“THORNS… THORNS… EVERYWHERE THORNS…”
What is an adaptation?
An adaptation is a “characteristic" - morphological, physiological or behavioral - that
makes an organism able to survive in their habitat.
Adaptations result from a process of natural selection - favorable characteristics that
are heritable become more common in successive generations.
Adaptations
Protection from
enemies
Motion
Food
Dealing with the cold
or heat
In the Botanic Garden of the National Museum of Natural History and Science in Lisbon, one can find
different examples of plant adaptations:
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1. Ceiba crispiflora H.B.K.
Silk floss tree
The English common name results from the mass of silk-like fibres that cover the seeds and
benefit its dispersal. The trunk is covered with prickles preventing animals from climbing and
reaching the fruits. The trunk of young specimens are green, enabling the trees to perform
photosynthesis during the deciduous period. The trunk also expands at the bottom, due to the
retention of water enabling the tree to survive the dry periods.
2. Magnolia grandiflora L.
Southern Magnolia
The leaves are leathery and coated with wax (shiny) to prevent water loss and facilitate sunlight
reflection.
When mature, the red seeds hang from fine threads and seed dispersal is usually done by birds and
mammals (the seed has to pass through the animal’s stomach to become viable).
3. Arbutus unedo L.
Strawberry Tree
It’s a Mediterranean species, perfectly adapted to fires which
are common in this region.
The reserve substances on the base of the trunk allow the
plant to survive and sprout after a fire.
4. Pinus pinea L.
Stone pine
Evergreen species, needle-shaped leaves to avoid the heat and water
loss in the summer .
It’s a typical plant from sandy soils with a well adapted root system.
5. Dracaena draco L.
Drago
The Drago has reserve substances at the trunk, as
an adaptation to the Macaronesian climate.
The aerial roots serve for support.
6. Opuntia ficus-indica (L.) Mill.
Indian fig opuntia
The leaves are reduced to spines in order to avoid water
loss and protect against herbivores.
The stem performs photosynthesis and reserves water.
Stomata open at night in order to allow the CO2 uptake
and water loss only during the cooler part of the 24-hour
cycle.
7. Datura aurea
During the night the flowers of Datura have an odor that
attracts their pollinators: bats.
It is a toxic plant as a protection against herbivores.
8. Taxus baccata L.
Yew
The entire plant is toxic as a form of protection
against herbivores.
The aril surrounding the seeds is the only non toxic
part of the plant, with a sweet taste and viscous
touch, allowing the birds to perform the seed
dispersal.
9. Ruscus aculeatus
This species has cladodes (photosynthetic stem) ending in a
spike as a way of protection against herbivores. The leaves
are very small in order to reduce the loss of water during the
heat.
The berry is toxic as a protection against herbivores.
Insects are the pollinators and birds are responsible for the
seed dispersal.
10. Taxodium distichum (L.) Rich
Swamp Cypress
The tree grows in swampy areas (hence the name) with
mild, warm weather, and it is well anchored by an
extensive root system; the base of the trunk is
surrounded
by
unique
structures
called
pneumatophores (cypress knees). These are roots that
have emerged from below ground to more easily access
the oxygen that is scarce in the flooded soils. These
adaptations can only be observed in swampy areas, not
in dry environments.
In the “Naturalist Collection” exhibition of the National Museum of Natural History and Science in Lisbon,
one can find different examples of animal adaptations:
Bubo bubo
Eurasian Eagle-Owl
Night vision and Silent flight, which makes it an effective
predator of rabbits and other small vertebrates.
Chamaeleo chamaeleon
Common Chameleon
Camouflage: the eyes move independently, allowing
environment observation without moving the head.
(the influence of changing color in camouflage is casual)
Alimentation/feeding: long tongue (up to 13 cm), fast
and sticky tip to trap insects.
Erinaceus europaeus
Western European Hedgehog
Hibernation: Accumulates large fat reserves that allow
hibernate (below 10 ° C).
Defense: It is a nocturnal animal. It’s body is covered with
hair transformed into thorns. When threatened he
defends itself by coiling into a ball of spines.
Platalea leucorodia
Common Spoonbill
It has a spoon-shaped beak, to
capture prey, maneuvering the beak
(semi-open in the sides) of a side to
other in shallow waters of estuaries
and rivers.
Anas platyrhynchos
Wild Duck
In Portugal, the Wild Duck is a non-migratory bird, because the
climate and conditions that remain stable throughout the year,
so there's no need to migrate to other regions in search of better
conditions.
They have webbed toes which facilitate propulsion in the
water.
They have strong sexual dimorphism:
Males have a green head, a white ring around his neck, the back
is gray and the breast was of a dark brown tone.
Females have a body-tone brown and are usually smaller than
males.
Phoca vitulina
Common seal
They have flippers, long tail, that allow swimming.
They have a fatty tissue layer under their skins and
a dense pelage that helps to maintain body
temperature.
Balaenoptera physalus
Fin Whale
Mammal with fusiform body for a better slide into the
water and members transformed into flippers for
swimming.
They have baleen plates that allow her into the filterfeeding process.
In order to feed, the whale opens its mouth widely and
scoops in dense shoals of prey (such as krill, copepods,
small fish), together with large volumes of water. Then it
shuts is mouth and presses its tongue against its upper
jaw, forcing the water to pass out sideways through the
baleen, thus sieving out the prey which it then swallows.
Paracentrotus lividus
Sea urchin
They have the body covered with spines. When it senses light,
they cover with shells, pebbles and seaweed, to protect
themselves.
It’s hard skeleton and cover with thorns is not enough to
protect them from some European crabs, starfish, sea and
fish.
Recurvirostra avosetta
Pied Avocet
The pied move the tip (thin and bent), side to side
to capture small worms in the area of estuaries
and rivers.
In order to feed "sweeps" continuously the mud
with his curved beak.