Picture galleries

Photo award 2025 - Category Aesthetics

Guinea baboons in the evening light. — Ä-01 Family portrait in the evening light
In addition to chimpanzees, Moyen-Bafing National Park is also home to countless Guinea baboons, which often attract attention due to their numbers and curiosity. The line between curiosity and mistrust is often very thin, and so these three baboons keep a close eye on us, just as we keep a close eye on them. The question often arises as to who is actually observing and studying whom more closely.

Green monkey with water droplets on its mouth. — Ä-02 Thursty
Water sources can be dangerous for vervet monkeys, that's why they are usually vigilant when they are drinking from a river. Here, a vigilant juvenile is photographed with a water drop after he drank from the river.

Close-up of a monkey sitting on a branch. — Ä-03 Caught looking
A quiet stare from the branches, as if returning the camera’s attention.

A Barbary macaque sits in a leafy landscape. Tree trunks can be seen in the background. — Ä-04 Barbary macaque in the mist
A female Barbary macaque (Macaca sylvanus) on an early morning in the fall.

A hybrid primate sits with its legs spread wide apart in a tree. — Ä-05 Boundaries blurred at the canopy
In a fragmented forest of Bangladesh, this first-generation hybrid between two globally threatened species– Phayre’s and capped langurs– stands as a rare sign of evolution in motion. Bearing traits of both parents, its calm gaze reminds us how ecological imbalance can blur the boundaries of species and survival.

A primate with mainly white fur was photographed in mid-jump. — Ä-06 I'm flying!
Verreaux's sifaka (Propithecus verreauxi) moves through the treetops.

A lemur calls out, orange leaves in the background. — Ä-07 Where are you?
A ring-tailed lemur (Lemur catta) vocalizing to its group. Contact calls, such as moans, are vital for maintaining social cohesion.

A young female guinea baboon lies in a sea of leaves. — Ä-08 Baboon in leaf litter
A young female guinea baboon lies in a sea of leaves.

A red-fronted lemur shows off its tail wrapped around its body. — Ä-09 Tail show
Redfronted lemurs use their tail in different ways when they rest. Sometimes they cuddle them, sometimes use like a scarf. Pata is using her tail here to give a perfect instagram picture.

A small baboon slaps the water, causing water droplets to fly everywhere. — Ä-10 Big splashes
The big paddles in the rainy season are great opportunities to play for the Guineababoons at Simenti field station, Senegal.

Photo award 2025 - Category Originality

Full moon in Salem — O-01 - Hindquarters of a female Barbary macaque at Affenberg Salem..

Men choir in the forest — O-02 - Four male Assam macaques form a united front against an opponent above them in the treetops. Such aggressive coalitions often determined the rise or maintenance of individual males' rank.

Male baboon — O-03 - Smile? Check. Hair in place? Well... Male baboon Sheriff is still practicing taking selfies.

No hair-pulling please! — O-04 - Assamese macaque males at Phu Khieo Wildlife Sanctuary form a linear dominance hierarchy that is established by direct one-on-one fights.

Wet assamese macaques — O-05 - The rainy season in Phu Khieo Wildlife Sanctuary is long and intense. From mid-March to October, monkeys and observers alike can expect to get soaked every day.

Through the mirror — O-06 - At Hanover Zoo, a child places its hand against the glass behind which a gorilla rests. In the reflection, it seems as if the great ape is gently holding the child in its arms: if we are meant to be so different, why do we see so much of ourselves in them?

Made you look — O-07 - A capuchin’s cheeky expression turns the canopy into a stage.

monkeys at a pond to drink — O-08 - During the scorching heat, a troop of Northern Pig-tailed macaques (Macaca leonina) gathers at a pond to drink in perfect unison. Their mirrored reflections evoke peace and harmony – until moments later, the Monkey Bar turns wild, with splashes of blood, poop, and pure primate drama!

male Phayre’s langur — O-09 - Locked in a tense standoff, a male Phayre’s langur (Trachypithecus phayrei) confronts his rival with raw intensity. His open-mouthed display– teeth bared, muscles tensed– embodies both warning and pride, an instinctive act to defend territory and hierarchy. In this fleeting clash of power and will, the forest mirrors the very struggles that define our own human world.

scent marking ring-tailed lemur — O-10 - A collared ring-tailed lemur (Lemur catta) scent marks a pole. Individual collars allow us to study key behaviors, such as scent marking

Photo award 2025 - Category Science

Field assistance in the open air indicates lemurs. — W-01 Look there!
The trained eyes of the field assistant (Fabi) at Kirindy forest spot the lemurs faster than we do.

