There is much quacking in trees and on the ground around our regenerating woodland property most mornings now, as the local Wood Ducks are congregating at our place to nest.
Checking out our for-Wood Duck nest box.This couple are a fan of our Boobook Owl nest box design.
I have relocated several nest boxes that the Wood Ducks tried to use (and failed for various reasons) last year to new locations all around the property, away from the busy house area. Also one single nest box in use generates less attention from duck egg predators, than three nest boxes on adjacent trees, a problem we had last year also.
The three Black Cockatoo nest boxes are popular with Wood Ducks too. They need very deep bedding, to raise the surface level to about 10cm below the entrance, so the ducklings can get out. Otherwise many can’t escape and die. Yes, learn the hard way year before last.Three is a crowd, this nest box is already taken!The Lookout.
So far, every Wood Duck sized nest box has evidence of Wood Duck interest this year. Fingers crossed, if they all are used, that’s quite a lot of ducklings! Just as well I’ve been hard at work reducing our fox population these past months. Our dam duck islands are getting plenty of use by day, and I think a pair of Woods or Pacific Blacks are sleeping on them by night.
One of my duck island experiments in use, for Wood Duck families to sleep on at night to keep them safe from predators. Our first Wood Duck nest box family in 2017 did just that, from the first night.
I haven’t had a chance to see if any eggs have been laid yet, it’s been a couple of weeks since my last peek. If not yet, it won’t be long now. Winter has been unusually mild here.
Update: we have our first sitting duck of the season, but the others are yet to start laying.
On Tuesday morning I just happened to see the final three ducklings jump out of their nest box from our back verandah using binoculars, after noticing dad bolt from the dam to the nest box tree. Six in total. Our last Wood Duck family for the season. Autumn ducklings.
Then they scooted quickly off to a neighbour’s dam.
Meanwhile there is a semi-resident Wood Duck family with three teenage ducklings at our dam most days. They are the survivors of the nest box families of eight, or nineteen ducklings. There is another family of seven ducklings about that I saw three weeks ago, all fingers and toes are crossed for them. Wood Duck families appear not to like sharing small dams such as ours. Ideas for next Spring anyone?
Our two nest box Kookaburra bubs are becoming more independent catching their own frogs etc, and the young nest box hatched Eastern and Crimson Rosellas are still all doing very well.
My dam-side wildlife cameras recorded quite regular visitation by two foxes over the past three weeks, an old fox and a young fox. The ducklings are sleeping by the dam each night, and are extremely vulnerable untill they can fly.
Few dams in the area have islands. I’ve since made more duck islands for the duckling family to use by night, as they did not like something about the island I made last year that was much used by our first Wood Duck family. It’s a bit like a floating island shanty town now. Our teenage Wood Duck family use one of the new islands some nights, but prefer to take their chances on the ground.
Two weeks ago I set up two soft-jaw foot trap sets on either side of the dam to get the foxes. Yes, these are perfectly legal to use. We’ve had much success previously. Two years ago I trapped and had friendly neighhbours shoot all 6 of our regular visiting foxes over a few months. Neighbours in the same bush patch as ours (surrounded by cleared pasture) reported having heard foxes calling regularly since living here for over a decade, up untill two years ago… It’s been quiet since they say.
So the efforts made on our property are having much wider benefits to the entire patch of bushland owned by many others. We had no foxes on our property except the very occasional visitor for over a year, wildlife cameras are watching closely.
Last Saturday, and then again on Tuesday… Gotcha! One less fox stalking our nest box ducklings that are sleeping at our dam, and nearby neighbourhood dams. Two foxes in three days, that’s a record for me. One each, for the traps set on either side of the dam. Both young recently independent foxes so am still after the older fella. But that’s a big improvement.
A half-day walk in a local National Park over the past weekend provided a reminder of the severe impact that feral predators can have our native ecosystems. On a 5 km stretch of track, I found two piles of Crimson Rosella feathers, just a couple of hundred meters apart. They’d not been there for long. These are the remains that we saw, probably there were many others well off the cleared track.
Improving habitat for wildlife includes some less fun stuff like feral predator control to be really effective. Planting native plants and watching them attract more birds as they grow, installing nest boxes and seeing new families emerge, these are the fun tasks.
Trapping and killing feral predators is much less fun, but such an important aspect of land management in Australia. It is an ongoing, never ending task, but absolutely necessary. What hope would our nest box ducklings have otherwise?
