Tiny Twigs

The Importance of Tiny Twigs by Curt Andrews

I still remember the first time I was kicked off a prospective client’s property for refusing to give them a price to top the large silver maple in their back yard. Anyone who has a passion for and appreciation of trees, has likely experienced a sense of sorrow when they’ve come across a beautiful tree which had its potential cut off just as it was maturing into its full splendor.

Curt at waterfall

You don’t have to be an arborist to understand the damage topping can do to the long-term health and structural integrity of a tree.  The request to inflict such damage on a tree is typically out of ignorance, so I took it upon myself to help this property owner understand the long-term ramifications of their request.  It was certainly an eye-opening experience, being called a few select names as I was hurriedly escorted back to the front gate.  

There are times and situations where severe pruning techniques may need to be considered and possibly implemented, but I have yet to come across an instance where topping a tree would properly address the list of reasons people have given.

While topping can often be considered extreme malpractice, have you ever considered the damage we can inflict when it comes to removing smaller branches or twigs?  The little branches which are found along larger branches and limbs.  The ones which snag your throw line or make it challenging to isolate your climbing line into your targeted branch crotch.

Arborists and recreational climbers alike often get annoyed by these small branches.  They seem so insignificant because they pale in comparison to the large limbs which create the structure of the tree.  Whether you are working or simply climbing to enjoy interacting with the tree, these twigs and branches can make things more difficult for you.  They also have a way of finding your eyes!

When teaching students and arborists about tree physiology and proper pruning techniques, many are surprised to learn about the importance of these small branches.  When taken to the extreme by removing all twigs and branches along a limb, you end up with a ‘lions tailed’ limb.  The only foliage remaining has the appearance of a tuft of leaves on the end of the limb.  Like topping, this practice is forbidden by the tree care industry’s governing bodies.  

One of the main issues is that this type of pruning promotes the lengthening of the branch at the expense of diameter thickness and strength.  The result is a weaker branch which is more likely to snap when subjected to wind.  Think of the trees which have developed in the woods.  They are tall and skinny with most of their branches in the upper crown where they have access to sunlight. 

When these wooded areas are cut down to make way for a construction project, the remaining trees are then exposed to winds they had not encountered during their development.  It is common for these trees to lose limbs and even split or snap along the trunk when subjected to wind forces from the side.  When sheltered amongst by surrounding trees, they put little energy in to developing structural growth to strengthen against side-winds.  Their energy went into growing taller.

Compare that to a tree which has grown in an open field.  These trees tend to have more branches along the trunk, have a larger trunk diameter to tree height, and are likely to have a nice trunk taper at the ground.  All of this provides for a sturdy tree which can withstand crosswinds.  The same holds true for the branches themselves.

There are times we may need to remove small branches and twigs in the inner-crown as we prepare the tree for a facilitated climb, or to provide a clean cut on twigs which may have snapped during our time spent in the tree.  If we remove too many of the twigs and smaller branches along the large structural limbs of a tree, we will inadvertently be causing the tree to redirect energy from diameter growth into lengthening the branch.  

Beech Tree looking up - Curtis M Andrews

We take great precaution to minimize our impact on the trees through practices like the use of cambium savers, so let’s not forget the importance of these seemingly insignificant parts of the tree.  They play a big role in how and where cells are generated and strengthened.  They provide for branch and trunk strength, as well as dampening the effect of winds on the tree.  Giving proper attention to the impact we have on a tree we enjoy today, will help to ensure others can experience its beauty in the years ahead.

Fortunately, I was never run off a property because I refused to lions-tail a tree.  There have been a few times where I was able to discuss the importance of the internal branches when someone wanted the inner crown stripped clean to show off branch structure.  Thankfully, these conversations have remained civil and resulted in a better understanding and appreciation for the structure of the tree, little twigs and all.

Gear Check

Gear Check - A couple of tips by Paul McCathie

When it comes to checking gear the number one question I get asked is “When do I know when something is too worn out to use?” 

This is indeed a difficult question to answer. We would all like for this to be a black and white issue but unfortunately it is not! Give a partially worn item to ten people and I’m sure you will get at least five differing opinions - no use to us when deciding on the fitness of any questionable piece of gear!

There are a few factors that come into play when checking gear. One of them is bias. When checking your own gear there is always a temptation to think "I’m sure I could get another year out this piece of gear… well, I think I could and it would be so expensive to replace and I’ve only had it ten months.” This doesn’t make any logical sense I know, but the fact is that money doesn’t grow on trees and this can override a lot of other decision making factors.

I am a LOLER (Lifting Operations and Lifting Equipment Regulations) Inspector for Arboricultural Equipment and therefore use their system for gear checking. On top of this, I employ another LOLER Inspector to check every piece of life support equipment I own. This removes the bias and makes sure I’ve had a second set of eyes giving my equipment a thorough inspection. It also helps to give me some black and white answers to those grey questions.

If you don’t have LOLER running in your country it may be an idea to get a buddy system working for gear checks. Check each other’s gear in as much of an unbiased way as possible. If there is still any doubt, I’d recommend getting an opinion from a qualified arborist.

Age of gear can be another issue. "How long should I keep using a harness or a karabiner?" The answer to this question is much easier to answer: "As long as the manufacturer recommends." What could be easier? However some manufacturer's instructions can be vague or just straight out hard to find. To help out here is a summary for European gear. I find this a very good summary and useful rule of thumb to go by.

So, number one, buddy up and cross check one another's equipment and always refer back to the manufacture's guidelines for length of time to use gear.