Mouse lemur in coconut illuminated by red light. Mouse lemur looks directly into the camera. — W-02 Novel object test in red light conditions
What makes an animal curious? In Kirindy, we test how wild mouse lemurs respond to different unnatural objects. Here, you see an animal peek out of a hollow coconut. All of our experiments with mouse lemurs are done at night in red light conditions to disturb the animals the least.

Image of the heart - MRI in bright neon colors of orange and purple — W-03 A glimpse into the inside of the macaque heart
Image of a macaque's heart MRI in 2-chamber view (2Ch). The photo was taken from a baseline MRI and before contrast administration.

Javanese monkey stands in experimental setting. — W-04 Which way to green?
This is Derek, one of our monkeys, performing an experimental task inside the Exploration Room—a specially designed space that allows us to study brain activity during natural movement. In this task, Derek first steps into a projected white box to start a trial. Then, a colored light appears on the floor. Each color is linked to a specific corner of the room, which Derek has learned through training. To succeed, he must walk to the correct corner and touch the screen to earn a reward. In the photo Derek is deliberating on where the "green" corner is. In everyday terms, it’s like thinking of the fridge, stove, or microwave in your kitchen and then walking to it. This experiment will help us to better understand how the brain represents goals in space and guides actions.

Thermal image of three monkeys interacting. Two adult monkeys are sitting opposite each other; one is holding up a small infant, while the other is watching it intently. The bright yellow-orange areas show warmer parts of the body, while the background appears in cool blue and purple tones. — W-05 MIMI: Male-infant-male interaction
Thermal image of a “male-infant-male interaction” between two male Barbary macaques (Macaca sylvanus). They “teeth chatter” to the few-weeks-old infant while holding it up.

A primate with brown-gray fur and a bushy tail climbs headfirst down a black tripod leg in a forest. The tripod stands on a forest floor covered with leaves. Dense green undergrowth and forest can be seen in the background. The lemur wears a blue collar with a transmitter. A small wooden box lies under the tripod. — W-06 The climber
Sometimes during the experiment, study subjects are getting curious for the researchers other equipment. Here, one of them is climbing onto tripod.

Night of Science 2025

Besucher schauen sich ein Video zum Exploration-Room an bei der Nacht des Wissens 2025

Prof. Treue auf einer Bühne bei der Nacht des Wissens 2025

Ein Besucher versucht einen Gegenstand in einer geschlossen Box zu ertasten bei der Nacht des Wissens 2025

Zwei Jungen schauen sich ein Poster mit MRT-Bildern für ihren Forscherpass an bei der Nacht des Wissens 2025

DPZ Forscherinnen erklären Kindern das Pipettieren bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einem Besucher ein Gehirnmodell bei der Nacht des Wissens 2025

Ein Gefäß mit benutzten Pipettenspitzen bei der Nacht des Wissens 2025

Prof. Treue erklärt Besuchern ein Video zum Exploration Room bei der Nacht des Wissens 2025

Eine DPZ Forscherin im Gespräch mit zwei Besuchern bei der Nacht des Wissens 2025

Ein DPZ Forscher im Gespräch mit einem Mädchen bei der Nacht des Wissens 2025

Ein DPZ Forscher erklärt einem Mädchen Mikroskopbilder bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einer Besucherin das Pipettieren bei der Nacht des Wissens 2025

Ein DPZ Forscher erklärt einer Besucherin ein Video bei der Nacht des Wissens 2025

Ein DPZ Forscher erklärt einer Besucherin das Pipettieren bei der Nacht des Wissens 2025

Ein DPZ Forscher erklärt einem Jungen MRT-Bilder bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einem Besucher Mikroskopbilder bei der Nacht des Wissens 2025

