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Author

Jurie du Plessis

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When the general public hear that I work at a museum, their first question is usually: “Now what do you do in the exhibitions?” When I tell them that I am a researcher and that part our duties is to collect and preserve biologicalspecimens for our research collection they would usually be very surprised about this. They are usually very interested about why we have these collections and why we need to collect so many specimens.

Museum collections have been around for many years, with the first formal natural history collections being traced back to the late 1600s. It is not uncommon for natural history collections to contain specimens that were collected more than 100 years ago. It is also not uncommon to read about natural history collections that house more than 1 million specimens.

Photo 2: Natural History Collections are an invaluable resource for various conservation efforts. For instance, locality data provide a valuable historical baseline against which to compare current species range distributions to determine potential range expansions or contractions.

Natural history collections serve as important research infrastructure. In the early stages of natural history collections, specimens were kept and preserved mainly to aid in the identification of new species. Known as types, these specimens were used to describe the physical characteristics of a newly discovered species. Early collections mostly consisted of either the whole dried specimen (e.g. plants and insects) or in the case of larger organisms such as birds and mammals the dried skin andthe skull and/or skeleton. Later preservation also included fluid-preserved specimens. In the last ca. 50 years the concept of an “extended specimen” has emerged and museums have started to collect more information and material associated with a single specimen. Together with inter alia the availability of new technologies and methods to better preserve material, the rapid development of computers and computer software, the emergence of digital networks and the advances in research methodologies, the scope and value of natural history collections has increased extensively.This, in turn, has opened the door for various multidisciplinary studies to answer some interesting questions and inform decision-making. Below are just a few interesting examples.

Photo 3: Example of the “extended specimen” concept. Apart from the conventional skin, skull and tissue preservation,natural history collections are now also able to extract and preserve the endo- and ecto-parasites (Galbreath et al. 2019).

To mix or not to mix? – translocation of elephants into the Addo Elephant National Park, Eastern Cape

The Addo Elephant National Park (AENP), Eastern Cape, South Africa, was officially proclaimed in 1931 to protect the remaining African elephants (Loxodonta africana) in the area after years of hunting. Eleven elephants were initially enclosed and their numbers increased gradually since then. By 2000 there were more than 150 individuals in the AENP. Interestingly, more than 90% of the AENP females did not have tusks, which  is a significantly  higher percentage than inpopulations elsewhere. This posed the question whether the AENP population were genetically unique and as such should have been managed accordingly.

To answer this, researchers compared tissue from recent Addo and Kruger National Park (KNP) samples and from two older samples from preserved individuals that were hunted in the 1920s in the Addo region and held in collections of the South African Museum (Iziko). They found that the older Addo samples were more closely related to the KNP samples, which made them conclude that tusklessness in the AENP  is probably a result of more recentbottlenecks and not because of earlier genetic divergences. As a result they could advise conservation officials to bring in elephant individuals from other areas to the AENP to increase genetic diversity.

What did they eat? – understanding the diets of fossil vertebrates

Paleontologists often use cues they find at fossil sites to reconstruct the biology of fossilized species and the environment they lived in. They will take these cues and compare themwith more recent evidence to detect similarities. Dental microwear has emerged as an important new methodology that scientists use to reconstruct the diets of early vertebrates. By comparing the patterns of microwear on fossilized teeth with those of more recent species, scientist are now able to tell whether the extinct species’ diet consisted of certain groups of plant materials. Through this, natural history collections have emerged as a valuable source of new information for paleontologists.

Where did it begin? – understanding the evolution and distribution of zoonotic diseases

The emergences of new technologies and procedures now enable natural history museums to include preserved blood samples in their collections. These samples provide researchers with a valuable opportunity to study zoonotic diseases. One such example is the Hantavirus, a pulmonary disease transmitted by rodents. After an outbreak during 1993 in the Americas, researchers conducted studies to trace the origin and spread of the virus. By analyzing preserved blood samples, from a few years before and after the 1993 outbreak, of the rodent host species that were held in two museums in the US,the researchers were able to trace where the virus originated and when it spread. From this they could then draw correlations with different factors to determine what triggered the outbreak and to predict potential outbreaks in future.

How far did they go? – understanding the movement of hunter-gatherers across late Quaternary southern Africa

Archeologists have discovered ostrich eggshell beads at two sites in the Highlands of Lesotho, Southern Africa, dating from about 33000 years ago. Since it is agreed that ostriches most probably did not occur in these areas, the question then was:  where did the beads originated from? This would give the researchers a good indication of how these early people moved around and what exchanges occurred. To answer the question, the scientists used various materials, including mammal collections housed at the National Museum, Bloemfontein, and the McGregor Museum, Kimberley, to determine the strontium isotope levels from different areas surrounding Lesotho and to compare this to the strontium levels of the beads from Lesotho. In the case of the mammal collections, the scientists collected tooth samples of rodents from known areas to determine the strontium levels. Based on the results of this study, it was concluded that the inhabitants of the archeological sites in Lesotho could have moved in excess of 300km to obtain these beads. It provided evidence that these people engaged in a much larger social network than what was previously thought.

Although the above are only a few examples of the potential usefulness of natural history collections, it is evident that these collections have a very important role to play in various research disciplines. The importance of this role is likely to increase further as new technologies and methodologies are developed. The challenge for natural history museums is to expand their collections in a manner that will keep up with these developments and that will still be relevant in many years to come. In order to do this, curators and collections managers will have to embrace the concept of an “extended specimen” and becomefamiliar with all the potential preservation techniques to serve the wider research community. Collecting and preservation will remain one of the most important functions of natural history museums into the future…

 

References

Burgman, J.H.E., Leichliter, J., Avenant, N.L. & Ungar, P. 2016. Dental microwear of sympatric rodent species sampled across habitats in southern Africa: Implications for environmental influence. Integrative Zoology 11: 111-127.

Cook, J.A. & Light, J.E. 2019. The emerging role of mammal collections in 21st century mammalogy. Journal of Mammalogy 100: 733-750.

Farrington, O. 1915. The Rise of Natural History Museums. Science 42: 197-208.

Galbreath, K.E. et al. 2019. Building an integrated infrastructure for exploring biodiversity: field collections and archives of mammals and parasites. Journal of Mammalogy 100: 382-393.

Schindel, D.E. & Cook, J.A. 2018. The next generation of natural history collections. PLOS Biology 16: e2006125.

Stewart, B.A. et al. 2020. Ostrich eggshell bead strontium isotopes reveal persistent macroscale social networking across late Quaternary southern Africa. PNAS: 1-10

Whitehouse, A. 2002. Managing small elephant populations: lessons from genetic studies. In: Kerley, G., Wilson, S. & Massey, A. Elephant conservation and management in the Eastern Cape. Terrestrial Ecology Research Unit, University of Port Elizabeth, Port Elizabeth.

Yates, T.L. et. al. 2002. The ecology and evolutionary history of an emergent disease: Hantavirus pulmonary syndrome. BioScience 52: 989-998.