One last thought - if there's not a summary of manufacture's instructions for US made gear, maybe someone would like to volunteer for the job! It would be a very useful document.

- Paul McCathie
Goodleaf Tree Climbing

Forth Post

Hi y’all!! by Griëtte “Lady D” van der Heide

I wish I could be writing this “Grove of the Month” while hanging upside down in a tree somewhere in Georgia, with my feet on a branch, where my friend Will Cottrell seems to be 24/7. Instead, this story is coming to you from West Harlem, where I am temporarily staying while teaching and doing lab work at Hunter College. As these words hit the paper, I feel immensely fortunate that I was introduced to tree climbing. At the same time, my brain cannot seem to comprehend that so many kids these days are deprived of such outdoor adventures.

View of Kibale National Park from a fruiting Ficus natalensis standing tall in the swamp.

Before heading to NYC, as a Dutch transplant living in hot, shrubby Texas, at the University of Texas in San Antonio, I started to miss my previous indoor and outdoor rock climbing adventures. This, combined with my tendency to hang around primates, led me to my first tree climbing adventure in 2013 at the Institute of Tropical Ecology and Conservation, in Panama. With some help from my academic advisor Dr. Joanna Lambert, Joe Maher as instructor, and two amazing graduate students as climbing buddies, I was all set for a month long rollercoaster ride-like tropical tree climbing course. Joe definitely has special hawk-like skills, spotting mistakes in my climbing hitch from tree crowns away. Jodie Rosam, beyond the ability to descend superfast whenever necessary, has special skills climbing with webbing in small trees. And Adam Clause spots, catches, and releases arboreal lizards in emergent figs before anyone else has a chance to catch their breath from the climb up. Without Joe’s brother Bill, I would not have been able to experience climbing on “stomach loads of grit” in the beautiful forests of Georgia. All these guys helped me tremendously and have been wonderful hosts and friends.


I have recently started to apply tree climbing techniques to my own doctoral dissertation research. I am interested in primates of all sorts; lemurs, monkeys, apes, nocturnal, diurnal, in zoos, and in the wild. Of all primates, I am most interested in arboreal, fruit-eating species. I adore Neotropical forests and their inhabitants, especially the subtropical forests in the Argentinean Chaco where I worked as a research assistant, for Dr. Eduardo Fernandez-Duque, with owl monkeys. These monogamous, territorial creatures roam the forest in small social groups, mostly during the dark hours of the day. High above the ground, they climb beautiful trees, using branches and lianas as hiding places, paths, and food sources. It was in Argentina, that I realized that the key to understanding arboreal primates means joining them in their canopy habitats. 


At Kibale National Park, in Uganda, I have started focusing my research on two monkey species: the grey-cheeked mangabey, and the red-tail guenon. I focus on fruit odors and how monkeys use smell to figure out if fruits are edible. Many primates have outstanding color and stereoscopic vision; thus the sense of smell has been deemed less important in the daily lives of primates. However, being a proper primate myself, I test my food by smelling, touching, and visually inspecting it, even before checking the “use before” stamp that other humans have conveniently added to my processed foods. Other primates must be using multiple sensory cues as well, but how and when do they use odor?


I probably climbed “a fig a day” during my three month stay in the high-altitude tropical forests of Kibale. Some fig species have fruits growing directly from the main trunk and branches. These figs have been challenging to climb, since the short white rope that I use to transfer got stuck behind these fist-sized fruits all the time. I gave up on those fig trees. They won the fight in 2014, but they will be challenged once more, when I return to Kibale. Chimpanzee researchers Dr. Martin Muller, Dr. Sherry Nelson, and graduate student Marian Hamilton, were not only great climbing friends at Kibale, but also a great resource. They “introduced” me to the best fig species of the forest (Ficus capensis), and… by accident, to life in the trees with chimpanzees. Although I had asked another primatologist what to do, ethically and wisely, when chimps happen to enter the tree you are climbing, I was not prepared for the long, silent, wait during the heat of the day. Since I was not in Kibale to disturb the monkeys and apes in their arboreal homes, I stayed in the fig for 3-4 hours, quietly, and slowly changing position occasionally, until – finally – the last chimpanzee left the tree and I descended with fruits and leaves as trophies. Back on the ground, I inhaled a liter of water and some chapattis. 

Griëte van der Heide, Jodie Rosam, and Adam Clause before climbing a giant tropical oak in Boquete, Panama. Picture by Joe Maher.

As part of my research, I collect fruits from the canopy to analyze olfactory cues. Obtaining the fruits from the tree crowns has been a major challenge. Once I am in a good position in a tree, I normally ask one of my Ugandan field assistants, Bruce and Sylevaster, to connect two or three 6-ft poles to a pruner head. I then haul up this system and try to let the heavy pruning head “fall” on some fruit-carrying terminal branches. It has become clear that I was not born to be an arborist. Respect for arborists though; pruning equipment is heavy! After collecting the cut fruits, and safely descending the pruner and myself, I carry the fruits back to camp. At night, I weigh, measure, and photograph them, after collecting the odors emitted from the fruits with a vacuum-pump. I then dry the fruits to analyze for nutritional content and toxins. We also watch monkeys feeding from figs and observe how they inspect fruits. 

I taught Bruce and Sylevaster some basic tree climbing facts. During my last week at Kibale, Bruce and I tried to rig this humongous Ficus natalensis. Even a sidewinder with extra extension (!) could barely get a weight bag over the nearest branch. Of course the weight bag got really, really stuck. We tried every trick I could think of, but only time made this fig forgive its potential intruders. Several days later, when he checked the tree for foraging monkeys, Bruce was finally able to release the bag from its airborne trap. Although Bruce and Sylevaster never climbed a tree, I am hoping that this year I can train to become a Facilitator and take several Ugandans up in a tree.

