20+
Species with documented grief or mourning behaviors
Days–Years
Duration of mourning behaviors documented in elephants
2009
Year Marc Bekoff published "Wild Justice" synthesizing animal grief research
All Taxa
Grief documented in mammals, birds, and possibly fish
What Is Animal Grief?
Animal grief — defined as a behavioral and physiological response to the death or loss of a bonded individual — has moved from anecdote to science over the past three decades. What was once dismissed as anthropomorphization (projecting human emotions onto animals) is now the subject of rigorous peer-reviewed research, with measurable behavioral, hormonal, and neural correlates documented across dozens of species.
The scientific question is not whether animals respond to loss — the evidence for that is overwhelming — but what the subjective quality of that response is. Do animals experience something analogous to the human emotion of grief, with its characteristic features of yearning, social withdrawal, and sustained suffering? The honest answer from comparative cognitive science: for many species, the behavioral evidence is consistent with a subjective grief experience, though we cannot access animal subjectivity directly.
Why This Matters for Welfare: If animals experience something like grief, then practices that routinely cause them loss — separating bonded pairs, breaking up social groups, killing companions — constitute welfare harms beyond the immediate physical. The dairy industry's routine separation of mother and calf, the slaughter of one pig from a bonded pair, the removal of a dominant hen from an established flock — all of these may cause experiences analogous to bereavement, with welfare implications that persist over days or weeks.
Evidence Across Species
🐘 Elephants
Elephants have the most extensively documented grief behavior in the animal kingdom. Research by Cynthia Moss, Joyce Poole, and colleagues from the Amboseli Elephant Research Project has accumulated decades of observational data:
- Elephants investigate the bodies of deceased herd members for hours to days — touching, smelling, and standing near them
- They return to bones of deceased relatives months or years later, touching the bones preferentially over other bones in the area
- Elephants show visible signs of distress (elevated temporal gland secretion, increased vocalizations) when near bones of a familiar individual
- Calves orphaned by poaching show post-traumatic symptoms including nightmares (sleep disruption), hypervigilance, and social withdrawal that persist for years
- "Funeral" behaviors: standing over dead calves, fanning them, attempting to lift them
The neurobiological basis is documented: elephants have highly developed limbic systems and temporal lobes, with spindle neurons (von Economo neurons) previously thought unique to humans and great apes — neurons associated with social emotion and self-awareness.
🐬 Dolphins & Cetaceans
Cetacean grief behavior, particularly "calf carrying," has attracted global attention. Documented cases include:
- Calf carrying: Female dolphins and orcas carrying the bodies of their deceased calves for days to weeks — surfacing to breathe while keeping the calf near the surface. Documented in at least 9 cetacean species. The behavior is unambiguous: mothers carry dead calves despite the energy cost and interference with their own survival behaviors.
- Orca mourning (J35/Tahlequah 2018): A Southern Resident orca named Tahlequah carried her dead calf for 17 days and approximately 1,000 miles — a documented, sustained mourning response that was widely observed and scientifically recorded. Tahlequah subsequently gave birth to a healthy calf, but the prolonged carrying behavior was extraordinary.
- Pod behavior changes: After the death of a dominant individual, orca and sperm whale pods show documented behavioral disruption — altered movement patterns, reduced foraging efficiency, and social reorganization lasting weeks to months.
🦍 Great Apes
Chimpanzee, gorilla, and bonobo responses to death are the most studied among non-human primates:
- Chimpanzees have been observed attending to and inspecting the bodies of deceased group members, including cleaning the body
- Mothers carry deceased infants for days to weeks — behavior documented in wild populations in Bossou, Guinea, and Gombe, Tanzania
- Jane Goodall documented Flint, a juvenile chimpanzee, dying of apparent grief and immune collapse within weeks of his mother Flo's death — one of the most compelling animal grief cases in the scientific literature
- Gorillas at zoos have been observed sitting near the bodies of deceased group members in apparent vigil
- Chimpanzees show behavioral depression (reduced activity, social withdrawal, reduced appetite) following loss of close associates — with cortisol elevation consistent with bereavement stress
🐦 Birds
Avian grief is documented across multiple taxa:
- Corvids (ravens, crows, jays): Corvids hold "funerals" — gathering around dead conspecifics in apparent investigation, sometimes going silent or alarm calling. Research by Kaeli Swift documented that American crows learn danger associations from dead conspecifics and show behavioral changes around crow corpses.
- Geese: Konrad Lorenz documented behavioral depression in greylag geese that lose their partners — a physiological response including slumped posture, reduced activity, and changed vocalizations. Many waterfowl species that mate for life show similar responses.
- Magpies: Documented placing grass "wreaths" near the bodies of deceased magpies and holding brief apparent vigils — behavior that superficially resembles human funeral rites.
- Parrots: Captive parrots show prolonged behavioral changes including feather plucking and social withdrawal after the death of a bonded companion — recognized by avian veterinarians as grief response.
