Sour crop, stress and trauma

Sour crop

The bird appears dull, feathers puffed out, with a crop still distended from the previous day's feeding. The food in the crop smells sour and may have been regurgitated. No appetite. What has happened is that the digestive system has effectively shut down, food has sat in the crop for 24 hours or more, and bacteria have flourished.

Causes are many: bacterial, fungal or parasitic infection, physical obstruction, bad food, feeding a large meal to a bird at the bottom of its weight.

Stress-induced seizures ("fits")

During initial handling, a fresh-trapped bird shows uncontrolled jerking or twitching of the shoulders and wings. The cause is stress. Affected birds can die within minutes.

Treatment: isolate the bird immediately in a dark, quiet, cool place, and give drops of dilute sugar water (or Gatorade) in the beak if needed; the sugar is absorbed through the mucosa. Decrease handling but monitor closely.

Cooper's Hawks are the species most susceptible, with Sharp-shinned Hawks close behind, and Sharp-shins are also the bird most likely to suffer fits generally. Goshawks are less prone but not immune.

Self-mutilation

A newly captured merlin repeatedly biting at its legs is showing maladaptation to the captive environment. Over-preening, feather plucking and leg-biting are all reported. Where environmental conditions are adequate this is rare. If it persists, the right answer is to feed the bird up and release it back to the wild.

Trauma

• Fractures. A raptor with a broken leg or wing should not be killed on the assumption that the bones cannot be set. Seek immediate veterinary care to limit damage from bone fragments and control infection.
• Crabbing injury. A wild raptor crabs with your bird and you find blood on its thigh: apply a topical antibiotic and take the bird to a vet for further evaluation. Puncture wounds from talons look trivial and are not.
• Lead toxicity from ingested lead shot in food requires immediate veterinary care, including binding the lead and supportive care. Neurological signs range from weakness to seizures, and often include paralysis of the gastrointestinal tract.
• Electrocution is often preventable, by all the listed means together: avoid flying near power infrastructure, be aware of perching hazards, and take the precautions the manual lists.
• Hormonal manipulation to induce molt, including thyroid hormone and progesterone, can be fatal and is discouraged.

Cold and wet

Hypothermia is a below-normal body temperature. A bird's core temperature normally runs 102 to 105 degrees Fahrenheit, and health is compromised if it falls below that for any period. A hawk may be left out in light rain but should be brought in if its feathers soak, because chilling lowers resistance to disease. A bird with ice on its feathers should be taken somewhere warm until dry. Winter water needs are nearly the same as summer, and some birds bathe daily right through the cold.