Rhesus Monkeys Know When They Remember [PNAS] [PubMed] [JSTOR
RR Hampton

Abstract: Humans are consciously aware of some memories and can make verbal reports about these memories. Other memories cannot be brought to consciousness, even though they influence behavior. This conspicuous difference in access to memories is central in taxonomies of human memory systems but has been difficult to document in animal studies, suggesting that some forms of memory may be unique to humans. Here I show that rhesus macaque monkeys can report the presence or absence of memory. Although it is probably impossible to document subjective, conscious properties of memory in nonverbal animals, this result objectively demonstrates an important functional parallel with human conscious memory. Animals able to discern the presence and absence of memory should improve accuracy if allowed to decline memory tests when they have forgotten, and should decline tests most frequently when memory is attenuated experimentally. One of two monkeys examined unequivocally met these criteria under all test conditions, whereas the second monkey met them in all but one case. Probe tests were used to rule out “cueing” by a wide variety of environmental and behavioral stimuli, leaving detection of the absence of memory per se as the most likely mechanism underlying the monkeys’ abilities to selectively decline memory tests when they had forgotten.

"Chimpanzees, gorillas, orangutans have been living for hundreds of thousands of years in their forest, living fantastic lives, never overpopulating, never destroying the forest. I would say that they have been in a way more successful than us as far as being in harmony with the environment."

Jane Goodall (primatologist, ethologist, anthropologist, UN Messenger of Peace, and overall beautiful ambassador of life on this planet)

Lately I haven’t been able to stop drawing great apes & fossil hominids. I draw them as one method of learning about them.

Here’s a little bit of me visually exploring probably the most culturally famous individual fossil hominid, an individual who lived about 3.2 million years ago on the land that is present-day Ethiopia, called “Lucy”, presumed female based on comparative pelvis physiology.

As part of the species afarensis in the group Australopithecus of the hominid family, “Lucy” was a close cousin of the family lines that all living humans descend from. Some earlier members of the group Australopithecus are ancestors of both “Lucy” and all humans. Lucy’s species, afarensis, is the closest relative of those common ancestors that we know of so far.

Lucy, the individual, was about 3 ft 7 in (1.1 m) tall, which seems very small to us but was not unusually short for members of the afarensis species. Generally speaking, members of the Australopithecus group had all the necessary hardware to walk upright, and probably did regularly.

More reading:





Why are testicles kept in a vulnerable dangling sac? It’s not why you think.

Soccer fans call it brave goalkeeping, the act of springing into a star shape in front of an attacker who is about to kick the ball as hard as possible toward the goal. As I shuffled from the field, bent forward, eyes watering, waiting for the excruciating whack of pain in my crotch to metamorphose into a gut-wrenching ache, I thought only stupid goalkeeping. But after the fourth customary slap on the back from a teammate chortling, “Hope you never wanted kids, pal,” I thought only stupid, stupid testicles.

Natural selection has sculpted the mammalian forelimb into horses’ front legs, dolphins’ fins, bats’ wings, and my soccer ball-catching hands. Why, on the path from the primordial soup to us curious hairless apes, did evolution house the essential male reproductive organs in an exposed sac? It’s like a bank deciding against a vault and keeping its money in a tent on the sidewalk.

Some of you may be thinking that there is a simple answer: temperature. This arrangement evolved to keep them cool. I thought so, too, and assumed that a quick glimpse at the scientific literature would reveal the biological reasons and I’d move on. But what I found was that the small band of scientists who have dedicated their professional time to pondering the scrotum’s existence are starkly divided over this so-called cooling hypothesis.

Reams of data show that scrotal sperm factories, including our own, work best a few degrees below core body temperature. The problem is, this doesn’t prove cooling was the reason that testicles originally descended. It’s a straight-up chicken-and-egg situation—did testicles leave the kitchen because they couldn’t stand the heat, or do they work best in the cold because they had to leave the body?

[read more]

Dolphins like to get high by sucking on puffer fish



Using a remote-controlled camera disguised as a sea turtle, marine biologists watched as young dolphins got themselves stoned by ingesting a nerve toxin released by puffer fish. And as if sharing a joint, the dolphins could be seen passing it around.

Puffer fish, when provoked, protect themselves by releasing a nasty toxin that can be deadly. But the dolphins appear to have figured out how to make the fish release it in just the right amount.

After chewing on the puffer fish and passing it around between one another, the dolphins appeared to enter into a trance-like state.

"[T]hey began acting most peculiarly, hanging around with their noses at the surface as if fascinated by their own reflection," noted zoologist Rob Pilley. "It reminded us of that craze a few years ago when people started licking toads to get a buzz, especially the way they hung there in a daze afterwards. It was the most extraordinary thing to see."

