At the start of the week, Sycamore Creek was free of ice. But ice cover developed as the week went on with complete ice-over on this frosty 3ºF morning. I don't recall seeing complete ice coverage at anytime last winter.
Despite the cold start to the day, the sun was out and I took to opportunity to visit a property about 5 miles away from Hogsback Acre where I will be conducting nest box monitoring later this year. If all goes according to plan I will have nest box cameras in an Eastern Bluebird and a Tree Swallow nest.
It is important to clean out the nest box between seasons. Removing old nest materials and feces helps to reduce pathogens and parasites that could be detrimental to the next box occupants. Cleaning out the nest box also provides some clues (and mysteries) to previous nest use.
Tree swallows are common cavity nesters in open fields and near wetlands where they hunt for flying insects. After selecting a nest box, the swallows build a nest inside containing a base of grass and other plant material. This is topped off by a bed of feathers which are placed in the nest such that they curve above and cover the eggs and nestlings. Tree swallows aggressively defend their nest boxes from other tree swallows (and humans checking the nest box) but will tolerate Eastern Bluebirds nesting nearby. This is why you may see multiple nest boxes on the same post.
Like tree swallows, wood ducks readily nest in boxes. Wood duck boxes are much larger than swallow boxes and are typically very near to a water source. At this property, there are at least four wood duck boxes. I was only able to inspect two of them without getting my feet wet. One box was devoid of any evidence of previous nesting and had some mouse droppings and urine inside. The other box was also devoid of nesting material but it contained two unhatched eggs and one hatched egg. This is still a mystery to me.
The wood duck hen places down feathers in the nest box and uses these to conceal the eggs when leaving the nest to forage. People who manage wood duck boxes typically add a fresh layer of wood chips to the bottom of the nest prior to the nesting season as supplemental nesting material. But neither down feathers and any other nesting materials where found in this box.
Wood ducks typically lay 12-24 eggs in each nest. The eggs are laid one per day but they are not incubated until egg laying has ceased. This strategy ensures that all eggs incubate at the same rate and hatch within hours of one another. This is important because the hen and the nestlings leave the nest about 24 hours after hatching, never to return to the box.
But this nest had only 3. Why?
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