Table 1 Factors initially considered as potential contributors to canine prevalence of disease agents transmitted by Ixodes scapularis and I. pacificus

Distribution

Abundance

% Infected

Canine contact

Local phenology

Tolerance to temperature and humidity

Activity

 Focus on adults as primary vector to dogs

 Host seeking behavior

 Host contact

 Feeding preferences and opportunities

  Deer population drives tick abundance

  Small mammal population drives infection prevalence

  Lack of lizards

  Diversity/dilution effect

 Tick encounters

 Questing behavior versus relative humidity

 Peridomestic encounters – access to areas

 Urbanization/Rate of development

Infection status (decreased survival versus increased cold tolerance)

Host factors

Presence and abundance (deer, small mammals, lizards)

 Dilution effect/host diversity

Habitat availability and quality

 Mast crop as a surrogate for host reproduction/fitness

Migratory bird patterns

Reproductive capacity and timing of vertebrate host reproduction

Population control programs in place locally

Abiotic host survival factors

 Temperature, water availability, substrate/nesting material, snow cover

Feeding preferences

Herd immunity of reservoir host populations

Hunting pressure/success

 Number of deer killed per county – harvest rates

 Hunting license versus hunting harvest – how active hunting is for that area

 Hunting limits due to development

Abiotic factors

Snow cover – depth, duration

Miles of roads – neighborhood roads (non-interstate/parkway/highway), trails

Soil type – clay versus sand in Northeastern USA

Hydrological features

I. scapularis

 Maximum temperature, warmest month

 Annual precipitation

I. pacificus

 Minimum temperature, coldest month

Daily temperature (high, low and average)

Relative humidity (average, high, low, duration)

Habitat factors

Land cover classification

 Urbanization in 3 categories – low, medium, high

 Rate of change

Forest cover

 Land cover classification (categorical), % canopy cover, NDVI, EVI (canopy structure)

 Crop phenology – maximum greening, minimum greening – when greening is happening

 Supervised vs unsupervised satellite imagery, derived data not currently off the shelf

 Forest type, forest fragmentation, forest edge length, forest composition, forest connectivity

 Forest fragments within X distance of road or urban area, close to population centers

Understory- could be modeled but is not measured

Detritus layers/leaf litter

 Targeted for future research but perhaps not currently available dataset

Soil maps/soil types

 World harmonized soil database

 Classification scheme

Proximity to rivers/drainage areas

Proximity to coast

Rain shadows

Rivers and streams

 Attract hosts

 Serve as corridors

 Provide humidity

Aspect/slope/topo index – derived from digital elevation models, available from hydro dataset

 More nymphal deer ticks on north- and east-facing slopes

 Effective distance – more ticks on uphill side of a payout

Ticks associated with east-facing woodland edges that slope down to water

Fire

 Eliminates leaf litter, changes food availability, changes microclimate

 Depending on timing, burn can increase number of infected ticks, so fewer ticks but higher infection rate

Park boundaries – proximity to parks

Social factors

Human population centers

Dog ownership, dog lifestyle

 Hunting styles that use dogs

 Breed of dog

Dog ownership increase – by region

More homes in tick habitat – demographic factors

Deer/vehicle collisions – deer crossing signs

Acaricide use/quality of care for dogs

Average household income

 Presence of clinics, proximity to clinics, number of vet clinics in an area, size of clinics

Cultural – forest foraging (mushroom hunting in Missouri)

Internet use

Social media

Smartphone use

Education level

Population density

 Housing type (average lot size, median home price, age of house unit, census tract size)