Disease-mediated bottom-up regulation: An emergent virus affects a keystone prey, and alters the dynamics of trophic webs

• Published in: Scientific reports Vol. 6; no. 1; p. 36072
• Main Authors: Monterroso, Pedro, Garrote, Germán, Serronha, Ana, Santos, Emídio, Delibes-Mateos, Miguel, Abrantes, Joana, Perez de Ayala, Ramón, Silvestre, Fernando, Carvalho, João, Vasco, Inês, Lopes, Ana M, Maio, Elisa, Magalhães, Maria J, Mills, L Scott, Esteves, Pedro J, Simón, Miguel Ángel, Alves, Paulo C
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 31.10.2016
• Subjects: Animals; Caliciviridae Infections - pathology; Caliciviridae Infections - veterinary; Caliciviridae Infections - virology; Eagles - physiology; Ecosystem; Ecosystems; Endangered populations; Female; Food Chain; Hemorrhagic Disease Virus, Rabbit - genetics; Hemorrhagic Disease Virus, Rabbit - isolation & purification; Keystone species; Lynx - physiology; Population Dynamics; Predators; Predatory Behavior; Prey; Rabbit hemorrhagic disease; Rabbits; RNA, Viral - chemistry; RNA, Viral - isolation & purification; RNA, Viral - metabolism; Sequence Analysis, RNA
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep36072

Emergent diseases may alter the structure and functioning of ecosystems by creating new biotic interactions and modifying existing ones, producing cascading processes along trophic webs. Recently, a new variant of the rabbit haemorrhagic disease virus (RHDV2 or RHDVb) arguably caused widespread declines in a keystone prey in Mediterranean ecosystems - the European rabbit (Oryctolagus cuniculus). We quantitatively assess the impact of RHDV2 on natural rabbit populations and in two endangered apex predator populations: the Iberian lynx (Lynx pardinus) and the Spanish Imperial eagle (Aquila adalberti). We found 60-70% declines in rabbit populations, followed by decreases of 65.7% in Iberian lynx and 45.5% in Spanish Imperial eagle fecundities. A revision of the web of trophic interactions among rabbits and their dependent predators suggests that RHDV2 acts as a keystone species, and may steer Mediterranean ecosystems to management-dependent alternative states, dominated by simplified mesopredator communities. This model system stresses the importance of diseases as functional players in the dynamics of trophic webs.