Yarak

Yarak is a weight journal for falconers. Log your bird's flying weight, the hunt, and the feed, and Yarak estimates its weight from hour to hour.

Log a hunt
• Flying weight before the hunt
• GPS distance or an effort level for the flight, and what it caught
• What it ate and the weight after feeding
• Weather, filled in from your location
• If you fly twice a day, add an entry for each flight

See the estimate
• Your bird's weight right now
• When it will reach the top of its flying range
• The highest after-feeding weight that keeps it on target for the next flight
• A confidence level, and how far off recent estimates were

How it estimates
Yarak starts from published research on raptor weight loss. That covers fasting loss by body mass, how much of each food the bird keeps, and how fast a meal passes. Each day you log, it learns your own bird's rate for each food and effort level. Your other birds give a new bird its starting point. Accipiters learn from accipiters, buteos from buteos, and falcons from falcons.

Plan the night
Set where your bird will be, such as indoors for the evening. The estimate then uses that temperature instead of the forecast.

Your data stays on your phone
• No account and no server
• Export everything to one file, and import it on a new phone
• Grams or ounces, miles or km, °F or °C
• Dark by default, for early mornings in the mews

Estimates are a guide. Weigh your bird and use your own judgement before you fly.