Volume 14, Number 1—January 2008
THEME ISSUE
International Polar Year
Perspective
Integrated Approaches and Empirical Models for Investigation of Parasitic Diseases in Northern Wildlife
Table 2
Numerical responses (changes in abundance of parasites) |
---|
1) Temperature-mediated increases in rates of development for free-living stages, or those in intermediate hosts |
2) Reduced parasite generation time, e.g., shifts from multiyear to single-year cycles, or from single to multiple within year |
3) Environment-mediated changes (increases or decreases) in survival rates for developmental stages |
4) Extension of season for parasite growth and transmission resulting from earlier thaw in spring and/or later freeze during fall |
5) Amplification of parasite populations over time through accelerated development, increased rates of transmission, survival, and availability |
6) Increases in parasite prevalence and abundance |
7) Changes in density-dependant linkages for hosts and parasites leading to altered patterns of abundance for host populations |
Functional responses (changes in host and geographic ranges) |
1) Shifting patterns of geographic range for hosts and parasites including latitudinal and/or altitudinal shifts |
2) Alterations in host range for parasites through geographic and host colonization, successful establishment in naive host species or host populations |
3) Changing phenology (timing) for habitat use through alteration of migration and migratory corridors, relative changes in spatial and temporal overlap |
4) Modification of ecotones and contact zones including northward or southward expansion for hosts and/or parasites if environmental tolerances are not exceeded |
5) Local extirpation because conditions exceed developmental tolerances |
Microevolutionary responses |
1) Local adaptation through selection for optimal patterns of development |
2) Directional changes in gene frequencies for parasites |
3) Geographic mosaics or ephemeral patterns of local adaptation and emergence |
Cumulative/synergistic responses |
1) Breakdown in mechanisms for ecologic isolation promoting faunal interchange for hosts and parasites and cascading changes in ecosystems |
2) Variable and cumulative synergy affecting the structure of entire parasite–host communities during episodes of climate change |
Page created: July 08, 2010
Page updated: July 08, 2010
Page reviewed: July 08, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.