A behavioral perspective on fishing-induced evolution
Thomas Klefoth
R. Arlinghaus2008, Trends in Ecology & Evolution
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
these results into more precise models of mobbing behavior will enrich our understanding of the evolution of cooperation, one of the more poorly understood problems in evolutionary biology. Effects of avian mobbing on roost use and diet of powerful owls, Ninox strenua. Anim. Behav. 55, 313-318 3 Flasskamp, A. (1994) The adaptive significance of avian mobbing. V. An experimental test of the 'move on' hypothesis. Ethology 96, 322-333 4 Curio, E. and Regelmann, K. (1986) Predator harassment implies a real deadly risk: a reply to Hennessy.
Figures (1)
Related papers
Predation risk drives the expression of mobbing across bird species
Behavioral Ecology, 2017
Many species approach predators to harass and drive them away, even though mobbing a predator can be deadly. However, not all species display this behavior, and those that do can exhibit different behaviors while mobbing different predators. Here we experimentally assessed the role of social and ecological traits on the expression of mobbing behavior in a bird community in SE Brazil (n = 157 species). We exposed birds to models of two morphologically similar diurnal owls that pose different risks, and assessed which species engaged in mobbing. Among those that mobbed, we evaluated how they adjusted their mobbing behavior depending on the predator type. We tested the hypothesis that only species that are at risk and can afford to mob engage in this antipredator behavior. We found that species that engaged in mobbing are in the body mass range of potential prey, forage in the understory or in the canopy, and form flocks. A species' social system did not influence its mobbing behavior. Furthermore, species that engaged in mobbing formed larger mobbing assemblages when facing a high-risk predator, but mobbed more intensely when facing a low-risk predator. Our findings support our predictions, namely that the expression of mobbing is limited by its costs.
Asymmetries in mobbing behaviour and correlated intensity during predator mobbing by nuthatches, chickadees and titmice
Animal Behaviour, 2009
You mob my owl, I'll mob yours: birds play tit-for-tat game
Scientific Reports
Reciprocity is fundamental to cooperative behaviour and has been verified in theoretical models. However, there is still limited experimental evidence for reciprocity in non-primate species. Our results more decisively clarify that reciprocity with a tit-for-tat enforcement strategy can occur among breeding pied flycatchers Ficedula hypoleuca separate from considerations of byproduct mutualism. Breeding pairs living in close proximity (20-24 m) did exhibit byproduct mutualism and always assisted in mobbing regardless of their neighbours' prior actions. However, breeding pairs with distant neighbours (69-84 m) either assisted or refused to assist in mobbing a predatory owl based on whether or not the distant pair had previously helped them in their own nest defense against the predator. Clearly, these birds are aware of their specific spatial security context, remember their neighbours' prior behaviour, and choose a situation-specific strategic course of action, which could p...
Mobbing calls signal predator category in a kin group-living bird species
Proceedings of the Royal Society B: …, 2009
Many prey species gather together to approach and harass their predators despite the associated risks. While mobbing, prey usually utter calls and previous experiments have demonstrated that mobbing calls can convey information about risk to conspecifics. However, the risk posed by predators also differs between predator categories. The ability to communicate predator category would be adaptive because it would allow other mobbers to adjust their risk taking. I tested this idea in Siberian jays Perisoreus infaustus, a group-living bird species, by exposing jay groups to mounts of three hawk and three owl species of varying risks. Groups immediately approached to mob the mount and uttered up to 14 different call types. Jays gave more calls when mobbing a more dangerous predator and when in the presence of kin. Five call types were predator-category-specific and jays uttered two hawk-specific and three owl-specific call types. Thus, this is one of the first studies to demonstrate that mobbing calls can simultaneously encode information about both predator category and the risk posed by a predator. Since antipredator calls of Siberian jays are known to specifically aim at reducing the risk to relatives, kin-based sociality could be an important factor in facilitating the evolution of predator-category-specific mobbing calls.
Mobbing as a trade-off between safety and reproduction in a songbird
Behavioral Ecology, 2010
Individuals' behavioral responses to predator stimuli may be constrained due to the needs of courtship and reproductive behavior. We tested whether alarm and mobbing behavior in response to predator stimuli was dependent on changes in reproductive behavior in chaffinches (Fringilla coelebs). Male chaffinches may suffer cuckoldry if they become separated from their mates during the fertile period, as would happen in cases of mobbing a predator. After the fertile period has ended, however, as their eggs and subsequent young become increasingly valuable, male chaffinches should devote more effort toward mobbing. We found that the time spent near the female and copulation rates was higher during the preincubation fertile period compared with the incubation period. However, the intensity of mobbing responses to a stuffed avian predator was higher during the incubation period. Furthermore, an experiment that manipulated calling behavior related to mobbing intensity showed that rates of extrapair copulations were higher in treatments of higher intensity mobbing. Taken together, these results indicate that during the breeding season, male chaffinches only engage in antipredator mobbing behavior after the fertile period has ended for their female mate. These data point to an important trade-off between current reproductive effort and antipredator responses.
