London Zoo Research Articles

Accidental gunpowder blast caused an uproar at London Zoo in 1874.

Accidental gunpowder blast caused an uproar at London Zoo in 1874.

Stepping on the scales: London Zoo's residents get a weigh-in.

Stepping on the scales: London Zoo's residents get a weigh-in.

FIVE YEARS OF PARTULA SNAIL PRE-EXPORT HEALTH SCREENING.

Between 2015 and 2019, a health screening was carried out annually on captive-bred Partula snails prior to export for reintroduction as part of an international effort to repopulate areas of French Polynesia, where the snails were extinct or critically endangered. In total, 129 separate tank populations of 12 different species were screened at ZSL London Zoo. Wet mounts and smears stained with modified Ziehl-Neelsen (MZN) of 535 fecal samples were examined, and 45% contained flagellated protozoa, and 35.5% had MZN-positive oocysts, measuring 3-5 µm in diameter. Smaller (2 µm) presumptive spores, MZN-positive bacilli, ciliated protozoa and nematodes were recorded less frequently. Fecal bacterial culture yielded mixed species, with a clear predominance of Myroides species (88.9% of samples). The MZN-positive oocysts (3-5 µm) were present in 6.5% of impression smears from the apices of 432 snails examined postmortem, plus acid-fast bacilli in a few cases, but no 2 µm spores. Mixed bacteria were cultured from coelomic swabs, with Myroides species again the most common (63.5%). Histologic examination was carried out on 292 snails. Autolysis affected almost 90% of those found dead but only 3.4% of euthanized snails. Histology commonly identified microsporidial sporocysts in the digestive gland and midgut epithelium of all but two species. Intracellular, extracytoplasmic Cryptosporidium-like organisms were also common in the midgut but were only observed when snails were fixed in 10% formalin (2017-2019), not ethanol. There were no clear pathologic changes associated with either organism. Pigmented hemocytic nodules were commonly observed, most frequently in the foot process; these were either age related or evidence of prior chronic inflammatory reaction and of low clinical significance. With no evidence of poor health and no significant organisms found, a total of 4,978 individuals representing 12 species were exported for reintroduction.

Field-based assessments of the seasonality of Culexpipiens sensu lato in England: an important enzootic vector of Usutu and West Nile viruses

BackgroundUsutu virus (USUV), which is closely related to West Nile virus (WNV), sharing a similar ecology and transmission cycle, was first reported in the UK in the southeast of England in 2020. Both USUV and WNV are emerging zoonotic viruses hosted by wild birds. The 2020 finding of USUV in England raised awareness of this virus and highlighted the importance of understanding the seasonality of Culexpipiens sensu lato (Cx. pipiens s.l.), the main enzootic vector of these viruses. Zoos are prime locations for trapping mosquitoes because of their infrastructure, security, and range of vertebrate hosts and aquatic habitats.MethodsThree independent zoo-based case studies at four locations that cover the seasonality of Cx.pipiens s.l. in England were undertaken: (i) London Zoo (Zoological Society London [ZSL]) and surrounding areas, London; (ii) Chester Zoo (Cheshire); (ii) Twycross Zoo (Leicestershire); and (iv) Flamingo Land (zoo; North Yorkshire). Various adult mosquito traps were used to catch adult Cx.pipiens s.l. across seasons.ResultsHigh yields of Cx.pipiens s.l./Culex torrentium were observed in Biogents-Mosquitaire and Center for Disease Control and Prevention Gravid traps in all studies where these traps were used. Mosquito counts varied between sites and between years. Observations of adult Cx.pipiens s.l./Cx. torrentium abundance and modelling studies demonstrated peak adult abundance between late July and early August, with active adult female Cx.pipiens s.l./Cx. torrentium populations between May and September.ConclusionsThe information collated in this study illustrates the value of multiple mosquito monitoring approaches in zoos to describe the seasonality of this UK vector across multiple sites in England and provides a framework that can be used for ongoing and future surveillance programmes and disease risk management strategies.Graphical