Zwei Besucher machen ein Reaktionszeitexperiment bei der Nacht des Wissens 2025

Prof. Behr im Gespräch mit einer Besucherin bei der Nacht des Wissens 2025

Ein Mädchen versucht einen Gegenstand in einer geschlossenen Box zu ertasten bei der Nacht des Wissens 2025

Zwei Jungen machen ein Experiment bei der Nacht des Wissens 2025

Zwei Jungen malen mit Umkehrbrillen bei der Nacht des Wissens 2025

Prof. Treue im Gespräch mit einem Besucher bei der Nacht des Wissens 2025

Ein DPZ Forscher erklärt Besuchern MRT-Bilder bei der Nacht des Wissens 2025

Zwei Besucher machen ein Experiment bei der Nacht des Wissens 2025

Prof. Treue erklärt Besuchern ein Video bei der Nacht des Wissens 2025

Eine DPZ Forscherin lacht, ein Junge macht ein Experiment bei der Nacht des Wissens 2025

Zwei Besucherinnen machen ein Experiment bei der Nacht des Wissens 2025

Zwei Besucher malen mit Umkehrbrillen bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einem Mädchen ein Experiment bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einem Jungen ein Experiment bei der Nacht des Wissens 2025

Eine DPZ Forscherin im Gespräch mit einem Mädchen bei der Nacht des Wissens 2025

Zwei Besucher machen ein Experiment bei der Nacht des Wissens 2025

Eine Besucherin testet ein Posenerkennsystem bei der Nacht des Wissens 2025

Eine DPZ Forscherin erklärt einem Jungen ein Experiment bei der Nacht des Wissens 2025

Zwei Besucher machen das Primatenquiz bei der Nacht des Wissens 2025

Eine DPZ Forscherin im Gespräch mit einer Besucherin bei der Nacht des Wissens 2025

Zwei Besucher machen bei ein Reaktionszeitexperiment bei der Nacht des Wissens 2025

Zwei Besucher machen bei ein Reaktionszeitexperiment bei der Nacht des Wissens 2025

Zwei Jungen mit Fotomasken vor der Selfiewand bei der Nacht des Wissens 2025

Der Info-Stand der Stabsstelle Kommunikation bei der Nacht des Wissens 2025

Ein Plakat des DPZ bei der Nacht des Wissens 2025

[Translate to Englisch:] Nacht des Wissens, Gruppenfoto

Ein Junge trägt Infektionsschutzkleidung und posiert vor einem Bild eines Coronavirus bei der Nacht des Wissens 2025

Besucher machen das Primatenquiz und Tierversuchsquiz bei der Nacht des Wissens 2025

Eine Besucherin ordnet Modelle von verschiedenen Stufen der Embryoentwicklung bei der Nacht des Wissens 2025

Photo award 2024 - Category Aesthetics

This gibbon has a light-colored, fluffy coat. It is about 40 cm tall from head to feet. — A white-handed gibbon at Phu Khieo Wildlife Sanctuary.

Drei langurs on branches in the dense forest. The animals are about 50 cm tall from head to foot. They have a tail that is about 70 cm long. — Phayre’s leaf monkeys at Phu Khieo Wildlife Sanctuary.

The head of a cute young animal fills the left half of the picture. The skin is dark, the eyes round and the fur brown. A green stalk runs vertically through the center of the picture. The monkey is clutching the stalk with its small hand and nibbling on it. — This picture was taken in the context of realising identification guides for the baboons in the long term project of the CRP Simenti.

The female is about 50 cm tall and golden brown in color. The infant has less dense fur. Hands and feeta are almost bare. — An infant Assamese macaques attempts to escape from its mother

A golden-headed tamarin with thick silky black fur sits on a bare branch against a deep blue sky. In the shoulder area, the fur is mane-like and orange-reddish. The face is hairless. — A few days after the translocation and release into a different forest area, this adult Golden-headed Lion Tamarin (Leontopithecus chrysomelas) climbs high on a tree apparently to observe its novel habitat and decide where to go.

Half-length portrait of a long-tailed macaque looking at the viewer. — A long-tailed macaque (Macaca fascicularis) breeding male with the name Caeser, presenting himself photogenically in the sun.