The effects of avian mobbing on a potential predator, the European kestrel, Falco tinnunculus
Animal Behaviour, 1990
European kestrels were observed being mobbed by other birds on 63 occasions. Eleven species were involved, and in two instances mobs were composed of more than one species. Both flight-hunting and perch-hunting kestrels flew significantly further between their foraging positions when they were mobbed than when they were not mobbed; on average, mobbing resulted in flight-hunting kestrels moving 6·8 times, and perch-hunting kestrels 2·7 times, the mean distances moved by non-mobbed birds. The mean strike distance of perch-hunting kestrels attempting to capture birds was significantly less than the distance between perches flown by perch-hunting kestrels when mobbed. These data provide quantitative support for the assumption that mobbing causes a predator to vacate its immediate foraging area. The activity of the kestrels also influenced the frequency that they were mobbed, with kestrels that were flight-hunting being mobbed more than expected compared with ones that were perch-hunting. Kestrels were observed being mobbed throughout the year, and there was no discernible difference in their response to mobbing between seasons. These results are discussed in relation to current ideas on the functions of avian mobbing.
The effects of predation risk on the use of social foraging tactics
Animal Behaviour, 2004
The effects of predation on the use of social foraging tactics, such as producing and scrounging, are poorly known in animals. On the one hand, recent theoretical models predict increased use of scrounging with increasing predation risk, when scroungers seeking feeding opportunities also have a higher chance of detecting predators. On the other hand, there may be no relation between tactic use and predation when antipredator vigilance is not compatible with scanning flockmates. We investigated experimentally the effects of predation risk on social foraging tactic use in tree sparrows, Passer montanus. We manipulated predation risk in the field by changing the distance between shelter and a feeder. Birds visited the feeder in smaller flocks, spent less time on it and were somewhat more vigilant far from shelter than close to it. Increased predation risk strongly affected the social foraging tactic used: birds used the scrounger tactic 30% more often far from cover than close to it. Between-flock variability in scrounging frequency was not related to the average vigilance level of the flock members, and within-flock variability in the use of scrounging was negatively related to the vigilance of birds. Our results suggest that in tree sparrows, the increased frequency of scrounging during high predation risk cannot simply be explained by an additional advantage of increasing antipredator vigilance. We propose alternative mechanisms (e.g. increased stochasticity in food supply, and that riskier places are used by individuals with lower reserves) that may explain increased scrounging when animals forage under high predation risk.
Predator chases by breeding waders: interspecific comparison of three species nesting in Iceland
2010
Local predation pressure predicts the strength of mobbing responses in tropical birds
Current Zoology, 2012
Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl's common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds [Current Zoology 58 : 751−760, 2012].
Related topics
Cited by
Explaining recreational angling catch rates of Eurasian perch, Perca fluviatilis : the role of natural and fishing-related environmental factors
Fisheries Management and Ecology, 2013
Angling catch records are frequently used to reveal fish population developments. It is therefore important to understand the determinants of angling catches. This study focused on angler-related, biotic and abiotic factors influencing catchability of Eurasian perch, Perca fluviatilis L. A multi-lake (21 lakes) study based on angling diaries collected in Mecklenburg-Vorpommern, Germany (2006, found that angler-related factors such as fishing experience, species preference and bait/lure type had a large impact on perch catch rates. Additionally, environmental conditions (nutritional status and water transparency) affected either the size or the number of perch caught by anglers. Catch rates varied seasonally, which was confirmed by an experimental fishery on a gravel pit (2008). This portion of the study showed that altered food availabilities in the course of the year caused food limitation in perch, which in turn facilitated high catch rates and female-biased exploitation in autumn. It is concluded that both anglerrelated and abiotic factors interact affecting perch catch rates and size of perch captured in recreational angling.
Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution?
PloS one, 2015
Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR) and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Fi...
The evolutionary legacy of size-selective harvesting extends from genes to populations
Evolutionary applications, 2015
Size-selective harvesting is assumed to alter life histories of exploited fish populations, thereby negatively affecting population productivity, recovery, and yield. However, demonstrating that fisheries-induced phenotypic changes in the wild are at least partly genetically determined has proved notoriously difficult. Moreover, the population-level consequences of fisheries-induced evolution are still being controversially discussed. Using an experimental approach, we found that five generations of size-selective harvesting altered the life histories and behavior, but not the metabolic rate, of wild-origin zebrafish (Danio rerio). Fish adapted to high positively size selective fishing pressure invested more in reproduction, reached a smaller adult body size, and were less explorative and bold. Phenotypic changes seemed subtle but were accompanied by genetic changes in functional loci. Thus, our results provided unambiguous evidence for rapid, harvest-induced phenotypic and evolutio...