But let’s not fool myself. I also want to facilitate climbs for selfish reasons. Hanging out in trees with some buddies is much more fun than experiencing tropical tree canopies by myself!! 

Griëtte “Lady D” van der Heide     

Third Post



2014-10-05 00.04.11

September 10-13, 2015

download pdf brochure

WHO: All adventure, research and educational tree climbers and interested land-management/recreation leaders.

WHAT: Southeastern Tree Climbing Workshop, sponsored by the Wildlife Resources Division of the Georgia Department of Natural Resources (WRD-DNR), and co-sponsored by the Global Organization of Tree Climbers (GOTC)

WHERE: The 6,400-acre Charlie Elliott Wildlife Center in Mansfield, Georgia, southeast of Atlanta

WHEN: September 10-13, 2015 (typically dry, with daytime highs in the low 80s and overnight lows in the lower 60s)

WHY: To improve climbing skills and wilderness ethics, meet outdoor professionals interested in recreational tree climbing, and climb with those people you only know through the internet

ESTIMATED COST: (Might change slightly due to unexpected expenses) $210 for lodging, meals and all activities (sharing of lodge rooms may be necessary to keep costs low); $170 for camping, meals and all activities; $20 for all-day Saturday activities and lunch. (Any funds left over after expenses will be donated to Charlie Elliott Wildlife Center)

CONTACT & RESERVATIONS: Jody Rice, Georgia DNR Wildlife Resources Division,  

This is the same workshop that was sponsored by Georgia DNR in 2004-2007 at Franklin D. Roosevelt State Park. The workshop had to be cancelled for a number of years after tornadoes tore through the park and totally destroyed the sleeping cabins and lodge/dining hall, uprooted hundreds of the tallest trees and filled the park lake with tons of debris. It will be several more years before that site is restored, but we don’t want to wait any longer to create a stronger bond between the recreational tree-climbing community and the agencies that manage our parks and wild lands.

“Although this is a regional workshop that likely will attract climbers from the Southeastern U.S., it is open to any tree climber from anywhere,” said Bill Maher, vice president of GOTC and one of the volunteer organizers. “One goal of this workshop is to encourage climbers to go home and find ways to work with local, state or national agencies in their area.”

Another goal, Maher said, “is to encourage climbers to organize and host regional workshops in their part of the country. A big complaint I get is that too many events are held in the Southeast. But many of the most active tree climbers live in the Southeast so naturally we’re going to do something close to our homes. Others could do the same near their homes. That’s probably the best way to make recreational tree climbing grow.”

Maher said in the past the Georgia DNR workshop attracted new climbers who were not able for one reason or another to attend the annual international Tree Climbing Rendezvous held every fall at various locations. “The annual Rendezvous is an awesome event that all climbers need to attend when possible,” he said, “but we realize that a lot of younger climbers and college researchers just don’t have the time or money to travel thousands of miles for a conference, so a regional workshop is probably the right alternative.”

 And Charlie Elliott Wildlife Center is the ideal location to re-start the workshops in the Southeast. Jody Rice, a veteran tree-climbing instructor and experiential educator with WRD-DNR, said Charlie Elliott has it all: more than a dozen canoeing and fishing lakes, miles of hiking trails, world-class bird and wildlife watching opportunities, a lodge with plenty of hotel-style guest rooms, excellent dining and meeting facilities, a convenient location, and – most of all – hundreds of acres of old-growth and second-growth hardwoods and pines.

Charlie Elliott Wildlife Center is less than an hour’s drive from Atlanta International Airport and is only minutes away from Interstates 20 and 75. It is located off Georgia Highway 11 near the town of Mansfield, southeast of Atlanta.

In addition to tree climbing, workshop participants can practice other outdoor and woodcraft skills with DNR staff and volunteers from other organizations at no extra cost, and check out Project Adventure’s on-site challenge course.  Those climbers with culinary talents are invited to help prepare the Saturday night Tree Climbers’ Dinner to be held under the picnic pavilion at the S.R. Campbell Aquatic Center next to Lake Margaret at the wildlife center. All other meals will be professionally prepared and served in the conference center’s dining hall.

download pdf brochure 

Second Post

Cradle in the Tree of Life - Part II by Dr. Donald Perry

Dr. Perry welcomes your comments and questions. Please email him at canopy evolution at

The fruits of our creativity – music, dance, mathematics, technology, and our awareness of the universe – are the result of evolutionary events that occurred in the murky depths of humanity’s distant past. Where and why this creative mind came into existence is the ultimate question of philosophy, religion and science.  

Some theorists place human origins in the development of language, others in rock throwing, still others in our unique form of walking upright. However, all of these suggestions are highly speculative.

A sign post to when the mind started becoming human exists in the archeological record. It is a remarkable stone tool with a complexity of form that defied explanation by over a century of scientists. It was made around two million years ago and was humanity's first technological invention. It was used for nearly that whole length of time, making it the most important and longest-lived invention ever made.

IMG_1751So what kind of life inspired this invention? As I was exploring the origin of human intelligence I came across an interesting piece on Robert Goddard, in the book Dragons of Eden, by Carl Sagan. Goddard was the inventor of modern rocketry and as it turns out he got his brilliant idea for space travel while climbing into a tree as a youth. Although there is debate about this point, some have said Sir Issac Newton got his brilliant idea concerning the gravitational force from watching an apple fall from a tree.