I’ve only found one pile of feathers on our property, two years ago. Apparently our place is safer for birds, than our nearby National Parks where little, if any feral predator control occurs. That is both rewarding for me and also very concerning too.
I spent all yesterday hanging in trees, trying out the new tree climbing gear. It is definitely less sketchy than my tall ladder for installing all but very low, small sized nest boxes & possum guards. The gear is designed for hanging about at heights totally hands free. Set up and use solo too, no extra help is needed. However it takes much more time and effort to set up than my tall ladder.
The middle photo shows the max height I can install nest boxes using my ladder, vs the box installed on the same tree yesterday using tree climbing kit.
I’ll not be installing all the boxes with rope only access, however we have Gang Gang Cockatoos and King Parrots in the region that won’t consider a hollow unless it is 9 (GG) or 10 (K) meters, or higher. That’s way too high to risk a ladder fall in my mind, climbing safety gear is absolutely necessary.
With rope-installed nest boxes, I can’t monitor the nest boxes as thoroughly to discover & fix any issues. I can change out 10-15 wildlife camera cards & batteries in an hour or less after a windy couple of days (causes full cards & flat batteries) for the ladder installed boxes, but this would take more than a whole day with tree climbing gear to scale 10-15 trees! Nest box monitoring is an important part of ensuring nesting success for us. So I’ll be keeping plenty of ladder accessible nest boxes for species that are less fussy.
The view from higher up is a nice reward. It’s good to have found a worthwhile use for skills learnt during years of trad rock climbing.
It’s moments like these that make my nest box efforts feel so worthwhile, particularly over the past year.
During the month of January despite two above 40 degree heatwaves, with our local average monthly temperatures being 6 degrees above the long-term average, including four (never previously recorded) consecutive days above 40 degrees, most of the Wood Duck eggs from the two nest boxes successfully developed and hatched as healthy ducklings at the end of last week.
On Saturday morning while checking out a new resident Eastern Brown Snake, I looked out at our dam to see Wood Duck mum, dad, and 19 day-old ducklings following behind! The ducklings had jumped from their nest box on Friday morning according to the wildlife cameras that I rushed to check shortly after. These are from the same nest box as our last successfully hatched clutch of Wood Duck eggs earlier this season. 21 eggs were laid (probably by a couple of females), 19 hatched.
I then discovered that the smaller clutch of Wood Duck eggs had also hatched and abandoned their nest box on Thursday evening according to wildlife cameras. This family came to visit our dam on Sunday afternoon. I had a hunch that this was a first-season nesting family, as the eggs were significantly smaller than other Wood Duck eggs I’ve seen in nest boxes previously. Given dad’s hilariously flighty responses to the falling ducklings (first video), I’d say this was a totally new experience for him!
This is such a rewarding conclusion to the nesting season for our feathered nest box residents.
Some more recent background and learnings:
On December 13th-14th, there were large storms causing significant rainfall resting in flooding for some areas locally. This triggered interest in late-season nesting by several Wood Duck pairs, with the first eggs laid within a few days of this rainfall in three of our nest boxes. One nest box was abandoned before sitting began, however with a full clutch of eggs laid.
The other two nest box Wood Duck females trooped on, with embryos in eggs somehow surviving numerous days where temperatures were well above the optimum duck egg incubation temperature of 37.5 degrees C.
I purchased some Thermochron temperature loggers after the four-day 40 degree heatwave, and installed these in four same-sized small parrot nest boxes facing NE, SE, SW and NW, and also one Thermochron hanging on the tree on the least-sunny side to record the ambient woodland temperature.
These recorded the inside-nest box and also outside temperatures during the second 40 degree heatwave, to give me an idea of the temperature differences between nest boxes installed at different orientations.
From this season, I know that Crimson Rosella chicks can survive a heatwave of four consecutive 36-37 degree days, but can’t survive four consecutive days of 40-42 degrees [36.5, 40.1 (2 chicks dead), 41.6, 41.4, 40.1 (last chick dead), 36.0]. It is likely that even 2 degrees cooler may enhance chances of survival in a nest box during a hot spell, if such a difference can be gained with better nest box orientation.
From my little experiment and temperatures logged by the Thermochrons, there looks to be a small difference in the maximum temperatures reached, and also the duration of max temps, depending on nest box orientation. South East is the winning orientation, with maximum temps 1-3 degrees less than the max for other orientations.