Recreational fishing selectively captures individuals with the highest fitness potential
Proceedings of the National Academy of Sciences, 2012
Fisheries-induced evolution and its impact on the productivity of exploited fish stocks remains a highly contested research topic in applied fish evolution and fisheries science. Although many quantitative models assume that larger, more fecund fish are preferentially removed by fishing, there is no empirical evidence describing the relationship between vulnerability to capture and individual reproductive fitness in the wild. Using males from two lines of largemouth bass (Micropterus salmoides) selectively bred over three generations for either high (HV) or low (LV) vulnerability to angling as a model system, we show that the trait "vulnerability to angling" positively correlates with aggression, intensity of parental care, and reproductive fitness. The difference in reproductive fitness between HV and LV fish was particularly evident among larger males, which are also the preferred mating partners of females. Our study constitutes experimental evidence that recreational angling selectively captures individuals with the highest potential for reproductive fitness. Our study further suggests that selective removal of the fittest individuals likely occurs in many fisheries that target species engaged in parental care. As a result, depending on the ecological context, angling-induced selection may have negative consequences for recruitment within wild populations of largemouth bass and possibly other exploited species in which behavioral patterns that determine fitness, such as aggression or parental care, also affect their vulnerability to fishing gear.
Largemouth Bass Selected for Differential Vulnerability to Angling Exhibit Similar Routine Locomotory Activity in Experimental Ponds
Transactions of the American Fisheries Society, 2012
Performance Assessment of Two Whole-Lake Acoustic Positional Telemetry Systems - Is Reality Mining of Free-Ranging Aquatic Animals Technologically Possible?
PLOS ONE, 2015
Acoustic positional telemetry systems (APTs) represent a novel approach to study the behaviour of free ranging aquatic animals in the wild at unprecedented detail. System manufactures promise remarkably high temporal and spatial resolution. However, the performance of APTs has rarely been rigorously tested at the level of entire ecosystems. Moreover, the effect of habitat structure on system performance has only been poorly documented. Two APTs were deployed to cover two small lakes and a series of standardized stationary tests were conducted to assess system performance. Furthermore, a number of tow tests were conducted to simulate moving fish. Based on these data, we quantified system performance in terms of data yield, accuracy and precision as a function of structural complexity in relation to vegetation. Mean data yield of the two systems was 40 % (Lake1) and 60 % (Lake2). Average system accuracy (acc) and precision (prec) were Lake1: acc = 3.1 m, prec = 1.1 m; Lake2: acc = 1.0 m, prec = 0.2 m. System performance was negatively affected by structural complexity, i.e., open water habitats yielded far better performance than structurally complex vegetated habitats. Post-processing greatly improved data quality, and sub-meter accuracy and precision were, on average, regularly achieved in Lake2 but remained the exception in the larger and structurally more complex Lake1. Moving transmitters were tracked well by both systems. Whereas overestimation of moved distance is inevitable for stationary transmitters due to accumulation of small tracking errors, moving transmitters can result in both over-and underestimation of distances depending on circumstances. Both deployed APTs were capable of providing high resolution positional data at the scale of entire lakes and are suitable systems to mine the reality of free ranging fish in their natural environment. This opens important opportunities to advance several fields of PLOS ONE |
Selection for Vulnerability to Angling in Largemouth Bass
Transactions of the American Fisheries Society, 2009
Although a great deal of effort has been expended to try to understand the consequences of fishing-induced selection by commercial fisheries, relatively little effort has been put into trying to understand the selective effects of recreational angling. We conducted a long-term selection experiment to assess the heritability of vulnerability to angling in largemouth bass Micropterus salmoides. Three successive generations of artificially selected largemouth bass were produced from a single experimental study population. Within each generation, individual adult largemouth bass were identified as having either high or low vulnerability to angling through a series of controlled catch-and-release angling trials. Individuals of each vulnerability group (high and low) were then selected from that population for breeding to produce the next generation. The response to selection for vulnerability to angling increased with each generation; that is, the magnitude of the difference between the high-and low-vulnerability groups of fish increased with each successive generation. Realized heritability was calculated as 0.146 (r 2 ¼ 0.995), indicating that the vulnerability of largemouth bass to angling is indeed a heritable trait. Our results indicate that recreational angling has the potential to alter the gene pool of wild fish populations, which may indirectly affect population characteristics such as survival, growth rate, and reproductive output as well as directly affecting angling success rates.