The influence of trees therefore is associated with the Copernican Revolution and The Renaissance – changes in human thinking that ended the Dark Ages, kicked off the age of science, and have led to space exploration.  Long before ancient Greeks discovered the earth was a sphere suspended in space, trees inspired our understanding of the nature of the universe. The earliest myths of Egyptians and Northern Europeans had universe trees with kingdoms and limbs holding up the cosmos.  New Guineans imagined we slid down a rope from a kingdom in the sky to live on the ground.  Closer to home, Eden was said to be a garden of the earth's fruiting trees. Myths show we have a deep and intimate respect for trees, but it seems to me myths are also telling us that a kingdom in the sky was a real place – once upon a time.

A naysayer would point out that forests have played an important role in the world's habitats for hundreds of millions of years. Both North America and Eurasia were fully forested until humans burned and cut them down. (Not much love for trees evident there!) Grand organisms, like the Giant Sequoias whose life spans approach immortality, should and would be a focus of mysticism. They were here before us and probably will be here after we are gone too.  It would be really odd if huge old growth, impressive, humbling trees, did not play a dominant role in origin myths.  So the significance of vague myths from around the world of a lost aerial home in trees has been routinely ignored.  As a result myths of an aerial home as a safe haven from the ferocious predators of the ground have never played a role in scientific theories about our origins.

Yet one does not have to look far to find a well of empirical evidence – genetically-based programs – displayed by children and the way we behave that tells a complementary story to myths. Many adults still climb and so do most children. Alex Honnold is a climbing machine who can free climb high rock faces barehanded. He demonstrates that humans are one of the best climbing species on earth.  His fingers tell a story that recalls Neanderthal times.


This phenomenal climbing ability is written directly into Alex's genes. Where did these genes come from? When we write evolutionary theories about a species it must always include the probable reason for possessing various traits. A turkey for example is a great runner that uses its sharp claws to dig up humus to find things to eat such as nuts and insects. While evolving to become a heavy bird of the ground (a bipedal ground species too), natural selection retained its ability to fly up to tree limbs to roost at night where it would be safe from predators. Finding food and escape from predation are essential elements driving the evolution of all species. An utterly absurd theory of turkey evolution would omit or ignore the role of flight.

And so the human evolutionary story is similar to that of the turkey in having two main branches – it, of course, must be about our upright walking and tool making, and also about our climbing. The story about our tool making and upright walking is found in all the libraries of the world. Yet oddly the stories on library shelves and documentaries are silent about what is the most important aspect of human nature – tree climbing! 

The following is the untold, most important half of the human evolutionary story. It is about a place where science and religion meet. The two walk, or should I say climb, hand in hand along a path lit by childhood nightmares of ferocious beasts, inexplicable instincts in infants, and bits of fossil evidence that lead to a new panorama of human origins. At path's end, our compulsion to design temples that reach into the sky, cathedrals that mimic the look and feel of towering old-growth groves, our gazing from penthouses, and our drive to build forests of concrete and steel, emerge as leftover  sentiments from a recent tree climbing past. We arrive at the place where the mind was born.

Respected books on human evolution continue to be based on Darwin's founding premise in his book The Descent of Man.  He claimed that the most important event in our origins was when we gave up climbing and left trees to begin living on the ground.  Activities on the ground, he said, stimulated the intellectual development of the mind.  While I do not doubt Darwin's theory of biological evolution, I have a much different human evolutionary view.  


I am an evolutionary zoologist and an avid tree climber.  I pioneered the exploration of the canopy's arboreal continent of hidden life for three decades.  This work gave me a bird's eye view of how we became human.

If our mind and body evolved solely on the ground, which is now commonly believed, why do we rank among the best climbers to have ever evolved?  How is it possible for construction workers to walk along a skyscraper’s narrow steel girders at dizzying, terrifying heights?  No ape can climb a thousand-foot cliff barehanded, nor can they build a tree house in a towering treetop as do the Korowai people of New Guinea. Our ability to work and build in trees far outdistances those of apes, and we stand apart from all other primates due to our ability to construct.  

Articles in both popular magazines and scientific journals tell us that when we abandoned tree climbing to walk on the ground, our hands were then free to make tools.  Tool use on the ground triggered the development of an enlarged brain and an enhanced intelligence. (A rebuttal of the aquatic ape yarn must wait.) But there is a problem with this view. We possess a menagerie of odd adaptations that could never have evolved on the ground. There is overwhelming evidence that some of the amazing leaps in human evolution – primitive tool making, the development of language, construction – can be traced to the period when we were spending more time in trees.

IMG_1647Strong evidence of an arboreal link is found in our children. They are born with an innate behavior known as the Moro reflex. This reflex is viewed as an oddity, but it is actually a network of precise neurological circuitry in the infant mind. While flaws in its expression help practitioners to determine the mental health of an infant’s brain, the evolutionary explanation of this hardwired reflex and how it once provided for the newborn's safety remain undiscovered by the medical and anthropological professions.  Physicians activate the Moro reflex by placing a baby on a table covered with soft spongy material, supporting its head in cupped hands, then allowing the head to drop slightly but suddenly while still being held. (Do not attempt this.) The baby flings its arms out sideways, its whole body stiffens, and a few seconds later the baby relaxes and begins to cry loudly. This reflex disappears after a few months.

The Moro reflex can also be triggered by sudden nearby movements or a loud noise.  To create such an instinctive reflex, life-threatening movements and noises had to have occurred for tens of thousands to hundreds of thousands, of years.  Where might that have taken place?  

