Topic: Fauna - overview

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SECTION NINE

FLORA AND FAUNA, PLUS WASH-UPS, FLOTSAM, ETC.

 LOCATION                                                                PAGE

 

Te Kawau Pa                                                            6

 

Rapanui North                                                         12

 

Rapanui South                                                        14

 

Pilot Point                                                                  18

 

Three Sisters Beach                                                31

 

The Point                                                                   52

 

Four Brothers Beach                                               56

 

Gibbs’ Fishing Point                                                           70

 

Beach One                                                                78

 

Beach Two                                                                85

 

Twin Creeks                                                              89

 

White Cliffs                                                               93

 

Follow-ups                                                                96

 

 

OVERVIEW

Though I am primarily concerned with the evolution of the Tongaporutu coastline, I also recorded everything else that I observed.  This included jellyfish wash-ups, birds, insects on the beach, rubbish, beached logs, etc.  (Fossil logs are covered in Section Three on Rock Strata and Fossil Trees, so they are only mentioned in passing in this section).  Some of this information may be of value to specific interest groups such as ornithologists or horticulturists.

At Rapanui, there is a Grey-faced Petrel colony.  It is the last mainland petrel breeding colony on the west coast of the North Island.  The Rapanui Grey-faced Petrel Trust is a non-profit environmental organisation, registered with the Charities Commission (RCC39637).  It has been set up to ensure the long-term protection of the breeding colony, along with other indigenous species.

For more information and/or to arrange a visit, please contact Evan and Emma on (06) 752-5988.  School parties and university students are particularly welcome.

With regards to the flora, this was mostly in connection with the dunes on either side of the Tongaporutu River.  However, I did make some observations regarding the plant communities that inhabit the rock stacks and some bush areas.

As with the other sections, everything that was observed will be placed in the relevant site it was observed at.  This will also include the areas to landward of the beaches.  For example, paddocks and hills.

With regards to photos taken from the hills, as they were on the Gibbs’ farm which is obviously private property, I first obtained their permission to do so.

Some of the things noted could be regarded as either irrelevant or at best eclectic.  This could well be true.  However, their relevance could reveal themselves over time.

Not everything will have been photographed.  For example, birds, wild cats, stoats etc, don’t sit around waiting to have their picture taken!  Especially by someone lugging a medium format camera primed for landscapes.  So, unless something is either dead, asleep or extremely tolerant, it will be a case of ‘spot the bird’ perched atop the rock stack for example.  Due to this limiting factor, the written notes in this section take on a greater importance compared to the other sections.

Plant material that is deposited or washed up on beaches will have two primary causal agents.  They are the weather, as in storms (Section Two), or cliff collapses (Section Four).  These agents can either act alone or in combination with each other.  For example, storms can sometimes cause cliffs to collapse, dislodging plants in the process.

There is considerable overlap with Section Eight on Beaches which cannot be helped.  It does show however, how inter-connected everything is, with some inter-connections more closely related than others.  These sections are designed to show the different aspects of that inter-connection.

The first time a specific bird or plant etc., is mentioned, I will also show its scientific name, if different from its common name.  I will only do this once however, otherwise it will make for tedious reading.  For example, cabbage tree (Cordyline australis).  Sometimes you may see something like this:  “Bush flies (Diptera spp ?)”.  The question mark signifies that the actual species is unknown.

You will see some comments regarding ‘orange algae’ on the cliffs from time to time.  I later learned that this was actually rust.  Just as iron corrodes – “wearing away of a substance from the surface by a chemical action” (dictionary explanation), so too do particular rock strata in the presence of water.  The greater the exposure to water, the greater the chemical reaction.  I have however, left my diary entry comments regarding ‘orange algae’ intact because it shows my ignorance of what it really was at the time.  Another possibility is that although the majority of ‘orange algae’ may actually be rust, others may actually be orange algae.

Re SPRATS.  On several occasions I observed a number of these fish trapped in pools.  Sometimes they’d be around 6 inches in length and were darkish blue on top, while on other occasions they’d be quite small, perhaps two to three inches in length.

Upon checking with Callum Lilley, Ranger/Technical Support Marine, Department of Conservation, I discovered that the generic term ‘sprat’ is quite misleading.  The fish I observed could have been:

Sprat – Clupea antipodum.  Dark blue/silver, approx 3 inches in length.

