Territorial Contests Research Articles

The kinematics of amblypygid (Arachnida) pedipalps during predation: extreme elongation in raptorial appendages does not result in a proportionate increase in reach and closing speed.

The link between form and function is key to understanding the evolution of unique and/or extreme morphologies. Amblypygids, or whip spiders, are arachnids that often have highly elongated spined pedipalps. These limbs are used to strike at, and secure, prey before processing by the chelicerae. Amblypygi pedipalps are multifunctional, however, being used in courtship and contest, and vary greatly in form between species. Increased pedipalp length may improve performance during prey capture, but length could also be influenced by factors including territorial contest and sexual selection. Here, for the first time, we used high-speed videography and manual tracking to investigate kinematic differences in prey capture between amblypygid species. Across six morphologically diverse species, spanning four genera and two families, we created a total dataset of 86 trials (9-20 per species). Prey capture kinematics varied considerably between species, with differences being expressed in pedipalp joint angle ranges. In particular, maximum reach ratio did not remain constant with total pedipalp length, as geometric scaling would predict, but decreased with longer pedipalps. This suggests that taxa with the most elongated pedipalps do not deploy their potential length advantage to proportionally increase reach. Therefore, a simple mechanical explanation of increased reach does not sufficiently explain pedipalp elongation. We propose other factors to help explain this phenomenon, such as social interactions or sexual selection, which would produce an evolutionary trade-off in pedipalp length between prey capture performance and other behavioural and/or anatomical pressures.

Negative density‐regulated contest performance promotes conflict resolution in a tree lizard

Abstract Territoriality is a behavioural adaptation resulting from intraspecific competition and reflects the strategy of how individuals share limited resources in the environment. As a consequence, territorial contests and levels of aggressiveness are strongly influenced by population density. The positive relationship between population density and the intensity of intraspecific competition may appear straightforward. However, empirical evidence regarding this association remains inconclusive. This ambiguity may be attributed to studies that have predominantly focussed on specific fight‐associated traits while overlooking potential interactions between multiple phenotypic characteristics and population dynamics. To examine the effects of population density and other ecological factors on the variation in fight behaviour as well as fight‐associated morphology and performance. We conducted population surveys and behavioural experiments using the Swinhoe's tree lizard across eight populations. Our findings revealed that males from higher density populations tended to engage in less intense fights and exhibited a weaker resident advantage in fights, which coincided with our findings on lower rates of injuries, weaker bite forces and smaller body sizes (and vice versa). Male‐specific variation in fight behaviour, morphology and performance along a density gradient suggests different evolutionary equilibria in territoriality influenced by local costs and benefits. Our study supports the significant role of negative density dependence as a fundamental regulator of eco‐evolutionary dynamics. The observed phenotypic variation emphasizes the importance of ecological and social factors in shaping ontogenetic growth and life‐history strategies. Our findings provide a basis for future investigations into pace‐of‐life syndromes and shed light on how phenotypic adaptation may shape population structure. Read the free Plain Language Summary for this article on the Journal blog.

Lizard Dewlap Color and Malaria Infection: Testing the Hamilton-Zuk Hypothesis

The Hamilton-Zuk hypothesis indicates that parasites may have a negative effect on the appearance of sexual traits within an infected individual. Anolis sagrei, or brown anoles, are small invasive lizards common throughout Florida and many other areas where they have been introduced. The colorful dewlaps under the chins of males are used as a signal during territorial contests with other males and as an ornament to attract females. Anoles may be infected by the malaria parasite Plasmodium floridense. In this study, we investigated the relationship of malarial infection with dewlap color and spectral brightness of A. sagrei. We achieved this by capturing male brown anoles, taking blood samples to examine for malarial infection, and recording the color of their dewlaps. We found that the dewlaps of infected Anolis sagrei had duller coloration than the dewlaps of uninfected lizards. These results provide support for the Hamilton-Zuk hypothesis. Our results suggest that infection by P. floridense could potentially influence fitness of the lizards by reducing the expression of their color signals. Additional research on fitness effects of the malaria parasite on anoles is important for fully understanding this phenomenon.