What Doesn't Kill You Makes You Wary? Effect of Repeated Culling on the Behaviour of an Invasive Predator
PLoS ONE, 2014
As a result of being hunted, animals often alter their behaviour in ways that make future encounters with predators less likely. When hunting is carried out for conservation, for example to control invasive species, these behavioural changes can inadvertently impede the success of future efforts. We examined the effects of repeated culling by spearing on the behaviour of invasive predatory lionfish (Pterois volitans/miles) on Bahamian coral reef patches. We compared the extent of concealment and activity levels of lionfish at dawn and midday on 16 coral reef patches off Eleuthera, The Bahamas. Eight of the patches had been subjected to regular daytime removals of lionfish by spearing for two years. We also estimated the distance at which lionfish became alert to slowly approaching divers on culled and unculled reef patches. Lionfish on culled reefs were less active and hid deeper within the reef during the day than lionfish on patches where no culling had occurred. There were no differences at dawn when removals do not take place. Lionfish on culled reefs also adopted an alert posture at a greater distance from divers than lionfish on unculled reefs. More crepuscular activity likely leads to greater encounter rates by lionfish with more native fish species because the abundance of reef fish outside of shelters typically peaks at dawn and dusk. Hiding deeper within the reef could also make remaining lionfish less likely to be encountered and more difficult to catch by spearfishers during culling efforts. Shifts in the behaviour of hunted invasive animals might be common and they have implications both for the impact of invasive species and for the design and success of invasive control programs.
Voluntary angler logbooks reveal long-term changes in a lentic pike, Esox lucius , population
Fisheries Management and Ecology, 2013
Sixty-two years of voluntarily collected angling logbook data from a large natural Danish lake were used to study variation in pike, Esox lucius L., CPUE (catch per unit effort), expressed as no. of captured pike per boat trip, as an index of stock size. Pike CPUE was positively related to pike release rate by anglers and negatively affected by certain commercial fishers. The stocking of young-of-the-year pike and a fishery-dependent index of perch, Perca fluviatilis L., abundance (which may be pike prey or predator depending on size) did not correlate with pike CPUE. Analyses of the size distribution of pike, based on sizes of annual record trophy pike captured by anglers, confirmed the negative impact of commercial pike fishing and revealed a positive influence of air temperature. It is concluded that high-quality angler logbooks that record effort and catch can be a cost-effective tool to inform lake fisheries management by revealing long-term population trends. Further, state space modelling, a statistical technique not yet seen in recreational fisheries science, is recommended as a tool to model proxies for population dynamics from angler logbook data.
Consistent Selection towards Low Activity Phenotypes When Catchability Depends on Encounters among Human Predators and Fish
PLoS ONE, 2012
Together with life-history and underlying physiology, the behavioural variability among fish is one of the three main trait axes that determines the vulnerability to fishing. However, there are only a few studies that have systematically investigated the strength and direction of selection acting on behavioural traits. Using in situ fish behaviour revealed by telemetry techniques as input, we developed an individual-based model (IBM) that simulated the Lagrangian trajectory of prey (fish) moving within a confined home range (HR). Fishers exhibiting various prototypical fishing styles targeted these fish in the model. We initially hypothesised that more active and more explorative individuals would be systematically removed under all fished conditions, in turn creating negative selection differentials on low activity phenotypes and maybe on small HR. Our results partly supported these general predictions. Standardised selection differentials were, on average, more negative on HR than on activity. However, in many simulation runs, positive selection pressures on HR were also identified, which resulted from the stochastic properties of the fishes' movement and its interaction with the human predator. In contrast, there was a consistent negative selection on activity under all types of fishing styles. Therefore, in situations where catchability depends on spatial encounters between human predators and fish, we would predict a consistent selection towards low activity phenotypes and have less faith in the direction of the selection on HR size. Our study is the first theoretical investigation on the direction of fishery-induced selection of behaviour using passive fishing gears. The few empirical studies where catchability of fish was measured in relation to passive fishing techniques, such as gill-nets, traps or recreational fishing, support our predictions that fish in highly exploited situations are, on average, characterised by low swimming activity, stemming, in part, from negative selection on swimming activity.
Spearfishing promotes a timidity syndrome and increases the safe operating distances in fish
ABSTRACTIn a landscape of fear, humans are altering key behaviors expressed by wild-living animals, including those related to foraging, reproduction and survival. When exposed to potentially lethal human actions, such as hunting or fishing, fish and wildlife is expected to behaviorally respond by becoming more timid, but proving such responses underwater in the wild has been challenging. Using a rich dataset collected in situ, we provide evidence of spearfishing-induced behavioral effects in five coastal fish species using the flight initiation distance (FID) as a proxy of predator avoidance and boldness. We document that spearfishing promotes a timidity syndrome (i.e., an increase of the average timidity of harvested populations) and that the wariness of prey’s wariness is influenced by individual size, level of protection offered through marine protected areas and the ability to recognize the risk posed by underwater human predators. In particular, we show that changes in the app...
