The Mystery of Pillow Mounds: Are They Really Medieval Rabbit Warrens?

September 22, 2024 Trebor2510

Contents

1 Introduction
2 Further Reading
3 Other Blogs

Introduction

Pillow mounds have long been identified by archaeologists as rabbit warrens—structures built during the medieval and post-medieval periods to manage rabbit populations for fur and meat. These long, low earthworks, often equipped with drainage ditches, were thought to provide ideal conditions for rabbits to burrow and breed. The case of Trowlesworthy Warren on Dartmoor is a well-known example, where there are now believed to be 64 pillow mounds spread across a 5 km area. However, recent archaeological findings and a closer look at the logistics of large-scale rabbit farming in this landscape challenge the established interpretation.

This blog will explore the traditional reasons archaeologists classify pillow mounds as rabbit warrens while presenting new evidence—including the scale of the site, environmental challenges, and the discovery of radiocarbon-dated materials—that casts doubt on this interpretation.

**Trowlesworthy Warren** is a massive Prehistoric Site with no barrows – The Mystery of Pillow Mounds

1. Traditional Interpretation: Rabbit Warrens

The identification of pillow mounds as rabbit warrens originates from medieval records describing the practice of rabbit farming, introduced to Britain by the Normans after the 11th century. Rabbits were a valuable resource for both their meat and fur, and the creation of controlled environments for breeding—called warrens—became widespread. Pillow mounds, typically rectangular and accompanied by drainage ditches, resemble natural rabbit burrows and were strategically placed in areas unsuitable for crop farming, such as Dartmoor.

At Trowlesworthy Warren, the extensive number of mounds spread across a large area appeared to reflect the large-scale management of rabbit populations, supporting this traditional view.

2. Characteristics of Pillow Mounds

The pillow mounds at Trowlesworthy Warren follow a typical form—long, narrow mounds constructed of earth, often measuring 20 to 50 meters in length and 5 to 10 meters in width. These mounds are often associated with shallow ditches designed to prevent waterlogging, which is essential for rabbits to thrive. Some mounds even feature stone-lined burrows or tunnels, leading archaeologists to interpret them as deliberately constructed habitats to encourage rabbit breeding.

3. Estimating Rabbit Populations Based on Mound Size

Historically, archaeologists estimated that each average-sized mound could support up to 100 rabbits. However, given the presence of larger mounds at Trowlesworthy, some as long as 50 meters and 10 meters wide, this estimate needs adjustment. Larger mounds could potentially support around 400 rabbits each.

Given that Historic England now recognizes 64 pillow mounds at the site, with an average of 400 rabbits per larger mound, the total rabbit population at Trowlesworthy Warren could have been as high as 25,600 rabbits. This indicates a massive scale of rabbit farming, far beyond the scope of a single small operation. Such an immense population would have required a complex system of management, including trapping, breeding control, and predator management.

4. Logistical Challenges of Large-Scale Rabbit Farming

While the estimated capacity of 25,600 rabbits suggests that Trowlesworthy Warren could have been an industrial-scale rabbit farm, several key logistical challenges make this interpretation difficult to support. Chief among these is the lack of infrastructure. Large-scale rabbit farming would have required roads or well-maintained tracks to transport rabbits from the remote Dartmoor landscape to nearby markets or towns. However, there is no visible evidence of roads or transportation infrastructure around the site.

Additionally, a warren of this size would have required a significant labor force, yet there are no substantial remains of warreners’ lodges or other structures to house workers. In smaller warrens, the warrener often lived on-site to manage the rabbits and prevent predators from attacking them, but the sheer size of Trowlesworthy Warren implies that a single person could not have managed such an extensive operation.

5. Environmental Unsuitability for Rabbit Warrens

An even more significant issue is the unsuitability of the landscape for rabbit warrening. Many of the pillow mounds at Trowlesworthy Warren are located near paleochannels—ancient riverbeds that are prone to seasonal flooding. Rabbits require dry conditions for burrowing and breeding, and any prolonged exposure to waterlogged soil would be detrimental to their health. The positioning of many mounds near these paleochannels makes them highly vulnerable to flooding during the wet season, raising serious questions about whether these mounds were truly designed for rabbits.

