1. If there were enough hollow trees, we wouldn’t need to build bird boxes. There aren’t enough hollow trees because the forest is too young and/or too intensively managed. One biologist I know, who used to work for the state, told me that the more conscientious foresters were always asking him, “How many den trees should we leave per acre?” But he refused to give them an estimate. “As many trees as you can leave, wildlife will use them.”
2. Whoever made this box seems to have had a barn in mind: red paint, corrugated steel roof. “No room at the inn…”
3. One always sees wood duck boxes near the water’s edge. Seems logical enough, except that wood ducks often nest up to a mile from the water. When they are less than 24 hours old, the ducklings climb out of the nest, using the long, sharp claws peculiar to their species, fall to the ground and follow their mother on foot to the nearest swamp, pond or stream, never to return to their nest.
4. Two years ago, one of our hunter friends saw a female wood duck going into a hole in a chestnut oak right on top of the ridge, about three quarters of a mile from the nearest body of water. This past spring, a different hunter was amazed one morning to encounter a wood duck leading her ducklings right down the middle of the Plummer’s Hollow Road. If she had nested in the same tree as the year before, the ducklings’ journey would’ve been over a mile long. I suppose that would be like taking a toddler on a ten-mile hike — on an empty stomach.
5. “The mother calls them to her, but does not help them in any way. The ducklings may jump from heights of up to 89 m (290 ft) without injury,” says the Cornell Lab of Ornithology page. There’s a heart-warming children’s book in all this, just waiting to be written.
6. Nest predators such as crows, raccoons and skunks tend to follow forest edges, including riverbanks. Raccoons are major predators on wood duck boxes such as the one in the photo above, which is not protected with metal flashing or placement on a pole over deep water, as some conservationists recommend. I wonder if their vulnerability to edge-dwelling predators is part of the reason some wood ducks nest so far from water? Or are they forced to nest farther away simply because they can’t find anything closer?
7. Songbirds often have to deal with nest parasites of different species, such as cowbirds and cuckoos. According to the Cornell page, wood ducks can parasitize each other: “If nest boxes are placed too close together, many females lay eggs in the nests of other females. These “dump” nests can have up to 40 eggs.” Barnyard behavior, in other words. One wonders as well about the possibility of unnaturally ideal nest boxes producing local populations too large to be healthy, as has happened with humans ever since the growth of permanent settlements. “Disease and parasites are not usually important causes of death, although diseases such as duck malaria and duck viral enteritis are known to affect Wood Ducks,” says this page from a Canadian site.
6. Wood ducks are “easy to care for and breed and have been commonly bred on game farms and in zoos for decades,” according to the Game Bird And Conservationist’s Gazette.
7. Want to start your own wood duck colony? Unfinished lumber is best, says the Gazette.
A square plywood structure or hollowed log can be used, but our experience is that optimal success is achieved with an inside diameter of 9-12 inches. There should be an entrance hole of about 4 inches in diameter at the top. It is usually best to use rough-cut lumber for constructing the box so that the hen can more easily climb up and out of the hole. But whether smooth or rough is used, it is always a good idea to install a ladder on the front inside wall of the box to make it easy for the female to climb out. The front inside wall leading up to the hole should either be scored with a saw every one half inch all the way up, or cross-kleets nailed up this inside wall to climb on. Also a ramp that is scored or thin pieces of lath or other wood cross nailed on it for traction is important for helping pinioned birds get into the box, and this ramp should be placed from the entrance hole at about a 45 degree angle down to the water surface or ground for pinioned birds to climb up to the hole on. Several inches of nest material like wood shavings, grass, etc. should be put on the bottom for them to nest in.
“The hen.” “Pinioned birds.”
8. I wonder why captive ducks would need nesting material? In the wild, the female lines her nest with down plucked from her own breast.
9. Providing nesting boxes may not be the same thing as raising captive birds in a game farm, for their beauty or for canned “hunts.” But it does presuppose at least a yearly commitment to return, clean out and repair the boxes. I’m not sure we can ever rest easy about the long-term survival of a species so dependent on human goodwill for its nesting habitat. The best approach would be to let the forests mature, let nature take its course.
10. The wood duck’s closely related congener, the Mandarin duck, is very similar in ecological niche and behavior, including nesting habits. The wild populations have not been as fortunate as their North American cousins, however, and again, bad forestry is the culprit, according to this site:
In 1911, the Tung Ling forest, a Mandarin stronghold, was opened up for settlement and thereafter forests were cleared. By 1928 few sufficient breeding areas remained. The current Asian population may be under 20,000 birds. One factor that has helped the Mandarin to survive is their bad taste. These ducks are not hunted for food.
The wood duck, by contrast, has been heavily impacted by over-hunting in the past.
“Mandarin Ducks are frequently featured in Oriental art and are regarded as a symbol of conjugal affection and fidelity,” notes the Wikipedia. “In reality, though, the ducks find new partners each year.”
11. A webpage from Maryland’s Department of Natural Resources, which erroneously states that wood ducks may nest “within about a quarter mile of suitable brood rearing habitat,” adds this fascinating tidbit: “Occasionally, wood duck females will nest in chimneys.”
12. Though migratory, wood ducks “have a phenomenal ability to return to the same breeding area year after year,” says the Oakland Zoo. Their strongest commitment, in other words, is not to each other — as East Asian lore about the Mandarin would have us believe — but to place.
Today is the deadline for the Festival of the Trees #6. Please send tree- or forest-related links to jadeblackwater at brainripples dot com for inclusion in the December 1st festival at Arboreality.