Female African Elephants Research Articles

CT reconstruction based 3D model of the digital cushion's blood supply in the hind foot of an African savanna elephant (Loxodonta africana).

Foot health is crucial for elephants, as pathological lesions of the feet are a leading cause of euthanasia in captive elephants, which are endangered species. Proper treatment of the feet, particularly in conditions affecting the digits and the digital cushion, requires a thorough understanding of the underlying anatomy. However, only limited literature exists due to the small population and the epidemiological foot diseases which often precludes many deceased elephants from scientific study. The aim of this study was to provide a detailed anatomical description of the blood supply to the African elephant's hindfoot. The healthy right hindlimb of a 19-year-old deceased female African savanna elephant was examined using computed tomography. Following a native sequence, 48 mL of barium-based contrast agent was injected into the caudal and cranial tibial arteries, and a subsequent scan was performed. The images were processed with 3D Slicer software. The medial and lateral plantar arteries run in a symmetrical pattern. They each have a dorsal and a plantar branch, which reach the plantar skin before turning toward the axial plane of the sole to reach the digital cushion from the proximal direction. An accurate 3D model of the arteries and the bones of the foot, a set of labeled images and an animation of the blood supply have been created for ease of understanding. In contrast to domestic ungulates, the digital cushion of the hindlimb is supplied differently from that of the forelimb. The lack of large vessels in its deeper layers indicates a slow regeneration time. This novel anatomical information may be useful in the planning of surgical interventions and in emergency medical procedures.

Maximum trunk tip force assessment related to trunk position and prehensile 'fingers' implication in African savannah elephants.

African elephants have a wide range of abilities using their trunk. As a muscular hydrostat, and thanks to the two finger-like processes at its tip, this proboscis can both precisely grasp and exert considerable force by wrapping. Yet few studies have attempted to quantify its distal grasping force. Thus, using a device equipped with force sensors and an automatic reward system, the trunk tip pinch force has been quantified in five captive female African savanna elephants. Results showed that the maximum pinch force of the trunk was 86.4 N, which may suggest that this part of the trunk is mainly dedicated to precision grasping. We also highlighted for the first time a difference in force between the two fingers of the trunk, with the dorsal finger predominantly stronger than the ventral finger. Finally, we showed that the position of the trunk, particularly the torsion, influences its force and distribution between the two trunk fingers. All these results are discussed in the light of the trunk's anatomy, and open up new avenues for evolutionary reflection and soft robot grippers.

Elephant trunks use an adaptable prehensile grip

Elephants have long been observed to grip objects with their trunk, but little is known about how they adjust their strategy for different weights. In this study, we challenge a female African elephant at Zoo Atlanta to lift 20–60 kg barbell weights with only its trunk. We measure the trunk’s shape and wrinkle geometry from a frozen elephant trunk at the Smithsonian. We observe several strategies employed to accommodate heavier weights, including accelerating less, orienting the trunk vertically, and wrapping the barbell with a greater trunk length. Mathematical models show that increasing barbell weights are associated with constant trunk tensile force and an increasing barbell-wrapping surface area due to the trunk’s wrinkles. Our findings may inspire the design of more adaptable soft robotic grippers that can improve grip using surface morphology such as wrinkles.

Abnormal prolactin secretion is associated with changes in metabolic health biomarkers in acyclic female African elephants (Loxodonta africana)

