Friday, 22 January 2021

Martins

There are two species of Martins in Australia, the Fairy Martin (Petrochelidon ariel) and Tree Martin (Petrochelidon nigricans). Both species are found right across Australia and in Tasmania. They are closely related to swallows and like them, chase insect prey in the air where they demonstrate their superb aerialist skills.

Fairy Martins are famous for their bottle shaped mud nests which they often build on man-made structures such as under building eves and road bridges and in concrete culverts. Where these sites are not available they will use cliff overhangs or even the trunks of trees. Tree Martins, as the name suggests, nest in tree hollows or cleaved wood or bark openings. Tree Martins often modify their nests with mud to restrict predator access. Both species nest colonially.

Catching Martins on the wing as they chase prey is challenging for photographers, so finding nests or birds gathering mud in the process of nest building – as the photos in this post show – is the easiest situation to obtain some relatively close shots, although your subjects are likely to have a bill full of wet mud.

Please click on photos to enlarge.

Fairy Martins




Bottle nests being constructed by a billabong in outback Queensland on the underside of a leaning Box tree or perhaps a Coolabah.


Fairy Martins on a cold morning with backs to the sun warming up.


Tree Martins, at the Bentley Plain Natural Features and Scenic Reserve, gathering mud and wet leaves used to modify/restrict nest hollow access.






Identifying Martins on the wing can be difficult however looking for the red heads and whiter rumps of Fairy Martins or the black/dark heads and dull rumps of Tree Martins are the best ID clues to use to separate these two closely related species in the field.


Thursday, 14 January 2021

Great Knots

Sadly Great Knots, a summer non breeding migrant to Australia, have suffered a shocking population decline in recent years due to the destruction by land reclamation of tidal flats habitat in the Yellow Sea used by the Knots to refuel on their migration. At the Federal level in Australia their conservation status is now listed as Critically Endangered. 

With greatly reduced numbers, finding Great Knots in southern Australia is now more difficult and when they are found, at least in East Gippsland, there are usually only a small number of birds. They often associate with Red Knots and Godwits. The Red Knots look similar, so similar that it can be a challenge to separate the two in the field. A recent edition of the Birdlife Magazine (Vol. 9 No. 4 December 2020) includes “Great Knot vs Red Knot” on page 64, which provides advice on features to look for to ID the two species. 

The following photos of two Great Knots were taken on the Gippsland Lakes in May 2016 – I have not posted these photos before. Their plumage suggests they are young or sub adult birds. Juvenile birds remain in Australia until their 2nd or 3rd year before migrating north with one staging stop on the Yellow Sea tidal flats before moving on to breeding areas in the alpine tundra of north east Siberia. 

The two Great Knots in the photos were feeding in shallow water at Albifrons Island near Crescent Island in the Gippsland Lakes National Park. It was mid-May on a sunny but cool autumn day and these birds seemed hungry as they foraged for small bi-valve molluscs and worms. 

Were they putting on weight for a migration flight to Siberia or were they perhaps preparing to over winter in Australia and only fly to the tropical north? 

Please click on photos to enlarge.








 Great Knot, note bill length is longer than the head.



Red Knot, note bill length is about the length of head or a little shorter.


Size comparison between our smallest migrant shorebird, a Red-necked Stint, and the Great Knot.









Sightings of Great Knots in East Gippsland are few and quite spread with only 23 records in Birdata and none since 2012. Finding Great Knots has now become a rare privilege so reporting any sightings of Great Knots is now more important than ever.

PS. This earlier Avithera post provides a side-by-side photo comparison of Red and Great Knots: http://avithera.blogspot.com/2016/02/knots.html