Why write about animals? Organization and the Daily Occurrences of London Zoo

ABSTRACT This article analyses as series of archival documents called the Daily Occurrences of the Zoological Gardens of London. These pro formas were the institutional working texts that allowed authorial statements to appear concerning the organization of London Zoo, including: animal arrivals, departures, births, deaths, work, visitor figures and finance. The Daily Occurrences classified, described, and curated the frames which were constructed around the display animals at the zoo. By contextualizing and paying critical attention to these managerial pro formas, this article undertakes an interdisciplinary reading of overlooked texts that organized how animals and humans entered into and exited out from a system of living exhibition. This article addresses the research question: how were animals and humans organized at the zoo? By looking to how animals were organized at the zoo this article contributes to wider discussions found in organization studies regarding the visibility and status of what constitutes animal labour.

A RETROSPECTIVE ANALYSIS OF THE MORBIDITY AND MORTALITY OF CAPTIVE NORTHERN BALD IBIS (GERONTICUS EREMITA), AFRICAN SACRED IBIS (THRESKIORNIS AETHIOPICUS), AND SCARLET IBIS (EUDOCIMUS RUBER) HOUSED AT THE LONDON ZOO FROM 2000 TO 2020.

Necropsy (n = 144) and medical (n = 121) records of captive northern bald ibis (NBI; Geronticus eremita), African sacred ibis (ASI; Threskiornis aethiopicus), and scarlet ibis (SCI; Eudocimus ruber) housed at the Zoological Society of London's London Zoo (LZ) from 2000 to 2020 were reviewed. Pododermatitis was a common cause of morbidity in all species (79 cases in 247 examinations). Trauma (58 of 144), the majority being caused by suspected collisions with stationary objects in the zoo's habitats, infectious diseases (32 of 144), predominantly valvular endocarditis (10 of 32), and aspergillosis (9 of 32) were major causes of mortality. The odds of a morbidity being related to toxicosis were 4.4 times greater in NBI than for ASI (95% CI, 1.5-13.3; P < 0.05); all cases in the NBI were plumbism. Overall, females of all species had 3.4 times greater odds of undetermined morbidity than males (95% CI, 1.5-7.9; P < 0.05), and the majority (16 of 25) were birds that were thin without an apparent cause. Nestlings had 11.3 times greater odds of nutritional morbidity than adults (95% CI, 1.7-73.0) and 5.5 times greater than juveniles (95% CI, 0.7-41.0; P < 0.05). These data have identified areas that require further study in the population of NBI, ASI, and SCI held at LZ.

Commercial television and primate ethology: facial expressions between Granada and London Zoo.

This article examines the significant relationship that existed between commercial British television and the study of animal behaviour. Ethological research provided important content for the new television channel, at the same time as that coverage played a substantial role in creating a new research specialism, the study of primate facial expressions, for this emergent scientific discipline. The key site in this was a television and film unit at London Zoo administered by the Zoological Society and Granada TV. The Granada unit produced 'Animal expressions', a twenty-five-minute television film based on research on monkeys and apes by the Dutch postgraduate student and soon-to-be-leading-authority Jan van Hooff. Recovering the production and multiple uses of 'Animal expressions', this paper offers the first sustained historical analysis of science on commercial television. I show how Granada patronage helped Van Hooff to support his argument that human expressions such as smiling and laughter shared common evolutionary origins with similar facial movements in nonhuman primates. Emphasizing the mutual shaping of science and ITV, I argue that 'Animal expressions' repurposed televisual conventions of framing talking heads, and blended serious science with the comedy of 'funny faces', thereby epitomizing Granada's public-service strategy at a time when commercial television was defending itself from criticism in the Pilkington report.

Animal Feeding, Animal Experiments, and the Zoo as a Laboratory: Paris Ménagerie and London Zoo, ca. 1793–1939: The Zoo as a Laboratory