In the forest, booming thunder and limbs crashing down would have been familiar loud sounds that caused great alarm.  If our ancestors lived on platforms and the platform was struck by a falling limb, a sleeping infant could easily bounce off the platform’s edge. In such a case heavy selection would account for the sideways-extended arms of the Moro reflex, along with a stiffening body that minimized rolling and stabilized an infant. The startle reflex, as it is also called, makes little sense as an adaptation for life on the ground.  For this reason it has never been understood.

Additional reflexes and behaviors possessed by infants weave a neurological fabric helping us link the Moro reflex to a climbing past.  Soon after birth, and while still virtually helpless, infants have the incredible capability of bearing their entire body weight by a single hand.  Their ability to grip hair with an iron fist is amusing to some, but it was not amusing in our ancestor's world.  Known as the grip-reflex, this feat of strength is often brushed aside as a vestige of pre-human evolution from a time when our infants, like other primates, needed a strong grip to cling to their mother’s fur as she clambered through the treetops.  Never is it pointed out that this reflex would provide safety to an infant clinging onto vines among high limbs.  Of course, few branches are found in cribs today, but cribs are ideal proving grounds for what infants really want to do.

A few months after birth children start climbing.  This occurs before they can walk and it becomes difficult to keep them safely in a crib.  The urge to climb is strong.  Is this urge leftover from an ancient time or is the infant's escape from the crib telling a more timely message?  Could this be telling us how we lived just a few tens of thousand years ago?

The instincts of all newborn animals, like the get-up-and-run behavior of newborn gazelles, are imperative programming for survival in the habitat where that animal will spend its life.  Escape is essential on a savanna, and in many other habitats as well.  Newborn humans practice climbing soon after birth. Within a few years they can often be found clambering among tree limbs with exceptional skill.  Gymnastic instructors have told me that nearly all of our youth have fantastic climbing capabilities.  Of course these abilities are genetically based.  Zoologically and biologically these can not be considered vestigial instincts.  Our young are playing out a recently essential drama before our very eyes.  We are witnessing recordings of our ancestral past. 

When infant instincts and capabilities are so well developed for climbing, one evolutionary explanation exists: recent and stringent natural selection anchored these instincts in the infant mind.  Very recently we were spending much more time in trees.  


This explains other instincts and physiology that are incongruous with life on the ground. Our young often screech at the top of their lungs to attract a parent’s attention, especially when the parent is out of sight.  This is not an adaptation for life on the ground.  While we can only speculate why such noise is needed in trees, it is definitely abhorrent for life on the ground.  There is a basic tenet followed by all terrestrial young – silence is golden.  Life on the ground mandates that young animals remain quietly huddled under the cover of grass and shrubs when parents or guardians are away. Only in dire circumstances would they cry out, because there is no sweeter music to a ground predator’s ear than a screaming, defenseless infant.

Oddly, anthropologists tell us that human intelligence and the invention of weapons evolved when we lived on savannas.  Yet savannas were incessant war zones of prehistoric times.  Before trudging out onto the savanna with its huge cats and other savage residents, it seems obvious we would have need of weapons.  So their invention must have come while we still inhabited forests.  Yet anthropological art portray our ancestors standing on the ground poised to attack a predator with rock or stick in hand.  A trip to grizzly bear country armed with only a rock would wake up any believer in that foolish anthropological myth.  The film Grizzly Man, a 2005 documentary film by German director Werner Herzog, ends with a disturbing story of people being eaten alive.  We can be confident our ancestor came fully armed during their invasion into the savannas.  

Other anthropologists think our ancestors slept on the ground. But exposure to roving packs of quadrupedal killers would quickly have spelled extinction for our species.  Why would we have not been like all apes, except the massively over-sized male gorilla, which build tree platforms to sleep out of reach of ground predators?  

Because no evidence of tree houses has been found in layers of fossiliferous clays, it is thought that our ancestors did not sleep in trees.  I believe the evidence is there.  However, if an absence of evidence confirms that we did not sleep in trees, then the absence of evidence confirms that we did not live in or frequent savannas either.  Before 40,000 years ago there is little evidence of protective shelters (there were not enough caves to house early human populations), effective weapons, or domesticated dogs, all of which would have been needed to dissuade the predators of the ground.

Anthropologists so desperately want us to sleep on the ground that they have pointed out to me that leopards are good climbers, so we would not have been safe in trees.  This, of course would mean that great apes and all the species that nest in trees find no protection by sleeping it trees?  It is established fact that predation is higher on the ground.   And shortly, I will show why leopards would have quickly learned to avoid any tree that smelled of humans, or have their head cleaved in two. 


In my work I have dealt with handling deadly poisonous snakes.  I would choose sleeping with those snakes hands down over the saber-toothed cats, hyenas and cave bear that roamed the ancient savanna.  Reason should direct theory.  So where would you rather have slept: on the ground with predators or in a tree-house?   

Anthropologists tell us that Homo habilis (Handy Man) lived on the ground when he developed the first tools.  He walked upright and had a significantly larger brain than Lucy (his presumptive tree climbing forebear).  He seemed to provide perfect evidence to support how the power of walking on the ground stimulated human intelligence.  It was also believed that Handy Man had given up climbing, but then someone examined the bones more carefully.  As it turns out, Handy Man was quite proficient at tree climbing.  Since Handy Man is the probable maker of the first tools, the empirical evidence shows that the first stone tools were made by tree climbers around two and a half million years ago.  Tree climbers!   

