Saturday, 18 February 2017

Pelican Rookery - Crescent Island - Gippsland Lakes

This post covers a few hours spent one morning at a Pelican breeding rookery on Crescent Island where breeding was still in full swing on Thursday 16 February 2017.

The Australian Pelican population is nomadic and eruptive and massive breeding events can take place opportunistically in places such as Lake Eyre following erratic rain events. More often however, less spectacular breeding events occur across the country adventitiously when local conditions permit.

Apparently, there are only a handful of permanent Pelican breeding colonies known in Australia with the Crescent Island colony on the Gippsland Lakes being one of these.

We are lucky to have a somewhat rare permanent Pelican breeding colony here.

The Pelican rookery at the east end of Crescent Island

A rough count while we were there resulted in a total of about 350 Pelicans at the east end of Crescent Island with around 50 juvenile birds in the crèche and perhaps as many as 20 more advanced or fledged juveniles out on the water near the colony included in the total.

The juveniles ranged in size from nearly fully fledged to birds that were only a few weeks old at most. There were about fifteen birds in courtship condition with pink bills so it was quite possible that there were birds on eggs and some still looking to breed at the colony.

Pelicans lay between 1 and 3 eggs, usually 2. Both parents share Incubation which takes from 32 to 35 days. Chicks are brooded constantly for about 7 days after hatching and after 25 days they leave the nest and join a crèche. From hatching the young take about 12 weeks to fledge.

As the young grow older the duration between feeds increases. During the 3 hours we were at the rookery I did not see any young birds being fed. Pelicans are diurnal birds and often forage and feed at night so it is possible the young are sometimes fed at night or early in the morning.

Part of the crèche of young Pelicans within the breeding rookery.

Another part of the crèche.
Adult birds in non-courtship plumage and bill colour resting on the margin of the crèche.
Some adult birds seem to surround the crèche presumably to protect the young birds.
There was a large range of ages and sizes of young birds from near fully fledged to only a few weeks old – note the very young bird beside the leg of the large adult bird near the centre of the photo. 
If you look closely at this photo and others of the young birds you will notice a significant range of eye and eye surround colours. This is thought to have evolved to help parents recognise their young within the crèche.
Another shot showing young birds with a variety of eye colours.
Some of the young birds in this photo are more advanced showing greater size and also feather development.

The young are in the crèche for about 3 months. A large amount of excrement must accumulate in the rookery during this time - the strong smell coming from the rookery when the light breeze was from the south west certainly confirmed this for us.

A few ravens and Silver Gulls worked the edges of the crèche looking for food opportunities.
Given the size of the pelicans, especially the adults on the outskirts of the crèche, I think the young are safe from predation by other birds. However, mortality among young Pelicans could be due to starvation if food is scarce or injury due to tramping within the hurly-burley of the rookery or the crèche.

The juvenile in the middle of this photo has a broken left wing – once its parents stop feeding it starvation or predators will soon claim its life. 

A number of birds had pink bills and pouches – this is a sign of courtship. These birds tended to congregate together on the water near the rookery and on occasion became animated with bill displays as seen in the following photos.

A small gathering of birds in courtship condition.

Pink bill display.

The slight crest on nape and neck is on show here.
Given pink bills are only present during short-lived courtship which only takes place in breeding colonies that are usually located in isolated locations on remote islands, this is not something most people would ever see or know about our iconic Pelicans!
The pink bill displays are certainly impressive.
Many adult birds came and went however the majority while I was there stayed within the colony or on the adjacent water. When do they forage and feed and when do they feed the young?
Same bird as above on approach for landing in the colony.

Some of the Pelicans including some advanced juveniles on the water near the breeding rookery – there are 58 birds in this photo.

There is no doubt Pelicans are one of our most well-known birds for a variety of obvious reasons. It was a privilege to be able to spend time observing their behaviour up-close in a breeding colony – and as it was in our own patch the experience was even more special for me.

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