Predator-mediated effects of severe drought associated with poor reproductive success of a seabird in a cross-ecosystem cascade.
Glob Chang Biol
; 25(5): 1642-1652, 2019 05.
Article
em En
| MEDLINE
| ID: mdl-30773758
ABSTRACT
Despite the profound impacts of drought on terrestrial productivity in coastal arid ecosystems, only a few studies have addressed how drought can influence ecological cascades across ecosystem boundaries. In this study, we examine the consequences of rainfall pulses and drought that subsequently impact the breeding success of a threatened nocturnal seabird, the Scripps's Murrelet (Synthliboramphus scrippsi). On an island off the coast of southern California, the main cause of reduced nest success for one of their largest breeding colonies is egg predation by an endemic deer mouse (Peromyscus maniculatus elusus). Mice on the island have an opportunistic diet of primarily terrestrial sources, but drastic declines in terrestrial productivity from drought might be expected to increase their reliance on marine resources, including murrelet eggs. We compiled data on terrestrial and marine productivity between 1983 and 2013 to determine how conditions in these ecosystems influence murrelet nest success. We found that the severity of drought had the strongest negative impact on murrelet nest success. We calculated that the reduction in fecundity during drought years due to increased egg predation by mice was substantial enough to produce a declining population growth rate. Nest success was much higher under normal or high rainfall conditions, depending on whether oceanic conditions were favorable to murrelets. Therefore, the more frequent and severe drought that is projected for this region could lead to an increased risk of murrelet population decline on this island. Our study highlights the need for understanding how species interactions will change through the effects of increasing drought and altered rainfall regimes under global change.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Comportamento Predatório
/
Ecossistema
/
Charadriiformes
/
Secas
/
Fertilidade
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
America do norte
/
Oceania
Idioma:
En
Revista:
Glob Chang Biol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Canadá