Urban Insecurity, Contested Governance, and Civic Resistance at the Colombia-Venezuela Border

Drawing on the case of the Cúcuta Metropolitan Area, this article explores how illicit cross-border flows and territorial conflicts shape urban space and security at the Colombia-Venezuela border. Conceptually, it approaches the border as infrastructure (Dijstelbloem 2021) and brings Idler’s ‘border effect’ (2019) into a dialogue with Sassen’s ‘urban capabilities’ (2012). The article builds on original empirical data gathered in interviews and focus groups. It shows, first, that the illicit flows of goods, people, and services facilitated by a porous border have contributed to a situation of territorial contestation between the state and violent non-state actors (VNSAs) in Cúcuta. The article discusses four interrelated dynamics that have affected the city’s security: the urbanisation of territorial contestation; violent struggles over authority and trafficking routes trickling into urban neighbourhoods; the exploitation of vulnerable city dwellers by VNSAs; and the militarisation of public space. Second, the article analyses the role of illicit flows in the making of unequal patterns of space-making both from below – as in the case of gasoline smugglers building informal settlements – and from above, with well-off corrupt city dwellers defending their affluent neighbourhoods financed by laundered money. Finally, the article goes beyond perspectives of vulnerability and violence by demonstrating that the border also represents a civic opportunity that can stimulate urban renewal and resistance.

Complex strategies: an integrative analysis of contests in Siamese fighting fish.

Animals use contests to attain resources and employ strategic decisions to minimise contest costs. These decisions are defined by behavioural response to resource value and competitive ability, but remain poorly understood. This is because the two factors are typically studied separately. Also, their study relies on overgeneralised assumptions that (i) strategies are fixed, (ii) modulated by the motivation or drive to fight and (iii) used to manage costs proportional to the timing of the loser's retreat. To address these problems, we adopt an integrative sequential analysis that incorporates competitive ability and resource value factors, to characterise territorial contest decisions in male Siamese fighting fish (Betta splendens). Individuals exhibited a chronological organisation of behaviour, engaging opponents first with frontal display, then switching to lateral display before deciding to attack, and reserved retreats for later stages. Using asymmetries in retreats as a proxy for outcome, the likelihood of winning was found to be mostly dependent on display. However, resource and contest conditions affected initiation latency, display, attack and retreat, suggesting that strategic decisions influence all behaviour. Overall, sequential behaviour varied consistently with individual aggressiveness and resource-value factors, and increasingly with information on competitive ability collected during the contest. This enabled shifts in tactics, such as disadvantaged individuals responding first with aggression and later with submission. Motivation to continue fighting, after interruption by startle, was also adjusted to information gathered during the contest and progressively with energetic state. Two clusters of correlated behaviours were identified, cost-mitigation (display and retreat) and escalation (initiation and attack), but changes in motivation were associated only with cost mitigation. Our findings contrast dominant assumptions that strategic decisions are fixed, controlled by motivational state and sufficiently described by outcome-dependent measures. We instead demonstrate that strategic decisions are complex, comprising functional changes in assessment, information use and motivational effects, which are not always inter-dependent.

The practice of alley gating in contemporary Jakarta: Visualizing the cross-class proliferation and territorial contestation

This paper provides empirical data on the community-based security practice of installing alley gates in Jakarta. Studies of gated communities in Indonesia have associated gating with the latent class conflict. Drawing on both qualitative and quantitative surveys of alley gate adoption, this paper shows that alley gating is a cross-class phenomenon. Moreover, the level of community's vigilance, that is, the degree of social capital in term of local security activities is presented as an alternative variable that can accommodate both the cross-class proliferation of gating and the local trajectory of gating.

