Amazon forests

Babakato – indri – largest lemur left on island – long necked, long limbed, yellow eyed, jackal like face, no tail (unusual for an arboreal animal)

Their song – may be the loudest animal sound in nature. Good for long distance communication (what does that suggest about their behavior?)– why? mates, territory

The are rare and need large territories for mates and offspring, produce one offspring per 3 years

M. Yadav & A.R. Main – studied macropods (kangaroos and related species) on western Australia’s islands

They calculated density (number of animals) / habitat area. Habitat areas were different sized islands off of coast of Australia

The density of macropods per area on the smallest island provides an estimate of the minium viable population sizw

Mark Shaffer – studied grizzlies and found that defining the minimum area for a top predator in the local food web will ensure that you have an area big enough for all associated species

Shaffer’s said that the minimum persistent population size is a population having a 95% probability of existing for 100 years

Stochastic factors (= random or unpredictable factors) often due to the environment

Genetic factors – genetic dift (changes in allele frequencies), founder affect (allele frequencies of initial members of a new population)

Habitat fragmentation which may be either a deterministic factor (human population growth and demand) or a stochastic factor (catastrophic floodings or fires) which impact a small population size can be devastating.

Ian Franklin – He establishes the minimum population size needed with respect to critical factors for survival and finds that:

Short-term inbreeding depression dooms populations with fewer than 50 individuals

Michael Soule – He also finds that the minimum population size is 50 (This supports Ian Franklin’s estimate). More than this minimum size is needed to hold inbreeding down to less than 1%. Below 50 individuals wild populations can decline due to recessive traits which affect infant mortality & loss of ability to reproduce.

Another concern is that speciation (the process of evolution of new forms) for larger organisms stops when there are too few animals and/or too little habitat variability. With too little habitat variability there may not be enough distinctively different areas and this would prevent allopatric speciation. So when speciation stops then the biological community becomes biologically less varied or rich in species.

Michael Soule & Bruce Wilcox – convene 1^st International Conference on Conservation Biology (late 70s) – this is a mission-oriented field of science. They publish a book on conservation biology (Conservation Biology: an Evolutionary and Ecology Perspective-the Brown Book). Topics of concern include habitat loss, biological extinction & cessation of ecological processes (speciation?)

Carl Jones brings back the wild kestrel from the brink of extinction
Timeline of accompllishments

1981 – 6 birds, 2 captive

1985 – 12 + 11 young wild birds and a few more captive

1988 – 40 wild birds, 21 captive on the island of Mauritius and 15 captive held elsewhere by the Peregrine Fund, in Boise, Idaho as a backup.

Coming back fro the brink there are currently 300 breeding pairs + 100 singletons throughout Mauritius

How can this work with such a small vulnerable population of birds? The Kestrel’s advantage it has always been relatively rare. A small population whose numbers fluctuated over time

Chronic inbreeding has been ongoing and as a result the homozygous recessive alleles (the dangerous forms of genes) have been safely culled out of population thus lightening the genetic load

Lesson to be learned is that when a larger population is rapidly reduced in size suffers acute inbreeding occurs and presents a short term threat to survival but for a chronically small population population fluctuations up and down don't have the same consequences.

Michael Soule & Mike Gilpin caution against the simplistic application of 50/500 rule as determining the minimum viable population – MVP. There was a concern some conservationists would use these poplation size as cut off points for decision purposes (such as don't waste time on trying to protect the smaller populations)

Viable Population Analysis introduced at the 2^nd International Conference of Conservation Biology

This argues that the MVP must be decided on a case-by-case, species-by-species basis –The real concern is the possible interaction of destructive forces which might send a population into a tailspin, an extinction trajectory.

Four destructive vortices can interact to worsen the situation for a vulnerable population – inbreeding, loss of adaptability (genetic load), habitat fragmentation, and demographics

Entry into one danger zone might facilitate entry into another thus increasing the population's vulnerability to extinction

Once there were 500,000 square miles – now this environment has been cut to ribbons

There have been many primates endemic to this type of forest such as the golden-head lion tamarin and golden lion tamarin, masked titi, black lion tamarin, four types of marmoset, and the big muriqui (Brachyteles arachnoides)

Forest destruction scenario - The Portugese arrive in 1600s, begin agriculture, find gold and diamonds inland , continuing growth of agriculture, construction of steel mills (requiring forest to provide charcoal for smelting), urban spraw so that now the forest is now only 5%

Muriqui’s decline from a population initially estimated at 400,000, dropped down to 2000 by 1972, and is now 300+, found in small colonies in forest fragments

Karen Strier – the Jane Goodall of muriquis – doctoral student in early 80s – persistently studied one population of muriquis, (about 80 individuals) – at Monte Claros research station (she helped developed this station)

Mating in forest – muriqui females mate w/ several males w/out conflict occuring between males

Males compete by the amount, and fertility of sperm, each male takes a turn breeding with a female and the best (most fertile) male wins.