Kaja Wierucka

A ring-tailed lemur (Lemur catta) vocalizing to its conspecifics. Moans are a contact call produced to maintain group cohesion.

Breast portrait of a black macaque biting into a juicy yellow-orange orange fruit — A female Tonkean macaque enjoying some delicious fresh oranges.

The mother monkey hugs her young. She has beige cuddly fur. The cub has black fur. In some places the pink skin shines through the fur. Both are surrounded by a dense forest. — Barbary macaque (Macaca sylvanus) female and its recently born baby sitting on a fallen Branch.

A fossa stands on the ground next to a tree trunk, filling the picture. The animal is about 50 cm tall, has round ears, dark brown fur, sturdy short legs and claws. — The fossa (Cryptoprocta ferox), endemic to Madagascar, is a formidable predator of lemurs.

Photo award 2024 - Category Originality

A young Assammakak is being cared for by its mother, who looks closely at the fur on its head. The monkey's ear shimmers a bright pink as the sun shines through it from behind. — Hot ear – a female Assamese macaque grooms her infant

Baboon dips bread roll into the water — A baboon dips the dry bread rolls into the water.

Sarah Schlagowski

E.coli bacteria were applied to a nutrient agar plate using a paper template. After a 24 h incubation period the first image was created. At intervals of 4, 8, 11 and 15 days the growth was documented and displayed in chronological order.

In this picture you can see Caesar, the male Javanera from the G4-Primate enclosure at the DPZ. Caesar was given an old issue of DPZ Aktuell to keep him occupied, and seems to have read it very carefully. — Here you can see Caesar the male Javan from the G4 primate enclosure here at the DPZ. The picture was taken by Vicky May Schröder, animal keeper. Ceasar has been given an old issue of DPZ Aktuell to keep him occupied & seems to have read it very carefully. I call it: ‘Where is the Sudoku page?’

Four young Assamese macaques (Macaca assamensis) attentively observe their surroundings from a safe distance. They stand or sit in a group, their eyes alert as they check out their surroundings at the Phu Khieo Wildlife Sanctuary. — Strength in numbers – immature Assamese macaques observe their surroundings from a safe distance

A young Assamese macaque (Macaca assamensis) in the Phu Khieo Wildlife Sanctuary yawns. It holds its hand halfway to its mouth and looks curiously at the camera as it takes a short break. — So boring! An infant Assamese macaque at Phu Khieo Wildlife Sanctuary

Branch parkour — While playing and bouncing from branch to branch, this young brown capuchin nearly fell and tried to climb back onto this branch

An adult male Tonkean macaque (Macaca tonkeana), with black fur, uses a stick to pick its nose and ingest nasal mucus, keeping its eyes closed. This behavior, which has been observed in several primate species, shows the macaque in a natural, curious act. — An adult male Tonkean macaque picks his nose with a stick to ingest nasal mucus, a behavior observed in several primate species

A young diademed sifaka (Propithecus diadema) clings to its mother as she elegantly leaps between the trees and floats through the treetops. — A sifaka (Propithecus diadema) infant holds on as its mother leaps effortlessly between trees, soaring high through the treetops.

Photo award 2024 - Category Science

A thermal image (thermography) shows a group of Barbary macaques (Macaca sylvanus) in conflict. The image is predominantly in deep blue tones, representing the cold areas of the monkeys. The deep blue noses of the monkeys are particularly clear, emphasizing their excitement during the conflict. The monkeys are seen in a dark environment, with their body outlines and positions recognizable through the heat signatures. The monkeys' faces and bodies are blurred and out of focus, which is typical of thermal images. — Thermal image of a group of Barbary macaques (Macaca sylvanus) in a conflict. Their arousal during the conflict is clearly visible on their cold (deep blue) noses.

