For the second year in a row, La Paz, Bolivia won the City Nature Challenge, a global event where people photograph biodiversity in and around cities across the globe. La Paz swept all three categories: with the most observations (126,435), most species (5,344) and most people participating (3025). Some 482 cities from 46 countries took place in this year’s event, held from April 28 through May 1st.

The City Nature Challenge is a collective endeavor developed by the Natural History Museum of Los Angeles County (NHM) and the California Academy of Sciences (CAS), in which people photograph biodiversity in and around cities across the globe. Primarily using the iNaturalist application – one of the world’s largest citizen science initiatives with more than 150 million observations to date – the City Nature Challenge is also a friendly contest to see which city can make the most observations of nature, find the most species, and engage the most people.

The metropolitan area of La Paz spans a more than 6,000 meter altitudinal range from a portion of Late Titicaca, across the Andes including the iconic Illimani peak, and down through cloud forests, into Amazonian influenced foothill forests. Most cities in the challenge were defined as the broader metropolitan area, thereby encouraging participants to register biodiversity within the city, but also in the surrounding areas.

Notable observations in La Paz included the hooded mountain toucan (Andigena cucullata) in the Andean cloud forests, two Liolaemus smooth-throated lizards found only in the La Paz valley, and a possible new species of fungi in the Cotapata National Park.

For the La Paz effort the Wildlife Conservation Society (WCS) led the organizing committee composed of the National Herbarium, the National Natural History Museum, the Institute of Ecology, the Bolivian Fauna Collection, the Biology Department of the San Andres Mayor University, the La Paz Municipal Government and WCS. A combination of an active organizing committee, in coordination with the Ministry of Education engagement with around 60 high schools and their inspirational teachers, as well as the highlighting of the city’s own protected areas with the Municipal government, and promotion of visits to the wilder outskirts of the city with environmental citizens groups and students from six universities, all supported by small funding opportunities provided by WCS and the BISA Seguros y Reaseguros S.A. in Bolivia, facilitated this resounding success.

This year, WCS joined forces with a second Bolivian city, Trinidad, to participate in the City Nature Challenge. Working with the Trinidad Municipal Government, the Beni Autonomous University and two of its research institutes – CIBIOMA and CIRA, the groups used the same recipe as La Paz, and won in all three categories for city population size (100,000 to 250,000 people) and came in 24th overall in observations. Five hundred-thirty participants tallied 15,722 observations and 2,030 species in a city one tenth the size of La Paz demonstrating the interest of the city in its biodiversity. The number of observations of capybara (Hydrochoerus hydrochaeris) and spectacled caiman (Caiman yacare) within the city limits demonstrated the proximity of wildlife, whilst the Bolivian pink river dolphin (Inia boliviensis) in the Ibare and Mamore rivers highlighted the importance of the Municipal Protected Area.

Dr. Rob Wallace, Senior Conservation Scientist at WCS remarked: “Many congratulations to both La Paz and Trinidad, and indeed all those around the world who participated in this massive citizen science initiative. La Paz is a city of extremes, relatively bereft of green spaces within the city and those remaining urban protected areas are increasingly threatened by encroachment from the urban sprawl. On the other hand, the countryside around the city is amazingly diverse both in terms of ecosystems and of course species. Trinidad is another matter, with wildlife actually walking along the street with a recent example being a giant anteater (Myrmecophaga tridactyla) wandering into a coffee shop! WCS is committed to on-the-ground and landscape-scale conservation and in Bolivia that includes two extraordinary places surrounding La Paz and Trinidad respectively – the Greater Madidi-Tambopata Landscape and the Llanos de Moxos Biocultural Landscape. However, as the world becomes more and more urban the importance of reconnecting the urban majority with biodiversity and nature cannot be overstated. This citizen science activity is an incredible way of doing that and harnessing additional support for conservation efforts.”

Dr. Carla Maldonado, Director of the National Herbarium commented “This is not only a triumph for La Paz, but also shows an increasing commitment and conscience about biodiversity and the importance of its conservation, particularly among the youth of the country.”

Rebeca Rivero, Director of CIBIOMA said: “The results in Trinidad reflect how nature is part of city life in this small city and municipality with enormous importance for biodiversity.”