Tree climbing is linked with tool making, as the best tool makers in the zoological world are climbers.  And it is a well hidden, but fully supported fact of zoology that tree climbing holds a significant position in the evolution of large brains.  With the exception of some aquatic species (the reason for this is explained in my book manuscript, The Descent), in all of evolutionary history the relatively largest brains among mammals, birds, and dinosaurs are found in climbing species.  Those species that shunned forests and trees always earned relatively small brains.  Something about tree climbing can promote encephalization in many species, and something about life on the ground favors a small brain in nearly all species!    

Given that we are one of the best climbers on earth, the zoological conclusion is inescapable. Climbing must be involved with the evolution of our brain.  We must have been doing some smart activities in trees that apes never imagined doing.  What were those smart activities?   

The noose around the neck of Darwin's ground theory is tightened by examining the origins of the use of the most important tool of early human evolution.  The “hand axe” first appeared around 1.7 million years ago and is the first tool with an elegant design.  This stone tool unquestionably marks our transition out of an apish realm, but understanding its function has been one of the greatest puzzles of human evolution.

The hand axe is a large, flattened, tear drop-shaped rock that weighs up to several pounds, sometimes much more.  The perimeter of this stone is sharpened all around.  Since earlier varieties were too heavy to be thrown effectively and much too large to be attached to a shaft as a spear point, the tool is called a “hand axe”.  (Early anthropologists produced art that placed the stone as a spear point, which now appears rather ludicrous.)  I would label the tool differently because it should be clear that striking prey with this tool would cause injury to the user.  On impact, its sharp-edged perimeter would slice into the hand that held it.  How the idea this stone was hand-held got on the blackboard is unfathomable, but get there it did, and it was generally accepted for decades.  

Puzzling over hand axe function has sparked a century of wild speculation.  The literature is full of ideas: it was used for digging, chopping, perhaps a discus.  Someone came up with “an ancient religious object.”   When something can’t be explained, religion is always there to lend a helping hand.


Some have called it the Swiss Army knife of ancient times.  However, Swiss Army knives are characterized by having many known functions, not many unknown functions.  It's all rather frustrating for anthropologists.  So some have reverted to calling the stone a “bi-face”, meaning it is a flattened rock with two sharp edges. But it is sharpened at the butt end too, giving it a heavy, cleaving, chisel end.  Take note of that end!

Our ancestors definitely had a function in mind.  Examining where these tools are found awakens an understanding of their use.  The typical deposition site is like Olorgesailie, Africa, where hundreds of hand axes lie together at the bottom of large mud holes in ancient stream beds.  In fact, most hand axes are found in ancient mud holes.  Safe storage areas some say, which is just one more unbelievable view that is inexplicably respected.

Our basic understanding of the activities that produced the human mind hinges upon the hand axe.  Therefore an analytical explanation of its function that fits the empirical evidence is needed, not guesses.

Here is what I see in the empirical evidence.  One essential clue to hand axe function is that some of them seem embedded, stuck, in the bottom muck of stream beds.  And another thing: mud holes in slow-running streams of ancient times would undoubtedly serve the same function as they do today.  They are excellent fishing/hunting locations.  

What is really exciting from a tree climber's perspective is that the ancient streams where hand axes were found meandered through gallery forest.  These forests boast really magnificent, old-growth trees with beautiful crowns that can spread over 150 feet in diameter.  Large limbs would have grown over waterways, enclosing the stream in a tunnel of high overhanging limbs.  Let's see.  Chimps carry rocks into treetops, don't they?  So it stands to reason that humans did too!   

The fog is finally dissipating, and along with it goes the need for speculation.  The hand axe’s hydrodynamic fusiform shape screams out its purpose.  It was designed specifically to be dropped from high limbs, heavy chisel end down.  In contrast to Handy Man's round stones, a hand axe could part the water with the killing force of a rifle bullet and cleave a brain case.  This is no exaggeration.  Rocks falling from those heights would be high powered projectiles.  Call it a gravity bullet.  Of course the mud holes have rounded stones in them too, telling us that any stone was better than none at all.  But the sharp perimeter of the hand axe would cut no matter what edge of the stone struck first.  It was the best possible design, a really smart design, to kill or maim surface-feeding fish and other prey that wandered in for a drink at a waterhole.  

I have given the tool its proper name: “drop-stone.”  The hunter would climb up and sit hidden on a high limb, motionless, the drop-stone held in position over the water.  He might then have released some bits of fruit to chum.  Then, with the first sign of rippling water, the fingers let go.  The hunter remained motionless until impact.  A child could do this.  The drop-stone was the first high-powered gun.


I can remember my step brother, cousin and I spending every free moment running around in the desert looking for lizards and ground squirrels.  We always brought them home. That is instinct.  When we went fishing, my father told us we had to eat everything we caught, to limit our take.  Without a doubt, ancestral children were provisioning the larder.  Occasionally, massive drop stones have been discovered that could kill large prey such as hippos.  While men would have likely used these stones, most of the stones could have been handled by everyone.  Youth would have played a significant role in the success of the family and tribe.  It is unfortunate that our children have lost this position in the clan.  It brought them both respect and responsibility.    

After the stones were dropped, some inevitably became lost in the mud.  Since large amphibious reptiles normally lurk about in fishing holes, it would often have been too dangerous to retrieve drop-stones.  These animals no doubt stole the kill at times.  Some of the stones could have been retrieved during dry spells, but we'll never know the details for certain.      

Drop-stone function is the only explanation that has ever embraced all hand axe data including locations, sizes, shapes, deposition numbers, positions in mud and weight.  The rules that determine the acceptance of a theory are dictated by Occam's Razor.  The most parsimonious theory is the correct theory.  A drop-stone function is an elegance of parsimony. 