Circulating prolactin aberrations (chronically high or low concentrations) have been shown to have strong associations with ovarian dysfunction in African female elephants. However, despite the well-established pleiotropic role that prolactin plays in human health, comprehensive metabolic effects from chronically elevated or suppressed prolactin have yet to be investigated in this species. In humans, in addition to amenorrhea, hyperprolactinemic women have shown increased risks for accelerated atherosclerosis, hyperandrogenemia, lowered metabolism, and insulin resistance. The aim of the study was to determine if elephants with long-term abnormal prolactin secretion were also experiencing alterations in metabolic biomarkers. One year of serum samples, collected biweekly, were obtained from female African elephants (n = 74) housed in North American zoos and categorized based on ovarian cyclicity and prolactin status: normal cycling, normal prolactin (NORMAL, n = 25), acyclic, high prolactin (HIGH, n = 25), or acyclic, low prolactin (LOW, n = 24). Each sample was further analyzed for measures of metabolic function, glucose metabolism, and cardiovascular health. Overall, thyroid hormones were significantly lower in both HIGH (TSH, T3, T4) and LOW (TSH) prolactin elephants compared to NORMAL counterparts. Additionally, HIGH prolactin elephants exhibited lower glucose, G:I ratios, and low-density lipoprotein values, but higher cholesterol concentrations compared to normal cycling females. Overall, LOW prolactin elephants exhibited higher body condition scores and G:I ratios, and higher concentrations of insulin, high-density lipoproteins, cortisol and testosterone, but decreased triglyceride values compared to NORMAL elephants in the study. Data suggest that HIGH prolactin elephants may be experiencing hypothyroidism as a comorbidity, whereas LOW prolactin elephants may be exhibiting aspects of insulin resistance, albeit different from human clinical data. Specific studies are suggested that would help elucidate the underlying mechanisms at play and increase our understanding of prolactin’s role in elephant physiology.

Immunocontraception of the female African savanna elephant (Loxodonta africana) in South Africa: from pipe dream to policy

Globally, African savanna elephants have been assessed as ‘endangered’. Consequently, additional threats and losses due to human–elephant conflict (HEC) could further exacerbate the species’ decline. In stark contrast, South Africa’s elephant populations are mostly confined within fenced-in reserves that impede natural processes such as migration. As ecosystem engineers, elephant population growth herein should be limited. Within South Africa, elephant management has evolved as differing wildlife philosophies from utilitarian conservation (‘nature for man’) to biocentric preservation (‘nature for nature’) and a combination thereof, have been practiced. Traditionally, both HEC and population control have been largely synonymous with lethal control, i.e. culling. However, with the increase of public or expert input to Policy, lethal control is not favoured by the public. As an alternative, immunocontraception of female African savanna elephants through non-invasive, native porcine zona pellucida (pZP) vaccinations has been employed successfully and is currently adopted in 43 elephant reserves across South Africa. Current legislation now recommends culling as the last population management resort. Newly promulgated legislation calls for wellbeing and welfare to be carefully measured in all biodiversity management decisions taken to minimise threats to biodiversity. As a keystone species, elephant is a direct driver of biodiversity change. Accordingly, and in light of these developments, all population management options, including immunocontraception, must be fully considered in South Africa’s largest national park, the Kruger.

Density-dependent habitat selection varies between male and female African elephants

Habitat selection models are the basis of an increasing number of conservation and management programs. Decision-makers rely on accurate models to assess animal distribution over space and time, and to recommend suitable actions that can alleviate human-wildlife conflicts. Despite a rapidly growing number of field studies on habitat selection, there remains a paucity of empirical evidence that selection is a density-dependent process that can impact males and females differently. Based on 11 years of monitoring, we demonstrate that the response of African elephants (Loxodonta africana) to land-cover types varied with population size, and that density-dependent adjustments differed between sexes. Specifically, our longitudinal follow-up of GPS-collared elephants revealed that elephants gradually decrease their selection for open woodlands and forests, as the population increased and the availability of palatable browse species decreased. Both sexes – though males more strongly – increased their travel rate together with their relative probability of selection of roads for travel. Also, elephants displayed a density-dependent increase in their selection of infrastructures, a response that was stronger for males than females. The risk of human-elephant conflicts thus increased with population size, with males being particularly prone to be involved in such conflicts. Overall, we provide rare empirical evidence that density-dependence in fine-grain habitat selection can differ between sexes. This information can be critical to accurately forecast potential human-wildlife conflicts, and for taking targeted and effective conservation and management actions.

Predictors of testosterone in zoo-managed male African elephants (Loxodonta Africana).