Young females, when pregnant, leave pack to go to new pack . this behavior reduces inbreeding

Studies of feces determine hormone and reproductive behavior which is non-intrusive so that there is no need to experiment w/ population (says Strier) and no for translocating females either to or fro

Water snake – Nerodia barteri paucimaculata – Texas snake which lives in rivers– feeds on fish in riffles (fast flowing areas of the river and are preyed upon by larger Nerodia which lives in still water. Nerodia barteri paucimaculata is short lived but prolific

The Corps of Engineers plans to dam below the confluence of the Concho and Colorado Rivers where the snake lives (this is not the same Colorado that flows through the Grand Canyon) and thus effectively fragments & isolate several small populations

Soule & Gilpin modeled habitat fragments for these snakes. They based their model on five kilometers stretches of the river which are considered big or small habitats depending on number of riffles in each stretch where the snakes live. The larger habitats patches just upstream of confluence is destined for flooding if the dam is built and the poorer habitats further upstream and down are places where populations are temporary as snakes in them swim from patch to patch.

Soule & Gilpin apply equilibrium theory the recolonization and extinction from patch to patch. But these are patches without a main population reserve resource. Thus this is a metapopulation (a population made up of subpopulations). And throughout this metapopulation there is an interaction of populations from neighboring patches which influences extinction or persistence for the whole population.

Soule & Gilpin’s population viability analysis suggests that the snake population persists only if the metapopulation is left intact. They say that if the metapopulation is further fragmented by a dam then a domino effect may result in the extinction one after another of the relatively more isolated small populations. Actually one population in the model appears to hang on tenuously. However it could be vulnerable to a small catastrophe like a tanker truck spill which would spell doom for the species of water snake

So the dam is built and the snake metapopulation is monitored and the results aren't in yet to verification of Soule & Gilpin’s model. Time will tell

The take home message is that now the world's species exist as metapopulations and there are no major reserve resources left. So the new model should be applied and the question is are subpopulations disappearing more often that reappearing?

It is assumed that some forms of each type of organism disappear over rates of a million years (David Jablonski) and that the rate of speciation normally keeps up with the background level of extinction

However mass extinctions do happen maybe due to climate change, asteroids hitting the earth. There's a hypothesis that our sun is associated with a death star which pulls asteroids across the earth's orbit every 26 million years as this mystery star periodically swings near our solar system.

Cretaceous event – 65 million years ago, the fall of dinosaurs, Alverez (father & son research team) find a layer in the earth about 65 million years old that has a high concentration Iridium throughout the world. The interesting and suggestive thing about Iridium is that it usually is present in low concentrations in the earth's geological layers but is found in much higher concentrations in asteroids. This is the basis for thinking that a large asteroid hit the earth at that time.

Permian event – 250 million years ago during which half of marine fauna (family level) was lost

Then there's the Pleistocene mini extinction about 10,000 years ago when many mammals were lost. Some feel that this was due to hunting pressure by humans

From neolithic (the new stone age) to modern times (exploration and expansion from Europe) island life is violated historically with the loss of many organisms and currently continents are undergoing the same fate

He traveled to and worked in Aru in the eastern part of the Indonesian island chain.

His persistence was rewarded with the capture of the lesser bird of paradise. Wallace was thoughtful about the existence of unobserved generations of this bird’s beauty in remote reaches of the Indonesian tropical forest. Wallace (in his publication Malay Archipelago) predicts that future human invasion of forests and the discovery of this type of natural beauty goes hand-in-hand with its inevitable disappearance. He wrote.....

“…should civilized man ever reach these distant lands, and bring moral, intellectual, and physical light into the recesses of these virgin forests, we maybe sure that he will so disturb the nicely-balanced relations of organic and inorganic nature as to cause the disappearance, and finally the extinction…”

He searches for this bird of paradise and wonders if Wllace’s predictions true for this animal.

At 3 am in the morning he awakens & searches for Lek tree with two guides, Mr. Gait and Mr. Samuels

And finally he hears the song of the bird of paradise “Suda suara cenderawasih”