🦁 Other Mammals
- Domestic dogs: Behavioral changes after loss of a bonded companion (human or animal) are well-documented — reduced appetite, searching behavior, changed sleep, and social withdrawal. A 2022 PLOS ONE study found 86% of dogs showed behavioral changes after losing a companion dog.
- Horses: Horses separated from bonded companions show elevated cortisol, increased vocalization, and reduced feed intake. Standing near the body of a deceased companion and apparent investigation are documented in domestic horses.
- Sea otters: Female sea otters have been documented carrying and grooming the bodies of deceased pups for days — behavior analogous to cetacean calf carrying.
- Giraffes: Multiple observations of giraffes standing near or nudging the bodies of deceased calves over extended periods.
- Seals and sea lions: Mother pinnipeds have been documented attempting to revive deceased pups and remaining near them for extended periods.
The Neurobiological Basis of Animal Grief
Grief has a neural basis that is highly conserved across mammals. The core components of human grief — yearning, separation distress, social withdrawal — map onto neurological systems present in all mammals:
| Grief Component | Neural System | Animal Evidence |
|---|
| Separation distress (yearning) | Opioid system; dopamine reward pathways | Opioid antagonists induce separation distress in all mammal species tested; social bonds rely on opioid reward system |
| Social withdrawal | Anterior cingulate cortex; amygdala | Lesion studies and comparative neuroimaging show these regions involved in social loss response across mammals |
| Anhedonia (reduced pleasure) | Nucleus accumbens; prefrontal cortex | Cognitive bias tests show reduced positive anticipation after social loss in rodents, pigs, and birds |
| Sustained stress response | HPA axis; cortisol elevation | Cortisol elevation after social loss documented in rats, mice, dogs, horses, primates, and birds |
Grief in Dairy: A Direct Application
The mother-calf separation that is standard in commercial dairy farming — typically occurring within hours of birth — is the most widespread grief-inducing practice in animal agriculture. Research is unambiguous:
- Cows vocalize (call) persistently for 2-4 days post-separation; both cow and calf show elevated cortisol
- The intensity of the vocalization response increases if the cow has had extended contact with her calf — suggesting the bond strength matters
- Cows whose calves die at birth sometimes still show searching and calling behavior if allowed to be near the body
- Repeated separations across lactations (typically 1-2 per year in dairy cows) may create chronic anticipatory anxiety
Extended suckling systems, where calves remain with mothers for weeks or months, are practiced on high-welfare farms and reduce both cow and calf distress at separation — but are rare in commercial operations due to the loss of saleable milk during the suckling period.
The "Does Not Apply to Farm Animals" Fallacy: A common response to farm animal grief evidence is "but these are food animals" — as though the designation "food animal" changes the neurobiological facts. The opioid and cortisol systems underlying separation grief in cows are identical to those underlying grief in dogs. The behavioral evidence is comparable. The moral salience of the grief is not altered by the economic category we assign to the animal experiencing it.
Scientific Debates
The animal grief literature has legitimate scientific debates that should be acknowledged:
- Anthropomorphization risk: Researchers must distinguish between behaviors that superficially resemble human mourning and behaviors that demonstrate analogous internal states. Not every animal body-inspection behavior necessarily involves grief-like experience.
- Conceptual death: Some researchers distinguish between "proto-grief" (behavioral responses to loss without necessarily conceptualizing death as final) and "full grief" involving death concept. The distinction matters philosophically but may not affect the welfare relevance.
- Individual variation: Grief responses show enormous individual variation — not all members of a bonded pair show the same response to loss. This mirrors human grief variation rather than undermining the reality of the experience.
- Cultural anthropology of death: Some researchers, including Barbara King, argue that the emphasis on "death recognition" misframes the question — what matters is the bond disruption response, not whether the animal cognitively represents death.
Welfare Implications
If we accept that many animals experience something genuinely analogous to grief, the welfare implications are significant:
- Social group stability should be maintained wherever possible in captive and farmed settings
- Bonded pairs should not be separated except where necessary for health or safety
- When separation is necessary (e.g., medical isolation), graduated separation and increased enrichment can mitigate the grief response
- Animals that have lost a bonded companion need welfare monitoring — behavioral changes including reduced eating, social withdrawal, and lethargy may indicate grief requiring intervention
- Mother-infant separation in dairy and other agricultural species should be delayed or graduated where feasible
Further Reading
- Wild Justice: The Moral Lives of Animals — Marc Bekoff & Jessica Pierce (2009)
- How Animals Grieve — Barbara King (2013)
- The Good Good Pig — Sy Montgomery (pig grief and bonds)
- Cynthia Moss, "The Amboseli Elephants" — field research compilation
- Support ElephantVoices and Amboseli Trust for Elephants — organizations documenting elephant grief and social life
Sources: Moss et al. (2011) Amboseli Elephant Research Project; King (2013) How Animals Grieve; Bekoff & Pierce (2009) Wild Justice; Zentall & Wasserman (2012) Comparative Cognition; Swift (2015) crow response to death, Animal Behaviour; Packer et al. (2022) dog grief PLOS ONE; Weary & Chua (2000) cow-calf separation UBC. Statistics current as of 2023.