1 Barnosky, A. D. et al. Has the Earth's sixth mass extinction already arrived? Nature 470, 51–57 (2012).

2 Ceballos, G. et al. Accelerated modern human-induced species losses: entering the sixth mass extinction. Sci. Adv. 1, e1400253 (2015).

3 Pimm, S. L., Jenkins, C. N., Abell, R. & Brooks, T. M. The biodiversity of species and their rates of extinction, distribution, and protection. Science 344, 1246752 (2014).

4 Newbold, T. et al. Global effects of land use on local terrestrial biodiversity. Nature 520, 45–50 (2015).

5 Tittensor, D. P. et al. A mid-term analysis of progress toward international biodiversity targets. Science 346, 241–244 (2014).

6 Hoffmann, M. et al. The impact of conservation on the status of the world's vertebrates. Science 330, 1503–1509 (2010).

7 Watson, J. E. M., Dudley, N., Segan, D. B. & Hockings, M. The performance and potential of protected areas. Nature 515, 67–73 (2014). This review of the history and effectiveness of protected areas proposes that conservationists should refocus on establishing large, connected, well-funded, and well-managed protected areas.

8 Naughton-Treves, L., Holland, M. B. & Brandon, K. The role of protected areas in conserving biodiversity and sustaining local livelihoods. Annu. Rev. Env. Resour. 30, 219–252 (2005).

9 Ricketts, T. H. et al. Pinpointing and preventing imminent extinctions. Proc. Natl Acad. Sci. USA 102, 18497–18501 (2005).

10 Runge, C. A. et al. Protected areas and global conservation of migratory birds. Science 350, 1255–1258 (2015).

11 Jenkins, C. N., Van Houtan, K. S., Pimm, S. L. & Sexton, J. O. US protected lands mismatch biodiversity priorities. Proc. Natl Acad. Sci. USA 112, 5081–5086 (2015).

12 Pouzols, F. M. et al. Global protected area expansion is compromised by projected land-use and parochialism. Nature 516, 383–386 (2014).

13 Convention on Biological Diversity (CBD). COP 10 Decision X/2: Strategic Plan for Biodiversity 2011–2010 (CBD, 2011).

14 Margules, C. R. & Pressey, R. L. Systematic conservation planning. Nature 405, 243–253 (2000). This landmark review spawned a field of research that uses geospatial tools, global data sets, and algorithmic software to prioritize conservation actions.

15 Rodrigues, A. S. L. et al. Effectiveness of the global protected area network in representing species diversity. Nature 428, 640–643 (2004).

16 Wilson, K. A., McBride, M. F., Bode, M. & Possingham, H. P. Prioritizing global conservation efforts. Nature 440, 337–340 (2006).

17 Venter, O. et al. Targeting global protected area expansion for imperiled biodiversity. PLoS Biol. 12, e1001891 (2014).

18 Joppa, L. N., Visconti, P., Jenkins, C. N. & Pimm, S. L. Achieving the convention on biological diversity's goals for plant conservation. Science 341, 1100–1103 (2013).

19 Wilson, K. A. et al. Conserving biodiversity efficiently: what to do, where, and when. PLoS Biol. 5, e223 (2007).

20 Fuller, R. A. et al. Replacing underperforming protected areas achieves better conservation outcomes. Nature 466, 365–367 (2010). Scrapping cost-ineffective protected areas and reallocating the funds can increase the efficiency and ecological value of conserved lands without increasing overall spending.

21 McCarthy, D. P. et al. Financial costs of meeting global biodiversity conservation targets: current spending and unmet needs. Science 338, 946–949 (2012).

22 Conde, D. A. et al. Opportunities and costs for preventing vertebrate extinctions. Curr. Biol. 25, R219–R221 (2015).

23 Moilanen, A., Wilson, K. A. & Possingham, H. P. Spatial Conservation Prioritization (Oxford Univ. Press, 2009).

24 Watson, J. E. M. et al. Bolder science needed now for protected areas. Conserv. Biol. 30, 243–248 (2016).

25 Ferraro, P. J. & Pattanayak, S. K. Money for nothing? A call for empirical evaluation of biodiversity conservation investments. PLoS Biol. 4, e105 (2006).

