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
Eric P. Hoberg*
, Lydden Polley†, Emily J. Jenkins†‡, Susan J. Kutz§, Alasdair M. Veitch¶, and Brett T. Elkin#
, Lydden Polley†, Emily J. Jenkins†‡, Susan J. Kutz§, Alasdair M. Veitch¶, and Brett T. Elkin#Table 2
Responses to climate warming and drivers for emergence of parasites and parasitic diseases in Arctic systems
| 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 |
