Sunday, 31 December 2017

Fairy and Little Tern portraits

As mentioned in the “Fairy Terns mating” post back in November, I have been assisting with photos for a juvenile small tern age classing project.  Field work is still underway as the terns are still breeding. During the photo sessions, which have been focused mainly on chicks and juveniles, I have captured photos of adult Little and Fairy Terns in breeding plumage so I decided to present some of the adult breeding plumage birds in this post.

In the field and at a distance, the very similar Little and Fairy Terns can be a challenge to ID if you are not familiar with them or do not have good close views. In East Gippsland, the two species overlap and breed together so we need to come to grips with ID of the two species. In non-breeding plumage, the two species are nearly impossible to separate. The existence of hybrid birds further complicates ID.

In the following images, you will see that the Fairy Terns have a small black area in front of the eye and the rest of the lore is white whereas the Little has a black pointed lore. Apart from this difference, the darker colour of the primary flight feathers on the Little and the lighter grey on the Fairy are the other distinguishing features. A dark tip to the yellow bill may also help ID, however some adult breeding plumage Fairy Terns have black bill tips, so this feature should only be taken into account together with the other two features mentioned.

Please click on photos to enlarge.

Fairy Tern Portraits

This is a classic Fairy Tern with an all yellow bill. They can look a little dumpy in the body compared with the more slender and streamlined Little, however depending on how the bird holds its feathers and it’s posture, this may not always be evident.
This Fairy Tern with a fish has a dark tip to the bill and is also banded and flagged.
Fairy Tern with fish.

Fish are brought back to the breeding colony to feed mates and young. Once mating is over fish exchange sometime takes place when incubation duties are handed over. Once the chicks hatch, fish brought to the colony are mainly for feeding young.

Another Fairy Tern with a fish.

The fish in the photos are a typical size with several species of fish being taken. The fact that the small terns have chosen to breed on the Gippsland Lakes shows there is a good supply of small fish available together with the other key factor – suitable nesting sites.

The Fairy Tern in the photo above is taking off.

Sometimes birds seem to take some time to find a recipient for the fish or sometimes the young are simply full and are not interested in the fish offering, in which case the adult usually eats the fish itself.

Another Fairy Tern with a fish in flight.
This Fairy Terns was perched on a piece of wood. Note the colour of the bill which is yellow, compared to the legs, which are more orange. Many birds including Littles exhibit this colour difference in the bill and legs.
Same bird as above.
This is probably a Fairy Tern

However, the bird in the above photo has a dark tip to the bill, the primary flight feathers look dark, the black in front of the eye extends well forward and there is a little dark speckling across to the base of the bill. Could this be a hybrid bird?

No question this is a Fairy Tern.

Little Tern Portraits

This is an Little Tern adult in breeding plumage.

Note the pointed black on the lore and dark outer primary flight feathers, however the dark bill tip is small – I have noticed this varies greatly. The bird is fluffed up so it does not look streamlined in this photo.

Another adult Little Tern in breeding plumage – the dark bill tip is larger on this bird compared with the one above.
This bird seemed to be the mate of the one above – note the much smaller dark tip on the bill.
This bird was nick-named Bling because of its silver metal band.
Front on view of Bling showing the eye is very rounded.

It is hard to pick up eye shine in terns and their eyes often look flat or even depressed, however this photo shows this is not the case. Also notice Bling may be starting to moult out of breeding plumage - the black on the forehead is looking patchy.

Bling was looking inquisitive in this photo and was generally behaving as if she (?) was going to nest, which seems late, but still is possible.
Little Tern sitting on a nest scrape.

I hope you have enjoyed the portraits of these beautiful and vulnerable small terns. There will be more posts in 2018 featuring the juvenile birds.

This is my last blog post for 2017.
Thanks for following my blog and I hope you have enjoyed the posts.

For those interested in stats, in 2017 there were 49 posts with 712 photos covering 109 species of birds.

I look forward to sharing more posts with you - best wishes for 2018.


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