Winter 2026 – 2027 Forecast

Will this winter bring irruptive birds
— and Salmonella?

Our ecological model links climate signals, conifer seed crops, and irruptive finch movements to predict the likelihood of salmonellosis outbreaks in North America.

Salmonellosis

Predicted Outbreak Risk

Outbreak likelihood is predicted separately for Western and Eastern North America. Risk is expressed relative to the historical average across all forecast years.

Western North America
High
33% above the historical average likelihood of a large outbreak (>500 reported cases)
Very LowBelow AvgAverageElevatedVery High

Cone crops are predicted to be below average across Western forests this season, increasing the likelihood of an irruption for nearly every species modeled here. Red-breasted Nuthatch and Pine Siskin are the most likely to irrupt.

Eastern North America
High
29% above the historical average likelihood of a large outbreak (>500 reported cases)
Very LowBelow AvgAverageElevatedVery High

Eastern cone crops are also predicted to run below average this year. Nearly every species is forecast to irrupt – most notably White-winged Crossbill and Pine Siskin.


In-Season Monitoring

Live Bird Health Tracking

Once the winter season of 2026–27 gets underway, Pine Siskin sightings reported to eBird will appear here too.


Irruption Forecast by Species

Bars show predicted irruption risk relative to the long-run average. A bar extending right means an irruption risk is elevated; left means an irruption is less likely than normal.

Western summary: Purple Finch, which had an unusually large irruption last season, is the only species predicted below average in the West this year. Every other species is forecast above average, led by Red-breasted Nuthatch and Pine Siskin — consistent with the widespread below-average cone crop expected across Western forests for 2026–27.

Methodology

The Ecological Cascade

Salmonellosis outbreaks in humans and wildlife are connected to climate through a chain of ecological processes that unfold over the course of the year.

🌡️
Climate Anomalies
Spring & summer temperature and precipitation signals
🌲
Conifer Seed Crops
Masting years drive food availability for irruptive finches
🐦
Irruptive Finches
Poor seed crops push birds south in large, dense flocks
🦠
Salmonella Outbreaks
Outbreaks in birds can spill over to humans and domestic animals

Full methodology is described in: Tonelli et al. (2026). An ecological cascade links climatic variability to avian irruptions and zoonotic salmonellosis.


Public Guidance

What To Do

Knowing what to look for — and how to respond — can protect your household, pets, and local birds during an outbreak.

Signs of Salmonella infection in birds

Ruffled/puffed-up feathers Lethargic, easy to approach Unwilling to move Trouble swallowing Diarrhea

If you see sick or dead birds

  • Remove feeders & bird baths for at least 2 weeks
  • Keep pets away from sick birds and feeder areas
  • Contact your local wildlife health agency
  • Dispose of dead birds using a gloved hand or plastic bag
  • Wash hands with soap and water after any contact

Preventive feeder hygiene

  • Clean feeders with a 10% bleach solution monthly
  • Rake up hulls and droppings below feeders regularly
  • Use tube feeders — they reduce fecal contamination
  • Avoid platform feeders during known outbreak years
  • Do not handle birds with bare hands

Human & pet health

  • Salmonella can infect cats, dogs, and rarely humans
  • Symptoms: fever, vomiting, diarrhea — seek care if severe
  • Immunocompromised individuals face higher risk
  • Do not let children handle sick or dead birds
  • Report unusual pet illness to your vet

Sources & Further Reading