The Guerrilla Gallery: A Rapid Ethnography about a Collaborative Public Art Installation in East Harlem

In the heart of East Harlem, New York City, a collective of artists called the Harlem Art Collective created the “Guerrilla Gallery”: A collaborative public art installation on a construction fence, to give residents a place to express themselves through art and messages. While East Harlem is characterized by murals depicting Puerto Rican flags and political causes, these symbols were absent in the Guerrilla Gallery, which instead exhibited predominantly Mexican cultural and political symbols. Was a territorial contestation taking place through art, a sort of identity negotiation to determine who “belongs” in the neighborhood? (Zukin, 1995) This article presents an ethnographic and photographic narrative of the Guerrilla Gallery and what it means to the people who live in the neighborhood. Using rapid ethnographic assessment procedures (Low et al., 2005), coupled with photographic cartography (Ulmer, 2017), this study presents the findings of interviews and the Guerrilla Gallery. The analysis revealed that, although there were instances of aesthetic conflict occurring in the gallery, these were not exclusively related to national cultures; gender and racial conflicts were also observed. Strong expressions of aesthetic empathy were also identified in the artwork. The Guerrilla Gallery became a meaningful space for the community in East Harlem, who not only appreciated it because of its aesthetic value and the possibility of expression it offers, but also because residents were able to connect with their roots, strengthen their local identity and pride, express empathy and solidarity with other social groups in the neighborhood or in faraway places, and resist changes or policies that affected their everyday lives.

Contested subterranean territory: Gold mining and competing claims to Indonesia’s underground

Worldwide, subsurface resources are typically the domain of the state. Their cataloguing and government-permitted extraction comprise key elements of state territorialization of the subterranean. However, like processes of territorialization aboveground, state control of the underground is always incomplete and subject to competing uses of space and resources. One of the clearest examples of this contestation is unlicensed small-scale mining. In this article, I examine a case of gold mining conflict in the Pongkor region of West Java, Indonesia. There, state-corporate and small-scale mining compete over the same gold reserves, directly confronting each other both above and below ground. Drawing on twelve months of ethnographic research, I analyze three ways that state-corporate and small-scale mining vie for control of these subterranean territories: regulating movement between the surface and subsurface, managing underground volumes, and deploying competing geological knowledges. I argue that verticality, volume, and the material and discursive features of the underground do not merely set the conditions for this conflict, but are also dynamics utilized to territorialize underground space. I call for further scholarly inquiry into contemporary, ongoing processes of subterranean territorial contestation and reproduction.

Asymmetric competition over space use and territory between native brown trout (Salmo trutta) and invasive brook trout (Salvelinus fontinalis).

Interference competition over food and territory can shape population structure and habitat use within and between species. The introduction of invasive species often leads to novel competitive interactions over shared resources and invaders can eventually exclude the native species from preferred habitats. Invasive brook trout (Salvelinus fontinalis) introduced to northern Europe have excluded native brown trout (Salmo trutta) from numerous headwater streams. The fact that invasive brook trout can displace the more aggressive brown trout is puzzling. However, the earlier spawning and hatching of brook trout, compared to brown trout, may lead to unequal competition due to size advantage and prior resident status of brook trout at the fry stage. In this study, we examine the effect of competition between brown trout and brook trout using the natural size distribution of the two species. In two consecutive experiments, we first measured space use and feeding of a fry (age 0+) in the presence of a juvenile (age 1+). In experiment 2, we assessed territorial interactions between the species at the fry stage (age 0+) and if smaller brown trout could compensate the disadvantage by manipulating residence duration. Fry of brook trout feed sooner and spend more time close to the larger individual than brown trout fry. We also found that brook trout fry won most territorial contests against brown trout, and that increased residence duration led to longer and more aggressive interactions. The results suggest that smaller brown trout are displaced to suboptimal habitats in the presence of a larger brook trout. Therefore, the later emergence from gravel beds resulting in the naturally occurring size disadvantage of brown trout at the fry stage may lead to unequal territorial interactions that could explain why brown trout are displaced from preferred habitats in sympatry with brook trout.

Do microplastics impair male dominance interactions in fish? A test of the vector hypothesis.