Reproductive complications for both male and female zoo-managed African elephants (Loxodonta africana) contribute to the rapidly declining population. In zoo-managed bull elephants, few studies have explored the potential physiological, physical, social, and environmental factors that influence bull fertility, particularly, androgen production. Testosterone is the essential steroid hormone for male sexual maturation and inadequate concentrations can be detrimental for spermatogenesis. Testosterone, fecal glucocorticoid metabolites, leptin, glucose, insulin, and triglycerides were analyzed from weekly fecal and blood serum samples taken over 6 months from six zoo-managed African elephant bulls (10-19 years of age). Testosterone levels were compared to endocrine factors, weekly social and environmental variables, daily musth signs, and body condition scores (BCS). The glucose-to-insulin ratio (G:I) was the only physiological biomarker found to be positively associated with testosterone. Predictive physical variables included Musth Score (+) and Moderate Exercise (+). Bulls with BCSsignifying overweight (BCS 4) had lower testosterone (36.6 ± 1.6 ng/g fecal extraction [FE]) than bulls with healthyBCS 3; 51.2 ± 4.9 ng/g FE). Numerous social variables influenced testosterone concentrations, including Total Contact Day (+), Female Interaction Day (+), Indirect Contact Day (+), Indirect Contact Night (+) and Total No Contact (-). Both percentage of Time Outdoor and Time Mixed positively influenced testosterone, whereas testosterone decreased for percentage of Time Indoors. Each additional daily browse opportunity increased testosterone by approximately 7 ng/g FE. In managed care, the emphasis should be placed on optimizing these predictors of testosterone production to promote bull reproductive health.

The relationship between distal trunk morphology and object grasping in the African savannah elephant (Loxodonta africana).

BackgroundDuring reach-to-grasp movements, the human hand is preshaped depending on the properties of the object. Preshaping may result from learning, morphology, or motor control variability and can confer a selective advantage on that individual or species. This preshaping ability is known in several mammals (i.e., primates, carnivores and rodents). However, apart from the tongue preshaping of lizards and chameleons, little is known about preshaping of other grasping appendages. In particular, the elephant trunk, a muscular hydrostat, has impressive grasping skills and thus is commonly called a hand. Data on elephant trunk grasping strategies are scarce, and nothing is known about whether elephants preshape their trunk tip according to the properties of their food.MethodsTo determine the influence of food sizes and shapes on the form of the trunk tip, we investigated the morphology of the distal part of the trunk during grasping movements. The influence of food item form on trunk tip shape was quantified in six female African savannah elephants (Loxodonta africana). Three food item types were presented to the elephants (elongated, flat, and cubic), as well as three different sizes of cubic items. A total of 107 ± 10 grips per individual were video recorded, and the related trunk tip shapes were recorded with a 2D geometric morphometric approach.ResultsHalf of the individuals adjusted the shape of the distal part of their trunk according to the object type. Of the three elephants that did not preshape their trunk tip, one was blind and another was subadult.Discussion and perspectivesWe found that elephants preshaped their trunk tip, similar to the preshaping of other species’ hands or paws during reach-to-grasp movements. This preshaping may be influenced by visual feedback and individual learning. To confirm these results, this study could be replicated with a larger sample of elephants.

Cohort consequences of drought and family disruption for male and female African elephants

Abstract Cohort effects, reflecting early adversity or advantage, have persisting consequences for growth, reproductive onset, longevity, and lifetime reproductive success. In species with prolonged life histories, cohort effects may establish variation in age-sex structures, while social structure may buffer individuals against early adversity. Using periods of significant ecological adversity, we examined cohort effects for male and female elephants (Loxodonta africana) over almost 50 years in Amboseli, Kenya. Mortality spiked during severe droughts with highest mortality among calves under 2 years and females over 40 years. Deaths of oldest females resulted in social disruption via matriarch turnover, with potential impacts on resource acquisition for survivors. We predicted that survivors of high mortality and social challenges would have altered life-history trajectories, with later age at first reproduction and reduced age-specific fertility for females and slow transitions to independence and late-onset of potential mating or musth among males. Contrary to expectations, there were no persisting early drought effects on female age at first conception while matriarch loss around puberty accelerated reproductive onset. Experience of an early life drought did not influence age-specific reproductive rates once females commenced reproduction. Males who survived an early drought exhibited complex consequences: male age at family independence was later with larger peer cohort size, but earlier with drought in year of independence (13.9 vs 14.6 years). Early drought had no effect on age at first musth, but male reproductive onset was weakly associated with the number of peers (negative) and age at independence (positive).