Evolutionary effects of fishing gear on foraging behavior and life-history traits
Ecology and Evolution
Even though most food production is now taking place under controlled conditions in farms, fishing is one exception where we rely on wild populations reproducing in their natural habitat, although we exploit them with industrialized technology and efficiency. The traits of wild fish are therefore still subjected to natural selection and may in addition evolve in new directions as they experience selective pressures from fishing and other human activities (Law & Grey, 1989). Identifying these selective drivers and understanding their
Opposite selection on behavioural types by active and passive fishing gears in a simulated guppy Poecilia reticulata fishery
Journal of Fish Biology, 2015
While effort has been invested in trying to ensure that this document is similar to the published one, it is by no means certain that this has actually been achieved. It is therefore strongly recommend to use the published version rather than this preprint.
Impacts of invasive fish removal through angling on population characteristics and juvenile growth rate
Ecology and Evolution, 2015
Exploitation can modify the characteristics of fish populations through the selective harvesting of individuals, with this potentially leading to rapid ecological and evolutionary changes. Despite the well-known effects of invasive fishes on aquatic ecosystems generally, the potential effects of their selective removal through angling, a strategy commonly used to manage invasive fish, are poorly understood. The aim of this field-based study was to use the North American pumpkinseed Lepomis gibbosus as the model species to investigate the consequences of selective removal on their population characteristics and juvenile growth rates across 10 populations in artificial lakes in southern France. We found that the maximal individual mass in populations decreased as removal pressure through angling increased, whereas we did not observed any changes in the maximal individual length in populations as removal pressure increased. Total population abundance did not decrease as removal pressure increased; instead, here was a U-shaped relationship between removal pressure and the abundance of medium-bodied individuals. In addition, population biomass had a U-shaped curve response to removal pressure, implying that invasive fish populations can modulate their characteristics to compensate for the negative effects of selective removals. In addition, individual lengths at age 2 and juvenile growth rates decreased as removal pressure through angling increased, suggesting a shift toward an earlier size at maturity and an overall slower growing phenotype. Therefore, these outputs challenge the efficiency of selective management methods, suggesting the use of more proactive strategies to control invasive populations, and the need to investigate the potential ecological and evolutionary repercussions of nonrandom removal.
Spatially structured interactions between lobsters and lobster fishers in a coastal habitat: fine-scale behaviour and survival estimated from acoustic telemetry
Canadian Journal of Fisheries and Aquatic Sciences, 2013
Fishing can have profound impacts on the ecology and evolution of marine populations. Understanding population-level changes ultimately depends on knowledge about individual survival and how it varies in time and space. We used acoustic tags and a network of receivers to monitor individual behaviour and fate of European lobster (Homarus gammarus) exposed to commercial and recreational trap fisheries on the Norwegian Skagerrak coast. In August 2011, 50 male lobsters above minimum legal size were tagged and monitored before and during the lobster fishing season. We also quantified the spatial and temporal variation in fishing activity. There was no significant effect of home-range size on the probability of surviving the fishery. However, there was substantial fine-scale spatial variation in fishing activity, and lobsters with short-term home ranges positioned away from trap-dense areas had a significantly higher survival probability. Also, the overall survival probability of 16.7% su...
Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management
Fish and Fisheries, 2014
Harvesting-induced evolution of collective risk-taking behavior and changes to the circadian system in a fish
2019
ABSTRACTIntensive and trait-selective harvesting of fish and wildlife can cause evolutionary changes in a range of life-history and behavioural traits. These changes might in turn alter the circadian system both at behavioral and molecular levels, with knock-on effects on daily physiological processes and behavioural outputs. We examined the evolutionary impact of size-selective mortality on collective risk-taking behavior and the circadian system in a model fish species. We exposed zebrafish (Danio rerio) to either large or small size-selective mortality relative to a control over five generations, followed by eight generations during which harvesting halted to remove maternal effects. Large size-selective mortality typical of many fisheries and specialized predators targeting larger size classes decreased collective risk-taking behavior compared to controls. The opposite occurred in response to small size-selective mortality typical of specialized fisheries and most gape-limited p...
