The Future of the Crum Woods

Presented by The Crum Woods Stewardship Committee
February 2008

The Crum Woods are one of the College's most distinctive treasures. The woods encompass 220-forested acres including 29.7 acres of swamps and floodplains and serve as a unique and valuable outdoor teaching laboratory for 35 courses in 12 departments. Among 72 liberal arts colleges in the Northeast, only seven have substantial college-owned forestlands within walking distance of campus. In addition to their curricular uses, the woods contain walking trails and provide recreational opportunities for both the Swarthmore College community and visitors.

Seven years ago, the Crum Woods Stewardship Committee (CWSC), comprising faculty, students, and staff, was formed to create a protection, restoration, and stewardship plan for the woods. In spring 2001, the CWSC commissioned Natural Lands Trust and Continental Conservation to prepare a Conservation and Stewardship Plan to provide recommendations that would secure the woods' long-term health and viability and identify any potential hazards or concerns.

In 2003, when the plan was completed, Natural Lands Trust and Continental Conservation reported that the Woods represents the only remnant of original forest in Delaware County but concluded that an overabundance of deer headed the list of factors threatening the woods. When deer population outpaces available habitat, the future health of the forest is placed at high risk. Currently, excessive deer browsing is limiting the ability of the forest to regenerate naturally. Consequently, as large trees die, no seedlings are available to replace them. The report characterized the effect of overpopulation of deer as "profound" for deer and forest, because deer eat mainly native species and facilitate the establishment and growth of non-native species that are not useful for deer. A public presentation and discussion of the issue was held in May 2004 and was attended by members of the College and neighboring communities.

Forest fragmentation, housing development, and the lack of large predators that once controlled deer numbers are the main causes of overpopulation. Following the 2004 report, the CWSC set out to understand how best to reduce the deer population to a sustainable size in a safe, humane, forest-science-based, socially responsible manner. The CWSC commissioned Natural Resource Consultants Inc. (NRC Inc.) to develop a deer management plan for the woods, with a clear mandate to evaluate all possible options. In November 2005, the College also commissioned an aerial infrared deer count to be conducted in and around the woods, which confirmed the plan's finding that deer numbers are well above the level recommended for maintaining a healthy forest ecosystem.

Two additional public forums were held on campus to discuss possible long-term strategies for dealing with the problem-the first in spring 2006, and another in spring 2007. During the most recent forum, the NRC discussed at length and fielded questions about its recommendation that a sharpshooter be hired to euthanize deer as the most humane, effective and socially responsible method to protect and restore the diverse ecosystems that have been placed at risk by the overabundance of deer in the woods.

As charged by the CWSC, the NRC looked carefully at all options described below.
Full report issued by the NRC [pdf]

  1. No action. This option was not recommended, because inaction would continue to make vulnerable the fragile and already weakened ecosystems of the woods.
  2. Mitigation techniques such as fencing, repellants, feeding, and establishing landscape planting resistant to deer browsing are not effective when dealing with landscapes on the scale of the Crum Woods. Deer repellants are neither practical nor effective to protect entire ecosystems. Fencing could be used to exclude deer but would change the character and function of the forest as an interactive landscape and would also change the nature of the deers' relationship to the woods as a valued component of their native fauna. Feeding deer would not necessarily result in their eating less natural vegetation and might exacerbate the problem.
  3. Predator restoration is sometimes suggested as a way to reestablish a balance between deer and forested ecosystems. In a suburban setting such as Swarthmore, this option is both impractical and dangerous to humans and domestic animals, which could become targets for animals such as cougars that prey on deer.
  4. Some communities "trap and transfer" their deer from problem areas to off-site locations. Most typically, the deer are transferred to either a site where they will ultimately be treated as livestock for meat or into a high-fence recreational "hunting" locale. In nearly all cases, the trap and transfer results in the deer being killed. This option requires a permit from the Pennsylvania Game Commission, which has a policy of not issuing such permits.
  5. Some communities are contemplating contraception techniques either through synthetic steroid hormones or immunocontraception vaccines or contragestation which terminates pregnancy. Although immunocontraception vaccines offer promise for wildlife management, no fertility control agents have been approved by the Food and Drug Administration or the Environmental Protection Agency. In addition to the regulatory hurdles, contraception is experimental in nature and has not been shown to be an effective management tool for free-ranging deer populations such as those inhabiting the Crum Woods. To date, no field studies document that this method could reduce deer to the densities required to meet the management goals of the Crum Woods. Finally, in order to be effective, the deer would need to have limited scale of movement and maintain low dispersal rates. The available published literature does not support the conclusion that this approach would be an effective deer management technique in the Crum Woods.
  6. Some communities "trap and euthanize" deer using either clover traps or drop nets. Drop nets, which are used to capture multiple deer, are not recommended as a humane option because of the time between when the animals are captured and actually euthanized. Clover traps are also not recommended as a humane or practical option. In both cases, deer will adjust their behavior as they learn about the dangers of the traps, diminishing their effectiveness over time.
  7. Although recreational hunting can, in many landscapes, be an effective mechanism for mimicking the population-stabilizing effects of natural predators, a review of urban/suburban deer programs through the contiguous 48 states does not produce a single example supported by quantitative, science-based data where deer populations were effectively reduced through recreational hunting in a situation similar to the Crum Woods. Additionally, the majority of the woods falls within safety zones and would not be huntable without waivers by dozens of adjacent residences.
  8. Some communities combine deer management techniques such as sharpshooting and controlled hunts by recreational hunters. However, the Crum Woods does not lend itself to recreational hunting, and this option is not recommended.

Having ruled out all other options, NRC concluded that sharpshooting utilizing bait and noctural removals would be the only effective approach that would meet the goals articulated by the CWSC. Other nearby communities that have adopted this deer-cull technique include the Wissahickon Valley, Pennypack, and West Fairmount parks. The procedure would be done by trained personnel at pre-approved sites, most likely at night. Deer are euthanized by a single shot from a vehicle or from a tree stand. Human safety is ensured by shooting only when there is a clear line of vision and by using a backstop that is provided by the shooter's relative elevation. Deer meat (venison) would then be donated to local groups feeding those in need.

The recommendation to proceed with a deer cull was heard by members of senior staff and by the Board of Managers during its December 2007 meeting. Although the CWSC agrees with the recommendation to proceed with a deer cull, additional community input is encouraged. If the College decides to proceed with a cull, it must ask Swarthmore Borough and Nether Providence Township to amend an ordinance to allow shooting on College property in these respective areas. The College would then, along with the Borough and Township, apply for a deer removal permit from the Pennsylvania Game Commission.

Student, faculty and staff forums will be held and we welcome additional community input before a final decision is reached this spring. If you have specific thoughts or suggestions you would like to share with the CWSC about the proposed deer cull, please send them to