A Scientific
Position Paper Opposing Further Archaeological Excavation at Gcwihaba Cave,
Botswana
Mike Buchanan,
Karstologist -2025
Abstract
This paper presents a formal objection to ongoing and proposed archaeological excavations within the Gcwihaba–Koanaka cave complex, Ngamiland, north-western Botswana. The site represents one of Southern Africa’s oldest, most intact karst ecosystems and functions as a critical bat hibernaculum and paleoenvironmental archive. Recent reports by Laurent Bruxelles, Director of the International Research Center SHARE (CNRS/University of the Witwatersrand), confirming the extraction of more than four tons of fossiliferous sediment from the Koanaka Hills after only one week of excavation (Bruxelles, 2025), reveal an alarming disregard for internationally accepted conservation standards. Such activities threaten irreversible ecological, geological and heritage damage and contravene Botswana’s Monuments and Relics Act (2001) as well as the principles of the Convention on Biological Diversity.
1. Introduction
Gcwihaba and the associated Koanaka cave system have long
been recognised as areas of exceptional natural and cultural value (Greig et
al., 2002; Buchanan, 2010). The 2002 Gcwihaba Cave Management Plan
expressly warns against any excavation likely to alter the cave’s microclimate
or disturb resident fauna.
Despite these protections, teams associated with the
University of the Witwatersrand have recommenced large-scale excavations. On 13
October 2025, Laurent Bruxelles publicly announced:
“After one week of excavation in the Koanaka Hills, together
with the team from the Botswana National Museum and with the help of the San
community of Xai-Xai, more than four tons of fossiliferous sediment have been
extracted. Now, it’s time to start sieving and sorting the bones, while the
geological team explores new sites and caves in the area.” (Bruxelles, 2025,
LinkedIn post)
The sheer volume of sediment removal within such a short
period confirms that destructive excavation is already under way, contrary to
both local management prescriptions and international best practice.
2. Ecological and Geological Sensitivity
Gcwihaba lies within the dolomitic Koanaka Group of the
Damaran Belt, forming an interconnected karst aquifer possibly extending into
Namibia (Buchanan, 2010). Even minor mechanical disruption can change airflow,
humidity, and groundwater balance (Williams, 2007).
The cave provides habitat for several Near Threatened bat
species—Rhinolophus denti, Nycteris thebaica, Hipposideros
commersoni, and possibly Miniopterus schreibersii (Greig et al.,
2002; Buchanan, 2010). These populations regulate insect ecosystems and sustain
cave nutrient cycles. Disturbance, especially through noise, dust and lighting,
can lead to permanent colony abandonment (Tuttle, 2000).
Bruxelles’ report of multi-tonne excavation strongly
suggests mechanical digging, transport and sieving, all activities known to
raise dust, alter temperature and humidity, and drive bat colonies from roosts
(Hamilton-Smith, 2006).
Section 10(2–4) of Botswana’s Monuments and Relics Act
(2001) prohibits any non-conservation use or development within one
kilometre of a National Monument without explicit ministerial approval. The Act
demands that such approval only be granted if the activity is “not incompatible
with the preservation of the national monument.”
The ongoing sediment removal, if authorised, conflicts
directly with this provision. Moreover, the scale of extraction breaches UNESCO
(2010) guidance requiring minimal disturbance to caves nominated for World
Heritage status.
Past controversies surrounding Witwatersrand-led cave
excavations, including those led by Lee Berger, have highlighted procedural
irregularities, insufficient peer oversight, and ethical lapses (Dirks et al.,
2015). The present actions in the Koanaka Hills demonstrate a continuing
pattern of disregard for environmental integrity and transparency.
4. International Conservation Obligations
The IUCN World Heritage Caves and Karst Study
(Hamilton-Smith, 2006) and Karst Management Guidelines (Williams, 2007)
define caves as “three-dimensional living systems” whose microclimates can be
permanently damaged by minimal disturbance. Excavation without a comprehensive
environmental and heritage impact assessment contravenes these standards.
The 2010 UNESCO Natural Heritage Application notes
that Gcwihaba and the Koanaka hills contain “the richest cave fossil deposit in
Botswana and possibly in Southern Africa,” and that these caves “have been
resealed after each research visit to preserve interior air composition.” The
current large-scale removal of fossiliferous sediments clearly violates this
principle of periodic resealing. Regardless of whether the sample sediments
were recovered from the subterranean or terrestrial.
- Immediate
suspension of all excavations and sediment removal within the
Gcwihaba–Koanaka karst system pending a full independent Environmental and
Heritage Impact Assessment.
- Investigation
by the Department of Environmental Affairs into the authorisation process
permitting extraction of several tonnes of fossiliferous material.
- Reinstatement
of the cave’s closed area status under the 2002 Management Plan,
with expansion to all connected karst features.
- Community
representation through the Cgae Cgae Tlhabololo Trust in all research
governance structures.
- Formation
of an independent oversight committee comprising karstologists,
chiropterologists and heritage specialists to evaluate all current and
future proposals.
6. Conclusion
The removal of tonnes of fossiliferous material from Koanaka
Hills in one week demonstrates precisely the kind of destructive intervention
the Gcwihaba Management Plan sought to prevent. These caves are fragile living
systems, repositories of biodiversity, geology, and human prehistory.
Excavation at this scale constitutes environmental vandalism masquerading as
science.
The Government of Botswana is urged to halt all such
activity, enforce statutory protections, and reaffirm the country’s leadership
in ethical, community-based conservation. Preservation, not extraction must
remain the guiding principle for Gcwihaba and its sister caves.
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