Territorial Behavior Research Articles

Effects of competition and predation operating at individual and population levels: an overview of results from a long-term field experiment.

After an overview of the discussion about the existence of intra- and interspecific competition that illustrates the contradictory opinions I conclude that long-term field experiments are needed for firm conclusions. I discuss in some detail the role of two factors that limit population size of secondary cavity nesting birds e.g. territorial behavior and adequate cavities. This is followed by an overview of experimental long-term field studies in Belgium showing that intra- and interspecific competition in a great tit-blue tit system exists. By using nestbox configurations with high densities of nestboxes that differ in the diameter of their entrance hole in replicate study plots it is possible to manipulate the breeding densities of great tit Parus major and blue tit Cyanistes caeruleus independently, thereby varying the intensity of intra- and interspecific competition between these two coexisting species. When blue tit densities are experimentally increased local recruitment of great tits increases, and adult great tit post-breeding dispersal to other study plots decreases, implying that great tits use blue tit density to evaluate habitat quality and that high blue tit density results in heterospecific attraction. The reverse is not true. An experimental increase in great tit density leading to an increase in interspecific competition in a plot where blue tit density was already high leads to a decrease in blue tit nestling mass (illustrating interspecific competition for food), but to a gradual increase in blue tit body size. Both are primarily caused by an increase in the body size of immigrants (caused by intraspecific competition for protected roosting holes) in contrast to the control plot, where neither is observed. I also summarize behavioral, ecological and possible evolutionary effects of sparrowhawks on blue tits after sparrowhawks settled in an isolated study plot halfway through the study: adult survival substantially decreased for both sexes, but more for females that laid large clutches, leading to selection for females that laid a smaller clutch. This led to a change in the reproduction/survival life-history trade-off. Adult winter weights and nestling weights decreased, and the heaviest fledglings were selected against. Furthermore the frequency of polygyny increased. The long-term experiments also document the role of the use of public information and that species that compete can be attracted to sites in which competitor density is high.

Territorial and Courtship Behaviour of Indian Common Crow Butterfly (Euploea core core)

Territorial and Courtship Behaviour of Indian Common Crow Butterfly (Euploea core core)

Population expansion and intensification from a Malthus-Boserup perspective: A multiproxy approach in Central Western Argentina

In Central Western Argentina (CWA), the incorporation of cultigens by hunter-gatherer populations has been much discussed. This paper explores the relationship between population dynamics, subsistence change, and burial patterns driven by the process of land use intensification and increasing reliance on maize. We hypothesize that territorial behavior emerged in the context of population growth and competition for resources with a high probability of failure, as expected in an arid environment. To evaluate this hypothesis, we explore four lines of inquiry in southern Mendoza (CWA): 1) the frequency of radiocarbon dates to estimate population dynamics; 2) the Juvenile Index as a fertility rate proxy; 3) the stable isotopes on human bone (δ13Cco, δ15N, δ13Cca) to reconstruct diet; and 4) burial patterns as an estimate of territorial control. Our results partially support our hypothesis: During an early stage, when maize started to appear in the diet, the population was increasing, and cemeteries emerged along with some signs of violence. The hypothesis is not supported in a second period, when maize consumption and population were highest, but large cemeteries disappeared. In light of this evidence, the effect of maize on human societies was not uniform and irrevocable, and the adoption of maize by human foragers contributed to a new and diverse set of human-environment relationships.

Adaptive shift of active electroreception in weakly electric fish for troglobitic life

