Joyce H Poole

• PHD University of Cambridge
• Managing Director at ElephantVoices

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 perio...

Understanding why related species combine calls in different ways could provide insight into the selection pressures on the evolution of combinatorial communication. African savannah elephants (Loxodonta africana), African forest elephants (Loxodonta cyclotis), and Asian elephants (Elephas maximus) all combine broadband calls (roars, barks, and cri...

Multi-level fission-fusion societies, characteristic of a number of large brained mammal species including some primates, cetaceans and elephants, are among the most complex and cognitively demanding animal social systems. Many free-ranging populations of these highly social mammals already face severe human disturbance, which is set to accelerate...

Growth from conception to reproductive onset in African elephants (Loxodonta africana) provides insights into phenotypic plasticity, individual adaptive plastic responses and facultative maternal investment. Using growth for 867 and life histories for 2652 elephants over 40 years, we demonstrate that maternal inexperience plus drought in early life...

http://www.theecologist.org/News/news_analysis/1800368/elephants_are_not_diamonds.html

Elephant/human conflict mitigation solutions have been explored with varying degrees of success. We present findings on a potential acoustic tool to reduce negative outcomes of male elephants entering agricultural areas in the region northeast of Etosha National Park, Namibia. We monitored elephant traffic within and outside the park boundary using...

Strong social bonds are uncommon among male mammals. In many mammals, however, males form all-male groups, providing opportunities for male-male bonds to emerge. We examined association patterns of male African elephants, Loxodonta africana, in all-male groups and assessed the influence of age and genetic relatedness on these associations. We also...

The value of age is well recognized in human societies, where older individuals often emerge as leaders in tasks requiring specialized knowledge, but what part do such individuals play in other social species? Despite growing interest in how effective leadership might be achieved in animal social systems, the specific role that older leaders may pl...

Proposes several new call types. • Describes a broad range of behavioral contexts and examines, qualitatively and quantitatively, the acoustic signals with which they are associated. • Makes a fi rst attempt to discriminate between proposed contextual call sub-types based on a number of acoustic measurements. • Uses these and contextual differences...

This chapter, which draws on photographs and descriptions in published material to describe many of the displays, signals, postures, and gestures of African elephants, aims to provide a detailed description of the varied elements in the behaviors of elephants so that they can be recognized and contextually understood in the field. Most of the entri...

As elephants compete for food, water, and mates, dominant groups and individuals will access higher-quality food resources and, in the case of males, a greater number of mates than those who are lower in rank. As elephants attempt to maximize their intake rate, they must make frequent decisions regarding when and where to go, with whom, and how lon...

Male elephants interact frequently with other elephants. Young males face feeding competition from females and other males, and all males compete over access to females. Rates of aggression among mature adult males tend to be high. Competition obviously affects male grouping and associations, which are explored further in this chapter. This chapter...

Walker and Stiles argue that elephant populations are not declining. The facts say otherwise. Loxodonta africana numbers have plummeted by more than 50% continent-wide in the past 40 years, a reduction now compounded by increases in range loss, conflict with humans, and resurgence in poaching ([ 1

Female mate choices. Analysis showing that nulliparous female elephants do not direct their oestrous behaviour appropriately towards musth males, unlike parous females. (0.02 MB DOC)

Data table to accompany Document S1. (0.03 MB DOC)

Female African elephants signal oestrus via chemicals in their urine, but they also exhibit characteristic changes to their posture, gait and behaviour when sexually receptive. Free-ranging females visually signal receptivity by holding their heads and tails high, walking with an exaggerated gait, and displaying increased tactile behaviour towards...

Tanzania and Zambia are petitioning the Convention on International Trade in Endangered Species (CITES) to “downlist” the conservation status of their elephants to allow sale of stockpiled ivory. But just 2 years after CITES placed a 9-year moratorium on future ivory sales (1), elephant poaching is on the rise. The petitioning countries are major s...

Genes of the vertebrate major histocompatibility complex (MHC) are crucial to defense against infectious disease, provide an important measure of functional genetic diversity, and have been implicated in mate choice and kin recognition. As a result, MHC loci have been characterized for a number of vertebrate species, especially mammals;however, ele...

Elephants show a rich social organization and display a number of unusual traits. In this paper, we analyse reports collected over a thirty-five year period, describing behaviour that has the potential to reveal signs of empathic understanding. These include coalition formation, the offering of protection and comfort to others, retrieving and ‘baby...

Nonrandom patterns of mating and dispersal create fine-scale genetic structure in natural populations - especially of social mammals - with important evolutionary and conservation genetic consequences. Such structure is well-characterized for typical mammalian societies; that is, societies where social group composition is stable, dispersal is male...

