⚖️ Weight Management Math · 6 min
Reading a weight log
Why this matters
The scale gives you a number. The log gives you a pattern, and the manual is explicit that patterns are the point.
By the end of this lesson you will be able to
- Interpret a multi-day weight trend rather than a single reading
- Relate a weight change to the variables that could have caused it
- Recognise when a weight change is a medical sign rather than a management result
What a log holds
Date, time, weight, what the bird was fed yesterday and how much, the temperature, whether it flew and how hard, and anything unusual about the mutes or castings. That is enough to explain almost every number you will ever see.
Reading a week
| Day | Weight | Change | Notes |
|---|---|---|---|
| Mon | 1,152 g | — | 70 g rat, flew 40 min |
| Tue | 1,148 g | −4 g | 70 g rat, flew 45 min |
| Wed | 1,131 g | −17 g | 70 g rat, 12°F overnight |
| Thu | 1,149 g | +18 g | 85 g rat |
| Fri | 1,147 g | −2 g | 70 g rat |
Wednesday is not a problem, it is a cold night: 17 g is 1.5% of body weight, the bird burned it staying warm, and Thursday's larger ration put it straight back. A falconer reading only Wednesday's number would have panicked. A falconer reading the week sees a stable bird and a cold snap.
When the trend is the symptom
The pattern that should worry you is gradual weight loss with a normal ration, especially alongside poor appetite and lethargy. The manual is blunt that such a picture could be any of several things, which is exactly why it belongs to a veterinarian rather than to your own guesswork. Add abnormal mutes or castings and the case gets stronger.
Two specific patterns from the Health section, both of which show first in the log:
- Aspergillosis: dramatic weight loss over days, with loss of interest in food but extreme thirst, and reluctance to exert. The end usually comes within a week, sometimes two days.
- Sour crop: the crop still distended the next morning from the previous day's feed. On the scale this reads as a bird that did not lose weight overnight, which is a signal, not a relief.
From the field
Your bird has lost 8 g a day for four days on an unchanged ration, and is now 4% under her flying weight. Nothing about the weather has changed. What is the log telling you? Not that she needs more food. A steady unexplained decline on a constant ration is a medical trend, and it is time to call the vet you lined up before you got the bird.
This lesson is part of the NY Falconry Exam course. Open it in the course to answer the retrieval checks that go with it, track what you have read, and quiz the whole unit. Lessons, quizzes and the glossary are free.