About

Gretchen C. Daily is the Bing Professor of Environmental Science and a Senior Fellow at the Woods Institute for the Environment at Stanford University. She is also affiliated, by courtesy, with the Freeman Spogli Institute for International Studies. Her research interests include land use, biodiversity dynamics, and ecosystem services, with a focus on understanding and promoting sustainable interactions between human activities and natural ecosystems. As a prominent figure in ecology and environmental science, she contributes to advancing knowledge in these fields through her academic and research activities at Stanford.

Research topics

• Geography
• Ecology
• Sociology
• Economics
• Political Science
• Business
• Environmental planning
• Environmental resource management
• Computer Science
• Economic growth
• Psychology
• Biology
• Social Science
• Natural resource economics
• Environmental science
• Environmental ethics
• Agroforestry
• Economic geography
• Geology
• Medicine
• Social psychology
• Cartography
• Oceanography
• Marketing

Selected publications

• The carrying capacity of a fragmented landscape depends on the home-range size of a species

  Advances in ecological research/Advances in Ecological Research · 2026-01-01

  book-chapter
  PublisherDOI

• High-quality surrounding landscapes mitigate avian extirpations from forest remnants

  Proceedings of the National Academy of Sciences · 2026-04-01 · 2 citations

  articleOpen access

  The species-area relationship (SAR) has long been used to predict extirpation rates from habitat loss, but these rates depend not only on habitat area but also on the surrounding landscape and species' habitat specialization. We collated global data from forest islands created by river damming and forest fragments resulting from clear-cut deforestation to examine the effects of matrix type (aquatic or terrestrial) and tree cover on avian SARs. Unlike oceanic islands, which are often millions of years old, anthropogenic forest islands provide a contemporary analog to forest fragments to understand matrix effects on SARs and serve as a baseline for worst-case scenarios of forest fragmentation. Our database comprises 50 datasets from 45 studies conducted in tropical and subtropical regions, totaling 1,954 bird species detected through 39,197 incidence records from 336 forest islands and 669 forest fragments. We found that bird extirpation rates were lower in fragments than on islands, especially for forest-dependent species compared to all species. Species losses were further reduced by increasing tree cover around forest remnants at local landscape scales of 300 m, highlighting the importance of small-scale conservation strategies. Moreover, even small forest fragments with greater nearby tree cover held high conservation value, emphasizing the crucial role of the surrounding landscape in mitigating avian extirpations from forest remnants. Beyond protecting forest remnants themselves, area-based conservation efforts would therefore be greatly enhanced by improving matrix quality and expanding tree cover in otherwise hostile landscapes.

  PublisherOA PDFDOI

• The carrying capacity of a fragmented landscape depends on the home-range size of a species

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-01-13

  preprintOpen accessSenior author

  ABSTRACT Population models have not considered the problem of home-range settlement when the grain of the landscape is smaller than the home-range size. We present an individual-based model addressing this problem that combines age-structured population dynamics, optimal foraging and habitat selection. During home-range settlement each juvenile tries to maximize her fitness, which depends on the proportion of high-quality habitat in her home range. We assume that home ranges do not overlap, which can happen because the home range is defended as a territory or because individuals avoid areas used by conspecifics. We show that the population supported by the landscape at equilibrium, the carrying capacity of the landscape, decreases with the amount of low-quality habitat cover. However, this decrease is non-linear, the carrying capacity starts to decline only below a critical habitat threshold. Furthermore, when the home-range size is larger than the grain of the landscape, the carrying capacity declines faster when the habitat is fragmented. Therefore species with small home-ranges persist in instances where species with large home-ranges go deterministically extinct. Species with large population growth rates have low critical habitat sizes, and are more resilient to habitat conversion.

  PublisherDOI

• Contrasting patterns of land use by resident and migratory bird assemblages in a tropical working landscape

  Oikos · 2025-05-20 · 5 citations

  articleOpen accessSenior author

  The spatial configuration and management of agricultural and other land‐use practices can affect ecological assemblages. However, the differences in how resident and migratory birds respond to land‐use are remain unclear, hindering our understanding of bird biodiversity responses to land use. In a tropical moist broadleaf forest landscape of southeastern Mexico, we assessed alpha, beta, and functional diversity as indicators of ecosystem functioning in resident and migratory birds across landscape‐ and habitat‐level gradients, incorporating distance to a protected area, understory vegetation cover, and three land uses: 1) primary forest, 2) secondary forest, and 3) cattle pasture. Compositionally, resident and migratory bird assemblages exhibited similar gradual shifts across land uses. However, while resident bird richness steadily declined with increasing distance from a protected area and simplification of understory vegetation structure, migratory bird richness did not change. Relative to primary forest bird assemblages, we found that migratory bird abundances were greater in secondary forest and cattle pasture, and migratory insectivores compensated for 68% of the abundance losses of resident insectivores in secondary forest and cattle pasture. Among these insectivores in secondary forest and cattle pasture, increases in migratory birds compensated for the abundance declines of resident birds that utilize foliage gleaning and sallying foraging methods. Our findings emphasize the importance of evaluating and managing landscapes around protected areas, highlight the distinct responses of resident and migratory birds to land use, and reveal the mechanisms that sustain ecosystem functions in modified landscapes.

  PublisherOA PDFDOI

• Male‐Like Plumage in an Urban Nesting Veraguan Mango: Evidence of a Female‐Limited Polymorphism?

