Prof. Joseph Levine, M.D. is an emeritus associate professor in the Division of Psychiatry, Faculty of Health Sciences, Ben Gurion University in Israel. Prof. Levine is a certified psychiatrist with clinical experience in controlled trials of adult psychiatric disorders and in psychotherapy. He was awarded a NRSAD independent investigator grant for the study of Creatine Monohydrate in psychiatric disorders -- mainly Schizophrenia. He resides and treats patients in Tel Aviv and all of central Israel.
Conversation 29: Socialization and mutual relations in birds
Greetings
As part of our review of the evolutionary manifestations of socialization in animals, this time we will discuss vertebrates, which are birds.
Birds, like humans and other animals, experience a range of emotions. While we may not fully understand the depth and complexity of their emotional experiences, scientific research has provided insights into the emotional lives of birds. Here are some key points: According to GPT 4 and other sources such as PUBMED and more after filtering and checking below is the range of estimated emotions:
1. Fear and anxiety: Birds can experience fear and anxiety in response to perceived threats or stressful situations. They may exhibit behaviors such as alarm calls, seeking shelter or trying to escape from dangers perceived by them.
2. Joy and happiness: Birds can also experience positive emotions associated with pleasure and happiness. They may exhibit behaviors such as singing, dancing or engaging in playful activities when they are in a positive and comfortable environment.
3. Bond and love: Many bird species form strong social bonds, especially with their mates or offspring. These bonds are often based on emotional bonds and can be seen through displays of affection, mutual nurturing or shared caregiving responsibilities.
4. Grief and Loss: Birds can experience grief and show signs of grief when they lose a mate, offspring or close companion. They may exhibit behaviors such as decreased appetite, reduced vocalizations, or increased withdrawal from social interactions.
5. Curiosity and investigation: Birds are known for their inquisitive nature. They often show interest in their surroundings, exploring new objects or environments. This behavior indicates a sense of curiosity and an emotional response to novelty.
6. Aggression and territoriality: Some species of birds exhibit aggressive behaviors, especially during the breeding season or when defending their territories. These behaviors are often motivated by emotional responses to perceived threats or competition.
It is important to note that these points are only estimates and there may be some anthropomorphism in them, that is, a projection of our feelings as humans. Thus, while birds can experience emotions, their experiences may differ from humans due to their unique sensory perceptions and cognitive abilities. Of course, more research is needed to deepen our understanding of bird emotions and the underlying mechanisms.
We note that birds have complex social structures that vary significantly between species. Here are some key aspects of the social life of birds:
1. Flock: Many species of birds form flocks, which can range from single individuals to thousands or even millions of birds. The pack has several advantages, including increased efficiency of food gathering and protection from predators. Some birds flock only at certain times, such as during migration or in winter.
2. Reproductive systems: Birds have a variety of mating and reproductive systems. Some birds are monogamous, forming long-term mating bonds with a single partner. Others are polygamous, where individuals have several partners in one breeding season. There are also species that are "cooperative breeders", where individuals other than the parents help raise the offspring.
3. Communication: Birds use a variety of signals to communicate, including sounds, visual displays, and touch. Birdsong is one of the most well-known forms of bird communication and is used for a variety of purposes, including attracting mates, defending territory, and coordinating activities within a group.
4. Altruism and cooperation: Some bird species even exhibit altruistic behavior, where individuals help others at a cost to themselves. This can include warning others of predators, sharing food, or helping to raise others' young. In some species, this cooperation is a central part of their social structure.
5. Territoriality: Many bird species are territorial, defending specific areas from others of their kind. This phenomenon is especially common during the breeding season, when males often defend territories to attract females to them.
6. Play: In several species of birds, especially crows, ravens and parrots, play behavior has been observed. This can include individual play, such as manipulating objects, or social games, such as aerial acrobatics or mock battles.
7. Hierarchies and dominance: In some bird societies, there is a clear hierarchy or pecking order, with dominant individuals having access to the best resources. This phenomenon can lead to a variety of social behaviors, including aggression, submission and appeasement.
Thus, many bird species have social hierarchies, sometimes referred to as "pecking orders". These hierarchies dictate the social ranking of each bird in the group, with higher-ranking individuals generally enjoying preferential access to resources such as food, mates, and nesting sites.
Pecking orders are established and maintained through a variety of behaviors. In many cases, a bird's rank is determined through physical contests or displays of aggression, with the winner receiving a higher rank. However, other factors can also play a role, such as age, size, or feather color. In some species, even vocalizations can be used to assert dominance or submission.