Microplastics (MPs) are widespread in aquatic environments and have become a critical environmental issue in recent years due to their adverse impacts on the physiology, reproduction, and survival of aquatic animals. Exposure to MPs also has the potential to induce sub‐lethal behavioral changes that can affect individual fitness, but these effects are understudied. Many plastic additives introduced during the manufacture of MPs are known endocrine‐disrupting chemicals (EDCs) that mimic the action of natural hormones, alter sexual and competitive behavior, and impair reproductive success in fish. In addition, EDCs and other aquatic contaminants may adhere to MPs in the environment, the latter of which may serve as transport vectors for these compounds (i.e., the vector hypothesis). In this study, we staged territorial contests between control males, and males exposed to virgin MP particles or to MPs previously immersed in one of two environmentally relevant concentrations of 17‐alpha ethinyl estradiol (EE2; 5 ng/L and 25 ng/L) to evaluate the independent and synergistic effects of exposure to MPs and a common environmental estrogen on male–male aggression and competitive territory acquisition in a freshwater fish, Pimephales promelas. Short‐term (30 days) dietary exposure to MPs did not impair the ability of males to successfully compete for and obtain a breeding territory. Overall levels of aggression in control and exposed males were also similar across trial series. These results help to fill a critical knowledge gap regarding the direct and indirect (vector‐borne) effects of MPs on the reproductive behavior of aquatic vertebrates in freshwater systems.

Function of a multimodal signal: A multiple hypothesis test using a robot frog.

Multimodal communication may evolve because different signals may convey information about the signaller (content-based selection), increase efficacy of signal processing or transmission through the environment (efficacy-based selection), or modify the production of a signal or the receiver's response to it (inter-signal interaction selection). To understand the function of a multimodal signal (aggressive calls+toe flags) emitted by males of the frog Crossodactylus schmidti during territorial contests, we tested two hypotheses related to content-based selection (quality and redundant signal), one related to efficacy-based selection (efficacy backup), and one related to inter-signal interaction selection (context). For each hypothesis we derived unique predictions based on the biology of the study species. In a natural setting, we exposed resident males to a robot frog simulating aggressive calls (acoustic stimulus) and toe flags (visual stimulus), combined and in isolation, and measured quality-related traits from males and local levels of background noise and light intensity. Our results provide support to the context hypothesis, as toe flags (the context signal) are insufficient to elicit a receiver's response on their own. However, when toe flags are emitted together with aggressive calls, they evoke in the receiver qualitatively and quantitatively different responses from that evoked by aggressive calls alone. In contrast, we found no evidence that toe flags and aggressive calls provide complementary or redundant information about male quality, which are key predictions of the quality and redundant signal hypotheses respectively. Finally, the multimodal signal did not increase the receiver's response across natural gradients of light and background noise, a key prediction of the efficacy backup hypothesis. Toe flags accompanying aggressive calls seem to provide contextual information that modify the receiver's response in territorial contests. We suggest this contextual information is increased motivation to escalate the contest, and discuss the benefits to the signallers and receivers of adding a contextual signal to the aggressive display. Examples of context-dependent multimodal signals are rare in the literature, probably because most studies focus on single hypotheses assuming content- or efficacy-based selection. Our study highlights the importance of considering multiple selective pressures when testing multimodal signal function.

Novel wing display and divergent agonistic behaviors of two incipient Psolodesmus damselflies.

