In September 2019, the U.S. Department of Interior’s Office of Insular Affairs awarded Island Conservation $244,756 “to implement a showcase eco-system rehabilitation and restoration project in the UNESCO-designated Rock Island Southern Lagoon of Palau,” an archipelago of nearly 450 small islands in the western Pacific. The focus of the project was to be “removing invasive rats from the Ngemelis Island complex and promote the recovery of seabird populations.”
Seven months later, the non-profit appealed to OIA for nearly a quarter-million dollars more, this time to “remove” cats from Palau’s Ulong Island. One would expect such a request to be a detailed account explaining, among other things, why, before even getting underway, their original project had so expanded in its scope as to justify a budget twice the size of the original.
Apparently, though, such rigor is unnecessary—perhaps even unwelcome—at OIA. Instead, a little creativity seems to be the key to winning over the agency’s decision-makers. Less than one month after receiving the request, the agency awarded Island Conservation $239,922 “to eradicate feral cats in the Ulong Island area of the Rock Islands Southern Lagoon.”
After briefly thanking OIA for funding their project to “remove” rats, authors of the Island Conservation proposal got to the point of their follow-up: “During preliminary research for this project, we identified that feral cats are also present at the site.”
“Consequently, we are seeking further support from the OIA to ensure full restoration of Ulong Island. Removal of rats alone will not permit full recovery of ecosystem services and protection of endemic and threatened species. Only the removal of both invasive species will generate the sought‐after improvements to reef health and human livelihoods that this project promises to deliver.”
There’s good evidence to show that removing either rats or cats is unlikely to protect island seabirds [1–3]. Still, Island Conservation’s follow-up request raises a number of questions. How well did they survey the island before submitting the first proposal, for example, if the presence of cats later came as a surprise? After all, Ulong appears to be no more than about nine square miles. And if no cats were detected during the initial survey, how many can there really be on an island this size?
Island Conservation’s proposal (obtained via public records request* and available as a PDF here) for eradicating cats includes a number of sweeping claims with little or no support. “In Palau,” reads one section, “feral cats are widespread and impact biodiversity, disturb ecosystem services, reduce the availability of natural resources, and spread diseases such as toxoplasmosis.” Like so much of the proposal, the justification for more killing is little more than arm-waving.
What the proposal lacks in specificity, though, it makes up for in creativity. In what might be a first in the ongoing campaign to kill cats, there’s this: “the feral cat problem in Palau has recently been in the spotlight with feral cats having been reported stealing food from rural communities.”
Other claims of alleged impacts are less creative, perhaps, but a stretch nonetheless.
“The impacts of both cats and rats on Ulong have resulted in a massive decline in the island’s seabird populations, disrupting the critical function that former bird colonies played in bringing nutrients from sea to land. In turn, this will have impacted adjacent coral reefs by removing an essential nutrient subsidy. Consequently, the site is not meeting its full potential as a tourist destination nor are subsistence fishers able to reap the rewards of a healthy coral reef.”
So, cats are to blame for declining seabird numbers and the poor health of the area’s coral reefs—all of which threatens tourism and subsistence fishing? The only supporting evidence provided by Island Conservation is a reference to a 2007 report from the Palau National Environmental Protection Council.
“According to the Palau National Invasive Species Strategy (2007), rats, feral cats, macaques, smothering vines, snails, algae, agricultural pests, and pathogens have invaded Palau, impacted the environment, the economy, human health, and even the traditional Palauan way of life.”
In fact, the report itself mentions cats only once, in defining “feral animals.” The section Island Conservation was apparently referring to reads somewhat differently.
“Monkeys, cockatoos, smothering vines, snails, aggressive fish, bottom-dwelling marine organisms, agricultural pests, and human disease-causing microorganisms: all of these and more have invaded Palau, and all are having impacts on the environment, the economy, human health, and even the traditional Palauan way of life” [4].
Perhaps the authors of Island Conservation’s proposal thought it prudent to give the rats and cats top billing, thereby highlighting the need for the organization’s (ever-expanding) services.
Threat assessment
As the authors of Island Conservation’s proposal note, climate change poses a significant threat to Palau’s coral reefs. However, the same 2017 NEPC report cited to support this claim is rather unambiguous about the current state of the reefs: “Palau’s coral reefs—the basis for much of the economy—are largely in good condition” with the exception of the “outer reefs on the East Coast,” which “are in poor condition following two Supertyphoons” [5]
Reading Island Conservation’s proposal, of course, one comes away with a very different impression—of both the overall condition of the areas coral reefs and the reason for recent damage. In addition, the threats suggested by Island Conservation are not among those cited as “pressures and threats” by NEPC: “overfishing, sedimentation from land, and the daily cumulative plus long-term impacts of climate change” [5].
