Sunday, 24 July 2016

About to depart; latest Grey Plover update.

In the past few weeks, we continued to observe Charlie concentrating its movement around the northern shore of the lake, which is about 2km to the northeast of its nesting area. Charlie has now arrived at the nesting area for 50 days, of which 28 days were spent on laying and incubating the eggs.

Charlie’s young should now be around 3 weeks old. We expect Charlie to leave its independent young very soon and start its journey back to non-breeding area in the south. Its young will follow a few weeks later.

Let’s get ready for the southward migration excitement!

Fig 1. Movement of Charlie away from the nesting area (shaded white) in July

Day 29-49: 1st – 21st July

The migration route of our birds is shown in the map below:

Ecosure (white), Mymi (red), Nad (blue) and Charlie (orange)

Distance travelled by our Grey Plover since departing Broome:
Leg Flag
Distance travelled

The Grey Plover project team:
Katherine Leung
Clive Minton
Ken Gosbell
Chris Hassell
Grace Maglio
Inka Veltheim
Maureen Christie
22 July 2016

Wednesday, 20 July 2016

Wader Quest the newsletter July issue out now.

Every three months Wader Quest issues an e-newsletter with up to date information on the comings and goings of the charity, what we are up to and what we are intending to be up to, in the coming months.

In addition every issue has a number of articles written specifically for the newsletter by guest authors about a great variety of subjects related to waders from around the world.

In this months issue (vol 3 issue 2), our tenth, for example there are articles about the Red Knots and Piping Plovers from the USA, Eurasian Curlew conservation efforts in the UK, updates on the Spoon-billed Sandpiper saga from Russia, the waders of Stewart Island from New Zealand, an update on White-fronted Plover research from South Africa, a wader hot spot in Belgium, a thought provoking article about the future of estuaries again from New Zealand and a piece on the waders in Poole harbour, also in the UK.

If you would like to see these articles in full and receive the quarterly e-newsletter with information about waders from around the world, then simply sign-up as a Friend of Wader Quest for just £5.00 a year for an individual subscription and you will be sent the latest newsletter and three more during the next 12 month period.

Furthermore, we are always looking for new writers to fill the pages each issue, so if you have an idea for an article, a photo you want to share or an artwork perhaps, then let us know.

Note to potential contributors: the e-newsletters are issued in January, April, July and October around the middle of the month (aim; 15th). Copy for inclusion should reach us by the 1st of the month of issue.

Sunday, 17 July 2016

Benthos aka wader food!

Benthos: the flora and fauna found on the bottom, or in the bottom sediments, of a sea or lake.

There are two types of benthos:

Zoobenthos: Zoobenthos comprises the animals belonging to the benthos.
Phytobentos: Phytobenthos comprises the plants belonging to the benthos.

They can be subdivided by size:

Macrobenthos: Visible organisms of a length greater than 1mm. Includes polychaete worms (worms with bristles like lugworms etc.), bivalves (seashells with two halves like cockles, oysters, clams and mussels), echinoderms (star fish, sea urchins etc.), sea anenomes, corals, sponges, sea squirts, turbellarians (flatworms), crabs, lobsters and cumaceans (comma shrimps). 

Meiobenthos: Organisms that are between 1mm and 0.1mm in size. Includes nematodes (roundworms), foraminiferans, water bears, gastrotriches (hairybacks), copepods and 
 ostracodes (seed shrimps).

Microbenthos: Organisms under 0.1mm in size. Includes bacteria, diatoms (algae), ciliates, amoeba and flagellates.

They can also be divided by their location:

Endobenthos: living buried, or burrowing in the sediment
Epibenthos: living on top of the sediments
Hyperbenthos: living just above the sediment

Wader bills have developed to take advantage of all forms of benthos as prey.

Long bills that penetrate the mud such as those of godwits will search for endobenthic organisms. Species feeding in this way will be doing so without the benefit of sight so their bills are sensitive to touch and pressure with nerve endings known as Herbst corpuscles which can detect the difference in pressure produced by a solid object in the wet mud. Many species feeding in this way will have rhynchokinetic bills which enables the upper mandible to be bent to allow the bird to strike and capture prey. This ability to forage blind means they are equally able to forage at night as they are during the day.

Black-tailed Godwit foraging for endobenthic prey.

Short bills such as those of the plovers will be taking mostly epibenthos and some endobenthos organisms that live near or just under the surface as they forage primarily by sight. This would obviously suggest that feeding at night would be a disadvantage. It is for this reason that plovers have such proportionally large eyes to maximise light gathering to facilitate night foraging. There is also a school of thought that suggests they may also be able to forage aurally which would also not be affected by the light level.

Northern Lapwing picking epibenthic prey from the surface of the mud.

The more delicate recurved sweeping bills of avocets will be seeking epibenthic prey on the surface of the mud and hyperbenthic organisms that are suspended in the water.

Pied Avocet sweeps the surface of the substrate foraging for epibenthos and hyperbenthos.

Some medium length billed birds, such as Red Knot may employ both methods of feeding - mainly tactile on the wintering grounds where it forages for endobenthos and mainly visual on the breeding grounds where it forages for non benthic creatures away from the benthic zone - with sensitive bills for tactile feeding and forward facing vision for visual feeding.

Red Knots will use tactile and visual foraging methods.

Remember, mud is not just mud, it is a community of organisms, collectively known as benthos, which waders depend upon to survive. 
Love your mud - they do!