Sexual selection via male competition is a strong evolutionary force that can drive rapid changes in competitive traits and subsequently lead to population divergence and speciation. Territorial males of many odonates are known to use their colorful wings as visual signals and to perform agonistic displays toward intruders. Psolodesmus mandarinus dorothea and Psolodesmus mandarinus mandarinus are two parapatrically distributed sister damselflies that share similar ecological characteristics but differ markedly in wing coloration. The wings of P. m. dorothea are mostly clear, whereas those of P. m. mandarinus have a large area of black pigmentation and a central white patch. We investigated whether territorial males of the two damselflies at breeding sites display distinct agonistic behaviors associated with their respective wing colors. Behavioral interactions between territorial and intruder males and their wing kinematics were filmed and analyzed for P. m. dorothea in Lienhuachih of central Taiwan, and P. m. mandarinus in Tianxiyuan andFusan of northern Taiwan. We observed that the P. m. mandarinus males exhibited a novel set of perched wing displays, which was not only absent in its sister P. m. dorothea but also previously unknown in Odonata. At breeding sites, perched rival males of P. m. mandarinus with pigmented wings exhibited escalating agonistic wing-flapping and wing-hitting displays toward each other. In contrast, territorial males of P. m. dorothea with clear wings engaged only in aerial chase or face-to-face hovering when intruder males approached from the air. These results indicate that the two sister P. mandarinus damselflies diverged behaviorally in territorial contests and support the hypothesis of coadaptation on the basis of wing colors and types of wing movement in Odonata. Our findings further suggest that divergent agonistic wing displays may play a pivotal role in the speciation mechanism of P. mandarinus damselflies. The sequential analyses of behavioral characteristics and progression suggest that P. m. mandarinus damselflies likely use mutual assessment of rivals in territorial contests.

Regenerated claws of the virile crayfishFaxonius virilis(Hagen, 1870) (Decapoda: Astacidea: Cambaridae) generate weaker pinching forces compared to original claws

AbstractCrustaceans are known for their ability to autotomize and regenerate their appendages. The appendages that are most often autotomized are their chela, often specialized as claws, which serve essential functions including foraging, fighting, mating, and predator defense. Crustaceans with autotomized or regenerated chelae may suffer decreases in their ability to perform these functions compared to individuals with intact or original claws. It is noteworthy that although regenerated claws can grow back to the expected size of an original claw, regenerated claws often differ from original claws in external morphology and internal musculature. Both male and female crayfishes wield a pair of enlarged claws. It surprisingly remains unknown how the regeneration of crayfish claws influences the claws’ ability to generate pinching forces, which has previously been shown to influence the outcome of territorial contests. We investigated the relationship between claw regeneration and claw strength among male and female virile crayfish, Faxonius virilis (Hagen 1870). We found that maximal pinching forces of regenerated claws were weaker than the maximal pinching forces of original claws in both sexes (36% and 40% weaker in males and females, respectively). Further, regenerated claws had proportionally less muscle mass compared to original claws of equivalent size. These results present evidence of how claw regeneration influences pinching strength in crayfishes and suggest that such regeneration may be the functional mechanism that produces dishonest (large but weak) claws in crayfishes, but behavioral observations are required to support this hypothesis.

Pervasive low‐frequency vocal modulation during territorial contests in Eurasian Scops Owls (Otus scops)

In several animal species, including birds, individuals are known to produce low‐frequency vocalizations during aggressive interactions with conspecifics. In this study, I investigated territorial interactions between male Eurasian Scops Owls Otus scops that occupied territories in a densely packed area. The single‐note hoot of the Scops Owl is generally thought to be highly repeatable; however, extensive recording of male–male interactions identified previously unrecognized variation in the structure of hoots. Male Scops Owls gave hoots at a frequency lower than usual when engaging in short‐distance contests with neighbouring males. Within‐subject analysis revealed that the caller’s average hoot frequency was positively correlated with the distance from its rival. During contests, males gradually reduced their hoot frequency as they approached one another, perhaps reflecting changes in the degree of escalation. Furthermore, there is evidence that male Scops Owls have voluntary control of their hoot frequency also on a very short time scale. Males gave deeper hoots immediately after the rival initiated countersinging, and returned to their usual frequency range at the end of the interaction. This study confirms in part the findings of other authors’ experimental work, where male owls adjusted their vocal frequency when challenged by an opponent. However, that study suggested that vocal frequency would encode information about the caller’s bodyweight. In contrast, the results of the present study cannot exclude the hypothesis that the hoot of the Scops Owl is a variable, conventional signal that reflects the willingness to escalate the conflict. The reliability of the signal could be maintained by the risk of retaliation by the opponent, usually located a few metres from the caller.

