Category: Conservation

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Spur Winged Plover Eggs

Spur Winged Plover nest found 13 August
Spur Winged Plover nest found 13 August
Spur Winged Plover nest 20 August. No pipping so assumed lost one to a predator, hedgehog?
Spur Winged Plover nest 20 August. No pipping so assumed lost one to a predator, hedgehog?
Eggs lightly covered in canola oil
Eggs lightly covered in canola oil
Eggs 2hrs later, Spur Winged Plover resumed sitting. Some oil lost but am not sure how much (or for how long) is required to kill it.
Eggs 2hrs later, Spur Winged Plover resumed sitting. Some oil lost but am not sure how much (or for how long) is required to kill it.

Because I know I have a predator I will not know if this technique works unless I still have eggs on the 17th of September.

From a different nest. If the SWP can loose eggs then so can the Dotterel.
From a different nest. If the SWP can loose eggs then so can the Dotterel.

Dropped some of to the Museum.

Collected from Point England -36.8796816, 174.8723308 On the 24th August 2014 Three eggs from two Spur Wing Plover nests which each had 4 eggs Collected from Alexandra Park -36.8908216, 174.779165 On the 24th August 2014 Three eggs from two Spur Wing Plover nests one had 3 eggs the other had 4 eggs Eggs collected from both sites to protect neighbouring (nesting) NZ Dotterel.
Collected from Point England -36.8796816, 174.8723308 On the 24th August 2014
Three eggs from two Spur Wing Plover nests which each had 4 eggs
Collected from Alexandra Park -36.8908216, 174.779165 On the 24th August 2014
Three eggs from two Spur Wing Plover nests one had 3 eggs the other had 4 eggs
Eggs collected from both sites to protect neighbouring (nesting) NZ Dotterel.

Still 3 eggs, 6 September
Still 3 eggs, 6 September
10 September: Hatched! 2 Chicks 30M away. Bugga.
10 September: Hatched! 2 Chicks 30M away. Bugga.
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Biodiversity

Auckland has so much Biodiversity and is a really exciting place to do environmental work.

Insect species per region (NZ Wildlife Trewick & Morgan-Richards 2014)
Insect species per region (NZ Wildlife Trewick & Morgan-Richards 2014)

Great example of what you can bump into.

NZ Dotterel Nest, Alexandra Park 9 August 2014.
NZ Dotterel Nest, Alexandra Park 9 August 2014.

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Spur Winged Plover Chicks

Spur Winded Plover Chick

I found seven chicks on the 22nd of July at Point England. We should reclassify them as an invasive species, the Dotterel don't have a hope competing with these birds.
I found four chicks on the 22nd of July at Point England. We should reclassify them as an invasive species, the Dotterel don’t have a hope competing with these birds.
Apparently farmers say they attack stock. This one was too worried about me to bother with the cow right nest to its nest.
Apparently farmers say they attack stock. This one was too worried about me to bother with the cow right nest to its nest.
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Chick Shelters

After presenting at a great event to discuss the future of Non-Beach Breeding Dotterel I left with some great advice. I plan to make Chick Shelters, when the parent alerts the chick I need to have one of these (every 10 meters or so) that the chick can run to.

Shelter Tests
Shelter Tests

I need to make it even shorter and longer, just to be sure. Interestingly I tried adding my decoy chick and it just worried the Pukeko who turned their heads sideways to stare at it in the shelter.

This is looking about right. Need to test again when the black back gulls are hungry.
This is looking about right. Need to test again when the black back gulls are hungry.
Camouflaged to minimise human tampering.
Camouflaged to minimise human tampering.
Maximum height seems to be about 180. Maybe I should reduce it (as a buffer).
Maximum height seems to be about 180. Maybe I should reduce it (as a buffer).
The cows are very interested in it, but not moving it.
The cows are very interested in it, but not moving it.
Added triangles, thinner plywood.
Added triangles, thinner plywood.
Little triangle at the top and 150 max height. Length still looking very important. 800.
Little triangle at the top and 150 max height. Length still looking very important. 800.
Triangle reinforcements needed, the cows busted this one.
Triangle reinforcements needed, the cows busted this one.
Chick Shelter Design
Final chick shelter design
Mass Production
Mass Production
Great effort by Chris from Watercare
Great effort by Chris from Watercare
Chris's shelters 140mm high (to the apex).
Chris’s shelters 140mm high (to the apex).

Everything is in place, now we just need some chicks. I need to do observational work to test a few things:

1. Do adults avoid the shelters?
2. Do the chicks use the shelters?
3. Are the shelters effective at protecting chicks from predators? If not lets lower them and check point 2.
4. Other benefits/ problems?