This article elaborates a local history of zoo feeding practices in order to shed light on the construction of knowledge at the zoo, its intersection with laboratory developments in life sciences, and the nature of zoo sciences. It relies on the case studies of two of the oldest zoological gardens in the world-the Jardin des Plantes Ménagerie in Paris (1793) and the London Zoological Gardens (1828)-both of which formed parts of major scientific institutions, thereby facilitating research on the dialogue between zoo knowledge and life sciences. The article argues that zoos developed around an experimental paradigm that consisted of testing on animals the (nutritional) variables of their survival within a highly constrained institutional framework. From the interwar period, the empirical nature of the zoo feeding economy was marked by slow and uneven changes, associated with the development of nutritional sciences as well as internal hygiene, pathology, and veterinary programmes. Despite transfers and networks of people, methods, experiments, concepts, and animals between zoos and life sciences laboratories, the former remained too impure as a research site to act as an extension of the latter. Zoos, however, needed external laboratories to support themselves with the scientific legitimacy that their “biopolitical modernisation” (Chrulew) required. In addressing programmatic changes as well as their impact upon the animals, this paper argues that trial-and-error experiments are constitutive of the zoo, contributing towards the definition of the nature of both zoo management and zoo sciences.

How to Get into the Pouch: Solving the Riddle of the Kangaroo Birth (1826–1926)

How does the newborn kangaroo get into the pouch after birth? This question was much discussed by naturalists around the globe between 1826, when Etienne Geoffroy Saint-Hilaire first addressed the issue, and 1926, when Ellis Troughton published a “definite” account of the debate. In its first part, this paper focuses on the investigations conducted at European zoos. The advent of kangaroos made it possible to investigate the riddle through observation. In the early 1830s, Richard Owen enlisted the aid of London Zoo to devise a research programme. He claimed that the mother put the embryo into the pouch using her lips, and naturalists in other Europeans zoos were eager to confirm Owen's hypothesis. In its second part, this paper contrasts the zoo-based investigations with observations made in Australia. Hunters and animal traders claimed that the joey travelled into the pouch without any assistance from the mother. This case study allows us to address a number of overarching questions: Could the zoo live up to its promise to generate knowledge in natural history, challenging the classical method of anatomical dissection? What practical difficulties did naturalists and animal keepers face in their observations? How did the information on the reproduction of marsupials circulate (or not) between metropolitan centres and colonial outposts? The riddle of the kangaroo birth casts light on the potential and the limitations of the zoo as a site for research.

An Improvement in Enclosure Design Can Positively Impact Welfare, Reduce Aggressiveness and Stabilise Hierarchy in Captive Galapagos Giant Tortoises

The interest in the welfare of zoo animals, from both the public and the scientific community, has long been biased towards mammals. However, growing evidence of the complex behavioural repertoires of less charismatic animals, such as reptiles, reveals the necessity to better comply with their welfare needs in captivity. Here, we present the effects of an enclosure change towards a more natural habitat in captive Galapagos tortoises (Chelonoidis spp.) held at ZSL London Zoo. Using behavioural observations, we found that the tortoises habituated to their new enclosure in six days. This represents the first quantification of habituation latency to a new enclosure in a reptile model to our knowledge—which is important information to adapt policies governing animal moves. The tortoises expressed time budgets more similar to those of wild individuals after their transition to the new enclosure. Interestingly, the hierarchy between the individuals was inverted and more stable after this change in environment. The tortoises interacted less often, which led to a decrease in the frequency of agonistic encounters. We also found that higher ambient sound volume was associated with increased likelihood of interactions turning into fights. Taken together, our results demonstrate the potential of appropriate enclosure design to improve reptile welfare.

How do Zoo Evening Events at ZSL London Zoo Affect Sumatran Tiger Behaviour and Enclosure

How do Zoo Evening Events at ZSL London Zoo Affect Sumatran Tiger Behaviour and Enclosure

Impact of Broad-Spectrum Lighting on Recall Behaviour in a Pair of Captive Blue-Throated Macaws (Ara glaucogularis)