The drainage ditches around the mounds, often cited as evidence of their use as rabbit warrens, are not connected to nearby streams or natural watercourses, meaning they would likely become waterlogged themselves, further exacerbating the problem.

6. Alternative Interpretation: Ritual or Funerary Landscape

Given the unsuitability of the land for rabbit farming, it is worth considering an alternative interpretation. The location of many pillow mounds near paleochannels suggests that these mounds could have served a ritual or funerary purpose. In prehistoric and early historic Britain, water was often associated with rituals and funerary practices, and waterways were seen as symbolic gateways to the afterlife.

The elongated shape of the pillow mounds could be interpreted as excarnation platforms—places where bodies were laid out to decompose naturally before their bones were collected and buried. The proximity to water in the form of paleochannels could have added a spiritual or ceremonial dimension to these activities. In this context, the pillow mounds may have served as burial markers or cremation platforms.

7. Radiocarbon Dating of Earlier Activity

Recent excavations at Trowlesworthy Warren have uncovered evidence that challenges the medieval rabbit warren theory even further. Beneath one of the pillow mounds, archaeologists discovered a hearth containing charcoal that was radiocarbon dated to the Iron Age—long before the introduction of rabbits to Britain. This finding suggests that the site was in use for other purposes well before the construction of the pillow mounds.

The Iron Age activity at the site may indicate that the pillow mounds were built on top of a much older ritual landscape, possibly repurposing prehistoric structures for medieval uses. This layered history raises the possibility that the mounds were originally constructed for ritual purposes and were later either adapted for rabbit farming or remained purely ceremonial.

8. Misinterpretation of Structural Features

The structural features of the mounds themselves—particularly the drainage ditches—may have been misinterpreted. While these ditches are often cited as evidence that the mounds were designed for rabbit warrening, they may have served other purposes, such as controlling water flow in a ritual landscape. In prehistoric cultures, the management of water was a significant aspect of both ceremonial and agricultural activities, and the presence of drainage ditches does not necessarily indicate medieval rabbit farming.

9. No Direct Evidence of Rabbits

Although pillow mounds are typically associated with rabbit warrening, not all excavated mounds have produced direct evidence of rabbits, such as bones, droppings, or other remains. The absence of such evidence at some of the mounds at Trowlesworthy Warren raises the possibility that not all of the mounds were used for rabbit farming. Some may have had different, possibly ritual or funerary functions, particularly those located near paleochannels.

10. Reconsidering the Scale and Purpose of the Site

While the traditional interpretation of pillow mounds as rabbit warrens remains plausible for many sites, the scale, layout, and environmental challenges of Trowlesworthy Warren suggest a more complex history. The lack of infrastructure, the unsuitability of the landscape for rabbits, and the discovery of Iron Age activity all indicate that these mounds may have been part of a ritual landscape long before the medieval period.

11. Alternative Use: Cremation or Excarnation Sites

The proximity to paleochannels and the radiocarbon dating of pre-medieval activity beneath some mounds point to the possibility that Trowlesworthy Warren was used for cremation or excarnation practices. The mounds could have served as funerary platforms, where bodies were laid out to decompose or be cremated before being deposited in burial sites. The location and shape of the mounds fit this hypothesis, as does their association with ancient watercourses, which often played a significant role in prehistoric ritual practices.

12. Conclusion: A Complex Legacy of Land Use

While pillow mounds are traditionally identified as rabbit warrens, the case of Trowlesworthy Warren demonstrates that these structures likely have a more complex history. The large scale of the site, the lack of infrastructure, and the unsuitability of the land for rabbit farming suggest that the mounds may have originally been constructed for ritual purposes in the prehistoric period, only later being adapted for or interpreted as medieval warrens. As more evidence emerges, including radiocarbon dating and further excavations, the true purpose of these enigmatic structures continues to evolve, offering a glimpse into the multilayered history of Dartmoor’s landscape.