Detection, prevalence, and transmission of avian hematozoa in waterfowl at the Arctic/sub-Arctic interface: co-infections, viral interactions, and sources of variation

Meixell, Brandt W.; Arnold, Todd W.; Lindberg, Mark S.; Smith, Matthew M.; Runstadler, Jonathan A.; Ramey, Andrew M.

doi:10.1186/s13071-016-1666-3

Table 2 Suite of models considered in Stage 1 to estimate probability of hematozoa infection (Ψ) and probability of detecting hematozoa mtDNA (p)

From: Detection, prevalence, and transmission of avian hematozoa in waterfowl at the Arctic/sub-Arctic interface: co-infections, viral interactions, and sources of variation

Model	K	Model description
(.)	1	pr (infection) does not vary
month	3	pr (infection) varies by month (May, June, August)
May models (17 May – 27 May)
sex	2	pr (infection) varies during May by sex
species	4	pr (infection) varies during May by species (MALL, NOPI, AMWI, LESC)
species + sex	5	pr (infection) varies during May by species and by sex to the same degree for all species
June models (10 July – 19 June)
sex	2	pr (infection) varies during June by sex
species	3	pr (infection) varies during June by species (MALL, NOPI, AMWI)
species + sex	4	pr (infection) varies during June by species and by sex to the same degree for all species
August models (28 July – 20 August)^a
age	2	pr (infection) varies during August by age (adult, juvenile)
sex	2	pr (infection) varies during August by sex
age + sex	3	pr (infection) varies during August by age and by sex to the same degree for both age classes
age * sex	4	pr (infection) varies during August by each age and sex class
(ad * sex) + (juv)	3	pr (infection) varies during August by age and by sex for adult birds
species	3	pr (infection) varies during August by species (MALL, NOPI, AGWT)
species * age	6	pr (infection) varies during August by species and age
species + age	4	pr (infection) varies during August by species and by age to the same degree for all species
species * sex	6	pr (infection) varies during August by species and sex
species + sex	4	pr (infection) varies during August by species and by sex to the same degree for all species
species * age + sex	7	pr (infection) varies during August by species and age, and by sex to the same degree for all species
species * sex + age	7	pr (infection) varies during August by species and sex, and by age to the same degree for all species
species * age * sex	12	pr (infection) varies during August by species, age, and sex
(ad * species * sex) + (juv * species)	9	pr (infection) varies during August by species and by sex for adult birds
August temporal trend models
+ day	1	pr (infection) during August varies in a linear trend with a single slope for all sources of variation
+ day * age^b	2	pr (infection) during August varies in a linear trend with a unique slope for each age class
* day	2+	pr (infection) during August varies in a linear trend with a unique slope for each source of variation

This suite of models was considered independently for each of three hematozoa genera (Leucocytozoon, Haemoproteus, Plasmodium). K = number of model parameters applicable only to modeling of Ψ or p in a given month and is not representative of the total number of model parameters. Age of birds was either after-hatch-year (adult) or hatch-year (juvenile). Species abbreviations: AGWT American green-winged teal, AMWI American wigeon, LESC lesser scaup, MALL mallard, NOPI northern pintail
^aAugust models were considered alone, with the additive temporal trend (+ day), with the temporal trend varying by age (+ day * age), and with the multiplicative temporal trend (* day)
^bModel structure was applied only to August models containing variation in age

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ISSN: 1756-3305

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