The behavior was recorded on camera by the makers of the nature documentary, Dolphins: Spy in the Pod — a series produced for BBC One. Here’s the trailer: (x)

And check out this wild robotic camera disguised as a sea turtle: (x)

(full article)

Many of you have seen my post on a dolphin’s recreational tool use, so this post shouldn’t really come as a major surprise. Yes, dolphins are highly intelligent social animals…. BUT this kind of recreational self-medication (different than medicinal / strictly anti-parasitic self-medication) is not particularly unique in the animal kingdom. Let’s take a quick look at a few other animals who enjoy some recreational self-medication…

~Black Lemur (Eulemur macaco)
The Black Lemur will seek out certain toxic millipedes (Charactopygus spp.), bite them to stimulate the millipede’s defensive toxin production, and then proceed to rub the wounded millipede all over their fur. A report on this fur anointing noted that after biting the millipede, the lemurs would grimace, with their eyes half-closed, and salivate profusely. (x)

Check out this BBC Nature video of this anointing behavior! (x)


~Chacma / Cape baboons (Papio ursinus)
Hamilton et al. (1978) classified a group of food items consumed  by these baboons as euphorics. These euphorics are “distinguished by their hallucinogenic properties and their high toxicity to humans and other mammals” and included such plants like the Large Fever-Berry (Croton megalobotrys), Crown of Thorns (Euphorbia avasmontana), Downy thorn-apple / moonflower (Datura innoxia), and Jimson weed (D. stramonium). (x)


~Horses and other livestock
Locoweed is the common name for any plant that produces swainsonine, typically plants of the  Oxytropis and Astragalus families in North America. This intoxicating-yet-dangerous plant is very palatable to lifestock, and is even considered the largest poison-plant problem in the Western United States! Livestock that chronically ingest large amounts of swainsonine can develop diarrhea, behavioral changes, congestive heart failure, vacuolization of tissues, and a medical condition known as locoism (a.k.a. swainsonine disease). (x,x)

~Reindeer (Rangifer tarandus)
Reindeer seek out the red and white caps of the ‘magic mushroom’ Fly Agaric (Amanita muscaria ). These toxic fungi provide a high reminiscent of flying, and is said to be similar to hallucinogenic effects of LSD. This magic mushroom wasn’t just limited to animal use, it is also fairly prevalent in shamanism and other religious rituals in the area. (x, x)

~Hummingbirds (Ensifera ensifera)
Some hummingbirds, like the sword-billed hummingbird, feed on the nectar of the Datura (spp.) flower. Each plant’s toxicity depends on the age, location, and weather conditions, and can result in a 5:1 toxin variation. Datura intoxication can produce delirium, inability to distinguish reality from fantasy, hyperthermia, violent behavior, dilated pupils, painful long lasting photophobia, and even pronounced amnesia.(x, x)

Sword-billed hummingbird approaching Datura flower to feed (x)


Additional Reading:

~Animal Pharm: What Can We Learn From Nature’s Self-Medicators (National Geographic)

[This is a very brief introductory article on self-medication behavior. If you guys would like me to do an in-depth article on this, just let me know!]


Dian Fossey was born on January 16, 1932, in San Francisco, California. While working as an occupational therapist, Fossey became interested in primates during a trip to Africa in 1963. She studied the endangered gorillas of the Rwandan mountain forest for two decades before her unsolved murder occurred in 1985, at Volcanoes National Park in Rwanda. Fossey told her story in the book Gorillas in the Mist (1983), which was later adapted for a film starring Sigourney Weaver.

Early Life

Primatologist and naturalist Dian Fossey was born on January 16, 1932, in San Francisco, California, and grew up with her mother and stepfather. Developing an affinity for animals at a young age, throughout her youth, Fossey was an avid horseback rider and an aspiring veterinarian. However, after enrolling in pre-veterinary studies at the University of California, Davis, she transferred to San Jose State College and changed her major to occupational therapy.

After graduating from San Jose in 1954, Fossey spent several months working as a hospital intern in California, and then moved to Louisville, Kentucky, where she began serving as director of the Kosair Crippled Children’s Hospital’s occupational therapy department in 1955. Living on a farm on the outskirts of Louisville, Fossey spent many off-hours happily tending to the livestock. But her contentment didn’t last long. She soon became restless, longing to see other parts of the world and setting her sights on Africa.

'Gorillas in the Mist'

In September 1963, Fossey embarked on her first trip to Africa—which cost Fossey her entire life savings at the time, as well as a bank loan—visiting Kenya, Tanzania, Zimbabwe and the Congo, among other areas. She soon met paleoanthropologist Mary Leakeyand her husband, archaeologist Louis Leakey, one of the best-known husband-wife teams in the history of science. 

Fossey then met Joan and Alan Root, native wildlife photographers who were working on a documentary of African gorillas at the time, and when the couple brought her along on one of their trips in search of the primates, Fossey was instantly enamored. She later explained her draw to gorillas in her 1983 autobiographical work,Gorillas in the Mist: “It was their individuality combined with the shyness of their behavior that remained the most captivating impression of this first encounter with the greatest of the great apes,” Fossey said. “I left Kabara with reluctance, but with never a doubt that I would, somehow, return to learn more about the gorillas of the misted mountains.”

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Enormous Underwater Fossil Graveyard Found

“National Science Foundation-funded anthropologists and paleontologists uncovered what could be the largest single collection of lemur remains ever found. What’s more, they found it in a most unusual place—hidden in a series of underwater caves in a remote desert region of Madagascar. 