Monitoring Behaviour in African Elephants during Introduction into a New Group: Differences between Related and Unrelated Animals.

Simple SummaryAfrican elephants are highly social animals that perform a so-called Greeting Ceremony in the wild when meeting elephants they are familiar with but have not seen for a certain timespan. Until now, it has not been known whether zoo elephants also show this unique behaviour. Therefore, this study was designed around the reunifications of two mother–daughter pairs that had been separated for 2 and 12 years, and two unifications of unrelated elephants, as a comparison. First contact was conducted in a protected setting, i.e., there was a fence between the animals to prevent possible fighting. Signs of the Greeting Ceremony shown by the elephants, the distance they kept to the separating fence, and the time until the elephants’ trunks touched for the first time were observed. The results demonstrate that the related elephants showed all behavioural characteristic of the Greeting Ceremony, kept close to the fence, and touched trunks after only a few seconds, while elephants that were not familiar with each other did not show a full Greeting Ceremony, stayed further from the fence, and touched trunks for the first time only after several minutes upon meeting. This study testifies that zoo elephants show the same typical social behaviour known from wild elephants (namely the Greeting Ceremony) and, therefore, behave species-specific. It also confirms the strong family bonds of elephants and the cognitive abilities of elephants, specifically their long-term social memory.The introduction of elephants into new groups is necessary for breeding programmes. However, behavioural studies on the reactions of these animals at first encounters are missing. In the present study, female African elephants (Loxodonta africana) living in zoos were observed during unifications with unfamiliar elephants (introduction of two to one females and one to two females; n = 6) and reunifications with related elephants (two mother–daughter-pairs; n = 4) that were separated for 2 and 12 years, respectively. First encounters of the elephants were observed and recorded by scan sampling. The parameters measured were (a) signs of the characteristic Greeting Ceremony, (b) distance to the fence separating the elephants during first contact, and (c) time until trunks touched for the first time. The data were statistically analysed with SPSS. The results showed that related elephants performed a full Greeting Ceremony on reunifications. Unrelated elephants only expressed a minor greeting. During first encounters, related elephants predominantly showed affiliative behaviour (p = 0.001), whilst unrelated elephants expressed more agonistic behaviour (p = 0.001). The distance to the fence was significantly smaller for related elephants than for unrelated elephants (p = 0.038). first contact of trunks occurred on average after 3.00 s. in related elephants and 1026.25 s. in unrelated elephants. These findings indicate that related elephants recognise their kin after up to 12 years of separation, meet them with a full Greeting Ceremony during reunification, and seek contact to the related elephant, while unrelated elephants are hesitant during unifications with unfamiliar elephants and express more agonistic behaviour. The results testify that zoo elephants show the same species-specific social behaviour as their conspecifics in the wild. It also confirms the cognitive abilities of elephants and the significance of matrilines for breeding programmes.