Once a pecking order is established, it can reduce conflict within the group, as individuals of lower ranks often submit to higher ranks rather than risk physical confrontation. However, a punctuation hierarchy can also be dynamic, with the ranks of individuals changing in response to changes in the group or their physical condition.
It is important to note that not all bird species have rigid social hierarchies, and the nature and importance of these hierarchies can vary greatly between species. Some bird species are highly territorial and largely even outside the breeding season, while others form complex social groups with multiple levels of hierarchy. Some species, such as many seabirds, breed in large colonies, but have little social interaction outside of their immediate pair bond and their interactions with their neighbors.
In species that have social hierarchies, this can be a major factor affecting the behavior and survival of individuals. Researchers studying these species often pay close attention to social hierarchy, as it can provide important insights into the social dynamics of the group and the selective pressures acting on individuals.
We note that social hierarchies, or "pecking orders", play a crucial role in the social organization of many bird species. They help regulate interactions within a group and can affect various aspects of an individual bird's life. Here are some of the main functions and benefits of social hierarchies in birds:
1. Reducing conflicts: A well-established social hierarchy can help minimize conflicts within a group. When the rank of each individual is clear, lower-ranked birds are less likely to challenge higher-ranked birds, reducing the frequency of aggressive encounters and maintaining group harmony.
2. Distribution of resources: Social hierarchies often determine access to resources, with higher-ranking individuals typically receiving preferential access to food, mates, and primary nesting sites. This can reduce competition for resources by making it clear who gets first choice.
3. Reproductive success: In many bird species, higher social status is associated with greater reproductive success. This could be due to better access to resources, more opportunities to mate, or better nesting sites, among other factors.
4. Learning opportunities: In some species, younger or lower individuals in the hierarchy can learn from observing the successful behaviors of individuals of higher rank. For example, in some species of social birds, the lower-ranking individuals observe the foraging behavior of the higher-ranking birds and learn from them efficient food-gathering techniques.
5. Health and survival: Social rank can also affect the health and survival chances of an individual bird. Higher-ranked birds may have better access to food and may be better protected from predators, which can lead to better overall health and longer lifespans.
While social hierarchies can offer these potential advantages, they can also create challenges, especially for lower-ranking individuals who may have reduced access to resources or mating opportunities. Thus, social hierarchies can be a significant source of natural selection in bird populations, when individuals are under constant pressure to improve their social status.
We will go on to say that birds have incredibly complex brains that allow them to engage in a wide variety of behaviors, including those we associate with high intelligence such as problem solving, tool use, and complex social interactions. Here are the key areas of bird brains and their functions:
The bird’s brain
1. Pallium: The pallium in birds is equivalent to the cerebral cortex in mammals. The pallium is involved in higher cognitive functions such as learning, memory and decision making. The pallium of birds is particularly large relative to their total brain size, especially in species known for their cognitive abilities, such as parrots and ravens.
2. Hippocampus: Just like in mammals, the brain region known as the hippocampus plays a key role in spatial memory and navigation in birds. This is especially important for migratory birds, which can navigate thousands of miles to return to the same breeding and wintering areas each year.
3. Hypothalamus: The hypothalamus is involved in a wide variety of physiological functions, including maintaining body temperature, regulating hunger and thirst, controlling the release of hormones and managing the biological clock.
4. Optic lobes: Birds have large optic lobes, reflecting their dependence on vision. These structures process visual information and play an important role in activities such as hunting, gathering food and avoiding predators.
5. The cerebellum: The cerebellum is involved in coordinating and regulating motor movements. This organ is especially important for birds, which need precise control of their movements in order to fly.
6. Medulla Oblongata or the elongated brain: this part of the brain controls automatic functions such as heart and breathing activity.
7. Striatum: The striatum is involved in motor control and learning, especially in relation to normal or routine behaviors.
8. Nidopallium and Mesopallium: These are areas of the bird's brain involved in auditory processing and are essential for producing sounds and recognizing bird calls. In songbirds, there are specialized areas in these regions that control the learning and production of song.
One unique aspect of bird brains is the presence of a structure called the "hyperpallium," which is a layer of cells that receives direct input from the visual system. This structure is thought to be involved in visual information processing, but its role is not fully understood.
It is worth noting that for many years, bird brains were considered relatively simple because they lacked the clear, layered structure of the mammalian neocortex. However, more recent research has shown that bird brains are capable of supporting complex cognitive abilities, suggesting that intelligence can evolve in different ways in different groups of animals.