Described as a lemur graveyard, the discovery of hundreds of potentially thousand-year old skeletons make it one of the most unique sites in the world. The finding, reported in this video, could be important for understanding human relatives and other animals and result in a totally new era for underwater paleontology.”

***And you thought you had some cool beans, kids. These beans are the coolest beans in the bean bag.

(Source: National Science Foundation)


If you’re like me, you’re currently in the midst of finals week. So here are a collection of motivational primates to help you out, for whatever type of motivation you need. Cute baby chimpanzee believes in you, and angry baboon is going to rip you to shreds if you don’t get that work done.

Feel-good fossils and motivational megafauna coming up next.

Wild chimps seen hunting with spears

Chimpanzees mostly eat fruit but occasionally supplement their diet with meat. A common prey is other primates and chimps have developed some fairly complex tactics for taking them down, often flanking around to force their prey into a trap where another chimp is waiting to ambush them. However one group have chimps have taken things a step further and started using spears in their hunt.

The Savannah chimps (so called because they live near the edge of the forest) hunt bush babies; a prosimian widely regarded as “cute”. Bush babies are nocturnal and hide in tree hollows during the day. They’re adept climbers so if a chimp were to try and reach in and grab them they could easily escape. To counter this the Savannah chimps have started breaking off tree branches, stripping off the bark and then sharpening the end with their teeth.

They then stabbed their spear into the bush baby “nests”; after which they would break open the tree and pull out their prey. Although the researchers couldn’t see if the bush baby was killed by the spear, they did note that “it made no attempts to escape, nor did it utter any vocalization.” The chimp then ate their victim (interestingly, they did not share it with other chimps as is the norm).

This makes them the only known animal (other than humans) l to use tools to hunt vertebrates.

The primatologists were also impressed with the complexity of the spear, requiring more steps to create than most other chimp tools. Not only do they sharpen the tip and strip the bark, but they also typically trim the tips of the tool first. This helps remove any damage caused by them snapping the branch off the tree; creating a more durable tool. This indicates a high level of planning, intelligence and murderous intent.

Next they’re going to figure out fire, then we’re fucked.

Pruetz, J. D., & Bertolani, P. (2007). Savanna Chimpanzees, Pan troglodytes verus, Hunt with Tools. Current Biology, 17(5), 412-417.

Comparative Study of a Human and Chimpanzee Skull
  • by Katy Wiedemann

“This is a comparative study of the similarities between a human and chimpanzee skull commissioned by Studio Livrela for the “Darwin’s Spot” project. The study was hand drawn in ink using a pointillism technique.”

  • Scientific Illustration Intern

    Marine Biological Laboratory — Woods Hole, MA, USA

  • Curator’s Assistant and Animal Care Specialist

    The Edna Lawrence Nature Lab — Providence, RI, USA

  • Studio and Gallery Assistant

    PONSHOP Studio and Gallery — Fredericksburg, VA, USA 

***View Katy Wiedemann’s portfolio and learn more about her work.

(Source: Katy Wiedemann)

It must be stressed that there is nothing insulting about looking at people as animals. We are animals, after all. Homo sapiens is a species of primate, a biological phenomenon dominated by biological rules, like any other species. Human nature is no more than one particular kind of animal nature. Agreed, the human species is an extraordinary animal; but all other species are also extraordinary animals, each in their own way, and the scientific man-watcher can bring many fresh insights to the study of human affairs if he can retain this basic attitude of evolutionary humility.
—  Desmond Morris, Manwatching; A Field Guide to Human Behaviour 

Visual Specialization and Brain Evolution in Primates [RSPB]
RA Barton 1998

Abstract: Several theories have been proposed to explain the evolution of species differences in brain size, but no concensus has emerged. One unresolved question is whether brain size differences are a result of neural specializations or of biological constraints affecting the whole brain. Here I show that, among primates, brain size variation is associated with visual specialization. Primates with large brains for their body size have relatively expanded visual brain areas, including the primary visual cortex and lateral geniculate nucleus. Within the visual system, it is, in particular, one functionally specialized pathway upon which selection has acted: evolutionary changes in the number of neurons in parvocellular, but not magno- cellular, layers of the lateral geniculate nucleus are correlated with changes in both brain size and ecological variables (diet and social group size). Given the known functions of the parvocellular pathway, these results suggest that the relatively large brains of frugivorous species are products of selection on the ability to perceive and select fruits using specifc visual cues such as colour. The separate correlation between group size and visual brain evolution, on the other hand, may indicate the visual basis of social information processing in the primate brain.

This article is required reading if you want to read his 2004 PNAS article since the PNAS article uses his previous findings to make speculative and receive counterintuitive results on the role of the parvocellular layers and magnocellular layers on binocularity. Both articles provide highly speculative hypotheses that can provide a long critique/thought/thinktank sessions. Nevertheless, these articles both provide information on the role of binocularity and speculates on whether the brain evolved due to more internal or external forces.