RESULTS

Adult Dotterel not worried about feeding near the shelters
Adult Dotterel not worried about feeding near the shelters
Welcome Swallows enjoying this one (tipped over)
Welcome Swallows enjoying this one (tipped over)
I keep loosing chicks and eggs, the parents of the only chick I have at the moment keep taking the chick out onto the field or the road so I have mown an area I think would be safer.
I keep loosing chicks and eggs, the parents of the only chick I have at the moment keep taking the chick out onto the field or the road so I have mown an area I think would be safer.
Hobbitown
Hobbitown
Also lined the road
Also lined the road

1. Do adults avoid the shelters? No.
2. Do the chicks use the shelters? No, small chicks hide in the grass which is quite long in spring. None of the small chicks lived long enough to be bigger chicks that might have made a longer dash to a chick shelter. The mown area created did not attract any Dotterel (Just Pied stilts, Herons and Spur Winged Plover).
3. Are the shelters effective at protecting chicks from predators? Untested, maybe try them at a mown or beach site.
4. Other benefits/ problems:

  • They help with orienteering in the field and you can also perch on them.
  • Cows broke about 20% of them, flipping was also an issue, I would consider using tent pegs to prevent cow flipping.
2 chicks in the shade of this chick shelter in Tawharanui
2 chicks in the shade of this chick shelter in Tawharanui
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Dotterel Calls


Territorial call (were-wit) of an NZ Dotterel. Note the distinctive groan from the upper throat. You can see it happen at 5 seconds but is hard to hear.

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Browns Island Mussel Reefs

Or what is left of them! Even the oysters are swamped by mud from the Tamaki estuary. Wikipedia needs updating:

“The flatter areas to the west have very large part submerged mussel beds which extent out 100 m (328 ft) from the shore preventing easy landing”.

Now the exposed rocks are surrounded by thick mud.

Some green mussels in the large clumps. They were not often dominant.
Some green mussels in the large clumps. They were not often dominant.
Most of the solo green lipped mussels were around 9-10cm.
Most of the solo green lipped mussels were around 9-10cm.
At least 50% of the mussels were blue, of the mussel groups at least 80% of those individuals were blue.
At least 50% of the mussels were blue, of the mussel groups at least 80% of those individuals were blue.
The water was very dirty. It had not rained for at least a day or two.
The water was very dirty. It had not rained for at least a day or two.
This mussel and ambitious eleven armed starfish look like they are suffocating.
This mussel and ambitious eleven armed starfish look like they are suffocating.
Most mussels were above the low tide line. I know this a feature of blue mussels but why were the green mussel following suit? I made the same observation on the Mission Bay reefs.
Most mussels were above the low tide line. I know this a feature of blue mussels but why were the green mussel following suit? I made the same observation on the Mission Bay reefs.
Another example
Another example
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Tamaki River East Roost

Source: Environmental Condition and Values of Mangere Inlet, Whau Estuary and Tamaki Estuary (2008)

Coastal Protection Area 1 (45a & 45b)Coastal Protection Area 1. Pakuranga Creek and Roost: One of the roosting sites used by some of the hundreds of wading birds that feed within the Tamaki Estuary. The whole of the Tamaki Estuary is a regionally important wildlife habitat and has been selected by the Department of Conservation as an Area of Significant Conservation Value (ASCV).

Coastal Protection Area 1 (49) Coastal Protection Area 1. Tamaki River East Roost. One of the roosting sites used by some of the hundreds of wading birds that feed within the Tamaki Estuary.

No birds roost here now. Are they still CPA’s? How has the habitat changed:

  • Mangroves
  • Coastal planting
  • More houses
  • More pets
Historical Pakuranga Roosting Spot
Nothing here now
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Times

Oil While I was cleaning up this rusted oil barrel that had been dumped near a stream in Selwyn Bush decades ago, I thought about how “times have changed”. I guess all I need to do is make them change faster.

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A Dotterel Breeding habitat at Tahuna Torea

After the last count of 50 Pukeko at Point England I am considering trying to find a better breeding habitat on the Tamaki Estuary for the local Dotterel. Michael Taylor can’t recall Dotterel showing any interest in the tidal mudflats in the lagoon area at Tahuna Torea. I am wondering why, as this seems the perfect spot.

Here is a map showing the current state of the islands which are potential roosting/ nesting spots.
Here is a map showing the current state of the islands which are potential roosting/ nesting spots.

Mangroves and other vegetation would need to be cleared to give the birds a 270° view. Gwenda Pulham made the observation that there are no sand hoppers to feed chicks and I should read HANZAB. Which states “Usually feed on firm exposed mudflats, sand or stones; avoid soft sticky mud, e.g. near mangroves.”

But I have seen birds with sticky mud on their beaks. (Ambury park)
But I have seen birds with sticky mud on their beaks. (Ambury park)

So how sticky is too sticky?

This is what most of the mud looks like. Note crab holes and my average footstep depth of 2cm.
This is what most of the mud looks like. Note all the mud snails and my average footstep depth of 2cm.
The mud around the islands is higher and only covered 30 min either side of high tide. Note the extra crab holes.
The mud around the islands is higher and only covered 30 min either side of high tide. Note the extra crab holes.

The odd Pukeko and roosting Caspian Tern is seen on the flats, and occasionally a Banded Rail. But mostly it’s White Faced Herons and Pied Stilts.

If it has a 30% chance or working then I am keen to:

  • Clear dense vegetation from the islands.
  • Remove or trim a large amount of the mangroves.
  • Import shell.
  • Reinforce the islands.
  • Experiment with decoys.

UPDATE: May 2014: Experts think this is a long shot and that I have a better chance of dealing with the Pooks at Point England by poisoning them. But an even better idea is Chick Shelters!

UPDATE: March 2024: Well that worked after all!