26 Naughton-Treves, L., Alix-Garcia, J. & Chapman, C. A. Lessons about parks and poverty from a decade of forest loss and economic growth around Kibale National Park, Uganda. Proc. Natl Acad. Sci. USA 108, 13919–13924 (2011).

27 Ferraro, P. J., Hanauer, M. M. & Sims, K. R. E. Conditions associated with protected area success in conservation and poverty reduction. Proc. Natl Acad. Sci. USA 108, 13913–13918 (2011).

28 Ferraro, P. J. & Pressey, R. L. Measuring the difference made by conservation initiatives: protected areas and their environmental and social impacts. Phil. Trans. R. Soc. B 370, 20140270 (2015).

29 Craigie, I. D., Barnes, M. D., Geldmann, J. & Woodley, S. International funding agencies: potential leaders of impact evaluation in protected areas? Phil. Trans. R. Soc. B 370, 20140283 (2015).

30 Coad, L. et al. Measuring impact of protected area management interventions: current and future use of the Global Database of Protected Area Management Effectiveness. Phil. Trans. R. Soc. B 370, 20140281 (2015). This paper describes progress towards a worldwide evaluation of the performance of protected areas.

31 Visconti, P., Bakkenes, M., Smith, R. J., Joppa, L. & Sykes, R. E. Socio–economic and ecological impacts of global protected area expansion plans. Phil. Trans. R. Soc. B 370, 20140284 (2015).

32 Leverington, F., Costa, K. L., Pavese, H., Lisle, A. & Hockings, M. A global analysis of protected area management effectiveness. Environ. Manage. 46, 685–698 (2010).

33 Geldmann, J. et al. Changes in protected area management effectiveness over time: a global analysis. Biol. Conserv. 191, 692–699 (2015).

34 Geldmann, J. et al. Effectiveness of terrestrial protected areas in reducing habitat loss and population declines. Biol. Conserv. 161, 230–238 (2013).

35 Bruner, A. G., Gullison, R. E., Rice, R. E. & da Fonseca, G. A. Effectiveness of parks in protecting tropical biodiversity. Science 291, 125–128 (2001).

36 Hilborn, R. et al. Effective enforcement in a conservation area. Science 314, 1266 (2006).

37 Joppa, L. N., Loarie, S. R. & Pimm, S. L. On the protection of “protected areas”. Proc. Natl Acad. Sci. USA 105, 6673–6678 (2008).

38 Laurance, W. F. et al. Averting biodiversity collapse in tropical forest protected areas. Nature 489, 290–294 (2012).

39 Gray, C. L. et al. Local biodiversity is higher inside than outside terrestrial protected areas worldwide. Nature Commun. 7, 12306 (2016).

40 Joppa, L. N. & Pfaff, A. Global protected area impacts. Proc. R. Soc. B 278, 1633–1638 (2011). Matching analysis of protected and unprotected areas shows that legal protection has reduced landscape conversion in 75% of 147 countries.

41 Barnes, M. D. et al. Wildlife population trends in protected areas predicted by national socio–economic metrics and body size. Nature Commun. 7, 12747 (2016).

42 Andam, K. S., Ferraro, P. J., Sims, K. R. E., Healy, A. & Holland, M. B. Protected areas reduced poverty in Costa Rica and Thailand. Proc. Natl Acad. Sci. USA 107, 9996–10001 (2010). Controlled matching methods reveal that protected areas in two very different countries had net positive effects on the livelihoods of local people.

43 Balmford, A. et al. A global perspective on trends in nature-based tourism. PLoS Biol. 7, e1000144 (2009). Although a decline in the level of outdoor recreation in some developed countries has raised concerns, this study finds an increase in visits to protected areas in most countries, especially poorer ones.

44 Maekawa, M., Lanjouw, A., Rutagarama, E. & Sharp, D. Mountain gorilla tourism generating wealth and peace in post-conflict Rwanda. Nat. Resour. Forum 37, 127–137 (2013).

