This really depends on your target species, and how seasonal their nest box usage will be. Also if nest boxes have only recently been installed, or if you already know they are someone’s home.
Weekly checks during my L-plated second year of having nest boxes meant that I was able to quickly identify that the Rosella nests were being raided, sometimes immediately after the first egg being laid. I quickly took action to prevent Sugar Glider access to all Rosella nest boxes, resulting in four successfully hatching clutches of Crimson and Eastern Rosella chicks that season.
The previous year, all 6 Rosella nesting attempts had failed, due to the nests being raided. Only eggshells remained. This happened because I wasn’t physically checking the nest boxes regularly, and also didn’t have wildlife cameras monitoring the nest boxes. I discovered that the nest boxes had been raided too late in the season, and had no idea of the likely culprate, or what action to take to protect the nests.
Regular monitoring also meant that I discovered that both Ravens and Brushtail Possums are partial to duck eggs, and enabled me to develop and test different strategies to prevent access or reduce the risk of a nest being raided. See more about this in the Nest box preditors and competitors sections.
For my possum nest boxes, I checked them every couple of months or so early on. However once they had regular occupants, now I check them every 3-6 months. I generally leave apparently unoccupied for-possum nest boxes for a year in the same place, and put a wildlife camera on it to see if there is action on some days that I’m missing from occasional visual checks. Some of my nest boxes are seasonally occupied by Sugar Glider mum & bubs, for about half the year during Spring and Summer, and then are empty for the rest of the year. In contrast, my two well-shaded Ringtail boxes are apparently occupied every day of the year.
In contrast, my for-bird nest boxes are only used during nesting season. Popular nest boxes can be used more than once in a season. I’ve had one clutch of ducklings hatch and leave, then within four days the next Ms Wood moved in and began laying! Unfortunately we haven’t managed to entice a nocturnal, hollow-sleeping species of bird to snooze by day in our nest boxes. I’d treat these like the possum nest boxes, except not disturb them physically at all and monitor only with a distant wildlife camera.
I monitor just a handfull of bird nest boxes with wildlife cameras year-round just to discover when nesting season is about to start. Just beware too, different species nest at different times, and have different environmental triggers for nesting (following spring or summer rainfall, or after the first warm week in spring). A camera on a few different sized nest boxes will be better than monitoring only nest boxes of the same size. Once birds begin to stake their nest box claims, I install all my available wildlife cameras to watch the bird boxes and do weekly visual checks during the potential egg-laying and nest renovation period to sort any issues quickly, such as eggs being raided. Once I am confident that our Sugar Glider & Brushtail access prevention strategies for the bird nest boxes are working well, then I’ll just watch the action from installed wildlife cameras.
Once sitting begins by mother bird, I stay well-clear and watch from a distance. Preferably with a watching wildlife camera with recently refreshed batteries and empty SD card! Once chicks hatch, you can tell by the hard-working parents ferrying food to the nest on a regular basis, I refresh the batteries & card of a watching wildlife camera, and visually check the chicks a couple of times (when both parents are away from the nest) well before the chicks fledge. If disturbed, chicks that are about to fledge may leave the safety of their nest early, significantly reducing their chances of survival.
For my Wood Duck nest boxes (they choose, off-label often!), I keep an eye on things during nest renovating and egg laying, and then stay well clear once sitting begins. Some Ms Woods may abandon their nest permanently if startled from the nest just the once. So select a quiet, out of the way location with minimal human disturbance for nest boxes intended for Wood Ducks! And don’t do anything strange and noisy nearby. Yeah I’ve made those mistakes.
I monitor my Wood Duck nest boxes with wildlife cameras installed on a tree 5-10m from the nest. This way if you are good at being quiet-footed, you can change out the card & batteries via a tall ladder with low risk of disturbing the sitting duck, to discover if she is indeed sitting (or has the nest been completely raided, or abandoned for another reason?), and what time she leaves the nest to feed. It’ll be the same time each day roughly. Once you know this, it is possible to have a sticky beak at the nest to see all is well from time to time with little risk of disturbing mum.
When it’s getting close to hatching day for the Wood Duck families (35 or more days from sitting start), I install a couple of wildlife cameras near the tree base looking from different angles at the predicted on-ground landing spot, to record when the ducklings leap from their nest and start their new life.
Really, don’t give up while Wood Duck mum is definately still sitting, no matter how many weeks have passed. I’ve had nest box ducklings arrive weeks after the expected hatch date – 63 days was last year’s recorded maximum! For big clutches of eggs (20+), the eggs will take longer to incubate because they are not kept as warm by mum, as a small clutch of 6-8 eggs.
More than one duck may contribute to a clutch of eggs, especially if nesting hollows are a scarce resource. One of the Wood Duck families last year hatched 19 ducklings from a clutch of 22 eggs. With two eggs being laid per day, more than one Wood Duck definitely contributed to that clutch of eggs!