Thermographic image of a male Barbary macaque (Macaca sylvanus) named Bernd taking a nap in his favorite position. The monkey is depicted in the colors red, pink and yellow and has curled up into a ball shape. — Thermal image of a male Barbary macaque (Macaca sylvanus) called Bernd who is napping in his favorite position

A magnified image shows a light-colored, soft, irregularly shaped substance, a cochlea, being held with tweezers. The background is dark, bringing the object into focus. — As part of the cochlear preparation, the cochlea was decalcified in EDTA for several weeks and bone lamella by bone lamella was removed. Here you can see the organ of Corti directly after opening both scalae and removing the stria vascularis

The image shows a cell engraved in red, which was created as part of the production of a stable cell line. A plasmid was transduced with Scarlet, which marks the cell. The cell looks as if it is calling for help. — The picture was taken on July 18, 2024 and shows a cell that was created as part of the production of a stable cell line. A plasmid was transduced with Scarlet.

A pair of red-brown titi monkeys (Plecturocebus cupreus) with radio collars groom each other high in the trees. — A radio-collared pair of red titi monkeys (Plecturocebus cupreus) groom each other high in the trees. The collars which are equipped with antennas allow the scientists to track the primates even in the dense jungle via telemetry.

A baby marmoset monkey sits on a white background, the background is also completely white. The animal looks cutely into the camera. — "Myrabello“. First of his name. A genetically modified marmoset monkey, son of Myriada and Wolgraf, raised by Belore and Innotiz.

A three-part image sequence shows a transparent container surrounded by colorful jelly balls. In the middle and lower shots, a dark hand of a primate can be seen moving through the spheres, causing some of them to shift. — A rhesus macaque (Macaca mulatta) is reaching for and grabbing a handful of colourful water bubbles with natural flavours.

It looks like a single capital letter “G” in a bold, sans serif style consisting of a multitude of small, rectangular shapes arranged close together. The “G” is in a light shade of gray and stands out clearly against the dark, almost black background. The individual shapes that make up the “G” have slight irregularities and shading that create a three-dimensional effect and give the letter a structured, almost pixel-like appearance. — The 9.4T MRI scanner at the DPZ, depicted using proton spectra acquired on this system.

The image shows a collection of red and green particles that look like a sea of stars and surround planet-like blue cell nuclei. This is a cancer cell line that has been infected with a dual-fluorescent virus (KSHV). The capsid of the virus glows red and the glycoprotein M glows green. The cell nucleus is shown in blue by Hoechst staining. The image was taken with a confocal microscope at the time of virus attachment. — This cosmos consists of a collection of red and green particles – like a sea of stars. The particles surround planet-like blue cell nuclei.

For this purpose, a cancer cell line was infected with a dual-fluorescent virus (KSHV). The capsid of the virus is red and the glycoprotein M glows green. The nucleus of the cell is shown in blue by Hoechst staining. The infection was imaged using a confocal microscope at the time of virus attachment.

Black and white microscope image of two comparable structures showing fine, branched line patterns. The left half shows a denser, more complex branching, while the right half has fewer and clearer line structures. — The complexity of the coronary arteries is illustrated using the right ventricle. Two non-human primates can only be recognised by the different structure of the cardiovascular system.
Back resolution:
left: Macaca mulatta und right: Callithrix jacchus
INFO: The photos were taken once on 25.03.2024 (right) and on 09.07.2024 (left) at the University of Veterinary Medicine Hannover.

Primates

A Barbary macaque at La Forêt des Singes in Rocamadour, France — These photographs were taken during a two-week stay at La Forêt des Singes in Rocamadour, France. Despite the short time, the Barbary macaques did not mind me coming up close, which enabled me to create very intimate portraits of them.

A young male of Assamese macaque

A young crab-eating macaque (Macaca fascicularis) on Monkey island in Cat Ba National Park, northern Vietnam. — A young crab-eating macaque (Macaca fascicularis). This species is distributed mainly in the South of Vietnam due to wildlife trade they were released on an island, Monkey island, belongs in Cat Ba National Park in northern Vietnam.

A female Assamese macaque at Phu Khieo Wildlife Sanctuary, Thailand. — Eye contact with a female Assamese macaque at Phu Khieo Wildlife Sanctuary, Thailand.

Young long-tailed macaques (Macaca fascilcularis) — Two young long-tailed macaques (Macaca fascilcularis) look curiously into the camera.

Common marmoset — Common marmoset (sub adults) at the enclosure at the German Primate Center in Goettingen.

