Assessing amphibian disease risk across tropical streams while accounting for imperfect pathogen detection

Author(s)

Ribeiro, Jr., Jose Wagner ^[1] ; Siqueira, Tadeu ^[1] ; DiRenzo, Graziella V. ^[2] ; Lambertini, Carolina ^[3] ; Lyra, Mariana L. ^[1] ; Toledo, Luis Felipe ^[3] ; Haddad, Celio F. B. ^{[4, 5]} ; Becker, C. Guilherme ^[6]

Affiliation

^[1] Univ Estadual Paulista Unesp, Inst Biociencias, Av 24A 1515, BR-13506900 Sao Paulo - Brazil

^[2] Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 - USA

^[3] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Lab Hist Nat Anfibios Brasileiros LaHNAB, BR-13083862 Campinas, SP - Brazil

^[4] Univ Estadual Paulista Unesp, Dept Biodivers, BR-13506900 Sao Paulo - Brazil

^[5] Univ Estadual Paulista Unesp, Ctr Aquicultura CAUNESP, Inst Biociencias, BR-13506900 Sao Paulo - Brazil

^[6] Univ Alabama, Dept Biol Sci, Tuscaloosa, AL 35487 - USA

• Document type: Journal article
• Source: Oecologia; v. 193, n. 1, p. 237-248, MAY 2020.
• Web of Science Citations: 2

Abstract

Ecologists studying emerging wildlife diseases need to confront the realism of imperfect pathogen detection across heterogeneous habitats to aid in conservation decisions. For example, spatial risk assessments of amphibian disease caused by Batrachochytrium dendrobatidis (Bd) has largely ignored imperfect pathogen detection across sampling sites. Because changes in pathogenicity and host susceptibility could trigger recurrent population declines, it is imperative to understand how pathogen prevalence and occupancy vary across environmental gradients. Here, we assessed how Bd occurrence, prevalence, and infection intensity in a diverse Neotropical landscape vary across streams in relation to abiotic and biotic predictors using a hierarchical Bayesian model that accounts for imperfect Bd detection caused by qPCR error. Our model indicated that the number of streams harboring Bd-infected frogs is higher than observed, with Bd likely being present at 43% more streams than it was detected. We found that terrestrial-breeders captured along streams had higher Bd prevalence, but lower infection intensity, than aquatic-breeding species. We found a positive relationship between Bd occupancy probability and stream density, and a negative relationship between Bd occupancy probability and amphibian local richness. Forest cover was a weak predictor of Bd occurrence and infection intensity. Finally, we provide estimates for the minimum number of amphibian captures needed to determine the presence of Bd at a given site where Bd occurs, thus, providing guidence for cost-effective disease risk monitoring programs. (AU)

• FAPESP's process: 16/07469-2 - Influence of forest cover on amphibian assemblages: a priori grouping of species in multi-species occupancy models
• Grantee: José Wagner Ribeiro Júnior
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 16/25358-3 - The chytrid fungus: from its origins to its consequences
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/07113-8 - Stream-dwelling anuran metacommunity structure and dynamics in the Atlantic Rainforest: a hierarchical approach that accounts for species imperfect detection
• Grantee: José Wagner Ribeiro Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/50424-1 - Scaling biodiversity in tropical and boreal streams: implications for diversity mapping and environmental assessment (ScaleBio)
• Grantee: Tadeu de Siqueira Barros
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/50741-7 - Diversity and conservation of Brazilian amphibians
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants