Ximena Nelson

• PhD
• Professor at University of Canterbury

Jumping spiders (family Salticidae) are known for their intricate visionbased behavior during encounters with prey and conspecific individuals. This is achieved using eyes specialized for discerning fine detail, but there has been minimal research on the capacity that salticids might have for visual performance under low ambient light levels. Here,...

The largest family of spiders, jumping spiders (Salticidae), is known for performing complex visually mediated predatory and courtship behavior. As cursorial predators, they rely on their sensory systems to identify objects at a distance. Based on these assessments, salticids perform flexible and target-specific behavioral sequences which demonstra...

Aquatic environments are an unusual habitat for most arthropods. Nevertheless, many arthropod species that were once terrestrial dwelling have transitioned back to marine and freshwater environments, either as semiaquatic or, more rarely, as fully aquatic inhabitants. Transition to water from land is exceptional, and without respiratory modificatio...

The nature and evolution of positive emotion is a major question remaining unanswered in science and philosophy. The study of feelings and emotions in humans and animals is dominated by discussion of affective states that have negative valence. Given the clinical and social significance of negative affect, such as depression, it is unsurprising tha...

Acoustic communication is widespread in beetles, is often sexually dimorphic, and plays a significant role in behaviours such as premating recognition, courtship, and copulation. However, the factors that determine the presence or absence of acoustic signalling in a given species remain unclear. We examined acoustic communication in bark beetles (S...

Putatively rare behaviours like tool use are difficult to study because absence of evidence can arise from a species’ inability to produce the behaviour or from insufficient research. We combine data from digital platforms and phylogenetic modelling to estimate rates of tool use in parrots. Videos on YouTube revealed novel instances of self-care to...

The use of substrate borne vibrational playback to control insect pests is a rapidly growing line of research targeting many problematic species. Among the control approaches currently being tested, vibrational deterrent playbacks that aim to prevent feeding and to drive pests away from the target area are comparatively under-explored. In experimen...

Decreasing responsiveness to repeated visual stimuli (i.e., the inability to sustain attention) in jumping spiders (Salticidae) parallels that found in humans. In humans, drugs affect vigilance, and previous work on salticids has shown that the “vigilance decrement” is unlikely to be sensory habituation and that caffeine ameliorates reductions in a...

The jumping spider Marpissa marina (Goyen, 1892) is endemic to Aotearoa New Zealand. In this paper, we redescribe the species. Marpissa marina was placed in the Northern Hemisphere genus Marpissa due to its subjective similarity to spiders in that genus. The original description lacked modern morphological diagnoses and useful illustrations. The de...

The ability of nervous systems to filter out irrelevant and repetitive stimuli may prevent animals from becoming ‘saturated’ with excess information. However, animals must be particular about which stimuli to attend to and which to ignore, as mistakes may be costly. Using a comparative approach, we explored the effect of interstimulus interval (ISI...

New Zealand’s kea parrot (Nestor notabilis) is a highly neophilic species that is attracted to human settlements and structures. These environments pose several risks to this endangered species, but also pose a management challenge in how to best ensure that a neophilic species is kept away from the allure of ever-changing human environments. One p...

Vibrational communication in the Auchenorrhyncha is an avenue of growing interest, with many pesticide‐free vibrational pest control programmes against auchenorrhynchan agricultural pests continuing to be developed around the world. Passion vine hoppers (PVH), Scolypopa australis (Walker) (Hemiptera: Ricaniidae), are an economically damaging pest s...

The photographic identification (photo‐ID) of individual animals can be time‐consuming and erroneous. Recent efforts to collect photographs of leopard seals (Hydrurga leptonyx) from across their range have necessitated the technological streamlining of photo‐ID. We constructed a dataset containing 595 photographs of the head and body of individuals...

Leopard seal (Hydrurga leptonyx) moult affects the application of glued tags used to monitor activity. Considering the possible effects of climate change on leopard seal activity and climate on pinniped moult, we assessed aspects of leopard seal moult in a warm region (New Zealand) of their range for the first time. Moult pelage colours resembled t...

New Zealand’s endangered mountain parrot, the Kea (Nestor notabilis), exhibits moderate male-biased sexual size dimorphism in linear body measurements (~5%) and a pronounced dimorphism in bill size (12–14%). Using stable isotope analyses of carbon and nitrogen in Kea feathers and blood sampled from a significant portion (~10%) of the extant populat...

Studying the prevalence of putatively rare behaviours, such as tool use, is challenging because absence of evidence can arise either from a species’ inability to produce the behaviour or from insufficient research effort. Here, we tackle this challenge by combining crowdsourcing and phylogenetic modelling to approximate actual rates of a rarely obs...

The propagation of animal vocalizations in water and in air is a well-studied phenomenon, but sound produced by bark and wood-boring insects, which feed and reproduce inside trees, is poorly understood. Often being confined to the dark and chemically saturated habitat of wood, many bark- and woodborers have developed stridulatory mechanisms to comm...

In recent years, increasingly interdisciplinary exchanges have demonstrated how scientific knowledge of captive cognition and behaviour can prove valuable for informing conservation efforts for endangered species. New Zealand’s endemic mountain parrot, the kea (Nestor notabilis), has shown ape-like performance across a range of cognitive tasks, yet...

New Zealand pest control operations commonly deploy toxic sodium fluoroacetate (1080) baits to control introduced mammalian predators and protect vulnerable native fauna, yet the highly intelligent kea (Nestor notabilis) is at risk of mortality following ingestion of toxic baits intended for their protection. We tested the retention of conditioned...

Jumping spiders (Salticidae) use exceptional vision, largely mediated by their forward-facing anterior lateral (AL) and anterior medial (AM) eyes, to pounce on prey from a distance. We evaluated depth perception through the use of 'texture density' (depth estimation through surface texture comparisons, with greater distances having higher textural...

The propagation of animal vocalizations in water and in air is a well-studied phenomenon, but sound produced by bark and wood boring insects, which feed and reproduce inside trees, is poorly understood. Often being confined to the dark and chemically-saturated habitat of wood, many bark- and woodborers have developed stridulatory mechanisms to comm...

Animals with small nervous systems may be prone to limitations in processing ability when confronted with a diversity of stimuli, especially if these involve multiple sensory modalities. We investigated the effect of the odour of the plant Lantana camara and its dominant volatile compound, β-caryophyllene, on the prey choice decisions of Evarcha cu...

Jumping spiders (Salticidae) are diurnal visual predators known for elaborate, vision-mediated behaviour achieved through the coordinated work of four pairs of camera-type eyes. One pair (‘principal’ eyes) is responsible for colour and high spatial acuity vision, while three pairs (‘secondary’ eyes) are mostly responsible for motion detection. Base...

Several non-mutually exclusive hypotheses have been proposed to explain the evolution of cognition in animals. Broadly, these hypotheses fall under two categories: those that pertain to the selective pressures exerted either by sociality or by the ecological niche in which animals live. We review these ideas and then discuss why the highly visual j...

The article Widespread army ant aversion among East African jumping spiders (Salticidae)

Animals often rely on different sources of information when making decisions about the environment. Here, we assessed whether two jumping spiders (Salticidae), Trite planiceps and Portia fimbriata, take two different sources of information into account when jumping over water, to which they are averse. Specifically, we investigated whether salticid...

The brown marmorated stink bug, Halyomorpha halys (Heteroptera: Pentatomidae), is regarded as one of the world's most pernicious invasive pest species, as it feeds on a wide range of economically important crops. During the autumn dispersal period, H. halys ultimately moves to potential overwintering sites, such as human-made structures or trees wh...

Jumping spiders (Salticidae) typically prey on a variety of arthropods of similar size to themselves, but rarely on ants. Using 28 salticid species from East Africa, we first investigated vision-based aversion to ants by recording latency to enter a transparent sealed chamber flanked by chambers containing living army ants (Dorylus sp.) or tsetse f...

Jumping spiders (family Salticidae) are known for their elaborate vision-based behaviour during encounters with prey and conspecifics. However, most research on their visual performance has been carried under bright light levels. Here, we investigated the capacity of two salticid species, Cyrba algerina (Portugal) and Cyrba ocellata (Kenya), to per...

Bark and ambrosia beetles and pinhole borers (Coleoptera: Curculionidae: Scolytinae and Platypodinae) are two subfamilies of weevils that use acoustic communication within plant tissue. These insects transmit and detect sound in a medium that is neither air nor water and they are among the smallest animals with sound-producing organs. Nevertheless,...

In jumping spiders (Salticidae), the vigilance decrement, or decrease in response to a repeated visual stimulus over time, directly parallels that found in humans. Explanations for the vigilance decrement in the human literature are heavily mentalistic and central nervous system (CNS) based, whereas response decrements in invertebrates are typicall...

To take an indirect route (detour) in order to reach a specific target requires complex cognitive processes. Yet more demanding, from the cognitive point of view, is when the goal is only visible at the beginning of the detour. In spiders from the family Salticidae, vision is a key sensory modality mediating navigation and prey search. Their acute...

Bark beetles (Coleoptera: Curculionidae: Scolytinae) are a speciose subfamily of weevils that primarily live in bark and consequently largely communicate using sound. Having colonized multiple countries outside its native range, Hylurgus ligniperda (Fabricius) is considered to be a successful invader, yet little is known about its acoustic communic...

Selection on individuals that incorporate risk to quickly and accurately make a priori navigational assessments may lead to increased spatial ability. Jumping spiders (Araneae: Salticidae) are characterized by their highly acute vision, which mediates many behaviors, including prey capture and navigation. When moving to a specific goal (prey, nest,...

Light-based stimuli elicited acoustic responses in male Hylesinus aculeatus Say (Curculionidae: Scolytinae: Hylesinina) instantaneously, with 100% reliability. Stridulations were elicited with a white light beam in a dark environment and recorded with an ultrasonic microphone. Acoustic responses were consistent, and, when compared with sounds produ...

The inability to maintain signal detection performance with time on task, or response decrement, has been widely studied. In animals with small brains, the ability to filter out repetitive, irrelevant stimuli may prevent the nervous system from being saturated with information. However, animals must be particular to which stimuli they attend and th...

The inability to maintain signal detection performance with time on task, or vigilance decrement, is widely studied in people because of its profound implications on attention-demanding tasks over sustained periods of time (e.g., air-traffic control). According to the resource depletion (overload) theory, a faster decrement is expected in tasks tha...

The inability to maintain signal detection performance with time on task, or vigilance decrement, is widely studied in people. Despite suggestions that limitations in sustained attention may be a fundamental characteristic of animal cognition, there has been limited research on the vigilance decrement in other animals. We conducted two experiments...

Positive emotional contagions are outwardly emotive actions that spread from one individual to another, such as glee in preschool children [1] or laughter in humans of all ages [2]. The play vocalizations of some animals may also act as emotional contagions. For example, artificially deafened rats are less likely to play than their non-hearing-impa...

Positive emotional contagions are outwardly emotive actions that spread from one individual to another, such as glee in preschool children [1] or laughter in humans of all ages [2] . The play vocalizations of some animals may also act as emotional contagions. For example, artificially deafened rats are less likely to play than their non-hearing-imp...

Vocal communication requires the sender to produce a sound, which transmits through the environment and is perceived by the receiver. Perception is dependent on the quality of the received signal and the receiver’s frequency and amplitude sensitivity; hearing sensitivity of animals can be tested using behavioural detection tasks, showing the physic...

Vocal communication requires the sender to produce a sound, which transmits through the environment and is perceived by the receiver. Perception is dependent on the quality of the received signal and the receiver's frequency and amplitude sensitivity; hearing sensitivity of animals can be tested using behavioural detection tasks, showing the physic...

We investigated whether biological relevance affects the perceptual processes underlying prey classification in jumping spiders (Salticidae). We used choice experiments with abstract and realistic representations of prey to test whether Hypoblemum albovittatum, a generalist predator, differs in how it classifies prey compared with Evarcha culicivor...

The jumping spider genus Myrmarachne (Salticidae) consists of over 200 species of morphologically accurate ant mimics, enabling Myrmarachne to evade ant-averse predators that confuse the spiders with ants (Batesian mimicry). A conspicuous but untested trait of Myrmarachne, which is frequently mentioned in the literature, is locomotory mimicry. For...

Traditional methods to determine stable isotope discrimination factors (Δ) between an animal's diet and tissue(s) are costly and time‐consuming. Consequently, data are only available for relatively few species and are completely absent from some orders, including parrots (Order: Psittaciformes). We present simple and cost‐effective methodologies fo...

Intraspecific variation can have important knock-on effects on population dynamics and ecosystem processes. There are good indicators that intraspecific differences may exist in the foraging ecology of kea parrots (Nestor notabilis). Kea breed in two markedly different habitats (alpine and temperate rainforest), and have pronounced sexual size dimo...

Mimicry is a phenomenon in which one species evolves to resemble another. Species that masquerade as ants are the most common kind of mimic. Yet they have been the least understood. But recent studies have pulled back the curtain on ant impersonators—and in so doing have revealed that mimicry is far more complex than once was thought. It turns out...

Some arachnids go to extraordinary lengths to mimic the appearance and behavior of ants

Conservation Behavior as an Emerging Discipline on the Brink of Success, or Unrealistic Ideal? It seems intuitively sensible that an understanding of the behavioral characteristics of animals, such as their home ranges, diets, mating systems, and dispersal me-chanisms, may be useful to inform conservation efforts in determining, for example, suitab...

The East African jumping spider Evarcha culicivora feeds indirectly on vertebrate blood by preferentially preying upon blood-fed Anopheles mosquitoes, the vectors of human malaria1, using the distinct resting posture and engorged abdomen characteristic of these specific prey as key elements for their recognition. To understand perceptual categoriza...

Associations in which a more vulnerable species gains protection by seeking out the company of a pugnacious “protector” species capable of deterring predators are documented among mixed-species groups from various taxa, but experimental studies are rare. We consider an unusual arthropod-based example in which the associate species, Phintella piante...

Aggressive mimicry occurs when an organism resembles some aspect of another organism (the model) in order to obtain prey through its deceptive resemblance. This may function either through the overt response of the receiver or through the lack of response of the receiver. Reviewing selected examples, I discuss some of the difficulties in ascribing...

Introduced mammalian predators have been implicated in the majority of avian extinctions on oceanic islands around the globe. Nowhere is this more apparent than in the decimated New Zealand avifauna, where introduced predators remain the primary threat to virtually all surviving endemic species, including the threatened New Zealand Falcon Falco nov...

The jumping spider Evarcha culicivora (Salticidae) has unusual links to Lantana camara, a plant species to which it is attracted. Three phytochemicals from the headspace of L. camara (1,8 cineole and especially β-caryophyllene and α-humulene) attract adult E. culicivora. These spiders, especially early-instar juveniles, feed on nectar, but adults m...

In this essay we outline how video-related technology can be used as a tool for studying animal behaviour. We review particular aspects of novel, innovative animal behaviour uploaded by the general public via video-based media on the internet (using YouTube as a specific example). The behaviour of animals, particularly the play behaviour focused on...

In a biodiversity conservation exercise a native raptor has been reintroduced to Marlborough, a wine-growing area in New Zealand's South Island, on the assumption that the abundant passerines attracted to the grapes will provide a natural food resource for this predator. As part of a study to assess the value of vineyards as habitat for the threate...

Jumping spiders (Salticidae) are renowned for their exceptional vision, but this does not preclude use of other senses. Here we provide evidence that olfactory pheromones are widespread in the Spartaeinae and Lyssomaninae, two subfamilies regarded as basal clades within the Salticidae. Pheromone use by salticids was tested in a series of experiment...

The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com-munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand's Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types: th...

Evarcha culicivora, an East African jumping spider (Salticidae), is the only spider for which there is evidence of innate olfactory affinity for particular plant species. Evarcha culicivora also actively chooses as preferred prey the females of Anopheles mosquitoes, and both sexes of Anopheles are known to visit plants for nectar meals. Here, we id...

To understand communication, the interests of the sender and the receiver/s of signals should be considered separately. When our goal is to understand the adaptive significance of specific responses to specific signals by the receiver, questions about signal information are useful. However, when our goal is to understand the adaptive significance t...

Ants are a dominant resource in the spider's world, and spiders have a variety of ways of exploiting this resource. Two broad domains of exploitation are reviewed, namely specializing on ants for food and specializing on ants for models to mimic. Exploiting of ants as a source of food includes preying on worker ants and also taking food out of the...

Evarcha culicivora is an East African jumping spider that feeds indirectly on vertebrate blood by choosing blood-fed female Anopheles mosquitoes as prey. Previous studies have shown that this predator can identify its preferred prey even when restricted to using only visual cues. Here, we used lures and virtual mosquitoes to investigate the optical...

Jumping spiders (Salticidae) are renowned for their high performing visual system. In addition to their prominent forward-facing telescope-like principal eyes, salticids possess two or three pairs of secondary eyes used for wide-angle motion detection. Salticids orient towards relevant sources of motion detected by the secondary eyes, enabling them...

Anthropogenic landscapes can be rich in resources, and may in some cases provide potential habitat for species whose natural habitat has declined. We used remote videography to assess whether reintroducing individuals of the threatened New Zealand falcon Falco novaeseelandiae into a highly modified agricultural habitat affected the feeding rates of...

Explanation of nest disturbance scores. (DOC)

Although a wide range of vertebrates have been considered in research on numerical competence, little is known about the role of number-related decisions in the predatory strategies of invertebrates. Here, we investigate how numerical competence is expressed in a highly specialized predatory strategy adopted by the small juveniles of Portia african...

Evarcha culicivora Wesolowska & Jackson 2003 is a jumping spider (Aranea: Salticidae) that has the distinction of being the only predator known to express an active preference for the vectors of human malaria (i.e., the mosquito genus Anopheles) and to feed indirectly on blood by choosing blood-carrying female mosquitoes as prey. Here we examine th...

The modular visual system of jumping spiders (Salticidae) divides characteristics such as high spatial acuity and wide-field motion detection between different pairs of eyes. A large pair of telescope-like anterior-median (AM) eyes is supported by 2-3 pairs of 'secondary' eyes, which provide almost 360 degrees of visual coverage at lower resolution...

Agricultural landscapes are becoming an important focus of animal conservation, although initiatives to conserve predators to date have rarely provided economic benefits to agricultural producers. We examined whether introduction to vineyards of the New Zealand Falcon(Falco novaeseelandiae), a species listed as threatened by the New Zealand Departm...

Communal predators may often need to make especially intricate foraging decisions, as a predator’s success may depend on the actions of its neighbours. Here, we consider the decisions made by Portia africana, a jumping spider (Salticidae) that preys on other spiders, including Oecobius amboseli (Oecobiidae), a small prey spider that lives under sma...

Adult raptors are thought to train their progeny in flight and hunting techniques during the period of dependence after fledging. Parental teaching is poorly understood but its effects may impinge on the success of reintroduction projects where juveniles are released into areas without adults, as is commonly done with raptors. We compared behaviour...

Among spiders, resemblance of ants (myrmecomorphy) usually involves the Batesian mimicry, in which the spider coopts the morphological and behavioural characteristics of ants to deceive ant-averse predators. Nevertheless, the degree of resemblance between mimics and ants varies considerably. I used Portia fimbriata, a jumping spider (Salticidae) wi...

Evarcha culicivora, an East African jumping spider (family Salticidae), was shown in an earlier study to have an affinity for the odor from two particular plant species, Lantana camara and Ricinus communis. The olfactometer used in the earlier study was designed for choice testing. Here we focus on L. camara and, by using a second olfactometer meth...

Previous research using computer animation and lures made from dead prey has demonstrated that the East African salticid Evarcha culicivora Wesolowska & Jackson (Araneae: Salticidae) feeds indirectly on vertebrate blood by actively choosing blood-carrying female mosquitoes as prey, and also that it singles out mosquitoes of the genus Anopheles (Dip...