Common marmoset — Common marmoset at the enclosure at the German Primate Center in Goettingen.

Common marmoset — Common marmoset at the enclosure at the German Primate Center in Goettingen.

Two female Assamese macaques grooming. — Two female Assamese macaques of the study population at Phu Khieo Wildlife Sanctuary grooming.

Barbary macaque (Macaca sylvanus) grooming each other — During sunny days Barbary macaques (Macaca sylvanus) like to sunbathe and participate in social grooming. Of course, all generations like to participate.

A young male Barbary macaque (Macaca sylvanus) — A young male Barbary macaque (Macaca sylvanus) keeps an eye on his group.

A young Barbary macaque mid-jump — Patience is key! I observed a group of juvenile and subadult Barbary macaques which were travelling across La Forêt des Singes, Rocamadour, and managed to capture this individual mid-air.

Madame Berthe’s mouse lemur — A Madame Berthe’s mouse lemur (Microcebus berthae) observing its photographer.

Two Barbary macaques (Macaca sylvanus) — Two Barbary macaques (Macaca sylvanus) snuggle to keep warm on a chilly March morning.

Two Barbary macaques grooming — A female Barbary macaque (Macaca sylvanus) keeps an eye on the observer while being groomed by a male; they use grooming as a way to maintain and strengthen their social bond.

Barbary macaque (Macaca sylvanus) — An old female Barbary macaque (Macaca sylvanus) munches on an apple at ‘La Forêt des Singes’, France.

[Translate to Englisch:] Ein junges Berberaffenweibchen (Macaca sylvanus) — A young female Barbary macaque (Macaca sylvanus) seems to enjoy a little breeze.

Long-tailed macaque (Macaca fascicularis) — Long-tailed macaque (Macaca fascicularis) in the outdoor enclosure at the German Primate Center.

Long-tailed macaque (Macaca fascicularis) — Long-tailed macaque (Macaca fascicularis) in the outdoor enclosure at the German Primate Center.

A female rhesus monkey (Macaca mulatta) with her offspring — A female rhesus monkey (Macaca mulatta) from the German Primate Centre with her offspring. (DPZ G5)

Assamese macaque (Macaca assamensis) — Drinking break with mirror reflection in the Thai rainforest

Two young gray mouse lemurs (Microcebus murinus) — Two young gray mouse lemurs (Microcebus murinus) looking out of their nest entrance

A moustached tamarin at Estación Biológica Quebrada Blanco, Peru — While photographing a group of moustached tamarins (Saguinus mystax) foraged in an inga tree at Estación Biológica Quebrada Blanco in Amazonian Peru, I got to share this face to face moment with one of the individuals. While foraging, this animal witnessed my presence and looked straight into the camera before continuing to feed on the tree’s fruits.

A female Barbary macaque (Macaca sylvanus) — A Barbary macaque (Macaca sylvanus) female and its recently born baby sitting on a fallen Branch.

Assamese macaque infant (Macaca assamensis) — This is a photo of a wild Assamese macaque infant (Macaca assamensis) living at the Phu Khieo Wildlife Sanctuary in Thailand, who was eating from a season fruit known with the scientific name "Urceola rosea".

Grey mouse lemur (Microcebus murinus) at dusk — A grey mouse lemur after releasing in the early evening in Kirindy, Madagascar.

A young green monkey (Chlorocebus sabaeus) — After the first rain, this young green monkey (Chlorocebus sabaeus) tries to catch some termites flying.

A juvenile Celebes crested macaque (Macaca nigra) being groomed by his mother — A juvenile Celebes crested macaque (Macaca nigra) being groomed by his mother on a big black rock on a beach

Ring-tailed lemurs in their enclosure at the DPZ

Ring-tailed lemurs at the DPZ

A Verreaux's sifaka (Propithecus verreauxii) in Madagascar — A Verreaux's sifaka (Propithecus verreauxii) with collar markings in Madagascar

Ring-tailed lemur (Lemur catta) — Ring-tailed lemur (Lemur catta) at the outdoor enclosure at the German Primate Center.

Ring-tailed lemur (Lemur catta) — Ring-tailed lemur (Lemur catta) at the outdoor enclosure at the German Primate Center.

