As you can see from this photo, when you spot a bird carrying (as opposed to eating) a mouth full of food, chances are they may be nesting. This is the male, about to fly to nest to feed the hungry youngsters.
He flies to the nest they have excavated in a large aspen and lands just below it
Then hops around towards the cavity before landing on the rim
Sometimes he would turn his head sideways as if he were trying to see into the cavity or maybe looking up. I wasn’t sure if this behaviour was a type of vigilance. In this shot you can see well the pointed stiffened central tail feathers that most woodpeckers have. These serve as a prop to help them in climbing and bracing against tree trunks.
Of course mum was hard at work feeding as well. In this photo you can see her pale, as opposed to red, throat and duller crown. She looks a little ragged from all the hard work...
Sometimes the pair would arrive at the nest at a similar time
On some occasions the male would make a straight line approach from in front of the nest
And land right on the cavity rim
When they left the nest they would dive low – a technique I have seen other cavity nesters use too. This is perhaps in part for ease of take-off but may also make their entrances and exits less conspicuous.
On this occasion she is carrying something in her bill. This is the fecal sack, i.e. the dropping of the chicks. In this way they keep the cavity clean and reduce the risk of predators detecting the nest by scent.
In the next 3 shots, the male shows the whole process – and he’s loaded (devoted parenting!)
He would usually fly to particular rotting tree a certain distance from the nest with deeply crevassed bark and get rid of the feces by hitting his bill sideways against the bark and sometimes scraping his bill against the tree. Here he is pausing after doing just that.
And then he would often give himself a good preen
Including rubbing the bill against his feathers. Presumably this helps to clean his bill before he brings more food back to the nest.
A little stretch and a mewing call or two and he was ready for action again...
Now you may have notices that these Yellow-bellied Sapsuckers don’t look particularly yellow in the belly. In worm plumage in fact their belly often looks more off-white than yellow. This photo shows you what they look like in the spring with fresh (brighter) plumage.
And you may also have wondered why “sapsuckers” always seem to be feeding mayflies and flying insects... as with many birds that vary their diet at different times of year, bugs are a wonderful food source to meet the high energetic demands of growing chicks (and maybe a little easier to feed to young than sap). So here’s an older shot of a Yellow-bellied Sapsucker making the characteristic sap wells that this species is so well known for…
And this what an immature bird looks like, also demonstrating the sap-feeding technique on an introduced tree species, locally referred to as "Russian Olive"
More photos of sapsuckers and other woodpeckers at: http://artusophotos.com/