Behavioral traits and territoriality in the symbiotic scaleworm Ophthalmonoe pettiboneae

Among marine invertebrates, polychaete worms form symbiotic associations showing a wide variety of host use patterns. Most commonly, they live solitary on hosts, likely resulting from territorial behavior, yet little is known of the precise nature of the involved interactions. Based on field and laboratory observations, we described the symbiotic association between Ophthalmonoe pettibonae and Chaetopterus cf. appendiculatus from Nhatrang Bay (Vietnam). Then, by experimentally manipulating the competitor-to-resource ratio, we analyzed symbiont behavior and we assessed whether the 1:1 uniform distribution observed in nature could be driven by agonistic territorial behavior. Hosts and symbiont populations had low densities, lacked size relationships and showed higher prevalence when denser. Symbiont behavior included territoriality, expressed through conspecific recognition and intraspecific aggressive interactions (pursuit and escaping, hiding, choosing position, aggressive fighting, and targeting a specific bite zone). Our experiments proved that territoriality led to host monopolization by a single symbiont, provided the first empirical evidence that symbiont body injuries were caused during territorial contests, and allowed us to first suggest that a marine symbiotic invertebrate may control a territory extending beyond its host, even including neighboring hosts. Overall, this is the first report of such a complex symbiotic behavior for an annelid polychaete.

Border Governance in Kachin State, Myanmar: Un/caring states and aspirant state building during humanitarian crises

AbstractSince 2011 renewed fighting between the Myanmar military and the Kachin Independence Army (KIA) has triggered the internal displacement of more than 100,000 people in Kachin state. This article examines how care practices and care ethics influence border governance in the context of humanitarian concerns in Kachin state in northern Myanmar, which shares a border with China. The situation in Kachin state at the China-Myanmar border reveals the contrasting territorial logics at stake, the contingency of governance at a time of political transition, and distinct ‘regimes of care’, as manifested through humanitarian relief, which all contribute towards border governance. Drawing on ethnographic research and interviews, the article highlights how care deficits are met by a separatist government, community organizations (both faith-based and secular), and diaspora populations which mobilize a range of networks and resources—forming webs of connections and interfacing with one another—to provide humanitarian relief. However, their actions and the ensuing flows of care could produce or deepen political subjectivities that are geared towards territorial contestation and separatism, thus changing expressions of border governance. The article further observes that the Kachin situation has wider implications for the peace negotiations taking place at the national level in Myanmar.

Territorial males do not discriminate between local and novel plumage phenotypes in a tropical songbird species complex: implications for the role of social selection in trait evolution

Whether novel traits involved in animal communication are favored or not by social selection depends on how receivers respond to them. If alternative traits arise at different locations or the same traits are perceived differently, then populations may diverge even when occupying similar environments. Aggressiveness towards bearers of novel versus familiar traits is informative about how male-male competition may drive phenotypic evolution, yet few studies have tested the function of signaling traits in social selection across populations. We assessed the role of a black pectoral band during territorial contests in two allopatric species of Neotropical passerine birds in the genus Arremon either having or lacking this plumage trait. Field experiments using taxidermic mounts and playback of conspecific songs revealed that males of both species were equally aggressive towards phenotypes bearing or lacking a pectoral band. Although evaluating physiological and social costs of bearing alternative traits and assessing female preferences is required to further examine the roles of social and sexual mechanisms in the evolution of plumage and geographic variation, our results indicate that social selection via male-male interactions is an unlikely driver of phenotypic divergence among populations of Arremon. Social selection via intrasexual competition for resources may drive phenotypic divergence and population differentation in animals, but few studies have tested predictions of this hypothesis by examining how alternative traits varying geographically are perceived in contexts of male-male competition. We assessed the behavioral response of territorial males in two species of Neotropical songbirds to taxidermic mounts having or lacking a black pectoral band, a geographically variable plumage trait. Irrespective of their own phenotype, males of both species were similarly aggressive to potential intruders bearing or lacking the pectoral band. In contrast with work suggesting male-male interactions may mediate trait evolution, our results indicate that pectoral bands in this system are unlikely targets of social selection via contests in which males compete for territories, and call for studies assessing long-term costs of bearing alternative traits or female choice as selective forces driving phenotypic evolution.