Many birds, including macaws, are highly visual animals able to detect a wide band of light wavelengths ranging into ultraviolet A, but in captivity, full-spectrum lighting is not universally employed. Where purpose-made bird lighting is used, this is typically made with the provision of ultraviolet B radiation and vitamin D3 synthesis in mind. Limited research in this field suggests behavioural and physiological benefits of broad-spectrum lighting provision, but more work is needed to broaden the taxonomic scope and to investigate its impacts on understudied areas of husbandry, including behavioural management. We compared the duration of time a bonded pair of blue-throated macaws at ZSL London Zoo opted to remain in an inside den after being recalled from an outdoors flight aviary, with and without the presence of artificial lighting in the form of High Output T5 Fluorescent lamps, which are rich in UVA and UVB wavelengths as well as those visible to humans. We hypothesized that the birds would remain inside for longer when T5 lighting was on, as they would be more visually comfortable. Using randomization analyses, we show that, over 54 trials split between winter and spring, the mean duration spent inside after recall increased from 81.04 to 515.13 s with the presence of the lighting unit, which was highly statistically significant. Our results are likely to be explained by much higher visibility of indoor surroundings creating a more hospitable indoor environment for the birds and will have implications for captive macaw management.

Does Handling for Public Talks in Zoos Affect the Behaviour of Captive Mexican Red-Kneed Spiders Brachypelma hamorii?

Zoos include invertebrates in visitor interaction sessions to educate and spread conservation messages to the public. Yet, the welfare implications of these encounters on invertebrates are unstudied. Empirical studies reveal negative effects of handling on vertebrate species, thus providing reason to investigate impacts on invertebrates. Mexican red-kneed spiders Brachypelma hamorii are regularly handled by keepers for public talks at the Zoological Society of London, London Zoo. This study investigates whether handling affects the spiders’ 24-h activity and enclosure usage. Three spiders were filmed under infrared light for 24 h following being handled, and on control (no-handling) days. The proportion of time that spiders spent under cover or exhibiting locomotion, limb-interaction, and object-interaction behaviour was recorded using instantaneous scan sampling. The spiders spent, on average, significantly more time under cover (7.8% increase) and exhibited significantly more limb-interaction behaviour (1.4% increase) on handling days. Handling for public talks therefore affects the behaviour and enclosure use of these captive Brachypelma hamorii. Although it is not yet possible to infer welfare implications, the presence of these behavioral responses suggests that protocols to monitor the behaviour of invertebrates following handling should be developed, and further behavioral studies are warranted to validate potential stress indices.

Mo Koundje (“Mok”): the life of a western lowland gorilla (c.1929–1938)

Mo Koundje (“Mok”) was a western lowland gorilla ( Gorilla gorilla gorilla) whose remains form part of the collection of Leeds Museums and Galleries. Before his early death from Bright’s disease (nephritis), he was hugely popular during six years of captivity spent at London Zoo. Newspapers from around the United Kingdom and across the globe reported Mok’s arrival at the Zoo, his exploits, illnesses and demise. While the archives of the Zoological Society of London tell us about the latter part of Mok’s life, tracing his life and journey before entering Europe has proved more difficult. However, French colonial archives held at the Archives nationales d’outre-mer, Aix-en-Provence, give glimpses of the life of his previous owner, Jean Charles André Capagorry, allowing us to piece together the long journey Mok made from a Congolese forest to a museum in Leeds.

SYSTEMIC ISOSPORIASIS (ATOXOPLASMOSIS) IN PASSERINE BIRDS AT THE ZOOLOGICAL SOCIETY OF LONDON, LONDON ZOO.

Infection with systemic Isospora species (systemic isosporiasis [SI]) is common in passerine birds and may cause substantial mortality in zoological collections. Ten years of postmortem records of 26 species of captive, nonnative passerine birds maintained at the Zoological Society of London, London Zoo, plus seven free-ranging species found dead within the zoo, were reviewed to assess cause of death and occurrence of SI (presence of merozoites in tissue impression smears and/or polymerase chain reaction [PCR] testing for Isospora DNA). The records of 287 juveniles and adults were reviewed, of which 161 had SI test results. The most common cause of death was physical (trauma, predation, drowning, and hypothermia), diagnosed in 39.0% of cases. Virulent SI was considered the cause of death in only nine individuals from five species (3.1% of all cases, 5.6% of tested birds). However, merozoites were recorded in 36.0% of the 150 individuals examined cytologically (representing 18 of the 33 species), while 45.3% of 53 spleen samples (14 species) were positive for Isospora DNA. Test agreement for the 42 birds tested by both methods was 69.0%. Assuming that the PCR result was correct in these, 37.9% of the 161 birds (21 species) were positive for SI at the time of death. These figures might underestimate prevalence because of poor DNA preservation and low numbers of individuals of some species tested. Eight new 28S rDNA sequences and 12 new internal transcriber spacer 1/2 sequences were amplified. Sequences from individuals of the same host species clustered together, suggesting a single Isospora species, and there was no evidence of overlap among hosts. These results confirm that systemic infection with Isospora species in zoo passerines is generally of low pathogenicity and most likely coevolved with their hosts. Severe disease may occur, however, with overwhelming exposure, secondary to immunosuppression, or following coinfection with another pathogen.