Effects of brown trout ( Salmo trutta L.) stocking and catch‐release practice on angling catches in the River South Rena in southeast Norway
Journal of Applied Ichthyology, 2019
Preserving of fish species and populations is important whether it is for exploitation or just for conservation. Management of fisheries aim to maintain fishable stocks that are attractive to anglers, and different means are performed. In this study from the River South Rena in southeastern Norway, conducted during 1991-2005, the effects of supportive stocking of hatchery reared brown trout (Salmo trutta L.) from 1996, and bag limit (BL) and catch-release (CR) practice for the target species brown trout, from 2002, were explored. Effects of supplemental brown trout stocking was not noticeable, except from one year following a year of exceptional high number of stocked fish, actually 41% of the catches, whereas in the following years this proportion remained constant about 10%, and the catches remained high in 2003 and 2004, mainly due to increased angling success rate after BL-CR introduction.
Harvesting-induced evolution of collective behavior in a fish
2019
Many fisheries around the globe preferentially capture large individuals with implications for the evolution of exploited populations. Fisheries-induced evolution may alter collective behavioral phenotypes through individual-level adaptations that affect boldness, swimming speed and tendency to follow social vs. environmental cues. Studying the behavioural mechanisms that give rise to possible changes in shoaling and other collective outputs is challenging in the wild, but first insights into whether intensive and size-selective harvesting could alter collective phenotypes and shoaling can be gathered through experiment of size-selective harvesting conducted in the laboratory. We present a multi-generation harvest selection experiment with zebrafish (Danio rerio) as a model species and demonstrate that large size-selective harvesting typical of global fisheries decreases risk-taking behavior of individuals, and surprisingly also decreases shoal cohesion. This counter-intuitive effec...
Conducting and interpreting fish telemetry studies: considerations for researchers and resource managers
Reviews in Fish Biology and Fisheries, 2019
Your article is protected by copyright and all rights are held exclusively by Springer Nature Switzerland AG. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Spatial ecology of coastal Atlantic codGadus morhuaassociated with parasite load
Journal of Fish Biology, 2015
Acoustic tags and receivers were used to investigate the spatial ecology of coastal Atlantic cod Gadus morhua (n = 32, mean fork length: 50 cm, range: 33-80 cm) on the Norwegian Skagerrak coast in 2012. Monthly home ranges (HR), swimming activity and depth use varied considerably among individuals and through the months of June, July and August. HR sizes for the period ranged from 0⋅25 to 5⋅20 km 2 (mean = 2⋅30 km 2). Two thirds of the tagged G. morhua were infected with black spot disease Cryptocotyle lingua parasites; these fish had larger HRs and occupied deeper water compared with non-infected fish. The infected fish also tended to be more active in terms of horizontal swimming. From an ecological and evolutionary perspective, any environmental change that modifies G. morhua behaviour may therefore also alter the parasite load of the population, and its conservation and fishery status.
Migratory passage structures at hydropower plants as potential physiological and behavioural selective agents
Royal Society Open Science, 2019
One Hundred Pressing Questions on the Future of Global Fish Migration Science, Conservation, and Policy
Frontiers in Ecology and Evolution, 2019
Migration is a widespread but highly diverse component of many animal life histories. Fish migrate throughout the world's oceans, within lakes and rivers, and between the two realms, transporting matter, energy, and other species (e.g., microbes) across boundaries. Migration is therefore a process responsible for myriad ecosystem services. Many human populations depend on the presence of predictable migrations of fish for their subsistence and livelihoods. Although much research has focused on fish migration, many questions remain in our rapidly changing world. We assembled a Lennox et al. Fish Migration Questions diverse team of fundamental and applied scientists who study fish migrations in marine and freshwater environments to identify pressing unanswered questions. Our exercise revealed questions within themes related to understanding the migrating individual's internal state, navigational mechanisms, locomotor capabilities, external drivers of migration, the threats confronting migratory fish including climate change, and the role of migration. In addition, we identified key requirements for aquatic animal management, restoration, policy, and governance. Lessons revealed included the difficulties in generalizing among species and populations, and in understanding the levels of connectivity facilitated by migrating fishes. We conclude by identifying priority research needed for assuring a sustainable future for migratory fishes.
