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Nat Commun ; 12(1): 3717, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162841


Rawls argued that fairness in human societies can be achieved if decisions about the distribution of societal rewards are made from behind a veil of ignorance, which obscures the personal gains that result. Whether ignorance promotes fairness in animal societies, that is, the distribution of resources to reduce inequality, is unknown. Here we show experimentally that cooperatively breeding banded mongooses, acting from behind a veil of ignorance over kinship, allocate postnatal care in a way that reduces inequality among offspring, in the manner predicted by a Rawlsian model of cooperation. In this society synchronized reproduction leaves adults in a group ignorant of the individual parentage of their communal young. We provisioned half of the mothers in each mongoose group during pregnancy, leaving the other half as matched controls, thus increasing inequality among mothers and increasing the amount of variation in offspring birth weight in communal litters. After birth, fed mothers provided extra care to the offspring of unfed mothers, not their own young, which levelled up initial size inequalities among the offspring and equalized their survival to adulthood. Our findings suggest that a classic idea of moral philosophy also applies to the evolution of cooperation in biological systems.

Comportamento Animal/fisiologia , Herpestidae/fisiologia , Reprodução/fisiologia , Comportamento Social , Animais , Animais Recém-Nascidos , Peso Corporal/fisiologia , Cruzamento , Feminino , Masculino , Modelos Teóricos , Gravidez , Predomínio Social
Biol Lett ; 15(12): 20190529, 2019 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-31795853


When breeding females compete for limited resources, the intensity of this reproductive conflict can determine whether the fitness benefits of current reproductive effort exceed the potential costs to survival and future fertility. In group-living species, reproductive competition can occur through post-natal competition among the offspring of co-breeding females. Spontaneous abortion could be a response to such competition, allowing females to curtail reproductive expenditure on offspring that are unlikely to survive and to conserve resources for future breeding opportunities. We tested this hypothesis using long-term data on banded mongooses, Mungos mungo, in which multiple females within a group give birth synchronously to a communal litter that is cared for by other group members. As predicted, abortions were more likely during dry periods when food is scarce, and in breeding attempts with more intense reproductive competition. Within breeding events, younger, lighter females carrying smaller fetuses were more likely to abort, particularly those that were also of lower rank. Our results suggest that abortion may be a means by which disadvantaged females conserve resources for future breeding attempts in more benign conditions, and highlight that female reproductive competition may be resolved long before the production of offspring.

Aborto Espontâneo , Herpestidae , Animais , Cruzamento , Feminino , Fertilidade , Humanos , Gravidez , Reprodução
Onderstepoort J Vet Res ; 72(2): 145-51, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16137132


A survey to determine the prevalence of bovine tuberculosis caused by Mycobacterium bovis and certain other infectious diseases was conducted on 42 free-ranging African buffaloes, (Syncerus caffer) from May to June 1997 in the Queen Elizabeth National Park, Uganda. Using the gamma interferon test, exposure to M. bovis was detected in 21.6% of the buffaloes. One dead buffalo and an emaciated warthog (Phacochoerus aethiopicus) that was euthanased, were necropsied; both had miliary granulomas from which M. bovis was isolated. None of the buffaloes sampled in Sector A of the park, which has no cattle interface, tested positive for bovine tuberculosis (BTB) exposure. The prevalence and distribution of BTB does not appear to have changed significantly since the 1960s, but this may be due to fluxes in the buffalo population. Serological testing for foot-and-mouth disease (FMD) demonstrated positive exposure of 57.1% of the buffaloes sampled, with types A, O and SAT 1-3, which is the first known report of FMD antibodies to A and O types in free ranging African buffaloes. Foot-and-mouth disease virus types SAT 1 and SAT 3 were isolated from buffalo probang samples. Two percent of the buffaloes had been exposed to brucellosis. None of the buffaloes tested had antibodies to rinderpest, leptospirosis or Q fever.

Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Búfalos , Febre Aftosa/epidemiologia , Mycobacterium bovis/isolamento & purificação , Tuberculose/veterinária , Animais , Feminino , Masculino , Estudos Soroepidemiológicos , Testes Sorológicos/veterinária , Tuberculose/epidemiologia , Uganda/epidemiologia
Vet Rec ; 150(1): 12-5, 2002 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-11817857


Between August and December 1996, there was an outbreak of a debilitating skin disease attributed to Sarcoptes scabiei infection in mountain gorillas (Gorilla beningei beringei) in Bwindi Impenetrable National Park in Uganda. All four members of a gorilla group which had been habituated to tourists were clinically affected; the infant male gorilla was most severely affected and died, the juvenile male showed serious manifestations of the disease and the two adult animals showed milder signs. The three older animals recovered after a single intramuscular dose of ivermectin. S scabiei mites were observed on skin scrapings and biopsies taken while the juvenile was immobilised and in postmortem samples taken from the infant. The clinical signs did not recur during the following year, and no other gorilla groups in the park were observed to be clinically affected.

Surtos de Doenças , Gorilla gorilla/parasitologia , Escabiose/epidemiologia , Escabiose/veterinária , Animais , Injeções Intramusculares , Inseticidas/uso terapêutico , Ivermectina/uso terapêutico , Masculino , Índice de Gravidade de Doença , Uganda/epidemiologia
J Zoo Wildl Med ; 32(4): 509-13, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12785708


A juvenile female mountain gorilla (Gorilla beringei beringei) of the Mubare tourist group in Bwindi Impenetrable National Park, Uganda, developed a severe, complete rectal prolapse that did not spontaneously resolve. Eight months prior, a juvenile female mountain gorilla of the Mubare group developed a mild, complete rectal prolapse that resolved spontaneously within 24 hr. Field guides reported that spontaneously resolving prolapses had been seen previously in two other juveniles, one of which was from the Mubare group. The tissue became increasingly necrotic and maggot infested over the course of 1 wk. Surgical intervention involved amputation of the affected rectal tissues and suturing the viable portion to the anal sphincter muscle with simple interrupted absorbable sutures. The surgery was performed in the field in accordance with Uganda Wildlife Authority policies. Antibiotics and anthelmintics were administered systemically, and the gorilla returned to the group. The gorilla appeared to recover fully after 3 wk. Histology of the resected rectal tissue confirmed intense inflammation and necrosis with myiasis but did not reveal an underlying etiology.

Doenças dos Símios Antropoides/cirurgia , Gorilla gorilla/cirurgia , Prolapso Retal/veterinária , Reto/cirurgia , Amputação/veterinária , Animais , Animais Selvagens , Doenças dos Símios Antropoides/patologia , Feminino , Prolapso Retal/patologia , Prolapso Retal/cirurgia , Reto/patologia , Técnicas de Sutura/veterinária , Resultado do Tratamento , Uganda