This temperature difference I think, could have the potential to be life-saving for those very hot days. Similar results are found by other studies, however the temperature differences I would expect, would vary depending on the specific environmental conditions.
Heat for our bird nest boxes is going to be an ongoing challenge to solve, for a number of reasons.
The native vegetation on our property is an open-canopy grassy woodland regrowing from being completely cleared land for 25 years. Open grassy woodlands by nature, are not very shady. Most of our young regrowth trees are small in diameter. This means that tree trunks do not provide shade for installed nest boxes for much of the day, as large-girthed trees would. Many of our little scribbly gums and brittle gums are a little smaller, to just a little larger in diameter as the installed nest boxes.
To prevent predation of bird eggs, chicks and also adult birds by our numerous resident Sugar Gliders and Brushtail Possums, I must install the bird nest boxes on tall, straight (possum-guardable) trees, that do not have nearby cover of trees and shrubs that a possum can use to cross to the nest box. In comparison the possum nest boxes are installed on trees shaded by stands of Black Wattle, they do not suffer the Summer heat so much!
So I am aware that heat is going to be a challenge we will increasingly struggle with for our bird nest boxes, as future climate predictions for this region are of warmer, wetter Summers, with longer and more extreme heatwaves. Winter and Spring are predicted to become drier.
The nesting by birds such as Rosellas and Wood Ducks are often triggered by significant rainfall events in dryer localities such as ours, indicating that they will likely nest later in the year and during the hotter months (November-December rather than September-October) given future local climate predictions. Winter and Spring were exceptionally dry during the past year in our region, with interest in nesting by birds apparent only in late Spring after the first significant rainfall in months.
I see this anomalous twelve month period with weather events apparently very similar to predictions of our regional future climate predictions (dry Winter and Spring, very hot and more wet Summer with more and hotter heatwaves), being a good road-test of nesting challenges and successes for our local birds with the impacts of climate change. Given the successes we’ve had this nesting season, with only losing one family of nest box chicks (Crimson Rosellas) despite the significantly hotter than normal weather, the future looks promising in spite of the apparent challenges.
Meanwhile I’ll continue to enjoy figuring out solutions to overcome some of these challenges.
I have also just purchased tree climbing kit, so will be installing nest boxes designed for larger parrot species much higher up in the trees during the coming weeks. This will hopefully interest Gang Gangs, Galahs, King Parrots, Yellow-tailed Black Cockatoos and a few other large parrot species that occur in the local area. We shall see.
2 + 2 + 1 Ringtails, mums & bubs & one solitary 4-5 Sugar Gliders in one box
1 x raided Crimson Rosella nest (eggs) 3 Crimson Rosella chicks in one nest box died from heat 5 x raided Wood Duck nests (eggs, by Ravens & Brushtails) ………………………………….. Last year’s nest box tally:
1 White Throated Tree Creeper chick 2 Kookaburra chicks 3 Wood Duck ducklings
6+ Brushtails in different boxes, different days 1 + 1 + 1 + ? single Ringtails in different boxes 4-6 Sugar Glider family in one box
5 x raided Crimson Rosella nests (eggs) 6 x raided Wood Duck nests (eggs, one Brushtail tried to kill sitting mum) …………………………………. First year nest box tally:
No successfully nesting birds
6+ Brushtails sleeping in every box they could fit into, on different boxes on different days 1 + 1 single Ringtails using one box each, most days 4-6 Sugar Glider mum & bubs in one box
We have had a sweltering three days with one more to go. With trepidation I looked in on the Crimson Rosella family nest box, to find two of the three chicks had perished. The smallest chick is clinging to life with no visible heat damage, goodness knows if it has suffered developmental damage from the extreme heat. It still has one more extremely hot day to survive.
With all fingers crossed that they had escaped in time, I checked on the Eastern Rosella family nest box. Relief, at the sight of an empty box with a few broken feather pieces. At least they didn’t cook inside the hot wooden box. Their chances are better as mobile fliers, able to seek out shady trees.
Who knows how our three sitting wood ducks are faring, if their eggs are still viable, if their ducklings will hatch. Any day now for the first sitting of the three.
The flying youngsters are all doing well despite the heat. Not happy about the conditions, but I see them about each morning and evening when home.
Late season nesting is a risky business in locations with very hot summers like ours.