Asymmetric competition and floater dynamics.

In territorial species, nonterritorial floaters may be critical to population dynamics. One theoretical framework, based on the assumption that floating is a strategic decision to forego reproduction, predicts that selection maintains an abundant floater population even if low-quality territories are available. However, existing models make two critical assumptions: all individuals have equal competitive ability, and every individual in a population has access to every available territory. We assess the consequences of relaxing these assumptions in a model of asymmetric competition with a trade-off between investment in competitiveness and reproductive success. Our results demonstrate that selection for greater competitiveness eliminates floater production unless the outcome of territorial contests has a strong stochastic component. Next, we suppose individuals can compete for territories only within a fixed neighborhood. If this constraint is sufficiently strong, our model predicts that a population will produce floaters. Finally, we show that our model makes novel predictions regarding the maintenance of trait variation and the relationship between this variation and the distribution of competitors among unequal territories.

Winner effects and switching assessment strategies facilitate fast and frugal decisions in territorial contests

Animals compete in contests over limited resources, and contestants with greater fighting ability, or resource-holding potential (RHP), typically win contests. Contest strategies have evolved to balance contest costs with the benefit of winning resources. Sometimes, contestants decide to leave by estimating their opponent's relative RHP. This strategy (mutual assessment) is cost-effective because it allows weaker opponents to leave contests against formidable opponents before accruing higher costs. However, acquiring reliable information can be costly. Here, we showed that in snapping shrimp ( Alpheus angulosus ) contests, contestants assessed relative RHP quickly and cost-effectively by assessing their opponent's recent contest success. By staging 26 contests between randomly matched individuals and 24 contests between RHP-matched individuals, we determined that snapping shrimp assessed their opponent's RHP during initial contest phases but no longer assessed relative RHP during escalated phases. Then, after staging 24 contests between individuals with contest experience the day prior, we found that snapping shrimp integrated RHP and recent contest success to make contest decisions. This strategy facilitated fast and accurate judgments when the recent winner was also larger but often resulted in the larger individual retreating when facing a small recent winner. Notably, these systematic biases were corrected when RHP differences were stark. Taken together, our findings demonstrate that by assessing recent contest success early in a contest, snapping shrimp can avoid risky contests. Furthermore, by integrating recent contest success with direct observations of RHP, contestants avoid losing contests prematurely. Similar assessment strategies may be widespread, because they circumvent risky contests while minimizing premature defeats from weaker recent winners. • Snapping shrimp switched from mutual assessment to cumulative assessment. • Snapping shrimp assessed their opponent's recent contest success. • Winner effects facilitated early and accurate contest decisions.

Perceived Adverse Effects of Separating Government Institutions for Disaster Risk Reduction and Climate Change Adaptation Within the Southern African Development Community Member States

Integration of disaster risk reduction (DRR) and climate change adaptation (CCA) is widely recognized as a solution for reducing the risk and impacts of disasters. However, successful integration seems elusive, and the two goals continue to function in isolation and in parallel. This article provides empirical insights into the perceived effects of separating government institutions for DRR and CCA within the Southern African Development Community member states. A mixed method research design was applied to the study. A total of 40 respondents from Botswana, Eswatini (until April 2018 Swaziland), Madagascar, Malawi, Namibia, South Africa, Tanzania, Zambia, and Zimbabwe participated in face-to-face interviews or an online survey. Five major effects of separating the organizations for DRR and CCA that impede efforts to reduce disaster risk coherently were identified: duplication of services, polarization of interventions, incoherent policies, competition for the same resources, and territorial contests. Given the continued fragmentation of institutions for DRR and CCA, highlighting these effects is important to emphasize the need for integrated approaches towards the reduction of disaster risk.