45 Ogutu, J. O. & Owen-Smith, N. ENSO, rainfall and temperature influences on extreme population declines among African savanna ungulates. Ecol. Lett. 6, 412–419 (2003).

46 Western, D., Russell, S. & Cuthill, I. The status of wildlife in protected areas compared to non-protected areas of Kenya. PLoS ONE 4, e6140 (2009).

47 Craigie, I. D. et al. Large mammal population declines in Africa's protected areas. Biol. Conserv. 143, 2221–2228 (2010). This continent-scale analysis shows that populations of 69 wildlife species in 78 protected areas declined by an average of 59% between 1970 and 2005.

48 Di Minin, E. & Toivonen, T. Global protected area expansion: creating more than paper parks. Bioscience 65, 637–638 (2015).

49 Mascia, M. B. & Pailler, S. Protected area downgrading, downsizing, and degazettement (PADDD) and its conservation implications. Conserv. Lett. 4, 9–20 (2010).

50 Mascia, M. B. et al. Protected area downgrading, downsizing, and degazettement (PADDD) in Africa, Asia, and Latin America and the Caribbean, 1900–2010. Biol. Conserv. 169, 355–361 (2014). This study of Earth's most biodiverse regions finds 543 instances in which protected areas were shrunk or defanged, most often to facilitate industrial-scale extractive industry and development.

51 Kareiva, P. Conservation science: trade-in to trade-up. Nature 466, 322–323 (2010).

52 Rodríguez, J. & Rodríguez-Clark, K. M. Even 'paper parks' are important. Trends Ecol. Evol. 16, 17 (2001).

53 Chazdon, R. L. Beyond deforestation: restoring forests and ecosystem services on degraded lands. Science 320, 1458–1460 (2008).

54 Lamb, D., Erskine, P. D. & Parrotta, J. A. Restoration of degraded tropical forest landscapes. Science 310, 1628–1632 (2005).

55 McAlpine, C. et al. Integrating plant- and animal-based perspectives for more effective restoration of biodiversity. Front. Ecol. Environ. 14, 37–45 (2016).

56 Janzen, D. H. & Hallwachs, W. in Costa Rican Ecosystems (ed. Kappelle, M.) Ch. 10, 290–341 (Univ. Chicago Press, 2016). An authoritative account of conservation history in Costa Rica's ACG.

57 Janzen, D. H. Costa Rica's Area de Conservación Guanacaste: a long march to survival through non-damaging biodevelopment. Biodiversity 1, 7–20 (2000).

58 Janzen, D. H. in Biodiversity (ed. Wilson, E. O.) 130–137 (National Academy, 1988).

59 Janzen, D. H. Management of habitat fragments in a tropical dry forest: growth. Ann. Mo. Bot. Gard. 75, 105–116 (1988).

60 Allen, W. Green Phoenix: Restoring the Tropical Forests of Guanacaste, Costa Rica (Oxford Univ. Press, 2001).

61 Janzen, D. H. & Hallwachs, W. DNA barcoding the Lepidoptera inventory of a large complex tropical conserved wildland, Area de Conservacion Guanacaste, northwestern Costa Rica. Genome 59, 641–660 (2016).

62 Smith, M. A., Hallwachs, W. & Janzen, D. H. Diversity and phylogenetic community structure of ants along a Costa Rican elevational gradient. Ecography 37, 720–731 (2014).

63 Janzen, D. H. Tropical ecological and biocultural restoration. Science 239, 243–244 (1988).

64 Janzen, D. H. & Hallwachs, W. in Man and his Environment: Tropical Forests and the Conservation of Species (ed. Marini-Bettòlo, G. B.) 227–255 (Pontificae Academiae Scientiarum, 1993).

65 Ehrlich, P. R. & Pringle, R. M. Where does biodiversity go from here? A grim business-as-usual forecast and a hopeful portfolio of partial solutions. Proc. Natl Acad. Sci. USA 105, 11579–11586 (2008).

66 Adams, W. M. et al. Biodiversity conservation and the eradication of poverty. Science 306, 1146–1149 (2004).

67 Soga, M. & Gaston, K. J. Extinction of experience: the loss of human–nature interactions. Front. Ecol. Environ. 14, 94–101 (2016).