The adaptive-shift hypothesis for the evolution of cave-dwelling species posits that ancestor species in surface habitats had exaptations for subterranean life that were exploited when individuals invaded caves. Weakly electric Gymnotiform fishes, nocturnal South American teleost fishes, have features that appear to be likely exaptations for troglobitic life. These fishes have active electrosensory systems in which fish generate weak electric fields that are detected by specialized electroreceptors. Gymnotiform fishes use their electric fields for navigation, prey capture (scene analysis), and social communication. Although active electrosensory systems appear to be exaptations for troglobitic life, as fish use these systems to “see in the dark”, producing electric fields is energetically costly. Cave habitats, which often are low in resources, may not be able to support such high energetic demands. Eigenmannia vicentespelaea, a species of weakly electric fish that is endemic to the São Vicente II cave in central Brazil, surprisingly generates stronger electric fields than their surface relatives. The increase in strength of electric fields may result simply from differences in size between cave and surface populations, but may also be due to lack of predation pressure in the cave or increases in “sensory volumes” and acuity that improve prey localization and capture. Eigenmannia vicentespelaea exhibits the classical phenotypes of any troglobitic fish: these fish have small to nonexistent eyes and loss of pigmentation. The closest living surface relative, Eigenmannia trilineata, inhabits streams nearby and has eyes and pigmentation. The electrosensory and locomotor behavior of both species of fish were measured in their natural habitats using a grid recording system. Surface Eigenmannia exhibited dramatic circadian changes in social behavior, such as hiding under rocks during the day and foraging in groups at night, while cave Eigenmannia displayed territorial behavior with no apparent circadian modulations. The territorial behavior involved electrical and movement-based interactions that may be a form of boundary patrolling. Electrosocial behavior and scene analysis are mechanistically interlinked because both stem from active sensing tactics.

Territorial behaviour of thrush nightingales outside the breeding season.

Territoriality is a common pattern of space use in animals that has fundamental consequences for ecological processes. In the tropics, all-year resident songbirds usually hold territories throughout the year, whereas most all-year resident temperate species are territorial only during the breeding season. In long-distance migrants, however, the situation is mostly unexplored. Here, we report findings from a Palaearctic-African migrant, the thrush nightingale Luscinia luscina. We found that only a fraction of the males was territorial in their East African winter quarters and that this was related to the stage of their song development. Individuals with full song were territorial towards other full songsters, but not towards birds that sang plastic song (i.e. an earlier stage of song development). Plastic singers were not territorial towards full songsters and often settled closely to territorial males. We suggest that territoriality of thrush nightingales in the winter quarters may be a by-product of rising testosterone levels that trigger song crystallization. Collectively, our study indicates that changes in territoriality can occur rapidly, giving rise to shifting proportions of territorial and non-territorial individuals in a population, which may lead to complex dynamics in settlement patterns and resulting ecological interactions.

Earliest Acheulian paleolandscape reveals a 1.7 million-year-old megasite at Olduvai Gorge (Tanzania)

FLK West (Bed II, Olduvai Gorge) contains the oldest association of Acheulian stone tools and exploitation of fauna (including megafauna) by hominins in the Pleistocene. Recently, the FLK West paleolandscape has been intensively studied, unveiling a spatial association between archaeological materials and hydrothermal resources. A new type of landscape use by hominins has also been documented around the area where the pene-contemporaneous FLK West and HWK site complex were formed, resulting in an array of habitats spanning thousands of square meters covered with large amounts of lithic artefacts. Here, we show how the intensive use of certain environments by hominins resulted in these “megasites”, in which hominins engaged in a variety of activities, complementary to those performed at discrete archaeological clusters like FLK West. Despite using these habitats redundantly as quarries, hominins performed extensive core reduction of several types of raw materials indicating a dexterity and careful planning undocumented in earlier periods. Here, we also show how palaeoecological reconstructions must be based on fine-scale geological analyses, given the palimpsestic nature of both geological and anthropogenic processes. The research reported here also uncovered an additional unknown source of metamorphic rocks for hominins at Olduvai, which questions a large part of previous modeling based on hominin provisioning exclusively at Naibor Soit. We also show that the manufacture of handaxes was slightly older than documented at FLK West and that they occur in isolation on the landscape in addition to being clustered at sites. This implies that at the beginning of the Acheulian, hominins were not only using and discarding handaxes at specific loci, but they also transported these tools for various activities across the landscape as part of their strategized adaptation to those environments. The occurrence of these intensively-used megasites hints at some territorial behaviors by early Acheulian hominins.

Jumping between narrow banks: social spacing of the stream-dwelling montane frog, Crossodactylus trachystomus (Hylodidae)

Spacing patterns among individuals can reveal many ecological and behavioral features, such as responses to resource availability and social organization. The study of the amphibian movements still constitutes a gap in the knowledge of the animal ecology, and the general issues of the patterns of home range are poorly known to date. Herein, we evaluated the social spacing of a small stream-dwelling frog (Crossodactylus trachystomus), an endemic species from the Espinhaço mountain range in southeastern Brazil. We found that C. trachystomus shows one of the smallest home ranges among anurans, indicating a high philopatry level. We also showed that the home range size did not differ between females and males, neither was influenced by individual body size, which reveals a possible limitation for the use of larger home ranges in riparian systems. The distribution of home ranges showed high overlap among adult males, suggesting a weak territorial behavior or a possible “dear enemy effect” for this species. Beyond expanding the knowledge about the spatial ecology and behavior of the genus Crossodactylus, our outcomes contributed to the understanding of space use and the social organization of frogs, revealing spatial patterns that can be expected for other stream-dwelling frog species.

