Comment on Balmford et al. (2009)

Balmford et al. [1] misrepresent our work [2,3] in several ways:

1. Our analyses and results were limited to the US & Japan. Our results for these countries are generally corroborated by the authors. We hypothesized that these trends in the US & Japan might be generalized to other rich, developed countries with large tracts of natural areas [2]. We do not hypothesize that these trends may be generalized to LDCs or to lands with few natural areas. However, the authors seem to insinuate otherwise. Indeed, another country matching our criteria of being rich and developed and having large tracts of natural areas (Australia) is also shown by the authors to have declining nature interest.

2. The authors state we did not show US camping and other hunting to be in downtrends, but this is not correct: our results show they are indeed in downtrends [2].

3. The authors state that videophilia is a plausible cause of declining nature interest, but that evidence is sparse. However, they do not cite or discuss our paper showing that videophilia is indeed a likely proximate cause for decline in US national parks visitation [4].

4. The authors hypothesize that many formal protected areas in richer countries are becoming increasingly crowded and thus less attractive to mature enthusiasts. We disprove this hypothesis for US national parks [4], however the authors do not cite or discuss this paper.

A key piece of our research has been to evaluate the implications of nature participation trends for biodiversity conservation. The authors state that falling visitation is mostly restricted to a few well-off countries, and that PA visitation is generally growing, but at a progressively lower rate (eventually falling below zero) with rising affluence. If correct, these findings do not negate our concern that disconnect with nature is potentially causing later disinterest with conservation in rich, developed countries with large tracts of natural areas; rather our concern is reinforced by the authors’ corroboration of trends in the US & Japan, and addition of Australia. If it is true that individuals from the wealthiest nations (sources of large donors and substantial global conservation funding) are spending less time in nature, then we are seeing a trend of great concern for biodiversity conservation.

The authors hypothesize that increased foreign ecotourism to LDCs may be responsible for the trends found. This hypothesis seems plausible to us, especially in view of a negative correlation with local affluence, and worthy of further examination. However, though a foreign ecotourism hypothesis is plausible we have substantial concern over its ramifications for the credibility of this study. The authors show that visitation and in some cases per capita visitation is rising in some countries, but the relative scale of declines and increases remains an important unknown. What proportion of the global nature recreation pie is represented? A 4% increase in Madagascar PA visitors is likely to reflect many fewer people than a 1.5% decline in Canadian PA visitors. In our paper we presented a pie chart reflecting the relative market share of each of our outdoor recreation variables [2]. It would be useful and informative for the authors to do the same with their data. For example in the US, foreign ecotourism is miniscule compared to natural areas visitation, camping, fishing, or hunting. The authors may well be comparing very minor increases in visitation in other countries due to foreign ecotourism with very major decreases in other forms of nature visitation. If so, they are merely documenting a minor countertrend, and may be misrepresenting their results by not publishing relatively small outright values.

On a related note, we agree strongly with comments in a concurrently published opinion piece [5] regarding relative data quality: "Pergams and Zaradic [2], for example, also sought data from countries such as Australia. They were sent data from two of eight states, one of which did not actually record visitor numbers—the figures were purely estimates. Australian tourism lobbyists quote park visitation estimates derived from very general off-site surveys of people's holiday intentions, carried out by the federal tourism agency. Such surveys are highly unreliable [2]. Even in face-to-face interviews with people who know you have been watching them, many report their own very recent actions inaccurately [6]. On-ground counts show the tourism surveys are inflated by 20–1,000% [7]. So, it's hard to measure small changes reliably" [5]. We were very explicit in our paper about our criteria for utilizing data, so that we would compare data of approximately equal quality and appropriateness (in other words, compare apples of equal ripeness rather than ripe apples and green oranges). We suggest that reliable results depend on using comparable data.

Ultimately, tracking visitor trends to PA is of interest primarily as a proxy for some of the more complex forces driving conservation that are much harder to quantify such as the cultural and political value placed on wild spaces. Global conservation efforts require understanding nature use trends and values on a relative scale in a global market. Testing the hypothesis that increased foreign ecotourism to LDCs is responsible for the trends found in the reported study is a valuable pursuit but requires comparable data of greater quality and equivalency than appears to be currently available. Comparing percent changes in visitation as equivalent units among nations varying greatly in population size and scale is likely to be both inaccurate and potentially misleading.

The trend of declining nature participation in the US and Japan reported in our work and further corroborated by the authors’ results is worrisome for global biodiversity conservation funding. Foreign nature-based tourism may be a short-term economic boon for less developed nations, as the authors suggest. However, if a larger global trend of disinterest with nature recreation continues, especially among the most affluent donor nations, then the long-term result for global biodiversity conservation is likely to be a bust.

Oliver R. W. Pergams & Patricia A. Zaradic
Red Rock Institute, Inc.
www.redrockinstitute.org


Literature Cited

1. Balmford A, Beresford J, Green J, Naidoo R, Walpole M, et al. 2009 A Global Perspective on Trends in Nature-Based Tourism. PLoS Biology 7(6): e1000144. doi:10.1371/journal.pbio.1000144.

2. Pergams ORW, Zaradic PA. 2008. Evidence for a fundamental and pervasive shift away from nature-based recreation. Proceedings of the National Academy of Sciences US 105:2295-2300.

3. Pergams ORW, Zaradic PA. July 8, 2008. Reply to Jacobs and Manfredo: More support for a pervasive decline in nature-based recreation. Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0803331105.

4. Pergams ORW, Zaradic PA. 2006. Is love of nature in the US becoming love of electronic media? 16-year downtrend in national park visits explained by watching movies, playing video games, internet use, and oil prices. Journal of Environmental Management 80:387-393.

5. Buckley R. 2009. Parks and Tourism. PLoS Biol 7(6): e1000143. doi:10.1371/journal.pbio.1000143.

6. Littlefair C, Buckley RC. 2008. Interpretation reduces ecological impacts of visitors to World Heritage Areas. Ambio 37: 338–341.

7. Buckley RC. 2004. The effects of World Heritage listing on tourism to Australian national parks. Journal of Sustainable Tourism 12:70–84.

Competing interests declared: Our comment responds in part to criticisms of our work Pergams & Zaradic (2008).