TY - JOUR
T1 - Host population dynamics in the face of an evolving pathogen
AU - Hochachka, Wesley M.
AU - Dobson, Andrew P.
AU - Hawley, Dana M.
AU - Dhondt, André A.
N1 - Funding Information:
This study would not have been possible without the participants in Project FeederWatch, whose observations are the basis for all analyses and whose financial support has ensured the continuity of the project. Many staff at the Cornell Lab of Ornithology have managed the participant and technical facets of this citizen science project. The paper was improved by comments from J.-M. Gaillard, the Associate Editor and three anonymous reviewers for the Journal of Animal Ecology. Partial support for the operation of the House Finch Disease Survey came from NSF grant NSF-DEB grant #0094456 under the NSF-NIH Ecology of Infectious Diseases program to A.A.D.; NSF-EF grant #0622705 under the NSF-NIH Ecology of Infectious Disease program to A.A.D.; NIH Grant #R01GM085232 to D.M.H. as part of the joint NIH-NSF-USDA Ecology and Evolution of Infectious Diseases program.
Funding Information:
This study would not have been possible without the participants in Project FeederWatch, whose observations are the basis for all analyses and whose financial support has ensured the continuity of the project. Many staff at the Cornell Lab of Ornithology have managed the participant and technical facets of this citizen science project. The paper was improved by comments from J.‐M. Gaillard, the Associate Editor and three anonymous reviewers for the . Partial support for the operation of the House Finch Disease Survey came from NSF grant NSF‐DEB grant #0094456 under the NSF‐NIH Ecology of Infectious Diseases program to A.A.D.; NSF‐EF grant #0622705 under the NSF‐NIH Ecology of Infectious Disease program to A.A.D.; NIH Grant #R01GM085232 to D.M.H. as part of the joint NIH‐NSF‐USDA Ecology and Evolution of Infectious Diseases program. Journal of Animal Ecology
Publisher Copyright:
© 2021 British Ecological Society
PY - 2021/6
Y1 - 2021/6
N2 - Interactions between hosts and pathogens are dynamic at both ecological and evolutionary levels. In the resultant ‘eco-evolutionary dynamics’ ecological and evolutionary processes affect each other. For example, the house finch Haemorhous mexicanus and its recently emerged pathogen, the bacterium Mycoplasma gallisepticum, form a system in which evidence suggests that changes in bacterial virulence through time enhance levels of host immunity in ways that drive the evolution of virulence in an arms race. We use data from two associated citizen science projects in order to determine whether this arms race has had any detectable effect at the population level in the north-eastern United States. We used data from two citizen science projects, based on observations of birds at bird feeders, which provide information on the long-term changes in sizes of aggregations of house finches (host population density), and the probabilities that these house finches have observable disease (disease prevalence). The initial emergence of M. gallisepticum caused a rapid halving of house finch densities; this was then followed by house finch populations remaining stable or slowly declining. Disease prevalence also decreased sharply after the initial emergence and has remained low, although with fluctuations through time. Surprisingly, while initially higher local disease prevalence was found at sites with higher local densities of finches, this relationship has reversed over time. The ability of a vertebrate host species, with a generation time of at least 1 year, to maintain stable populations in the face of evolved higher virulence of a bacterium, with generation times measurable in minutes, suggests that genetic changes in the host are insufficient to explain the observed population-level patterns. We suggest that acquired immunity plays an important role in the observed interaction between house finches and M. gallisepticum.
AB - Interactions between hosts and pathogens are dynamic at both ecological and evolutionary levels. In the resultant ‘eco-evolutionary dynamics’ ecological and evolutionary processes affect each other. For example, the house finch Haemorhous mexicanus and its recently emerged pathogen, the bacterium Mycoplasma gallisepticum, form a system in which evidence suggests that changes in bacterial virulence through time enhance levels of host immunity in ways that drive the evolution of virulence in an arms race. We use data from two associated citizen science projects in order to determine whether this arms race has had any detectable effect at the population level in the north-eastern United States. We used data from two citizen science projects, based on observations of birds at bird feeders, which provide information on the long-term changes in sizes of aggregations of house finches (host population density), and the probabilities that these house finches have observable disease (disease prevalence). The initial emergence of M. gallisepticum caused a rapid halving of house finch densities; this was then followed by house finch populations remaining stable or slowly declining. Disease prevalence also decreased sharply after the initial emergence and has remained low, although with fluctuations through time. Surprisingly, while initially higher local disease prevalence was found at sites with higher local densities of finches, this relationship has reversed over time. The ability of a vertebrate host species, with a generation time of at least 1 year, to maintain stable populations in the face of evolved higher virulence of a bacterium, with generation times measurable in minutes, suggests that genetic changes in the host are insufficient to explain the observed population-level patterns. We suggest that acquired immunity plays an important role in the observed interaction between house finches and M. gallisepticum.
KW - Mycoplasma gallisepticum
KW - arms race
KW - emerging disease
KW - house finch Haemorhous mexicanus
KW - population dynamics
KW - population limitation
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U2 - 10.1111/1365-2656.13469
DO - 10.1111/1365-2656.13469
M3 - Article
C2 - 33821505
AN - SCOPUS:85103546970
SN - 0021-8790
VL - 90
SP - 1480
EP - 1491
JO - Journal of Animal Ecology
JF - Journal of Animal Ecology
IS - 6
ER -