Evolution of territoriality in Hylinae treefrogs: Ecological and morphological correlates and lineage diversification.

Given the diverse nature of traits involved in territorial defence, they may respond to different selective pressures and then exhibit distinct patterns of evolution. These selective pressures also may cause territorial behaviour to be associated with environmental and morphological variables. Such associations, however, have mostly been studied at the intraspecific level, being phylogenetic analyses of territoriality in a broad taxonomic framework rare in the literature. We used the anuran subfamily Hylinae to test (1) whether two territorial-behaviour traits with different levels of aggression-territorial call and physical combat-are evolutionarily more labile than a morphological trait used in physical combat-the spine-shaped prepollex; (2) whether reproduction in lentic waters and phytotelmata, as well as resource scarcity, might favour the occurrence of territoriality; (3) if physical combat is more important than territorial call for the evolution of body size and sexual size dimorphism and (4) the relationships between territorial-behaviour traits and lineage diversification. We mainly used the literature to build two datasets with different levels of certainty. Territorial-behaviour traits exhibited intermediate levels of phylogenetic signal in Hylinae, whereas the phylogenetic signal for the presence of the spine-shaped prepollex was strong. We found support for the hypothesis that reproduction in lentic water favours the occurrence of territorial behaviour, because the expression of territorial-behaviour traits was more associated with reproduction in lentic than in lotic waters. Territorial-behaviour traits were not correlated with annual precipitation nor with habitat complexity. Body size and sexual size dimorphism were not correlated with the presence of territorial call nor with physical combat. We identified negative correlations between diversification rates and physical combat. Relationships of territorial call and physical combat with diversification rates suggest that these territorial behaviours influence evolutionary processes in different ways.

Seasonal variation in the diurnal activity pattern of Eurasian blackbirds (Turdus merula) in the forest

Camera traps are increasingly used to estimate the density of animals as well as their activity patterns. As camera traps allow monitoring of animals over long periods of time without disturbance, they are especially useful to observe changes in diurnal activity patterns over time. In ornithology, camera trapping is still in its infancy. To our knowledge, no study has yet investigated the activity pattern of a songbird over the full annual cycle. We used camera traps in the Rammert, a small mountainous forest area near Rottenburg in Southwest Germany to monitor the diurnal activity pattern of forest-dwelling Eurasian blackbirds (Turdus merula). As the activity level of animals is known to be affected by day light, we used double-anchoring transformation of day times to account for the variation in sunrise and sunset across the different seasons. By generating activity models, we investigated the pattern of blackbird activity during the four seasons of the year and compared the patterns of male and female birds, respectively. A significant difference between a unimodal activity pattern in spring and a bimodal pattern for the rest of the year was found which might be related to breeding and territorial behaviour in spring. Moreover, we observed that the activity pattern of males and females overlapped greatly but still showed some variation in the number and timing of density peaks.

Comportement De Territorialité De Propithecus Deckenii Dans Les Aires Protégées Complexe Tsimembo Manambolomaty Et Mandrozo

This study aims to understand the behavior territoriality of the lemur Decken's Sifaka Propithecus deckenii in the Protected Areas (PAs) Complexe Tsimembo Manambolomaty and Mandrozo in the central-west of Madagascar between November 2017 and April 2018, and between July and October 2018. The continuous focal animal sampling method was used to monitor eight groups of Sifakas, two groups of the intact habitat and two groups from the disturbed habitat in each PA. Scent marking frequencies per focal groups differs between the two habitats types and is influenced by sex in favor of males. Season does not impacted this activity. The home range (define by MCP and 95% Kernel density estimate) and core area varies between monitored groups and the daily path length can reach 234 ± 98 m to 362 ± 110 m. These parameters are not influenced by season and habitat types. However, the intensity of territory use does not have any variation among the studied groups. The mean average « defensibility index » value for P. deckenii is 1.74 ± 0.70 (n = 8). The studied species has ability to adjust their territorial behavior, despite the degradation of habitat in sustainable use zones