On the relevance of animal behavior to the management and conservation of fishes and fisheries
Environmental Biology of Fishes, 2022
from animal behavior to support management and conservation actions. Dr. David L. G. Noakes is an influential ethologist who did much foundational work related to illustrating how behavior was relevant to the management and conservation of wild fish. We pay tribute to the late Dr. Noakes by summarizing the relevance of animal behavior to fisheries management and conservation. To do so, we first consider what behavior has revealed about how fish respond to Abstract There are many syntheses on the role of animal behavior in understanding and mitigating conservation threats for wildlife. That body of work has inspired the development of a new discipline called conservation behavior. Yet, the majority of those synthetic papers focus on non-fish taxa such as birds and mammals. Many fish populations are subject to intensive exploitation and management and for decades researchers have used concepts and knowledge
Related papers
Kill before being killed: an experimental approach supports the predator-removal hypothesis as a determinant of intraguild predation in top predators
Behavioral Ecology and …
Intraguild predation (IGP) has been explained in terms of competitor-removal, food-stress and predatorremoval hypotheses. Only the first two hypotheses have been fairly well studied. To test the predator-removal hypothesis as a force determining IGP in avian predators, we performed a field experiment to simulate the presence of an IG predator (eagle owl Bubo bubo dummy) in the surrounding of the nests of four potential IG prey (black kite Milvus migrans, red kite Milvus milvus, booted eagle Aquila pennata and common buzzard Buteo buteo). To discard the possibility that an aggressive reaction towards the eagle owl was not related to the presence of the IG predator, we also presented a stuffed tawny owl Strix aluco, which is a potential competitor but cannot be considered an IG predator of the studied diurnal raptors considered in the experiment. While almost always ignoring the tawny owl, raptors chiefly showed an interspecific aggressive behaviour towards their IG predator. Our results seem to support the predator-removal hypothesis, as the IG prey may take advantage of the diurnal inactivity of the IG predator to remove it from their territory. However, the recorded behaviour may be also considered as a special variety of mobbing (i.e. a prey’s counter-strategy against its predator), where the mobber is sufficiently powerful to escalate predator harassment into deliberate killing attempts. In their turn, eagle owls can respond with an IG predatory behaviour aimed at removing IG prey species which are highly aggressive mobbers.
Referential mobbing calls elicit different predator-searching behaviours in Japanese great tits
Animal Behaviour, 2012
Effects of avian mobbing on roost use and diet of powerful owls,Ninox strenua
Animal Behaviour, 1998
We observed the species and numbers of mobbing birds and their effects on a large, nocturnal, bird-eating predator, the powerful owl, together with the pattern of owl predation on mobbing and non-mobbing species. Owls were mobbed on 35 occasions by seven of 44 species of forest birds at a site composed of open forest (88% by area) and rainforest (12%). The majority of bouts involved individuals of a single species, although mixed groups were observed on nine occasions. Regular mobbers were between 4 and 26% of the owls' body weight. Owls abandoned their daytime roosts during 20% of bouts and responded by calling or actively monitoring mobbers during 54% of bouts. Mobbing appeared to explain why owls roosted in rainforest significantly more often than expected by its availability, mobbing being significantly less frequent in rainforest than in open forest. Only one mobbing species regularly occupied rainforest and the canopy of roosts in rainforest was denser than that in open forest, thus reducing the chances of an owl being detected by potential mobbers. Twelve species of forest birds were within the range of prey size of the powerful owl (75-800 g): six were mobbers and six non-mobbers. The frequency of owl predation on non-mobbers was 8.75 times that on mobbers. The species in this study took a high risk by mobbing a very large predator, but benefited by greatly reducing their chances of predation.
The presence of conspecific females influences male-mobbing behavior
Behavioral Ecology and Sociobiology
Many prey species mob predators to drive them away, thereby reducing their immediate and future predation risk. Given that mobbing is risky, it may also serve as an opportunity for males to advertise their phenotypic quality to females; however, this idea remains untested. We tested this hypothesis with a field experiment in southeastern Brazil that assessed the response of sexually dimorphic bird species to models of two diurnal owls: a ferruginous pygmy owl (Glaucidium brasilianum), which mainly eats small birds, and a burrowing owl (Athene cunicularia), which mainly eats invertebrates and thus poses a low risk to birds. Across 19 bird species, the mobbing intensity was higher when facing the less-dangerous owl, and more males engaged in predator mobbing than females. The mobbing intensity of males was higher with a larger number of conspecific females present. This finding indicates that males may use mobbing to display their phenotypic quality to females, suggesting that predator mobbing may be influenced by sexual selection. Significance statement Predation is an important evolutionary force, often leading to an evolutionary arms race between predators and their prey. A puzzling form of prey-predator interactions is predator mobbing. In a wide range of species, prey individuals approach predators and show characteristic visual and acoustic displays. The primary function of mobbing is to drive the predator away; however, it may also serve as an opportunity to advertise phenotypic quality to conspecifics. Field experiments showed that the mobbing intensity of males increased with the number of conspecific females in the audience, suggesting that female choice may influence the evolution of mobbing behavior.