68 Janzen, D. H. Hope for tropical biodiversity through true bioliteracy. Biotropica 42, 540–542 (2010).

69 Janzen, D. H. Now is the time. Phil. Trans. R. Soc. B 359, 731–732 (2004).

70 Janzen, D. H. Setting up tropical biodiversity for conservation through non-damaging use: participation by parataxonomists. J. Appl. Ecol. 41, 181–187 (2004).

71 Schmiedel, U. et al. Contributions of paraecologists and parataxonomists to research, conservation, and social development. Conserv. Biol. 30, 506–519 (2016).

72 Janzen, D. H. & Hallwachs, W. Joining inventory by parataxonomists with DNA barcoding of a large complex tropical conserved wildland in northwestern Costa Rica. PLoS ONE 6, e18123 (2011).

73 Basurto, X. Bureaucratic barriers limit local participatory governance in protected areas in Costa Rica. Conserv. Soc. 11, 16–28 (2013).

74 Finnegan, W. A Complicated War: the Harrowing of Mozambique (Univ. California Press, 1993).

75 Daskin, J. H., Stalmans, M. & Pringle, R. M. Ecological legacies of civil war: 35-year increase in savanna tree cover following wholesale large-mammal declines. J. Ecol. 104, 79–89 (2016).

76 Pringle, R. M. How to be manipulative: intelligent tinkering is key to understanding ecology and rehabilitating ecosystems. Am. Sci. 100, 30–37 (2012).

77 Cumming, D. H. M., Mackie, C. S., Magane, S. & Taylor, R. D. Aerial Census of Large Herbivores in the Gorongosa National Park and the Marromeu Area of the Zambezi Delta in Mozambique (Direcção Nacional de Florestas e Fauna Bravia, 1994).

78 Dutton, P. A dream becomes a nightmare: Mozambique's ferocious 15-year bush war has devastated a once rich and abundant wildlife. Afr. Wildlife 48, 6–14 (1994).

79 Tinley, K. L. Framework of the Gorongosa Ecosystem, Mozambique. PhD thesis, Univ. Pretoria (1977). This exquisite 320-page study documents the ecology of PNG from 1968 to 1972, providing a benchmark for post-war restoration efforts.

80 Dunham, K. M. Aerial Survey of Large Herbivores in Gorongosa National Park, Mozambique: 2004 (Carr Foundation, 2004).

81 Governo da República de Moçambique & Parque Nacional da Gorongosa. Acordo de Gestão Conjunta do Parque Nacional da Gorongosa. Entre O Governo da República de Moçambique, Representado Pelo Ministério do Turismo E A Gregory C. Carr Foundation. http://www.gorongosa.org/sites/default/files/research/acordo_gestao_conjunta_do_parque_nacional_da_gorongosa.pdf (2008). The legal contract establishing the public–private partnership for the co-management of PNG (in Portuguese).

82 Ford, A. T. et al. Large carnivores make savanna tree communities less thorny. Science 346, 346–349 (2014).

83 Stalmans, M. Monitoring the Recovery of Wildlife in the Parque Nacional da Gorongosa through Aerial Surveys http://www.gorongosa.org/sites/default/files/research/053-wildlife_count_report_2000_2012_july2012.pdf (2012).

84 Rodríguez-Echeverría, S. et al. Arbuscular mycorrhizal fungi communities from tropical Africa reveal strong ecological structure. New Phytol. 213, 380–390 (2017).

85 Correia, M., Timóteo, S., Rodríguez-Echeverría, S., Mazars-Simon, A. & Heleno, R. Refaunation and the reinstatement of the seed-dispersal function in Gorongosa National Park. Conserv. Biol. 31, 76–85 (2016).

86 West, P., Igoe, J. & Brockington, D. Parks and peoples: the social impact of protected areas. Annu. Rev. Anthropol. 35, 251–277 (2006).

