DOI: 10.5061/dryad.bnzs7h49x
title: Data from: Host population dynamics in the face of an evolving pathogen

description: 1. 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. 2. 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 northeastern United States. 3. 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). 4. 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. 5. The
 ability of a vertebrate host species, with a generation time of at least
 one 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.
description: Three of the four data files are collected by volunteer observers
 taking part in projects coordinated by the Cornell Lab of Ornithology; the
 fourth data file contains a set of latitude-longitude locations laid on in
 a grid across the study area.  The data describing the relative abundances
 of the bird species, the House Finch (<em>Haemorhous mexicanus</em>) were
 collected in Project FeederWatch.  The process of data collection, and
 examples of use of these data can be found in the following
 papers: Bonter, D.N. & Cooper, C.B. (2012) Data
 validation in citizen science: a case study from Project FeederWatch.
 Frontiers in Ecology and the Environment, 10, 305-307.
 Greig, E.I., Wood, E.M. & Bonter, D.N. (2017) Winter
 range expansion of a hummingbird is associated with urbanization and
 supplementary feeding. Proceedings of the Royal Society B: Biological
 Sciences, 284, 20170256. States, S.L., Hochachka, W.M.
 & Dhondt, A.A. (2009) Spatial variation in an avian host
 community: implications for disease dynamics. Ecohealth, 6,
 540-545. Zuckerberg, B., Bonter, D.N., Hochachka, W.M.,
 Koenig, W.D., DeGaetano, A.T. & Dickinson, J.L. (2011) Climatic
 constraints on wintering bird distributions are modified by urbanization
 and weather. Journal of Animal Ecology, 80, 403-413.
 The data describing prevalence of disease caused by the bacterium
 Mycoplasma gallisepticum were collected and processed as described in the
 paper with which this data archive is associated, and is papers
 including: Dhondt, A.A., Badyaev, A.V., Dobson, A.P.,
 Hawley, D.M., Driscoll, M.J.L., Hochachka, W.M. & Ley, D.H. (2006)
 Dynamics of mycoplasmal conjunctivitis in the native and introduced range
 of the host. Ecohealth, 3, 95-102. Dhondt, A.A.,
 Tessaglia, D.L. & Slothower, R.L. (1998) Epidemic mycoplasmal
 conjunctivitis in House Finches from eastern North America. Journal of
 Wildlife Diseases, 34, 265-280. Hartup, B.K., Dhondt,
 A.A., Sydenstricker, K.V., Hochachka, W.M. & Kollias, G.V. (2001)
 Host range and dynamics of mycoplasmal conjunctivitis among birds in North
 America. Journal of Wildlife Diseases, 37, 72-81.
 States, S.L., Hochachka, W.M. & Dhondt, A.A. (2009)
 Spatial variation in an avian host community: implications for disease
 dynamics. Ecohealth, 6, 540-545.
description: The data files in this package are designed to be read into an R
 script that is a supplemental document published with the paper with which
 this data archive is associated.  Running this R script will read in the
 data files, and then run all analyses and generate all output that are
 used in this paper. The ReadMe file associated with this archive describes
 all of the variables in the data tables within this data archive. Note
 that there are 2 versions of this ReadMe document: (1) an ASCII text
 version that should be universally readable, and (2) a PDF version for
 which formatting will make the contents more comprehensible by anyone who
 can view the contents of the PDF version.