A Qualitative Risk Assessment for Bluetongue Disease and African Horse Sickness: The Risk of Entry and Exposure at a UK Zoo.

Bluetongue virus (BTV) and African horse sickness virus (AHSV) cause economically important diseases that are currently exotic to the United Kingdom (UK), but have significant potential for introduction and onward transmission. Given the susceptibility of animals kept in zoo collections to vector-borne diseases, a qualitative risk assessment for the introduction of BTV and AHSV to ZSL London Zoo was performed. Risk pathways for each virus were identified and assessed using published literature, animal import data and outputs from epidemiological models. Direct imports of infected animals, as well as wind-borne infected Culicoides, were considered as routes of incursion. The proximity of ongoing disease events in mainland Europe and proven capability of transmission to the UK places ZSL London Zoo at higher risk of BTV release and exposure (estimated as low to medium) than AHSV (estimated as very low to low). The recent long-range expansion of AHSV into Thailand from southern Africa highlights the need for vector competence studies of Palearctic Culicoides for AHSV to assess the risk of transmission in this region.

Robert McNeill Alexander. 7 July 1934—21 March 2016

Neill Alexander graduated in natural sciences at the University of Cambridge in 1955. After a PhD at Cambridge and a lecturership at the University College of North Wales in Bangor, he was appointed to the chair of the Department of Pure and Applied Zoology at the University of Leeds in 1969. At that stage, he switched his research interests abruptly from fishes to the mechanics of legged locomotion. He conducted experiments with a variety of mammals, calculating forces, stresses and strains in muscle fibres, bones and tendons. His speciality became the application of mathematical models to animal locomotion, including repurposing the Froude number, devised by the Victorian engineer William Froude (FRS 1870) for use with ships, to estimate the speed of dinosaurs based on the spacing of their fossil footprints. Subsequent work included modelling the optimization of mammal performance and the minimization of energy costs. In 1992, following an announcement that London Zoo would have to close as a result of shortage of funds, Neill was appointed secretary of the Zoological Society of London. During the period of his secretaryship, the Society's finances recovered, with both its zoos (London and Whipsnade) breaking even in 1993 and the Society returning a surplus in each subsequent year. Neill was awarded the CBE in 2000. The National Portrait Gallery holds his portrait by John Arnison.

“Accustomed to Female Domination”: Women, Mass Media, and Animal Intimacy in Interwar Britain

This essay analyzes four visual sources that shed light on the relationship between gender and animal intimacy in interwar Britain. They are all photographs that appeared in print media, and all relate to the production of wildlife films. The first is a montage of six photographs showing a woman’s friendship with the “strange savage beasts” of the London Zoo; the second is an advertisement for a popular remedy; the third shows a director shooting a zoo film; the fourth contains shots from a documentary made in 1938. The essay focuses on three women—Gladys Callow, Mary Field, and Evelyn Spice—all former schoolteachers who became involved in the production of zoo films. By analyzing this series of images, connections between contemporary ideas about gender, animal tameness, and colonial domination are established, reflecting shifts in the depiction of animal intimacy in early twentieth-century Britain.