Common marmoset (Callithrix jacchus) — A common marmoset (Callithrix jacchus) enjoys its locust.

Green monkey — Hauke, a green monkey is carefully scanning the sky. Has he maybe seen a raptor or heard a drone?

Crested macaque (Macaca nigra) — A juvenile crested macaque playing in a hollow tree

Long-tailed macaques (Macaca fascicularis) with juvenile — Long-tailed macaques (Macaca fascicularis) with juvenile, Ketambe, Gunung Leuser National Park, Aceh, Sumatra, Indonesia.

Hamadryas Baboon in the enclosure at the German Primate Center

A female (left) and a male (right) hamadryas baboon in the coastal desert in Eritrea.

Hamadryas baboon in the outdoor enclosure at the DPZ

Hamadryas baboon (Papio hamadryas) — Hamadryas baboon (Papio hamadryas) at the outdoor enclosure of the German Primate Center.

This Madame Berthe's mouse lemur eyes the silent observers as if frozen.

A female Tonkean macaque posing in the morning light

An adult male Tonkean macaque picks his nose with a stick to ingest nasal mucus, a behavior observed in several primate species

In the early morning hours, before the sun rose above the canopy, a group of moustached tamarins (Saguinus mystax) foraged in an inga tree at Estación Biológica Quebrada Blanco in Amazonian Peru. The picture is a portrait of a vigilant individual of the group, looking out for potential threats.

An adult female vervet monkey (Chlorocebus sabaeus) after spotting a model python in the grass during field experiments.

Rhesus monkeys (maccaca mulatta) at the outdoor enclosure of the German Primate Center, Goettingen

A rhesus macaque at the DPZ

A rhesus macaque at the DPZ

Rhesus macaque (Macaca mulatta) in an enclosure at the German Primate Center (DPZ).

A wild mandril — This adult male mandrill was born in the wild 11 years ago. Among other characteristics, facial coloration can indicate the beginning of adulthood in males. The intensity of these colors changes throughout the life of an individual.

A wild baby mandril — Baby mandrills get habituated to the researchers around them quite fast. However, after taking a two-week break from the field this 2-month-old female gave me a hard time following her. At the end of the day, we were back to normal.

A wild female mandril with her young. — Mother mandrill takes a little nap while breast-feeding her baby.

An elderly female Assamese macaque near the field station in Phu Khieo, Thailand.

A Moustached tamarin (Saguinus mystax) — My favorite resting spot, Moustached tamarin (Saguinus mystax)

A Barbary macaque — A Barbary macaque enjoys its reward for pulling the lever on the box.

Sifaka (Propithecus verreauxi) — Sifaka (Propithecus verreauxi) in Kirindy Forest, Madagascar

A Celebes crested macaque with young — A Celebes crested macaque (Macaca nigra) with young

Verreaux's sifaka (Propithecus verreauxi) mother with her two months old baby — The one armed Verreaux's sifaka (Propithecus verreauxi) mother with her two months old baby, in Kirindy forest Madagascar.

A female crested macaque with young — A small crested macaque infant (Macaca nigra) is enjoying the time on his mother’s belly when they climb up the sleeping tree. The photo has been taken in Tangkoko-Batuangus Nature Reserve, Nord-Sulawesi, Indonesia.

Common marmoset — Common marmoset (Challithrix jacchus) in the animal facility at the German Primate Center

Common marmoset — Common marmoset (Challithrix jacchus) in the animal facility at the German Primate Center

West African green monkey (Chlorocebus sabaeus) with a face full of pollen — No new Chlorocebus species, but a member of the well-known West African green monkey (Chlorocebus sabaeus), which dived deep into flowers and now acts as a pollinator.

A male Barbary macaque relaxes in the afternoon sun — A male Barbary macaque relaxes in the afternoon sun on a slow day without many tourists at La Forêt des Singes, Rocamadour.

An infant Verreaux's Sifaka (Propithecus verreauxi) — An infant Verreaux's Sifaka (Propithecus verreauxi) is learning how to pick leaves from thorny twigs.

A young male Barbary macaque — A portrait of the young Barbary macaque male called ‘Allo’.