Tree cover and built-up area regulate the territory size in Eurasian Magpie Pica pica in Ladakh, India

Eurasian Magpie Pica pica is one of the well-studied corvids, but the majority of our understanding of this species is from Europe. In India, its distribution is restricted to some valleys of Ladakh such as the northwestern part of the Indus, Nubra, Zanskar, Drass, and Suru. The present study aimed at understanding the territorial behavior of this species in small urban settlements of Ladakh region. Twenty-five pairs were studied in March 2020–April 2021. Territories were outlined for each color-banded individual, and data on habitat variables (namely built-up, agriculture, and green cover) was extracted. Generalized linear mixed models were used to study the effect of the habitat structure on territory size. The territory size (Mean ± SD) was 0.042 ± 0.025 km2, with tree cover comprising the highest proportion (24.36 ± 15.41 %) of area within territories. Built-up area was a feature of all territories, highlighting the affinity of magpies towards human presence. Presence of tree cover and built-up area significantly (~ <0.002) reduced territory size. High adaptability, foraging, and nesting opportunities, and protection from predators have been recognized as the reasons for magpies’ affinity with human habitation. Foraging opportunities are minimal outside human settlements in this region, magpies’ territories are largely shaped by the fulfilment of foraging requirements.

Home advantage in tennis exists independent of competition level, gender and COVID-19 restrictions: evidence from German team tennis competitions

ABSTRACT While home advantage (HA) is a well-supported phenomenon in sports, the mechanisms responsible for its occurrence are not conclusively known. Research on HA in individual and amateur sport is scarce so far and situations where several plausible mechanisms do not apply are rare. Motivated by these aspects, the present study aims to investigate HA in an individual sport with a highly limited influence of three major factors (spectators, referees and travel) by investigating nearly 33,000 matches in almost 4000 tennis competitions from Germany. Based on separate analysis of competition levels (amateur to professional sports), competitions of both genders and competitions played before and during the COVID-19 pandemic, we find that HA exists in team tennis and its degree is not significantly influenced by these situational variables. These results support the notion that, in contrast to a widespread belief, an influence of spectators on athletes or referees is not a prerequisite for the existence of HA, at least in this sport. Moreover, HA seems to be a very general phenomenon existing widely independent of situational factors, suggesting that at least a significant part of HA is caused by physiological or psychological aspects like territoriality, expectations or learned behaviour. HIGHLIGHTS - Nearly 33,000 tennis matches in almost 4000 team competitions have been analysed. - Strong evidence for the existence of home advantage in tennis independent of competition level, gender and COVID-19 restrictions. - Results are evidence that home advantage exists in individual sports. - Results suggest that spectator support or a spectator-induced referee bias are not required for home advantage.

SEXUAL DIFFERENTIATION OF AGGRESSIVE BEHAVIOR IN THE CHICKS OF THE BLACK-HEADED GULL (<i>LARUS RIDIBUNDUS</i>, LARIDAE, CHARADRIIFORMES) IN THE NATURAL ENVIRONMENT

Sexual differentiation of social behavior in gulls and its mechanisms remain unexplored beyond the breeding season. We described the development of aggressive territorial behavior in males and females of black-headed gulls at the age of 1–4 weeks, modeling the intrusion of a peer to the nesting territory. We also hypothesized that the sex differentiation of aggressive behavior may appear as a consequence of the development of small early differences between siblings in behavioral stress response. To test this assumption, we investigated the relationship between the priority among brood in aggressive contact with the intruder, and the within-broods level of activity of a chick to stress. To measure the behavioral stress response, we used the social isolation of chicks within a small water area with an island in the middle. Longer attempts to swim outside the fenced area were regarded as a more proactive stress response. At the age of up to 3 weeks, there were no sex differences in the aggressiveness, but the stress response of males was more proactive than that of their sisters, and a more proactive chick in the brood was usually the first to attack the intruder. At the fourth week of life, the aggressiveness of males increased significantly, and in broods of two sexes, brothers began to play a leading role in protecting the nesting territory in the absence of parents. They attacked the intruder more often and made aggressive calls more frequently. Thus, we were the first to reveal sexual differentiation of territorial behavior in gull chicks in the pre-fledging period. Our results suggest that under natural conditions, where the intruder does not persist in staying in the other nest, but recedes immediately when counteracted, more proactive males use to attack the intruder earlier than sisters do. As a result, they gain experience of aggressive interactions, and develop higher abilities of aggressive responses to social challenges.

