Juvenile tern ID?

On a recent boat trip to Crescent Island in the Gippsland Lakes National Park south of Paynesville to check on the Pelican breeding rookery, we found a lone – no adults present -small juvenile tern which we could not identify there and then in the field. We could see it was neither a Fairy or Little Tern which we are very familiar with given we have been monitoring their breeding colonies on the Gippsland Lakes for over five years now. 

Please click on photos to enlarge.

A small juvenile tern on a sand spit caught our attention – but what species was it?

This photo gives a size comparison with a Silver Gull and Black Swan.

The bird had distinctive red legs and some red in the bill which was potentially an ID guide, however the Morcombe and P&K guides we had on our smart phones were no help as they either did not show juvenile legs on terns or where they did for possible contenders they showed black legs. Given the mottled plumage was the fledging feathers this bird must have been no older than 6 months in which case it was raised during the summer breeding season just passed. So that ruled out species such as White-winged Black Terns which breed in the northern hemisphere – only locally breeding tern species would be possible.

Fortunately the juvenile bird was very obliging as it preened allowing us to approach closely by boat and get some good photos for later ID at home with access to other guides. Until then we had to contain our excitement that we may have found a rarity in our patch.

The small tern preened as we approached.

The bird was briefly disturbed by other much larger species on the sand spit giving an opportunity for a flight photo showing wing and tail feathers to assist with ID before it quickly settled back on the spit and continued preening. Like many young birds this juvenile tern appeared to be a little naïve making it vulnerable to predators.  

Once home I consulted the Australian Bird Guide by Menkhorst et al, which in my opinion is currently the best field guide available, especially with respect to juvenile species. That said we are spoilt for excellent bird field guides in Australia such as the Slater, Simpson & Day, Pizzey and Morcombe guides – I have copies of them all and regularly consult these guides. 

It soon became apparent the juvenile small tern in question was a Whiskered Tern. The presence of Whiskered Terns in East Gippsland is rather sporadic depending on seasonal conditions however they are frequent visitors and do breed in our area – so our mystery juvenile tern was not a rarity as hoped for and while a Whiskered Tern was somewhat of an anticlimax in this case the following photos show it to be a beautiful small tern which I was happy to have photographed.

For photos of adult Whiskered Terns and information regarding an East Gippsland breeding event please see the following Avithera post: http://avithera.blogspot.com/2017/01/whiskered-tern-breeding-colony-lake.html

As this example shows, modern digital cameras have become an essential birding tool as they greatly enhance identification of bird species. 

White-faced Heron at Point Impossible

Point Impossible is located in the Breamlea Flora and Fauna Reserve on Zeally Bay just east of Torquay, Victoria. The Point is a low rocky headland where Breamlea Creek, a tidal creek, discharges into the bay on the east side of the point. When we were there, the tide was at its lowest, exposing large areas of sand and sea-weed covered rock shelves. This is a popular surfing and dog-walking spot with many dogs on the beach off-leash in spite of the signs prohibiting this.

At first site there appeared to be few birds about however a closer scan of the exposed sand revealed about 30 Red-capped Plovers and 2 Hooded Plovers busy feeding. One of the plovers was a juvenile showing successful breeding in the season just finished. Beach nesting birds struggle on the Surf Coast due to the huge number of people visiting the beaches for recreation and dog exercise.

A scan of the rock shelves revealed about 20 loafing Silver Gulls, one distant Pacific Gull and a White-faced Heron (Egretta novaehollandiae) stalking prey in the rock pools. 

Please click on photos to enlarge.

The Heron looked into one pool intently, indicating it might be onto something. 

I checked the two photos above to make sure my light settings were ok for the overcast-sky conditions and while checking, the Heron captured a small fish. I thought the Heron showed experience when it immediately flew a short distance away from water to deal with the struggling fish so if it dropped the fish it could not easily escape into a weedy rock pool. 

However this gave time for five of the nearby loafing but ever opportunistic Silver Gulls to fly in and harass the Heron with the hope of pirating its meal. 

Again demonstrating experience the Heron was not distracted by the pesky gulls and soon swallowed its catch. 

With the fish gone, the gulls soon departed, leaving the Heron to continue hunting in the Point Impossible rock pools while the tide was low.

Note: You might have noticed from the scientific name in brackets above that the White-faced Heron is in fact an egret being in the genus Egretta. But, in the vernacular, “egret” applies to herons that are white, for example Great, Intermediate and Cattle Egrets which are in the genus Ardea and are herons. In these examples of a heron and some egrets, the vernacular names are in a way the opposite to the taxonomic genus, and thus the vernacular names have no taxonomic significance.