The most important invention of human prehistory, the invention that shows when we crossed the threshold from ape to human, was an arboreal design.  

Before there could be an Einstein there was the first Einstein.  That tree climbing Einstein gave birth to humanity when he/she combined potential gravitational energy with the first technological invention  – a teardrop-shaped cutting edge that was the high powered rifle of antiquity.  It was the most enduring invention in human history.  Tree climbing is what made us human.  Geneticists tell us we share up to 98% of our genes with apes.  This drives home the point that our brain circuitry, bodies, hands, fingers nearly everything that we are, evolved primarily for analyzing and utilizing the arboreal world.  It is very difficult to find genes that can be attributed to life at the ground.  The parsimony of my climbing theory in explaining the empirical evidence establishes it as the leading explanation for the evolution of the human body and mind. 

My book The Descent blows away the cobwebs spun during a century and a half of anthropological thought.  It rests on the single simple premise that, not long ago, our ancestors were spending much more time in trees.  In the trees, we invented language, construction, rope, knots, stone throwing, drop-stones, spears, and more.  With these inventions we were able to challenge the beasts of the savanna.  

For over thirty million years of our evolution as primates we had a safe harbor in the trees from the predators of the land.  It was only around 50,000 years ago that we moved our homes out of  that aerial kingdom and began building them on the ground.  This was so recent that this period may well have filtered down into our myths.  No wonder we place deities in sky-high kingdoms and design cathedrals with an ambiance that mimics the high limbs of old-growth trees.  No wonder our children long for a tree house.    

When I climb into a high cradle of limbs I feel as if I am going home.  I have roots imbedded in the arboreal sky. Is this feeling a memory from that time when the Arboreal Continent provided us safer harbor?  Perhaps.  But what is certain is the empirical evidence telling us that what made us human were the activities our ancestors did in trees.  

It was in a high cradle in that nearly forgotten kingdom in the sky safe from leopards that we first opened our eyes to gaze in wonder at the sparkling stars of the universe.  And now a neurological celestial tree having outstretched limbs reaching to the heavens seems to be lifting us toward the stars. 

Copyright © 2014 Donald R. Perry. Published in this Blog with Dr. Perry’s permission. Pictures courtesy of TCC.

First Post

Climbing the Tree of Knowledge Part I by Dr. Donald Perry

Dr. Perry welcomes your comments and questions. Please email him at canopy evolution at

In 1973 I took a class in tropical biology where I was astounded to learn that while most rain forest species lived in the tropical rain forest canopy, it had yet to be explored. Without a doubt, many species new to science resided within that realm, not to mention the amazing natural history hidden there. But this treasure chest of biological diversity had remained unexplored for good reason. The most-prolific canopy communities are found living on top of broad limbs within the crowns of emergent trees -- rain forest giants. Their trunks can be up to twenty feet in diameter (including the buttresses) and the first limbs are often over ninety feet above ground. While humanity’s amazing exploratory efforts had recently allowed us to walk on the moon’s sterile surface, there was still no effective method for exploring earth’s “arboreal continent” – home of the most-complex communities of life in the known universe.


Andy Starrett, my professor at California State University Northridge, stared at me with an incredulous expression as I told him my crude plan to climb emergent trees. He had stretched mist-nets between the buttressed toes of these trees to capture bats for research, an extremely important group that pollinates and disperses many rain forest trees and plants. He didn’t try to dissuade me from this challenging biological adventure, perhaps because heights were in his blood too; his father had owned the construction company that built the Empire State building.

My first trip to Costa Rica was in June 1974, a time when that country still had vast expanses of jungle. My book, Life Above the Jungle Floor, is the first chronicle of rain-forest canopy life and it was the model for the feature film Medicine Man.

My simple plan was to throw a weight tied to a fishing line over a high tree limb, tie a heavier cord to the fishing line and pull that up, then pull a climbing rope into position with the heavier cord. I used mountaineering equipment to climb the rope. This allowed me to avoid the trunk where a dense tangle of leaves and vines concealed deadly tree vipers, ants and wasps to name a few. Of course I couldn’t escape every risk; support branches can be rotten. Since I was the only climber in Costa Rica at the time, I would be on my own if I fell or got stuck high in a tree.

It proved to be impossible to reach high limbs with the weighted fishing line so I searched for a large tree with a small neighbor. A beautiful emergent, Dipteryx panamensis, was in full bloom next to a smaller tree near the research station at Finca La Selva.

It was fairly easy climbing into the smaller tree and by noon I had succeeded in pulling the rope over the Dipteryx’s lowest branch. The rope, however, had become tangled in the smaller tree, and in order to dislodge it, I decided to jump and swing under the large limb. This proved to be a thrill for which I was ill-prepared. I stepped off the limb and dropped into a frightening near freefall. With what seemed like tremendous speed, I began to swing on a huge arc. The ride was similar to a roller-coaster as I slowed to a brief stop at the top of the far side, followed by a stomach-wrenching drop as I retraced the swing, now backwards.

The following year I returned with a crossbow. It allowed me to shoot the fishing line over limbs 150 feet high. This simple tool, along with an assortment of mountain-climbing gear, was the first effective tall-tree climbing method. Beginning in 1976 I used this method to take numerous scientists and several La Selva tourists on tree-climbing, canopy tours. I published the method in the journal Biotropica in 1978, and ever since the method has been used by researchers and explorers worldwide. Especially satisfying is that this method was critical for the investigation of tall trees like the coastal redwoods of California, my home state.