Finally, we will discuss the ability of birds to identify both members of their own species, other species, other animals, and even humans.
Thus, many bird species have the ability to recognize and distinguish between individual birds. This identification can be based on a variety of cues, including visual, auditory and possibly even olfactory signals.
Here are some ways birds can recognize each other:
1. Visual identification: Birds can identify each other based on physical characteristics. For example, many bird species have unique plumage patterns or colors that can help them identify individuals. Other species, such as ravens and crows, may recognize individual faces.
2. Voice recognition: Birds can recognize each other's voice. This phenomenon is especially common in species that have complex songs or calls. For example, songbirds often have unique songs that they use to identify themselves and others.
3. Behavioral identification: Some birds may identify others based on their behavior. For example, a bird may identify a mate based on a unique courtship display, or a parent may identify its chick based on a begging call.
4. Smell: While the sense of smell is often considered relatively weak in birds compared to mammals, recent research has suggested that some birds can use smell for identification. For example, studies have shown that patron saint and albatross species can recognize individual scent signatures.
The ability to recognize individuals can therefore have significant advantages for birds. For example, this ability can help them maintain marital relationships, identify relatives, avoid aggressive encounters with dominant people, and navigate complex social hierarchies.
However, individual recognition is not universal among all bird species, and recognition mechanisms can vary significantly between different species.
We will continue and ask if birds can recognize faces of other birds, of other animals, and of humans?
The answer is yes, and it is interesting in connection with the fact that several species of birds have shown the ability to recognize the faces of other birds, of other animals, and even of humans. This ability is not universal among all bird species, and the degree to which a bird can recognize faces can depend on its species and its personal experiences. Here are some examples:
1. Crows and Ravens (Corvids): These birds are especially known for their facial recognition abilities. Studies have shown that crows can remember the faces of humans who have posed a threat to them and can pass this information on to other crows. They react differently to familiar human faces than to unfamiliar faces. Also, it is likely that they can recognize the faces of other crows.
2. Pigeons: Pigeons have been shown in laboratory environments to be able to distinguish between different human faces in photographs, indicating that they have a good ability to recognize faces.
3. Parrots: Some species of parrots, such as African gray parrots, have shown the ability to recognize their owners and other familiar humans, suggesting that they can distinguish between different human faces.
4. Chickens: Chickens can recognize each other and differentiate between more than 100 other chickens based on their facial features.
The ability to recognize faces provides several advantages. It can help birds detect potential threats, identify potential family members or mates, and navigate social hierarchies. However, more research is needed to fully understand the extent of this ability in different bird species and the mechanisms behind it.
Birds' ability to recognize faces appears to involve many areas of the brain, and the specific brain structures can vary between species. However, some key areas commonly involved in visual processing and recognition include:
1. Pallium: The pallium in birds, similar to the cerebral cortex in mammals, is involved in higher order processing and is likely involved in face recognition. The pallium contains several areas that process different types of sensory information, including visual stimuli.
2. Optic lobes: The optic lobes, which are part of the tectopogial pathway in birds, play a significant role in processing visual information. The tectopogial pathway includes the retina, optic tectum (part of the midbrain) and the telencephalon (frontmost part of the brain). This pathway is considered the primary visual pathway in birds.
3. Entopalium: This area of the bird's brain receives direct input from the optic tectum and is responsible for processing visual information. Research suggests that the entropy may be particularly important for fine visual discrimination tasks, such as distinguishing between different people.
4. Nidopallium and Mesopallium: These areas are thought to be involved in auditory processing and are essential for bird song production and auditory recognition. If birds use vocal cues along with visual cues for identification (as many species do), these areas could also play a role in personal identification.
It is worth noting that the understanding of the bird brain and its function has changed significantly over time, and there is still a lack of knowledge about exactly how birds process and recognize visual information. Additionally, while we know that some birds can recognize individual faces, the cognitive processes underlying this ability are still poorly understood. We note that this is an active field of research in animal cognition and neurobiology.
Below we will present a number of abstracts of interest to our topic first in English and immediately after in Hebrew translation that demonstrate the abilities of birds mainly crows but also pigeons in facial recognition including those of humans.
Crows
Front Physiol. 2019 Feb 27;10:140.
