Table 3.
Suite of models considered in Stage 2 and Stage 3 to estimate probability of hematozoa infection (Ψ)
| Model | K | Model description |
|---|---|---|
| Stage 2 – Co-infection modelsa | ||
| Stage 1 | 0 | pr (infection) varies by top supported model structure from Stage 1 |
| Haem | 1 | pr (infection) varies by Stage 1 and by co-infection with Haemoproteus parasites |
| Leuc | 1 | pr (infection) varies by Stage 1 and by co-infection with Leucocytozoon parasites |
| Plas | 1 | pr (infection) varies by Stage 1 and by co-infection with Plasmodium parasites |
| IAV | 1 | pr (infection) varies by Stage 1 and by co-infection with Influenza A Virus |
| Serostatus | 1 | pr (infection) varies by Stage 1 and by Influenza A Virus serostatus |
| Co-infection variation | ||
| * month | 3 | pr (infection) varies by Stage 1 and by co-infection differently for each month |
| * species | 5 | pr (infection) varies by Stage 1 and by co-infection differently for each duck species |
| * age | 2 | pr (infection) varies by Stage 1 and by co-infection differently for each age class |
| * sex | 2 | pr (infection) varies by Stage 1 and by co-infection differently for each sex class |
| Stage 3 – Body condition models | ||
| Stage 2 | 0 | pr (infection) varies by top supported model structure from Stage 2 |
| BCI | 1 | pr (infection) varies by Stage 2 and by body condition |
| BCI * month | 3 | pr (infection) varies by Stage 2 and by body condition effect that is different for each month |
| BCI * species | 5 | pr (infection) varies by Stage 2 and by body condition effect that is different for each species |
| BCI * age | 2 | pr (infection) varies by Stage 2 and by body condition effect that is different for each age class |
| BCI * sex | 2 | pr (infection) varies by Stage 2 and by body condition effect that is different for each sex class |
Models were considered independently for each of three hematozoa genera (Leucocytozoon, Haemoproteus, Plasmodium) and were applied only to estimation of Ψ. K = number of model parameters in addition to those supported in the previous stage of model selection and BCI is the body condition index
aEach co-infecting agent was considered alone, and varying multiplicatively with co-infection variation structures