Monitoring the location of conspecifics may be important to social mammals. Here, we use an expectancy-violation paradigm to test the ability of African elephants (Loxodonta africana) to keep track of their social companions from olfactory cues. We presented elephants with samples of earth mixed with urine from female conspecifics that were either...

Animals can benefit from classifying predators or other dangers into categories, tailoring their escape strategies to the type and nature of the risk. Studies of alarm vocalizations have revealed various levels of sophistication in classification. In many taxa, reactions to danger are inflexible, but some species can learn the level of threat prese...

The costs of inbreeding depression, as well as the opportunity costs of inbreeding avoidance, determine whether and which mechanisms of inbreeding avoidance evolve. In African elephants, sex-biased dispersal does not lead to the complete separation of male and female relatives, and so individuals may experience selection to recognize kin and avoid...

The ability to discriminate between call types and callers as well as more subtle information about the importance of a call has been documented in a range of species. This type of discrimination is also important in the vibrotactile environment for species that communicate via vibrations. It has recently been shown that African elephants (Loxodont...

Male African elephants experience intense intrasexual selection in gaining access to oestrous females, who represent a very scarce and highly mobile resource. An unusual combination of behavioural and physiological traits in males probably reflects this intense selection pressure. Males show prolonged growth, growing throughout much or perhaps all...

There are a few mammalian species that can modify their vocalizations in response to auditory experience. We describe two examples of vocal imitation by African Savannah Elephants (Loxodonta africana), a terrestrial mammal that lives in a multitiered fission-fusion society. The first case of vocal imitation involves Mlaika, an adolescent female Afr...

There are a few mammalian species that can modify their vocalizations in response to auditory experience--for example, some marine mammals use vocal imitation for reproductive advertisement, as birds sometimes do. Here we describe two examples of vocal imitation by African savannah elephants, Loxodonta africana, a terrestrial mammal that lives in a...

Social trauma: early disruption of attachment can affect the physiology, behaviour and culture of animals and humans over generations.

Musth is a state of heightened sexual and aggressive activity in male elephants. Between 1992 and 1997, young orphaned musth male African elephants (Loxodonta africana) that had been introduced to Pilanesberg, South Africa, killed more than 40 white rhinoceros (Ceratotherium simum). The killing ceased after six older male elephants were introduced...

A series of playback experiments using two elephant vocalizations, the 'musth rumble' and the 'oestrous call', was carried out in Amboseli National Park to examine signalling and assessment in African elephants, Loxodonta africana. In response to the musth rumble of a high-ranking male other musth males approached the speaker aggressively, whereas...

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The scientific community now agrees that, more than anything else, it is the killing of African elephants for the ivory trade that has caused the very dramatic declines in elephant populations witnessed over the past decade. Based on samples of ivory trade data, recent population modelling and field data, the authors discuss the implications of the...

Male guarding of females, male mating success and female choice were studied for 8 years among a population of African elephants, Loxodonta africana. Males were not able to compete successfully for access to oestrous female until approximately 25 years of age. Males between 25 and 35 years of age obtained matings during early and late oestrus, but...

Predictions derived from game theory suggest that animals should not signal their intentions during conflict situations. However, during the period of musth, male elephants,Loxodonta africana, announce a state of heightened aggression with signals that are unbluffable. Since smaller musth males in poor condition are able to dominate larger, normall...

Several types of low frequency calls made by African elephants, Loxodonta africana, and the contexts in which they occurred are described. These calls had fundamental frequencies ranging from 14–35 Hz and sound pressure levels as high as 1033dB (re 20 Pa) at 5 m from the source. Very low frequency sounds are subject to very little environmental att...

Male Loxodonta africana spent more time in association with females during musth than during non-musth periods. Males were more aggressive during their musth periods. Occurrence and duration of musth were age-related: no male under 24 yr was seen in musth; bouts of musth among younger individuals were short and sporadic, while older males experienc...

Urine samples were obtained from free-ranging African elephants that were considered to be in and out of musth. Testosterone concentrations, measured by radioimmunoassay were significantly greater in males that were in or around the time of behavioural musth. This study supports a correlation between the observed behavioural characteristics of must...

The phenomenon of musth in male Asian elephants, Elephas maximus, has long been recognized1. Musth, which has been likened to rutting behaviour in ungulates2, refers to a set of physical and behavioural characteristics displayed periodically by adult male elephants. The most obvious manifestations are a sharp rise in aggressive behaviour, copious s...