Monday, 22 September 2014

Where the Fig Parrots Nest

Having found nesting holes of the endangered southern Queensland race of fig parrots in the mangroves, I thought that I would look around the mangroves near Cairns for fig parrot nests.  In one afternoon, I found about twenty nests so it seems that the urban-mangrove fringe is a major nesting habitat.

My favourite fig parrot has now been committed to her nesting hole for more that three months.  As she is in a very busy area, she is fairly tolerant to people and even tall vehicles brushing the foliage of the tree she lives in.  Unfortunately, she suddenly realised that I was intently watching the nest.  Being in an urban area, I am restricted as to where I can place the camera and had to go within about 4 m of the nest.  This was too much for the little bird, which jumped out of the hole and flew away.  Fortunately she later returned to the nest but after the fright, she became very cryptic and was hard to observe.  She has relaxed a bit since but I need to stay at least 6 m away.  Fig parrots living in the woods are not used to people and is better to give them at least 20 m of clearance.  If you have a flip out screen on you superzoom camera, you might use that to watch the birds to avoid the need to stare directly at the birds.

Cyclopsitta diophthalma macleayana
Don't trust the humans
It seems that my favourite fig parrot is not the only urban fig parrot.  There is a giant fig tree at Barlow Park in the centre of Cairns which has fig parrots in a trimmed up tree branch, a perfect demonstration that trimming trees in a certain way can create habitat for these little fellows.  The British use a technique call fracture pruning to leave some dead wood in tree crowns for their wildlife.  We could do something similar here, however fracturing the end of a dead branch would allow the centre to rot out quickly and fig parrots reject trees with hollow centres as far as I can tell.  Years ago, I strapped a heap of reject didgeridoos to the trees in my yard but nothing wanted to live in those.  Falling didgeridoos are dangerous so I connected them to the tree with fencing wire. A strand of wire would run along the top of the didgeridoo with some loops of wire wrapped around the instrument.   The other end of the wire was threaded through some poly hose and secured around a solid live branch.  This way, the didgerdoo could not become deadly.  A few super duper cable ties and some UV stable rope might also be a quick way of ensuring that dead wood can't fall until it has crumbled.

Fig parrot nest hollows in a pruned branch
- this tree was on the mangrove edge before the park was filled.
Close-up of the holes, not all holes become nests
- perhaps the wood needs to be not to hard and not too soft
My first mangrove edge fig parrot hollow was spotted on my drive to town.  It was in a dead pillar of a tree that is right beside the road verge.  In a short period of time, I found a few dozen fig parrot holes in tall stag trees.  The favourite trees are dead northern paperbark, Melaleuca leucadendra, which found at the very  edge of mangrove swamps.  In fact, they are so close to the mangroves that the small about of climate change induced sea level rise has killed many of them.  When you live on the high tide line, 3 mm per year of sea level rise over thirty years is a big deal.   I can remember all of these trees being within a strip of saltwater couch beside the mangroves.  Now the trees are in the mangroves and the wide grassy strip is gone as the mangroves have squeezed it out.  The dead melaleucas are very tall, almost 30 m tall and stand clear of the surrounding mangroves and beach vegetation so provide an exposed clear trunk.  Melaleuca wood is also much softer and less durable than eucalypt or acacia timber and I have found no nests in the later species.
Paperbarks that were born in grassland will die in the mangroves thanks to sea level rise
The massive branches of dead giants are perfect for fig parrots
There is one other factor that warrants a mention.  I have been trying to set a camera trap to catch a striped possum.  I suspect striped possums eat fig baby fig parrots if they can catch them.  Where there is striped possum sign, there are few fig parrots nests.  I suspect that fig parrots are doing best in places where pussy cats keep the striped possums out.  Fig parrot central is a peninsular like patch of habitat that juts into a Cairns suburb.  There is a strip of bush with tall paperbarks at the edges that is separated from the houses by a thin band of mangroves.  Most of the nest trees are within 50 m cat infested suburban land.  Conversely, I also occassionally find parrot nests that appear to have been enlarged which suggests that stripped possums may be using parrot nests for dens.  More research is needed.  Southern Queensland has a huge population of possums and perhaps some dead trees should be fitted with possum guards to give their endangered fig parrots a chance.

Many of the branches eventually snap at or near fig parrot nesting holes

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