Behavioural Responses to Temporary Separation of a Captive Herd of African Elephants (Loxodonta africana)

Elephants are highly intelligent animals with a huge capacity for social cognition, living in large, long-lived, related herds. In captivity, it is extremely difficult to meet all of the species’ ecological needs, as well as those required individual by individual, but improvements are continually being made. After identifying impaired welfare, one collection made the decision to relocate four female African Elephants (Loxodonta africana) to a different facility. As the worlds’ largest land mammal, many safety, welfare, and logistical considerations were undertaken. The elephants travelled in two pairs, a mother–daughter pair and an older unrelated female and a younger unrelated female with a strong social bond. As a result, there was a short gap in between transports, allowing for further habituation to transport crates and the heat of summer. The changes in both social and individual behaviours of the two females remaining when their group was temporarily reduced from four to two were investigated using one-zero sampling. The study determined the daily activities of the elephants comparing ‘before transport’ to ‘after transport’ for the two remaining elephants to establish any changes in their behaviours as a result of this disturbance. Post transport, there was an increase in both human-audible vocalisations and temporal gland secretions, and hugely decreased play behaviour was observed. The dynamic between the remaining pair was also altered with more tactile behaviours from mother to daughter seen but more submission from daughter to mother. This led to the conclusion that the elephants, although mostly unrelated and living in an ‘unnatural’ captive setting, had the same signs of stress and behavioural change as would a highly related group if separated.

Genital infection by Aerococcus viridans in a captive african elephant (Loxodonta africana)

ABSTRACT: Aerococcus viridans is an emerging pathogen for humans and livestock animals, mainly associated with genitourinary infections cases. Its occurrence in wild mammals has never been reported. The aim of this study was to determine the etiological agent associated with clinical a case of a genital infection in a female African elephant (Loxodonta africana). Phylogenetic analysis and antimicrobial susceptibility profile of the isolate were also addressed. The animal presented frequent cases of genital infection with intermittent white secretion. Purulent secretion was sampled and submitted to bacteriological exam. The isolate obtained was thus identified by phenotypic and molecular methods as A. viridans and was found to be similar to human pathogenic isolates in BLASTn and phylogenetic analysis. The isolate was sensitive to almost all antimicrobials evaluated, presenting resistance to ciprofloxacin and norfloxacin. This is the first report of occurrence of A. viridans infection in the genital tract of an African elephant.

Molecular identification and geographic origin of a post-Medieval elephant finding from southwestern Portugal using high-throughput sequencing

Molecular species identification plays a crucial role in archaeology and palaeontology, especially when diagnostic morphological characters are unavailable. Molecular markers have been used in forensic science to trace the geographic origin of wildlife products, such as ivory. So far, only a few studies have applied genetic methods to both identify the species and circumscribe the provenance of historic wildlife trade material. Here, by combining ancient DNA methods and genome skimming on a historical elephantid tooth found in southwestern Portugal, we aimed to identify its species, infer its placement in the elephantid phylogenetic tree, and triangulate its geographic origin. According to our results the specimen dates back to the eighteenth century CE and belongs to a female African forest elephant (non-hybrid Loxodonta cyclotis individual) geographically originated from west—west-central Africa, from areas where one of the four major mitochondrial clades of L. cyclotis is distributed. Historical evidence supports our inference, pointing out that the tooth should be considered as post-Medieval raw ivory trade material between West Africa and Portugal. Our study provides a comprehensive approach to study historical products and artefacts using archaeogenetics and contributes towards enlightening cultural and biological historical aspects of ivory trade in western Europe.

Air temperature and diet influence body composition and water turnover in zoo-living African elephants (Loxodonta africana).

African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (2H2O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d−1; females: 241 ± 28 l d−1) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2–3 days to avoid critical water loss of approximately 10% body mass in hot conditions.

Importance of old bulls: leaders and followers in collective movements of all-male groups in African savannah elephants (Loxodonta africana)

In long-lived social species, older individuals can provide fitness benefits to their groupmates through the imparting of ecological knowledge. Research in this area has largely focused on females in matrilineal societies where, for example, older female African savannah elephants (Loxodonta africana) are most effective at making decisions crucial to herd survival, and old post-reproductive female resident killer whales (Orcinus orca) lead collective movements in hunting grounds. In contrast, little is known about the role of older males as leaders in long-lived social species. By analysing leadership patterns of all-male African savannah elephant traveling groups along elephant pathways in Makgadikgadi Pans National Park, Botswana, we found that the oldest males were more likely to lead collective movements. Our results challenge the assumption that older male elephants are redundant in the population and raise concerns over the biased removal of old bulls that currently occurs in both legal trophy hunting and illegal poaching. Selective harvesting of older males could have detrimental effects on the wider elephant society through loss of leaders crucial to younger male navigation in unknown, risky environments.