Description of the Clausiidae family

Rearing records suggest that most temperate species can be found in a number of different deciduous trees, but some Clusiidae have also been found in conifers, and larvae of Sobarocephala have been found in termite colonies, as well as decaying wood, found the larvae evidently associated with the burrows of coleopterous insects and to be relatively sluggish and slow moving. Clusiidae larvae are probably at least facultatively predaceous on larvae of other wood-boring insects. The objective of the manuscript was to describe the territorial behavior of the males and also the biological Clusiidae. This work consists of bibliographical research of scientific articles published in national and international academic scientific journals classified by the Coordination for the Improvement of Higher Education Personnel (CAPES). Document analysis was used as a data collection method to gather information on theoretical books, theses banks, university dissertations, documents and digital platforms websites such as HAL, SSRN and ResearchGate.

Territoriality in Post-conflict Neighbourhoods: Unravelling the Dynamics of Territorial Marks in Ile-Ife, Nigeria

ABSTRACT The pervasiveness of territorial marks in post-conflict neighbourhoods elicited this study. Relying on residents’ perceptions, the study explored the dynamics underpinning residents’ use of territorial marks. Primary data was collected by administering questionnaires to residents of various neighbourhoods within the study area. Physical observations were conducted to identify all residential neighbourhoods and categorised into three homogenous zones. From each homogenous zone, 30 neighbourhoods were purposively selected. In total, 2055 buildings were identified within these selected neighbourhoods. Thereafter, systematic sampling was employed, resulting in the selection of 206 residents living in separate dwelling units. Findings revealed significant territorial behaviour across all socioeconomic classes. Indigenous territorial marks were predominantly used across all income groups as elements used to communicate land ownership. The study concluded that while crime prevention may be correlated with territoriality, however, in post-conflict neighbourhoods, the need to demarcate land boundaries and communicate ownership was more important, as demonstrated in the adoption of indigenous elements as territorial marks. The paper concluded that in these neighbourhoods, territoriality is chiefly a land boundary regulation mechanism. The paper recommends clear-cut land policies in post-conflict communities while advocating for the recognition of indigenous territorial marks in Afro-centric literature.

The use of song playback experiments to study the social mechanisms of bird settlement decisions

Acoustic playback techniques involve broadcasting of various sound stimuli to simulate the presence of a certain species. In this article, we applied a variation of the method using automatic sound-reproducing stations (ASRS), which imitate the daily vocal activity of birds that is close to natural. We investigated whether acoustic playback experiments help to examine the role of social cues for bird settlement decisions, as well as to detect the presence of rare and low-density species. Using this method, we were able to increase the local density of the rustic bunting Ocyris rusticus Pallas, 1776 (Emberizidae) – species, which is currently listed in the Red Book of the Russian Federation (2001). The findings of our study show that rustic buntings preferred to settle on plots where the song imitating the presence of conspecifics was broadcasted by ASRSs. In addition, the playback method was used to examine the social structure of the population of the wood warbler Phylloscopus sibilatrix Bechstein, 1793 (Sylviidae), a small species that lives here on the northern periphery of the range. The wood warbler songs were broadcasted by ASRSs before the arrivals of the first conspecifics to the breeding area. Songs with different acoustic activity (2 or 6 trills per min) were used to create a difference between the social environments on plots. The gathered data showed a display of two different behavioral responses of individuals (males) to different song types broadcasted on plots. Based on this observation, the main hypothesis is about the existence of both conservative and opportunistic male reproductive strategies of the wood warbler. The results demonstrate the possibility of using acoustic playback techniques to study the role of acoustic signals in territorial behavior and social structure of a bird population. Understanding the ways birds make settlement decisions is essential for the development of conservation practices.

Each Personality Performs Its Own Function: Boldness and Exploration Lead to Differences in the Territoriality of Swimming Crabs (Portunus trituberculatus).