All species from the jumping spider (Salticidae) genus Portia appear to be predators that specialize at preying on other spiders by invading webs and, through aggressive mimicry, gaining dynamic fine control over the resident spider’s behavior. From previous research, there is evidence that P. fimbriata, P. labiata and P. schultzi derive signals by...

1. Remote videography allows continuous and reviewable recording of unique behaviours with minimal disturbance to focus individuals. It is therefore an excellent, although often unaffordable, method for observing the behaviour of wildlife in the field. 2. We describe a digital video-based remote videography design that costs under USD 900 and requi...

Belonging to a size category that makes them vulnerable to a wide variety of predators, spiders have evolved a bewildering array of anti-predator adaptations, which can be clustered under two broad categories, primary and secondary defence. Primary defences are ploys by which the spider avoids provoking pursuit by, and interaction with, the predato...

Although many spiders build prey-capture webs, spider foraging strategies include species that, instead of building webs, deploy silk in other ways for prey capture. Additionally, there are species that capture prey, either by ambush or by active pursuit, without making notable use of silk in the process. There are striking examples of predatory sp...

Background/Question/Methods Land use intensification is driving range reduction and even extinction of many iconic species, despite the potential ecosystem services provided by these species. Although it is well documented that conserving natural enemies of insect pests may provide direct biological control benefits, comparatively little research...

Jumping spiders, or salticids, sample their environment using a combination of two types of eyes. The forward-facing pair of 'principal' eyes have narrow fields of view, but exceptional spatial resolution, while the two or three pairs of 'secondary' eyes have wide fields of view and function especially well as motion analysers. Motion detected by t...

Signal design can reflect the sensory properties of receivers. The death adder, Acanthophis antarcticus, attracts prey by wriggling the distal portion of its tail (caudal luring). To understand the design of this deceptive signal, we explored perceptual processes in a representative prey species: the Jacky dragon, Amphibolurus muricatus. We used 3D...

The prey choice behavior and predatory strategies of two East African assassin bugs, Scipinnia repax (Stäl 1961) and Nagusta sp. (Hemiptera: Reduviidae), were investigated in the field and the laboratory. Both of these species are from the subfamily Harpactorinae and specialize in eating spiders. They prey especially often on social jumping spiders...

Myrmarachne bakeri Banks 1930 is a polymorphic, generalized ant-mimicking jumping spider. In this study, variation in its polymorphic characters was observed and described. Myrmarachne bakeri varies in color, glossiness and patterns; and differs from other polymorphic ant-like spiders because it becomes polymorphic before adulthood. Morphological c...

Despite the conceptual appeal of how morphological mimics visually distinguish between conspecifics and their models, scant attention has been given to this topic. Accurate discrimination between ants and conspecific spiders is likely to be under strong selection because approaching an ant may result in the spider's death, while approaching a diffe...

Dominance affects mating and reproductive success in many group-living species. Potential mechanisms include subordinates being inherently less attractive and social constraints imposed by dominant individuals. To test the former possibility, we measured morphology in 45 male fowl, Gallus gallus, prior to group formation. Males were then assigned t...

What to attack is one of the most basic decisions predators must make, and these decisions are reliant upon the predator's sensory and cognitive capacity. Active choice of spiders as preferred prey, or araneophagy, has evolved in several distantly related spider families, including jumping spiders (Salticidae), but has never been demonstrated in an...

Many predators are averse to attacking ants and many palatable arthropods are Batesian mimics of ants. We considered whether aggregating Batesian mimics of ants can become more repelling to ant-averse predators by, as a group, resembling groups of ants (collective mimicry). Myrmarachne melanotarsa is a gregarious ant-like jumping spider (Salticidae...

Phintella piatensis is an unusual jumping spider because, despite being neither myrmecophagic nor myrmecomorphic, it associates with ants, including dangerous weaver ants. Although salticids typically spin cocoon-like nests for use as shelters, the nests of Phintella are unusually dense. These play an important role in how Phintella adapts to livin...