Searching for Face-Category Representation in the Avian Visual Forebrain
William James Clark 1, Blake Porter 1, Michael Colombo 1
Abstract
Visual information is processed hierarchically along a ventral ('what') pathway that terminates with categorical representation of biologically relevant visual percepts (such as faces) in the mammalian extrastriate visual cortex. How birds solve face and object representation without a neocortex is a long-standing problem in evolutionary neuroscience, though multiple lines of evidence suggest that these abilities arise from circuitry fundamentally similar to the extrastriate visual cortex. The aim of the present experiment was to determine whether birds also exhibit a categorical representation of the avian face-region in four visual forebrain structures of the tectofugal visual pathway: entopallium (ENTO), mesopallium ventrolaterale (MVL), nidopallium frontolaterale (NFL), and area temporo-parieto-occipitalis (TPO). We performed electrophysiological recordings from the right and left hemispheres of 13 pigeons while they performed a Go/No-Go task that required them to discriminate between two sets of stimuli that included images of pigeon faces. No neurons fired selectively to only faces in either ENTO, NFL, MVL, or TPO. Birds' predisposition to attend to the local-features of stimuli may influence the perception of faces as a global combination of features, and explain our observed absence of face-selective neurons. The implementation of naturalistic viewing paradigms in conjunction with electrophysiological and fMRI techniques has the potential to promote and uncover the global processing of visual objects to determine whether birds exhibit category-selective patches in the tectofugal visual forebrain.
J Vis. 2011 Mar 31;11(3):24.
Asymmetrical interactions in the perception of face identity and emotional expression are not unique to the primate visual system
Fabian A Soto 1, Edward A Wasserman
Abstract
The human visual system appears to process the identity of faces separately from their emotional expression, whereas the human visual system does not appear to process emotional expression separately from identity. All current explanations of this visual processing asymmetry implicitly assume that it arises because of the organization of a specialized human face perception system. A second possibility is that this finding reflects general principles of perceptual processing. Studying animals that are unlikely to have evolved a specialized face perception system may shed fresh light on this issue. We report two experiments that investigated the interaction of identity and emotional expression in pigeons' perception of human faces. Experiment 1 found that pigeons perceive the similarity among faces sharing identity and emotion, and that these two dimensions are integral according to a spatial model of generalization. Experiment 2 found that pigeons' discrimination of emotion was reliably affected by irrelevant variations in identity, whereas pigeons' discrimination of identity was not reliably affected by irrelevant variations in emotion. Thus, the asymmetry previously reported in human studies was reproduced in our pigeon study. These results challenge the view that a specialized human face perception system must underlie this effect.
J Vis. 2011 Mar 31;11(3):24.
Asymmetrical interactions in the perception of face identity and emotional expression are not unique to the primate visual system
Fabian A Soto 1, Edward A Wasserman
Abstract
The human visual system appears to process the identity of faces separately from their emotional expression, whereas the human visual system does not appear to process emotional expression separately from identity. All current explanations of this visual processing asymmetry implicitly assume that it arises because of the organization of a specialized human face perception system. A second possibility is that this finding reflects general principles of perceptual processing. Studying animals that are unlikely to have evolved a specialized face perception system may shed fresh light on this issue. We report two experiments that investigated the interaction of identity and emotional expression in pigeons' perception of human faces. Experiment 1 found that pigeons perceive the similarity among faces sharing identity and emotion, and that these two dimensions are integral according to a spatial model of generalization. Experiment 2 found that pigeons' discrimination of emotion was reliably affected by irrelevant variations in identity, whereas pigeons' discrimination of identity was not reliably affected by irrelevant variations in emotion. Thus, the asymmetry previously reported in human studies was reproduced in our pigeon study. These results challenge the view that a specialized human face perception system must underlie this effect.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2017 Dec;203(12):1017-1027.
Comparing the face inversion effect in crows and humans
Katharina F Brecht 1 2, Lysann Wagener 3, Ljerka Ostojić 4, Nicola S Clayton 4, Andreas Nieder 3
Abstract
Humans show impaired recognition of faces that are presented upside down, a phenomenon termed face inversion effect, which is thought to reflect the special relevance of faces for humans. Here, we investigated whether a phylogenetically distantly related avian species, the carrion crow, with similar socio-cognitive abilities to human and non-human primates, exhibits a face inversion effect. In a delayed matching-to-sample task, two crows had to differentiate profiles of crow faces as well as matched controls, presented both upright and inverted. Because crows can discriminate humans based on their faces, we also assessed the face inversion effect using human faces. Both crows performed better with crow faces than with human faces and performed worse when responding to inverted pictures in general compared to upright pictures. However, neither of the crows showed a face inversion effect. For comparative reasons, the tests were repeated with human subjects. As expected, humans showed a face-specific inversion effect. Therefore, we did not find any evidence that crows-like humans-process faces as a special visual stimulus. Instead, individual recognition in crows may be based on cues other than a conspecific's facial profile, such as their body, or on processing of local features rather than holistic processing.