While working on my Ph.D. at UCLA in 1979, I developed the first canopy zipline with the help of John Williams, This rope system allowed both lateral and vertical travel, so I was able to investigate a volume of rain forest. The story was published in Smithsonian, magazine (June 1980 and in, Scientific American 1984) published the story featuring me hanging from my system on the front cover.

At the end of the Smithsonian Altered States article I hinted at the future of my research -- the role played by climbing in the evolution of human intelligence. Those were exciting times. I wrote, “I felt I could almost be Man’s arboreal ancestor.” While climbing, I marveled that the human nervous system was especially well-designed for canopy work. A few times, I had the odd sensation of regressing deeply into the murky past, almost becoming the human ancestor-- as in the film. I would then find myself on a live virtual tour, clambering along the same arboreal trails taken by our ancestors on their evolutionary path to humanness. After several decades of study, the seed of that rumination has grown into a book I have copyrighted but have not yet published called The Descent. It is the first comprehensive theory of human brain evolution.

Shortly after the Smithsonian Ramapithecus” article, I was cornered by a student anthropologist at a cocktail party. “Man’s arboreal ancestor”, he began to lecture, “was at the time, this belief was held by nearly the entire anthropological community. Parroting current views, he explained how scientists were certain that upright walking, hunting with weapons and self awareness evolved after our ancestors quit climbing trees. It was thought that our ancestors had abandoned their arboreal lifestyle at least fifteen million years ago. In other words, there was no “arboreal human ancestor”. What this student and many others didn’t know was that they had been sold a myth.


The Ramapithecus myth grew from a stubborn theoretical bias for life on savannas. Because the thought of being recently related to a silly grinning primate with hands for feet has always been unacceptable, fossil hunters knew what they had to find: a more-sophisticated, less-apelike ancestor. So for the last century and a half, every shard of bone has been forced into a puzzle it doesn’t fit. The puzzle’s image is the one of pure conjecture based on Darwin’s idea of our origins. So when a few teeth and bits of jaw were discovered, the artwork depicted an “ape person” walking upright on a savanna with no forest in sight. The imagined being was holding a weapon, but it was too crude to be used for protection against the super-sized predators of the time. That could not have been our ancestor; it would have been gobbled up into extinction if it set foot on a savanna.

The Ramapithecus myth vanished with the uncovering of a more-complete set of the animal’s bones. Ramapithecus turned out to be something very much like an orangutan.

Around the time of Ramapithecus’ fall, anthropologists took another blow. They remained steadfast in their belief that we were not closely related to chimps and that upright walking originated around 15 to 20 million years ago -- after we abandoned the trees. Meanwhile, scientists outside of anthropology, molecular biologists, began to experiment with tests that convincingly established chimpanzees as our closest relative. Somewhat unnoticed is that this finding brought the climbing era of human evolution to just six million years ago, over fifty percent closer to the present. A climbing past was pushing its way up the timeline.

The sixties, seventies and eighties affected a perfect storm with swell after swell sinking unreasonable anthropological theories. A prime example was the famous discovery of Lucy. With the death of Ramapithecus she had become the flag bearer; the new, first human ancestor thought to have favored full-time life at the ground. But as with the feeble weapon drawn in Ramapithecus’ hand, there was no empirical evidence that Lucy had abandoned tree climbing. In fact the fossil record revealed her ape-like fingers; fingers that must have been used for climbing!

Prominent anthropologists focused on Lucy’s bipedalism, hoping she could further distance us from tree-climbing animals. She lived 3 million years ago, and while her bipedalism demonstrates that she could leave the trees, her fingers tell us she could also climb very well. (It is now known that upright walking originated while we were devoted tree climbers).

The search for the origins of upright walking overshadowed an extremely important point. Just as now, upright walking in no way prevented climbing. Nevertheless, an article in Scientific American quoted a leading stating that since Lucy had legs like humans, her legs would have broken if she had climbed. The statement reveals a deep vein of bias against climbing that has chronically hindered the anthropological community’s ability to accurately interpret the data.

Anthropologists justified this position with the anti-evolutionary notion that climbing fingers were not used for climbing. They labeled climbing fingers “evolutionary baggage”. When mole-like claws are seen on the front feet of an insectivore, it suggests digging. Fins on the arms of a fissiped suggest a  seal-like manner of swimming. So it holds to reason that very strong curved fingers, arms and upper torsos on a bipedal ancestor indicates climbing. Negating what we see— claws are not used for digging, fins are not used for swimming, fingers are not used for climbing — is simply not allowed in real science. The fact is: all adaptations are evolutionary baggage. They are tools of survival that must be unpacked and put to use. Lucy was a seventy-pound defenseless bipedal ape said to be living in a savanna habitat. Given the populations of huge predators at the time, Lucy either put her baggage to work climbing or she became extinct.

With 20/20 hindsight, I could be accused of taking cheap shots at anthropological myths. However, I have been proposing an ancestral human canopy connection for thirty years and while the literature consistently supports my view, there is no support for the anti-climbing views held by anthropologists.


I have examined the evidence of numerous ancestors from eight million years ago, up to and including Neandertals, and found a wealth of climbing adaptations and probable behaviors that were either overlooked or categorized as unimportant. Whatever the case, they remain unreported. This unreported climbing data from the fields of morphology, behavior, archeology and paleontology is precisely what led me to originate the first comprehensive theory of human evolution. I call this the “scansorial theory” (climbing theory). My theory answers the single, most-important question of philosophy and science. It shows where human intelligence began and why. It is a story about who we are and where we came from that has never been told.

Copyright © 2014 Donald R. Perry. Published in this Blog with Dr. Perry’s permission. Pictures courtesy of TCC.

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