Download Relationships with Nature signs 18 March

Relationships in Nature
400 x 530mm
An
Hangers on
epiphyte is
a plant that grows on
another plant, using it for
physical support but not
as a source of nutrients.
Nest epiphytes
are the most obvious.
These can grow so big
and heavy that they crash
dangerously to the
ground, earning the
nickname ‘widowmakers’.
Some are more
tree-like and the most
spectacular of these is northern rata (above). A
seedling, geminating in the top of tall host trees
(like rimu or puriri), sends out roots that over
several decades grow to the ground, surround
the host and form a trunk. The underlying host
rots away leaving behind a hollow central cavity.
At the other end of the size
spectrum – we have a
number of epiphytic
orchids. Not large and
showy like tropical orchids
but small, hard to spot and
often sweetly scented.
Relationships in Nature
Give & take
Mutualism
or symbiosis is a ‘win-win’
situation between two
living things.
Here’s an example - the
kereru eats the large
berries of trees like
taraire & puriri.
The berries give the bird
energy and the hard seed
is pooped out along with a
little bit of fertiliser
allowing the seed to grow
into a new tree in a new
place. Clearly the plant
and the birds both benefit.
Some
fungi invade and can kill trees, but
others are more co-operative. These ‘good’
fungus bind to tree roots and get food in the
form of sugars from the host. The plant gets
more minerals because of the fungal activity in
the soil. Normally hidden underground, the
fungus ‘fruit’ (commonly a mushroom or
toadstool) pops up underneath the trees in
autumn.
Beech trees & manuka
in particular have a very close relationship
with these
mycorrhizal fungi.
Native bees, weta,
geckos & bats also help
shift pollen and seeds between
flowers as they feed on nectar.
Relationships in Nature
A one way
Relationship
Parasites are
plants or animals that
benefit by living in or on
another species to the
disadvantage of the host.
Cuckoos are well-known
brood parasites throughout
the world. That means they
invade and parasitise the
nests of other birds. Here in
New Zealand, the migratory
shining cuckoo lays its egg
in grey warbler nests. Once
hatched, the larger cuckoo
chick evicts any remaining
warbler eggs or chicks and is
Plants can be parasitic too.
Mistletoes
are semi-parasitic. They steal some of their
nutrients and water from their host but make
then raised alone by the grey
the rest in the normal manner through
warbler adults.
photosynthesis. Our native mistletoes, found
mainly on beech trees, have been decimated
by possums, vegetation clearance, and the
decline in native bird species that act as
pollinators and seed-dispersers.
275 x 300mm
Relationships in Nature
Who did this?
Life size
A kawakawa
caterpillar!
The kawakawa moth lays
its eggs on many plants
but mainly kawakawa
leaves like this one. The
eggs hatch and the
hard-to-spot nocturnal
caterpillars chew very
noticeable, distinctive
round holes in the leaves.
400 x 380mm
Relationships in Nature
HIGH RES PHOTO TO COME
What is this?
A puriri caterpillars front door!
A puriri caterpillar spends its first year
: Tony
Photo
feeding on the forest floor but then
Wills
finds a tree (often a puriri) and bores a
hole in the trunk for its home. It covers
the entrance with a diamond-shaped
lid made of caterpillar silk and
Their tunnels
sawdust. It chews away at the nice
later become
fresh wood near the entrance and
good homes
grows big and fat before pupating
for tree weta.
(this can take between 2 and 7 years!).
Actual size!
The adult puriri moths
emerge in spring, live
Fact
only a few days and
These are our largest
during this time the
native moths -
female lays about 2000
females have a
eggs on the forest floor.
wingspan up to
150 mm.