  Ecology and Evolution · 2025-08-31 · 1 citations

  articleOpen accessSenior author

  ABSTRACT A first instance of parental care by a male‐plumaged hummingbird from a sexually dimorphic species contributes important natural history understanding and helps illuminate the possibility of interesting female‐limited polymorphisms across hummingbird species. Using photos and 2.5 min of video taken at close proximity, we documented a Veraguan mango ( Anthracothorax veraguensis ) with male plumage both incubating eggs and later feeding nestlings in the town of Palmar Norte in southern Costa Rica. Based on plumage characteristics and range, we rule out the similar green‐breasted mango ( A. prevostii ) that occurs in close geographic proximity. On‐ground exploration and Google Earth imagery revealed the landscape surrounding the nest as a heterogeneous mix of urban, residential, and agricultural land. Given our assumptions about the bird's sex and age, we speculated on potential mechanisms for male‐like plumage in adult female Veraguan mango (and related species in the Anthracothorax genus), including age‐related plumage ontogeny and the interaction of social and ecological selection pressures. Our observation contributes valuable information to the natural history of the Veraguan mango and opens the possibility of a female‐limited polymorphism in the species.

  PublisherOA PDFDOI

• Acute mental health benefits of urban nature

  Nature Cities · 2025-07-30 · 15 citations

  article
  PublisherDOI

• Rare hummingbird mimicry: urban nesting by a male-plumaged female Veraguan mango

  2025-06-07

  preprintOpen accessSenior author

  Male plumage mimicry by adult females of sexually dimorphic hummingbird species provides an intriguing system for understanding social and ecological selection mechanisms. However, our understanding of female male-mimicry is limited by a lack of behavioral observations of wild hummingbirds with male plumage, such as in giving parental care. Using photos and 2.5 min of video taken at close proximity, we documented a Veraguan mango (Anthracothorax veraguensis) with male plumage both incubating eggs and later feeding young in the town of Palmar Norte in southern Costa Rica. Based on plumage characteristics and range, we ruled out the similar green-breasted mango (A. prevostii) that occurs in close geographic proximity. Using Google Earth imagery, we characterized the landscape surrounding the nest as a heterogeneous mix of urban, residential, and agricultural land. We speculated on potential mechanisms that may maintain female-limited polymorphisms in the Veraguan mango and related species, including the interaction of social and ecological selection pressures. This observation provides the first empirical evidence of male-mimicry polymorphism in the Veraguan mango, contributing valuable information to the species’ natural history and to the broader understanding of male-plumaged females in hummingbirds.

  PublisherOA PDFDOI

• Wearable data link urban green space to physical activity

  Nature Health · 2025-11-24 · 2 citations

  article
  PublisherDOI

• Observation of a Veraguan mango ( Anthracothorax veraguensis ) with male-like plumage providing parental care

  2025-06-05 · 1 citations

  preprintOpen accessSenior author

  Male plumage mimicry by adult females of sexually dimorphic hummingbird species provides an intriguing system for understanding social and ecological selection mechanisms. However, our understanding of female male-mimicry is limited by a lack of behavioral observations of wild hummingbirds with male plumage, such as in giving parental care. Using photos and 2.5 min of video taken at close proximity, we documented a Veraguan mango (Anthracothorax veraguensis) with male plumage both incubating eggs and later feeding young in the town of Palmar Norte in southern Costa Rica. Based on plumage characteristics and range, we ruled out the similar green-breasted mango (A. prevostii) that occurs in close geographic proximity. Using Google Earth imagery, we characterized the landscape surrounding the nest as a heterogeneous mix of urban, residential, and agricultural land. We speculated on potential mechanisms that may maintain female-limited polymorphisms in the Veraguan mango and related species, including the interaction of social and ecological selection pressures. This observation provides the first empirical evidence of male-mimicry polymorphism in the Veraguan mango, contributing valuable information to the species’ natural history and to the broader understanding of male-plumaged females in hummingbirds.

  PublisherOA PDFDOI

• Coastal business perception of coral value and payment for coral restoration

  Scientific Reports · 2025-03-18 · 2 citations

  articleOpen access

  Coral reefs provide important economic benefits to coastal businesses, supporting recreation and tourism and protecting property from storms. Yet, these benefits are at risk worldwide as corals decline rapidly, and investment in restoration is lacking. With their direct dependence on coral health, coastal businesses may represent an important sector for funding coral restoration; however, it is unclear whether businesses perceive coral reef services as valuable or themselves as reef stewards. We measured business perceptions of coral health and value in Hawai'i and identified traits correlated with business decisions to participate in coral restoration at three payment thresholds. We found that businesses see limited economic value in coral reefs. In areas where corals provide substantial ecosystem services (flood protection, tourism revenue), businesses did not consistently rate coral value as high. Nonetheless, businesses showed strong willingness to pay for coral restoration, which was linked to pro-nature motives, reputation, and Native Hawaiian ownership. Results highlight key strategies for engaging private entities in coral restoration.

  PublisherOA PDFDOI

Recent grants

• DISSERTATION RESEARCH: Modeling Bird and Bat Mediated Pest Control Services Across Costa Rican Countryside

  NSF · $15k · 2012–2014

Frequent coauthors

• Paul R. Ehrlich

  126 shared

• Taylor H. Ricketts

  University of Vermont

  66 shared

• Stephen Polasky

  University of Minnesota

  61 shared

• Hua Zheng

  Chinese Academy of Sciences

  53 shared

• Zhiyun Ouyang

  Chinese Academy of Sciences

  51 shared

• Carl Folke

  Stockholm University

  51 shared

• Rebecca Chaplin‐Kramer

  Stanford University

  42 shared

• Jeffrey R. Smith

  Princeton University

  42 shared

Education

• Ph.D., Environmental Earth System Science

  Stanford University

  1992

• M.S., Environmental Earth System Science

  Stanford University

  1988

• B.A., Environmental Science and Public Policy

  Harvard University

  1983