Nocturnal Behaviour of Three Zoo Elephants (Loxodonta Africana)

Few studies have investigated the behaviour of zoo elephants and how their personality is expressed when exposed to different stimuli e.g. a higher number of visitors. Observing the nocturnal behaviour is especially important, because it reveals information about the welfare of the elephants when they are not normally observed. The nocturnal behaviour of three female African elephants (Loxodonta africana) in Aalborg Zoo, Denmark, was studied to create activity budgets and to evaluate if 1) a period with a 4.8 times increase in visitors affected the nocturnal behaviour; and 2) the three elephants exhibited differences in personality. Behavioural data were collected for six nights between 20:00-06:00, and all-occurrence sampling was used to record all types of behaviour. The average of the three elephants showed that the most common behaviours observed during the night was feeding (43±6%) followed by lying (28±5%) and inactive behaviour (16±5%). The elephants laid down an average of 2.4-3.1 hours per night starting at 20:00, and they never laid down before 22:00. No clear pattern of behavioural changes of the elephants was found when there was an increased number of visitors in the zoo. When comparing the intervals of time, the individuals spent on a certain behaviour, and thereby comparing the individuals, several significant differences were found between the medians and interquartile range (IQR). Significant differences were also found in the slopes of the medians, IQR, skewness, and kurtosis for the distribution of the time intervals of the behaviours between the period with lower number of visitors and the period with a higher number of visitors. In an overall perspective, the results indicated that the elephants displayed distinct personalities.

The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces.

Population-level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure the behavior of two female African elephants across three treatments to evaluate the independent effects of complexity and space. Preoccupancy observations were conducted in the elephants' older exhibit, which consisted of a smaller, more simple yard (630 m2 ). Subsequent postoccupancy observations measured behavior in two different spaces in the new exhibit: a larger, complex yard (15,000 m2 ), and a smaller, but complex yard (1,520 m2 ). The elephants' overall activity levels were greater in complex habitats, regardless of their size. Similar effects of habitat complexity oversize were observed with greater rates of foraging and lower rates of being stationary. Furthermore, elephants were out of view of visitors significantly more in the small, simple yard compared to either of the more complex habitats. However, exhibit size affected the incidence of stereotypic behavior (with lower rates of stereotypy in the larger exhibit compared to the smaller yards) and investigatory behavior (elephants investigated their environments more with increasing size and complexity). Behavioral diversity also increased with exhibit size and complexity. These results indicate that space availability alone is not sufficient to enhance the behavioral welfare of zoo elephants. Therefore, facilities with limited space can still encourage species-appropriate behaviors and improved welfare for the elephants in their care by converting a small, simple area into a more complex habitat.

Anatomy of the Proboscideal Nerve in the Proboscis of the African Elephant (Loxodonta africana)

