Dear Aggie: I have a small flock of ducks and geese. How do I tell which ones are male or female?
Answer: Telling the difference between Donald and Daisy can be difficult, but is an important skill. Maintaining a balance of drake to hen or gander to goose ratio is essential for maintaining the health and well-being of your flock. Unlike wild waterfowl, which may practice seasonal monogamy or pair for life, domestic ducks and geese are polygamous, where one male can successfully breed several females. Having too low of a male to female ratio can result in low fertilization productivity. Whereas having too high of a male to female ratio in your flock can result in male aggression or overbreeding of females, both of which can result in serious injury or death to your waterfowl. The appropriate male to female ratio can be dependent on a number of factors (breed, flock size, season, enclosure, intended animal use, etc.), but generally one drake for every four to six hens or one gander for every two to four geese is sufficient. Each flock is different, ganders in particular can be very selective of their mates, whereas drakes can be quite promiscuous. Make sure you watch your flock closely and regularly check for signs of under breeding (such as a high number of unfertilized eggs), over breeding (such as feather loss, head/neck injuries, etc.), or aggression.
There are a number of ways to determine the sex of your waterfowl without handling them, and can depend on the breed and age of your waterfowl. Some of the most common ways are through plumage, feather development, size, bill shape and color, feet size, vocalizations, behavior and many more. Research your particular breed to be able to identify these differences.
The most accurate method (besides waiting to see if they lay an egg) of identifying the sex of your waterfowl is vent sexing, which involves manipulation and observation of the cloaca. If done improperly, vent sexing can result in serious injury to the waterfowl. Keep in mind the younger fowl are especially delicate and susceptible to injury. Adult waterfowl also have powerful wings, sharp nails, and nippy beaks, which can cause you injury. As such it is recommended to learn from an experienced handler before attempting on your own.
To begin, catch the waterfowl and gently lay them on a flat solid surface, breast facing up and feet facing away from you. Bend the bird’s tail, toward its back and hold in place. Expose the vent by moving feathers and down, with your thumbs. Using your thumbs and forefingers, very gently spread the vent, while applying slight downward pressure to invert the cloaca. If a small protruding penis is exposed, congratulations, it’s a boy. If an oviduct is exposed, congratulations it’s a girl ... probably. You may need to release and reapply pressure to expose a retracted penis. Don’t keep the bird in the position for over 30 seconds, so as not to cause undo stress, and potentially harm the bird. Gently release pressure, from the vent. Ensure that the cloaca retracts and is enclosed within the vent before releasing the bird.
Exposing and identifying the genitalia of waterfowl can be challenging for both beginners and experts alike. Individual birds can be marked using a leg band, recorded and checked again at a later time to confirm accuracy. Using different colored leg bands within a flock, can also assist in observing and recording behavior within the flock.
Question answered by John Buneta, farm ops educator, email@example.com.