Anchovy – Engraulis australis.  Blue/silver, 3-4 inches in length.  More common i the north of New Zealand.

Pilchard – Sardinia neopilchardus.  Silver, slightly darker above, 5 to 8 inches in length.

To confuse the matter further, the Encylopaedia of New Zealand, 1966, states:  “Other fish sometimes confused with these species and erroneously called ‘herrings’ are the mullets, (yellow eyed and grey), young mackeral and kahawai and the ‘whitebait’ young of the freshwater inanga.” 

This was written by Lawrence, James Paul, B.SC, Fisheries Division, Marine Department, Wellington.

Callum and I concluded from photos and my description of the ‘sprats’, that they were most likely to be young yellow-eyed mullet – Aldrichetta forsteri.

Though I now know as of April 2012 what the fish actually were, I decided to leave the diary entries of ‘sprats’ or ‘pilchards’ in place because they were my initial, uneducated guesses at the time.

The same is true of some other things.  For example, “reeds”.  It was only when I looked them up, that I realized that one of the following were what I actually observed.  Leafless sedge – Wiwi, Scirpus nodusus, or Wi, Juncus pallidus).  I believe the “reeds” I observed were the latter.

Another example is mussels.  I believed that the tiny black mussels were the smaller versions of the larger mussels.  Again, thanks to Callum, I discovered that they are in fact two distinct species.  The small black mussels are Xenostrobus pulex/Limnoperna pulex, while the large mussels are blue mussels – Mytilus.  Allowing for this, my comments concerning attrition rates still basically applies to both kinds of mussels.

As can be seen, my observations of the flora and fauna were mostly quite basic as my main concern was coastal erosion, with a specific emphasis on cliff collapses.  Though I double-checked my scientific names with knowledgeable people, some allowance for what was unknowable by me at the time, must be made.  This also applies to my reference authorities by stint of them not having observed what I saw first-hand.

For example, with regards to “shags”, there are several species of shags.  I didn’t know which species I actually observed at any given time.  And as David Medway, an authority on birds, wasn’t there with me at the time, this places obvious limits on him and others.

During the course of this project, I have recorded the ongoing loss of the Three Sisters Beach dune.  Due to this, a number of plant species growing on this dune have become locally extinct (washed into the sea).  I refer to these as micro-extinction events.  On a singular basis, this doesn’t appear to matter too much because the plants are present at other locations.  However, if dune loss occurs in other places due to, say, sea-level rise, then these micro-extinctions become collective-extinctions which could ultimately result in the total extinction of one or more flora and/or fauna.

 

REFERENCE SOURCES:

BIRDS

Wikipedia.

New Zealand Birds, an Artist’s Field Studies, by Raymond Ching, published by Reed Methuen Publishers Ltd, Auckland, New Zealand, 1986.

The Birds of Pukeiti, by David G. Medway, published by Zenith Publishing, New Plymouth, New Zealand, 2006.

AUTHORITY:  David G. Medway, past President (2000 – 2006), of the Ornithological Society of New Zealand.

TERRESTRIAL FLORA

Wikipedia.

New Zealand Flowers and Plants in Colour, by J.T. Salmon, published by A.H. & A.W. Reed, New Zealand, 1963.

Plant Icons of New Zealand, by Glyn Church and Pat Greenfield (photographer), published by David Bateman Ltd, Auckland, New Zealand, 2005.

AUTHORITY:  Glyn Church.  Glyn has a Masters of Horticulture from the Chelsea Physic Garden in London, the United Kingdom.  He has also written several books and run his own plant nursery.

MARINE FLORA AND FAUNA

Wikipedia

AUTHORITY:  Callum Lilley, Ranger/Technical Support Marine, Department of Conservation.

OTHER FAUNA

Wikipedia

AUTHORITY:  Callum Lilley, Ranger/Technical Support Marine, Department of Conservation.

FROGS

AUTHORITY:  Sarah Herbert, Herpetologist.  (www.ecogecko.co.nz.)

Wikipedia

 INSECTS

Wikipedia

AUTHORITY:  Landcare Research, Bug Classification.

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