(In awe and wonder at) All Creatures Great and Small

My job as an industrial hygienist and occupational physician takes me to some very interesting workplaces. I remain in thrall and awe of hazards both great and small and the challenges for containment and control. In January 2016, I had the opportunity to literally, take a walk on the wild side. Until then, little did I know that designated zoo staff were required to hold firearm licenses to enforce public safety if a ‘dangerous animal’ escaped. My contract was to do their firearm medicals. Of course, I was not going to be charged any entry fee! And no, I was not forbidden to meet & greet the other animals. The visitors on site were in fun day mode, clustered into groups and families, doing the rounds of the animal enclosures. My singleton self, shod in Wellingtons, wearing a visitor badge, taking notes on a piece of paper, wielding a smartphone and afflicted with a serious case of the shutterbug, did arouse some strange looks (strange beings, these bipeds). I was pinching myself to be doing a workplace walkthrough (the inhabitants of the wallaby enclosure would probably prefer ‘workplace walkabout’) in what was for other people, a fun zone. Only while interviewing the staff did it sink in that I had the privilege of being the first occupational physician of the oldest zoo in the world. It turned out that in its nearly 200-year history, staff of ZSL London Zoo and Whipsnade Zoo had never before spotted a specimen of the rare subspecies of doctors who call themselves occupational physicians. Need I add that I was impressed with the role of the zoos in conservation work and the hard work and dedication of the staff?

A Model for Dental Age Verification Using Ultrastructural Imaging for Modern and Fossil Representatives of the Rhinocerotidae Family

Simple SummaryDetermining the age of an animal based on remains, especially fossil remains, is challenging. The age of an individual can be estimated from ultrastructural analyses of teeth. Therefore, in this study, an attempt was made to establish a relationship between the age of a rhinoceros and the ultrastructure of its tooth. The subject of these examinations was a tooth that originated from a female white rhinoceros that died at Kiev Zoo. The age of the female was known. She did not give birth during her life, so pregnancy did not influence the tooth ultrastructure. For ultrastructural examination, ground sections of the tooth were obtained and slides were observed under a light microscope in white light as well as in polarized light with the use of a lambda filter. In addition, gold-coated preparations were imaged in a scanning electron microscope. Three sections were cut out of the specimen: Horizontal through the tooth crown, horizontal through the upper part of the root, and longitudinal. In subsequent stages they were investigated to see the annual growth lines of mineralized dental tissues of cement and dentine. These lines were counted from the root canal center to the cheek surface of the tooth. The most satisfactory results were obtained on the horizontal section through the upper part of the root, where distinct growth lines were observed in the dentine, and their number for both roots was consistent with the known chronological age of the animal.The analyses were performed on a right third premolar (P3) of a white rhinoceros female (Ceratotherium simum, Burchell 1817). The specimen was born in captivity at London Zoo (Zoological Society of London), then in the 1970s transferred to Kiev Zoo (Peremohy Avenue), Ukraine, and was kept there until it died at a documented chronological age of 48 years. The female died because of its age, which indicates it was kept in good conditions adequate to the requirements of this species. Photographs and micrographs with radiological documentation were taken on the said tooth. Its structural characteristics were determined, and on the occlusal surface areas and points of anatomical constitution of its crown were identified. The tooth was also histologically evaluated via sections taken horizontally in a mesial-distal plane through the crown, horizontally in a mesial-distal plane through the coronal portion of the root, and longitudinally in a lingual-buccal plane through the crown and the root. Preparations with ground sections were made and observed in white, polarized, and reflected light. In the subsequent stage X-ray and SEM imaging has also been used, for analysis of the distribution of annual growth layers of mineralized dental tissues of cement and dentine, counted from the root canal center to the buccal surface. An attempt was also made to confirm the annual season in which the animal died, based on cement growth lines. It was observed that the growth lines were visible in all the analyzed sections, in dentine and cement. In the cement, the lines were relatively few and did not represent the attested age of the animal. The analysis of the coloration of the cement lines indicated that the animal was regularly fed a diet that was not seasonally differentiated. From the X-ray examination comes a conclusion that the animal did not suffer from periodontal diseases. Visible growth lines were observed on the dentine. On the horizontal section through the crown growth lines in the dentine were few and unclear. On the longitudinal section, both on the caudal and rostral roots, these lines were clearly visible and much more numerous than expected considering the known age of the animal, as more than 50 were counted. On horizontal sections through the upper part of both roots, distinct growth lines were observed in the dentine, and their number—48 for both roots—corresponded precisely to the age of the animal. The results of our study indicate that this method has significant potential for application to verify the age at death for modern and fossil representatives of rhinoceros.