The elephant proboscis (i.e., trunk), a unique muscular organ formed by the combined narial and upper lip region, is a complex muscular hydrostat adapted for a multitude of functions, including grasping, holding, and transporting objects, siphoning, holding, and spraying water, and communication. The proboscis has previously been described as containing tens of thousands of muscle fascicles, each working individually to help bend, curve, and curl the trunk in all directions at any point along its length. Although the muscular system of the proboscis has previously been described in some depth, the unique nervous innervation of the proboscis has been given minimal attention. Here, the previously frozen head of an adult female African elephant (Loxodonta africana) is dissected to investigate the anatomy of the neuromuscular anatomy of the proboscis in more depth. In addition to the complexity of interlacing muscle fascicles and the integrated connective tissues, we identified the proboscideal nerve, a large, 2.5 to 3 centimeter thick nerve that is unique to elephants. The proboscideal nerve is made up of the combined distal nerve fibers of the infraorbital branch of the maxillary nerve (CN V3) and zygomatic branch of the facial nerve (CN VII). Specifically, as the infraorbital branch of the maxillary nerve (carrying sensory innervation) exits the cranium through the infraorbital foramen, the zygomatic branch of the facial nerve (carrying motor innervation) runs along the ventral border of the zygomatic arch and joins the maxillary nerve rostrodorsal to the masseter muscle to form the proboscideal nerve. The proboscideal nerve then travels down the length of the proboscis transmitting small sensory and motor nerve fibers to all muscle fascicles and surrounding skin and tissue. Given this anatomy, fine‐tuned neuromuscular control and coordination of the individual nerve fibers are necessary to control the diverse movements that occur throughout the length of the proboscis. This specialized evolutionary adaptation helped shape a functionally innovative organ that grew, modified, and persisted throughout the course of proboscidean evolution.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Hyperprolactinemic African elephant (Loxodonta africana) females exhibit elevated dopamine, oxytocin and serotonin concentrations compared to normal cycling and noncycling, low prolactin elephants†.

Many zoo elephants do not cycle normally, and for African elephants, it is often associated with hyperprolactinemia. Dopamine agonists successfully treat hyperprolactinemia-induced ovarian dysfunction in women, but not elephants. The objective of this study was to determine how longitudinal dopamine, serotonin, and oxytocin patterns in African elephants are related to ovarian cycle function. We hypothesized that dopamine concentrations are decreased, while oxytocin and serotonin are increased in non-cycling, hyperprolactinemic African elephants. Weekly urine and serum samples were collected for eight consecutive months from 28 female African elephants. Females were categorized as follows: (1) non-cycling with average prolactin concentrations of 15 ng/ml or greater (HIGH; n=7); (2) non-cycling with average prolactin concentrations below 15 ng/ml (LOW; n=13); and (3) cycling with normal progestagen and prolactin patterns (CYCLING; n=8). Both oxytocin and serotonin were elevated in hyperprolactinemic elephants. Thus, we propose that stimulatory factors may play a role in the observed hyperprolactinemia in this species. Interestingly, rather than being reduced as hypothesized, urinary dopamine was elevated in hyperprolactinemic elephants compared to CYCLING and LOW prolactin groups. Despite its apparent lack of regulatory control over prolactin, this new evidence suggests that dopamine synthesis and secretion are not impaired in these elephants, and perhaps are augmented.

Prolonged ovarian acyclicity is associated with a higher likelihood of developing hyperprolactinemia in zoo female African elephants.

Hyperprolactinemia is a common disorder of the hypothalamic-pituitary axis, and a cause of ovarian dysfunction in women. Currently, over half of non-cycling African elephant females in North America also are hyperprolactinemic, suggesting a similar link between these two conditions may exist. The objective of this study was to determine the relationship between acyclicity and prolactin status by comparing mean prolactin concentrations of bi-weekly samples collected over a 1-year period in 2012 with 20 years of historical weekly progestagen data to assess cyclicity. Females were categorized as: 1) non-cycling with an average prolactin concentration of 15 ng/ml or greater (HIGH; n = 17); 2) non-cycling with an average prolactin concentration below 15 ng/ml (LOW; n = 16); and 3) typical temporal patterns of progestagen and prolactin secretion (NORMAL; n = 45), and evaluated based on length of time (in years) they had experienced ovarian inactivity. Results showed that the majority of HIGH prolactin elephants had been acyclic for at least 5 years, and in a number of cases (n = 9) for over 10 years. By contrast, most of the LOW prolactin elephants had experienced acyclicity for less than 5 years. Finally, there was a positive association between duration of acyclicity and mean prolactin concentrations, with an increase in the likelihood of having higher prolactin concentrations the longer an individual was acyclic. This study highlights the importance of longitudinal hormonal datasets to examine temporal changes in biological functioning and better understand the etiology of infertility problems.