Birds
Endemic – found in only one place -
Ashy-faced Owl (Tyto glaucops)
Hispaniolan
Trogon (Priotelus roseigaster)
Migratory
1. Some
nest in Haiti –
Caribbean Martin (Progne dominicensis) Breeds
in Haiti Feb. – Aug
Brown Noddy (Anous stolidus) Breeds
in Haiti Apr. – Aug
2. Some
nest in the US –
Northern Parula (Setophaga americana)
Osprey (Pandion haliaetus)
Map of flyways
Thus important to protect birds in all countries and ecosystems.
Habitat = ecological or environmental area that is inhabited by a particular
species of animal, plant, or other type of organism.
In tropics, birds have greater territories than in temperate
regions.
Territory =
Ex., in Amazon 3 – 4 hectares (7.5 – 10 acres)
Temperate = 1 hectare (2.5 acres)
Tropical birds susceptible to fragmentation of their habitat. Chapter 14 in the kindle version.
Fragmentation
= when habitat is divided into smaller parts.
Forests – the disturbances we talked about – clearing forests
etc.
Aquatic habitats – damming rivers, diverting streams, plowing
wetlands, destroying mangrove.
Also – building roads through, planting fields.
Results of fragmentation
Reduced amount of habitat
Reduced quality of habitat
Edge
to surface area increases,
thus
more vulnerable to more destruction
Intrusion
by invasives, disease etc.
More
litter, more trees die at edge
RESULTS – reduced
biodiversity!
How far apart habitats are is also important
Think of the migrating birds – need habitat all the way along
their route.
Reduced birds =
Reduced seed dispersal
Fragmentation reduces insects as well, which in turn reduces
their predators.
Reduced biodiversity in tropics will reduce birds that migrate
between biomes, thus affect other biomes.
What can help? Corridors = connections between
fragments that allow animals to pass between the fragments.
INSECTS
Folivorous –
leaf eating
Many folivorous insects in the tropics.
Because there are more specialists in tropics?
Specialist = an
organism that has a narrow niche – either food or habitat.
Or just because there are more trees?
Let’s look at the numbers.
A tree in a temperate forest in Monrovia Central Europe had 29
insect species per 100 m2 leaf tissue.
Comparable type of tree in tropics of New Guinea had 23.5.
BUT Monrovia central europe had 21 species of trees per hectare,
while New Guinea had 152/ha.
Conclusion – more trees!
Not more specialists.
Specializing on specific plants –
Many plants in tropics produce defense compounds which
are repellant to toxic.
Yet insects specialize on these plants.
So either immune to the toxins, or minimize their exposure.
Example minimize =
– caterpillars of genus Melinaea feed on plants in Solanaceae
family (tomato).
Caterpillars cut the veins so that the toxin doesn’t reach the
leaf tissue they eat.
Example immune =
Heliconid butterflies 50 species
– caterpillars feed almost exclusively on Passiflora – passionflower – a vine of 500 species
-
Contains cyanogenic glycosides and cyanohydrins
-
Helioconids have enzymes to sequester these
cyanogens
In turn, the butterflies are toxic. Have obvious coloration to warn birds.
The coloration is said to be aposematic – warning.
Some plants have compounds that can help us in medicine –
anti-cancer compounds. Scientists have
found that the aposematically colored insects tend to be on the plants that
have these compounds.
Insects as pollinators
Beetles pollinate the Victoria water lily.
The white flower - strong
ordor and warm - 11C warmer than ambient
temperature.
Attracts Cyclocephala ssp. beetles that enter and become
trapped. During night become covered
with pollen, and flower turns red and lost scent and warmness. Beetle goes to another white flower.
Long-distance pollinators
Fig wasps travel 5 – 14 km (3 – 8.5 m).
Borneo – they fly above canopy where winds are strong.
