the ant. This was regarded by E. O. Wilson and Bert Hölldobler in ''

Journey to the Ants ''Journey to the Ants: a Story of Scientific Exploration'' is a 1994 book by the evolutionary biologist Bert Hölldobler and the biologist Edward O. Wilson. The book was written as a popularized account for the layman of the science earlier presen ...

'' as the most extraordinary parasitic adaptation among ant parasites. Another mite only lives on the eye of another species and '' Rettenmeyerius carli'' lives on the base of worker's mandibles. Scientists are continuing to study the specimens Rettenmeyer collected during his life and one researcher told the BBC that she expected that the number of associated species could potentially double once the work is completed. After his death a set of papers on army ants were published in '' Insectes Sociaux'' in memory of his work. In 2016, a grant was awarded to create an online database of the Rettenmeyer's collection of over two million specimens.

Photography

Rettenmeyer was known for his ability to photograph previously unseen aspects of army ant behaviour and his photographs appeared in ''

National Geographic ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widely ...

'', the '' Audubon Encyclopedia of Wildlife'', ''

National Wildlife Federation The National Wildlife Federation (NWF) is the United States' largest private, nonprofit conservation education and advocacy organization, with over six million members and supporters, and 51 state and territorial affiliated organizations (includin ...

'', and ''Smithsonian'' magazine. Among his accomplishments was photographing army ants mating for the first time, as well as estimating the longevity of the queen by recapturing a specimen. Overall his photographs appeared in over 100 publications. In 2006 he published a self-produced DVD titled ''Astonishing Army Ants'' using footage that he had collected over 35 years. It was reviewed as being extremely information rich and a "must-see for ant enthusiasts" but so full of facts it is exhausting to watch. In January 2009 he was still working on another DVD titled ''The World’s Largest Animal Association'' documenting the hundreds of animals he found associated with ''E. burchellii''.

Teaching

From 1960, during the later years of his PhD he began to teach at the University of Kansas, until he moved to the University of Connecticut in 1971. There he taught biology, social insects and photography for biologists. As well as this he was responsible for resurrecting the

Connecticut State Museum of Natural History The Connecticut State Museum of Natural History was located in Storrs, Connecticut, as part of the University of Connecticut. The small museum contained a variety of scientific and archaeological collections about the cultural history of souther ...

which he was the founding director of. Although the origins of a natural history museum at the University of Connecticut existed as early as 1881, Rettenmeyer was the force behind establishing a proper museum to house the university's specimens which opened in 1985. He continued as the director until his retirement.

References

External links

Carl W. and Marian E. Rettenmeyer Army Ant Guest Collection
at the University of Connecticut. {{DEFAULTSORT:Rettenmeyer, Carl 1931 births 2009 deaths People from Meriden, Connecticut Swarthmore College alumni Myrmecologists 20th-century American zoologists Biologists from Connecticut