The boldness and exploration of animals are closely related to their territoriality, with relevant studies having important applications in wildlife conservation. The present study establishes a behavior observation system measuring the boldness and exploration of swimming crabs (Portunus trituberculatus) to clarify the relationship between boldness, exploration, and territoriality, as well as to provide a behavioral basis for the construction of marine ranching. The behavioral tests of crabs in a safe environment (predator absence), a dangerous environment (predator presence), and habitat selection (complex and simple habitat) are analyzed. A territorial behavior score is calculated as an evaluation index of territoriality. The correlation between the swimming crabs' boldness, exploration, and territoriality is analyzed. The results show that there is no boldness-exploratory behavioral syndrome. In predator absence or presence environments, boldness is dominant in territorial behavior and positively correlates with territoriality. Exploration plays a vital role in habitat selection tests but has no significant correlation with territoriality. The experimental results preliminarily show that boldness and exploration jointly develop the difference in the space utilization ability of crabs with different personalities, improving the adaptability of swimming crabs in different conditions. The results of this study supplement the behavior rules of the dominant species of typical fishery resources in marine ranches, providing a basis for achieving animal behavior management function in marine ranches.

Does capacity to produce androgens underlie variation in female ornamentation and territoriality in White-shouldered Fairywren (Malurus alboscapulatus)?

Historic bias toward study of sex hormones and sexual ornamentation in males currently constrains our perspective of hormone—behavior—phenotype relationships. Resolving how ornamented female phenotypes evolve is particularly important for understanding the diversity of social signals across taxa. Studies of both males and females in taxa with variable female phenotypes are needed to establish whether sexes share mechanisms underlying expression of signaling phenotypes and behavior. White-shouldered Fairywren (Malurus alboscapulatus) subspecies vary in female ornamentation, baseline circulating androgens, and response to territorial intrusion. The moretoni ornamented female subspecies is characterized by higher female, but lower male baseline androgens, and a stronger pair territorial response relative to pairs from the lorentzi unornamented female subspecies. Here we address whether subspecific differences in female ornamentation, baseline androgens, and pair territoriality are associated with ability to elevate androgens following gonadotropin releasing hormone (GnRH) challenge and in response to simulated territorial intrusion. We find that subspecies do not differ in their capacity to produce androgens in either sex following GnRH or simulated territorial intrusion (STI) challenges. STI-induced androgens were predictive of degree of response to territorial intrusions in females only, but the direction of the effect was mixed. GnRH-induced androgens did not correlate with response to simulated intruders, nor did females sampled during intrusion elevate androgens relative to flushed controls, suggesting that increased androgens are not necessary for the expression of territorial defense behaviors. Collectively, our results suggest that capacity to produce androgens does not underlie subspecific patterns of female ornamentation, territoriality, and baseline plasma androgens.

Understanding the Ecosystem Carrying Capacity for Romanichthys valsanicola, a Critically Endangered Freshwater Fish Endemic to Romania, with Considerations upon Trophic Offer and Behavioral Density

The most recent assessment (2008) of the IUCN Red List of Threatened Species classified Romanichthys valsanicola as critically endangered (CR). In December 2022, an expert team from the National Institute for Research and Development in Environmental Protection Bucharest investigated the presence of the species in historical locations and in other potential sites. The authors correlated public data to the actual habitat area to calculate the potential species density in relation to the specific territorial behavior. The ecological carrying capacity was represented by the consensus between the behavioral density limitations and the trophic limitations of the actual species potential habitat. Both trophic availability and populational density present encouragingly high values for the sculpin perch in the Valsan River, indicating that the natural habitat could host a considerably higher number of individuals.

Seasonal Dynamics and Environmental Drivers of Goliath Grouper (Epinephelus itajara) Sound Production

The Goliath groupers are known to produce characteristic low frequency vocalizations (“calls”) during spawning aggregations and as part of territorial behavior. Acoustic monitoring for Goliath grouper calls around Florida has historically occurred between July and December to capture the spawning season, with a particular focus on August–November. Because of the unique waveform of the Goliath grouper call, we implemented a noise adaptive matched filter to automatically detect Goliath grouper calls from year-round passive acoustic recordings at two wrecks off Florida’s Gulf of Mexico coast. We investigated diel, temporal and environmental factors that could influence call rates throughout the year. Call rates peaked in August, around 0300 EST and just after the full moon. The Goliath groupers were more vocal when background noise was between 70 and 110 dB re 1 µPa. An additional smaller peak in call rates was identified in May, outside of the typical recording period, suggesting there may be other stimuli besides spawning that are eliciting high sound production in this species. Goliath grouper sound production was present year-round, indicative of consistent communication between individuals outside the spawning season.