87 Chan, K. et al. When agendas collide: human welfare and biological conservation. Conserv. Biol. 21, 59–68 (2007).

88 Torchia, C. Recovering from war, Mozambican park again faces conflict. AP Newshttp://bigstory.ap.org/article/0a6acdd9e6bb4080b4fe1b9586dc96a7/recovering-war-mozambican-park-again-faces-conflict (18 December 2016).

89 Club of Mozambique. Gorongosa Park signs agreement with Entreposto to convert game reserve into protected area. Club of Mozambiquehttp://clubofmozambique.com/news/gorongosa-park-signs-agreement-entreposto-convert-game-reserve-protected-area/ (1 December 2016).

90 Seddon, P. J., Griffiths, C. J., Soorae, P. S. & Armstrong, D. P. Reversing defaunation: restoring species in a changing world. Science 345, 406–412 (2014).

91 Powers, J. S., Becknell, J. M., Irving, J. & Pèrez-Aviles, D. Diversity and structure of regenerating tropical dry forests in Costa Rica: geographic patterns and environmental drivers. For. Ecol. Manage. 258, 959–970 (2009).

92 Davies, R. in Wildlife Conservation by Sustainable Use (eds Prins, H. H. T., Grootenhuis J. G. & Dolan, T. T.), 439–458 (Springer, 2000).

93 Nakano, S. & Murakami, M. Reciprocal subsidies: dynamic interdependence between terrestrial and aquatic food webs. Proc. Natl Acad. Sci. USA 98, 166–170 (2001).

94 McNally, C. G., Uchida, E. & Gold, A. J. The effect of a protected area on the tradeoffs between short-run and long-run benefits from mangrove ecosystems. Proc. Natl Acad. Sci. USA 108, 13945–13950 (2011).

95 Pringle, R. M. The Nile perch in Lake Victoria: local responses and adaptations. Africa 75, 510–538 (2005).

96 Schuetze, C. Narrative fortresses: crisis narratives and conflict in the conservation of Mount Gorongosa, Mozambique. Conserv. Soc. 13, 141–153 (2015).

97 Hebert, P. D. N., Penton, E. H., Burns, J. M., Janzen, D. H. & Hallwachs, W. Ten species in one: DNA barcoding reveals cryptic species in the Neotropical skipper butterfly Astraptes fulgerator. Proc. Natl Acad. Sci. USA 101, 14812–14817 (2004).

98 Smith, M. A., Wood, D. M., Janzen, D. H., Hallwachs, W. & Hebert, P. D. N. DNA barcodes affirm that 16 species of apparently generalist tropical parasitoid flies (Diptera, Tachinidae) are not all generalists. Proc. Natl Acad. Sci. USA 104, 4967–4972 (2007).

99 Smith, M. A., Woodley, N. E., Janzen, D. H., Hallwachs, W. & Hebert, P. D. N. DNA barcodes reveal cryptic host-specificity within the presumed polyphagous members of a genus of parasitoid flies (Diptera: Tachinidae). Proc. Natl Acad. Sci. USA 103, 3657–3662 (2006). This study integrates DNA barcoding, biodiversity inventory, and morphological taxonomic analysis to discover hundreds of undescribed cryptic species and their highly host-specific food-web interactions.

100 Smith, M. A. et al. Extreme diversity of tropical parasitoid wasps exposed by iterative integration of natural history, DNA barcoding, morphology, and collections. Proc. Natl Acad. Sci. USA 105, 12359–12364 (2008).

101 Burns, J. M., Janzen, D. H., Hajibabaei, M., Hallwachs, W. & Hebert, P. D. N. DNA barcodes and cryptic species of skipper butterflies in the genus Perichares in Area de Conservación Guanacaste, Costa Rica. Proc. Natl Acad. Sci. USA 105, 6350–6355 (2008).

102 Tallis, H. & Lubchenco, J. Working together: A call for inclusive conservation. Nature 515, 27–28 (2014).

103 Wilson, E. O. Biophilia (Harvard Univ. Press, 1986).

104 Abelson, A. et al. Expanding marine protected areas to include degraded coral reefs. Conserv. Biol. 30, 1182–1191 (2016).

105 Jetz, W. et al. Monitoring plant functional diversity from space. Nature Plants 2, 16024 (2016).