And what about those “massive declines” in seabird populations? One would expect such a claim to be supported with at least a couple citations, yet none is provided. Nothing about declining seabirds and nothing about the cause being cats and rats. I’ve been unable to locate any predation studies of conducted on Ulong Island, or in Palau more generally. Moreover, a study published just last month found that the number of endangered Micronesian scrubfowl observed on Ulong was significantly greater than estimates from four nearby islands popular with tourists (just like Ulong), more closely resembling observations from nearby islands not visited by tourists [6].
To be clear: this was not a predation study and the scrubfowl are not seabirds. Even so, if the island’s cats (and rats) are truly responsible for “massive declines” in its seabird population, one would expect some mention of this threat in such a detailed survey of the island. Instead—in an interesting twist—the study’s authors highlight a different threat: “tourism activities and facilities” might be adversely affecting scrubfowl breeding and “augmenting rodent populations through supplementary food provision” [6].
This, of course, raises a question that goes to the very heart of Island Conservation’s proposal: Is “meeting its full potential as a tourist destination” really good for Ulong’s plant and animal life? (Of course, taking such questions seriously might jeopardize support for the project from local stakeholders heavily reliant on tourism.)
A lack of creativity when it’s most needed
Unfortunately, the Island Conservation team’s creativity ran out before they identified their intended method of “removal.” Their budget includes $2,500 for “high‐powered air rifle, case, and accessories for the humane removal of feral cats”—even though previous, well-documented eradication campaigns have demonstrated the relative ineffectiveness of shooting cats [7–9].
(As an aside—it strikes me as odd that an organization so deeply involved in eradication efforts actually requires more rifles—or footwear and backpacks, also included in the budget—but these discrepancies are in keeping with the rest of the proposal.)
No doubt, there will be additional requests for funding from Island Conservation. As the organization notes in its proposal, “The UNESCO‐designated [Rock Island Southern Lagoon] is a logical starting point to cultivate invasive species management skills in Palau and demonstrate the feasibility of eradicating feral cats from islands” (emphasis mine).
Many thanks to Jodie LoMeli for bringing this story to my attention.
*Island Conservation did not respond to my request for a copy of their proposal.
Literature Cited
- Courchamp, F.; Langlais, M.; Sugihara, G. Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 1999, 68, 282–292.
- Fan, M.; Kuang, Y.; Feng, Z. Cats protecting birds revisited. Bulletin of Mathematical Biology 2005, 67, 1081–1106.
- Gambino, J.; Martínez-Martínez, M.V.; Salau, K.; Soho, E.L.; Hiebeler, D.E.; S⬚ánchez, F.; Murillo, D. Cats Protecting Birds Revisited with a Spatial Approach.; 2007.
- NEPC Palau National Invasive Species Strategy; Palau National Environmental Protection Council, 2007;
- NEPC 2017 State of the Environment Report Republic of Palau; Palau National Environmental Protection Council, 2017;
- Radley, P.M.; Davis, R.A.; Doherty, T.S. Impacts of invasive rats and tourism on a threatened island bird: the Palau Micronesian Scrubfowl. Bird Conservation International 2020, 1–13, doi:10.1017/S0959270920000246.
- Bester, M.N.; Bloomer, J.P.; Aarde, R.J. van; Erasmus, B.H.; Rensburg, P.J.J. van; Skinner, J.D.; Howell, P.G.; Naude, T.W. A review of the successful eradication of feral cats from sub-Antarctic Marion Island, Southern Indian Ocean. South African Journal of Wildlife Research 2002, 32, 65–73.
- Veitch, C.R. The eradication of feral cats (Felis catus) from Little Barrier Island, New Zealand. New Zealand Journal of Zoology 2001, 28, 1–12.
- Campbell, K.J.; Harper, G.; Algar, D.; Hanson, C.C.; Keitt, B.S.; Robinson, S. Review of feral cat eradications on islands. In Island invasives: eradication and management; Veitch, C.R., Clout, M.N., Towns, D.R., Eds.; IUCN: Gland, Switzerland, 2011; pp. 37–46.