Sci Rep. 2022 Jan 12;12(1):589.
Neurons in the pigeon visual network discriminate between faces, scrambled faces, and sine grating images
William Clark 1, Matthew Chilcott 2, Amir Azizi 3, Roland Pusch 4, Kate Perry 5, Michael Colombo 5
Abstract
Discriminating between object categories (e.g., conspecifics, food, potential predators) is a critical function of the primate and bird visual systems. We examined whether a similar hierarchical organization in the ventral stream that operates for processing faces in monkeys also exists in the avian visual system. We performed electrophysiological recordings from the pigeon Wulst of the thalamofugal pathway, in addition to the entopallium (ENTO) and mesopallium ventrolaterale (MVL) of the tectofugal pathway, while pigeons viewed images of faces, scrambled controls, and sine gratings. A greater proportion of MVL neurons fired to the stimuli, and linear discriminant analysis revealed that the population response of MVL neurons distinguished between the stimuli with greater capacity than ENTO and Wulst neurons. While MVL neurons displayed the greatest response selectivity, in contrast to the primate system no neurons were strongly face-selective and some responded best to the scrambled images. These findings suggest that MVL is primarily involved in processing the local features of images, much like the early visual cortex.
Proc Natl Acad Sci U S A. 2012 Sep 25;109(39):15912-7.
Brain imaging reveals neuronal circuitry underlying the crow's perception of human faces
John M Marzluff 1, Robert Miyaoka, Satoshi Minoshima, Donna J Cross
Abstract
Crows pay close attention to people and can remember specific faces for several years after a single encounter. In mammals, including humans, faces are evaluated by an integrated neural system involving the sensory cortex, limbic system, and striatum. Here we test the hypothesis that birds use a similar system by providing an imaging analysis of an awake, wild animal's brain as it performs an adaptive, complex cognitive task. We show that in vivo imaging of crow brain activity during exposure to familiar human faces previously associated with either capture (threatening) or caretaking (caring) activated several brain regions that allow birds to discriminate, associate, and remember visual stimuli, including the rostral hyperpallium, nidopallium, mesopallium, and lateral striatum. Perception of threatening faces activated circuitry including amygdalar, thalamic, and brainstem regions, known in humans and other vertebrates to be related to emotion, motivation, and conditioned fear learning. In contrast, perception of caring faces activated motivation and striatal regions. In our experiments and in nature, when perceiving a threatening face, crows froze and fixed their gaze (decreased blink rate), which was associated with activation of brain regions known in birds to regulate perception, attention, fear, and escape behavior. These findings indicate that, similar to humans, crows use sophisticated visual sensory systems to recognize faces and modulate behavioral responses by integrating visual information with expectation and emotion. Our approach has wide applicability and potential to improve our understanding of the neural basis for animal behavior.
Proc Biol Sci. 2012 Feb 7;279(1728):499-508.
Social learning spreads knowledge about dangerous humans among American crows
Heather N Cornell 1, John M Marzluff, Shannon Pecoraro
Abstract
Individuals face evolutionary trade-offs between the acquisition of costly but accurate information gained firsthand and the use of inexpensive but possibly less reliable social information. American crows (Corvus brachyrhynchos) use both sources of information to learn the facial features of a dangerous person. We exposed wild crows to a novel 'dangerous face' by wearing a unique mask as we trapped, banded and released 7-15 birds at five study sites near Seattle, WA, USA. An immediate scolding response to the dangerous mask after trapping by previously captured crows demonstrates individual learning, while an immediate response by crows that were not captured probably represents conditioning to the trapping scene by the mob of birds that assembled during the capture. Later recognition of dangerous masks by lone crows that were never captured is consistent with horizontal social learning. Independent scolding by young crows, whose parents had conditioned them to scold the dangerous mask, demonstrates vertical social learning. Crows that directly experienced trapping later discriminated among dangerous and neutral masks more precisely than did crows that learned through social means. Learning enabled scolding to double in frequency and spread at least 1.2 km from the place of origin over a 5 year period at one site.
See you soon,
Dr. Igor Salganik and Prof. Joseph Levine
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