Records of Mobbing Behavior in Venezuelan Wild Birds
Ornitologia Neotropical, 2023
Mobbing is a survival strategy in which a small bird a(acks larger and more powerful perceived enemies (e.g., potenAal predators) to drive them away from the vicinity. This paper reports and describes mobbing events performed by Venezuelan wild birds, which were recorded opportunisAcally in different localiAes of the country. A total of 31 species from 15 families were recorded in 131 mobbing events. Individual mobbing was the tacAc most frequently recorded in 83 mobbing events (63%) whereas 36 events (28%) involved the addiAonal assistance of conspecifics, and only 12 (9%) involved non-conspecific allies. Birds tended to mob individually when the enemy was flying but they tended to do so as a group when the enemy was perched. Most of the recorded mobbing events (109 events, 83%) served an anA-predatory funcAon, but mobbing was also performed for food resource protecAon (17 events, 13%), and site defense (five events, 4%). Mobbing behavior was recorded during the breeding season in 16 species with 75 mobbing events (58%) occurring in that period. Eight mobber species were also mobbed. Most mobbing events (98%) were iniAated by the weaker species (bird having smaller body size or mass). Important differences were found in body size and body mass between the mobber and mobbed species. In general, a mobber engaged in mobbing against other birds of similar or larger body size (up to 5.6 Ames larger) or larger body mass (up to 117.5 Ames heavier). In most mobbing events (54%) a mobber a(acked birds that doubled it in size, and in 75% of the events, the mobbed bird was three Ames heavier than the mobber. Only the Roadside Hawk Rupornis magnirostris and the Tropical Kingbird Tyrannus melancholicus were exposed to true danger when they were counter-a(acked, and almost caught, by Common Black Hawks Buteogallus anthracinus. The records collected here contribute to the data on mobbing behavior in wild birds worldwide and noAceably improve the repository of available knowledge in Venezuela and the Neotropical region. Resumen • Registros de comportamiento de acoso en aves silvestres venezolanas El acoso es una estrategia de supervivencia en la cual un ave pequeña ataca a enemigos más grandes y poderosos (e.g. depredadores potenciales) para expulsarlos de las inmediaciones. Este arkculo reporta y describe eventos de acoso en aves silvestres de Venezuela, registrados de manera oportunista en diferentes localidades del país. Un total de 31 especies pertenecientes a 15 familias fueron registradas en 131 eventos de acoso. El acoso individual fue la tácAca más común, registrada en 83 eventos de acoso (63%), mientras que en 36 eventos (28%) fue necesaria la asistencia adicional de conespecíficos y solo en 12 (9%) se involucraron aliados no conespecíficos. Las aves acosadoras prefirieron acosar solas cuando el enemigo estaba volando, mientras que se inclinaron por acosar en grupo cuando el enemigo estaba posado. La mayoría de los eventos de acoso registrados (109 eventos, 83%) cumplieron una función anAdepredadora, pero el acoso también fue realizado para proteger un recurso alimentario (17 eventos, 13%) y defender un lugar estratégico (cinco eventos, 4%). El comportamiento de acoso fue registrado durante el período reproducAvo en 16 especies y 75 eventos de acoso (58%) ocurrieron durante el mismo. Ocho especies acosadoras también fueron acosadas. La mayoría de los eventos de acoso (98%) fueron iniciados por la especie más débil (el ave de menor talla o masa corporal). Se encontraron diferencias importantes entre el tamaño y la masa corporal del ave acosadora y el ave acosada. En general, un ave acosadora parAcipó en un evento de acoso con otras aves del mismo tamaño o superior (hasta 5,6 veces más grande) o de mayor peso (hasta 117,5 veces más pesada). En la mayoría de los eventos (54%) un acosador tuvo que acosar aves que duplicaban su tamaño y en 75% de los eventos triplicaban su peso. Solo el Gavilán Habado Rupornis magnirostris y el PiArre Chicharrero Tyrannus melancholicus estuvieron expuestos a un verdadero peligro cuando fueron contra atacados por el Gavilán Cangrejero Buteogallus anthracinus, que por poco los captura. La información recolectada incrementa los datos relacionados al comportamiento de acoso en aves silvestres a nivel mundial y mejora de manera importante el conocimiento disponible en Venezuela y la región Neotropical.
Effects of relatedness on social-foraging tactic use in house sparrows
Animal Behaviour, 2009
The increased risk of predation enhances cooperation
Proceedings of The Royal Society B: Biological Sciences, 2010
Theory predicts that animals in adverse conditions can decrease individual risks and increase long-term benefits by cooperating with neighbours. However, some empirical studies suggest that animals often focus on short-term benefits, which can reduce the likelihood that they will cooperate with others. In this experimental study, we tested between these two alternatives by evaluating whether increased predation risk (as a correlate of environmental adversity) enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behaviour, among breeding pied flycatchers Ficedula hypoleuca. We tested whether birds would join their mobbing neighbours more often and harass a stuffed predator placed near their neighbours' nests more intensely in areas with a higher perceived risk of predation. Our results show that birds attended mobs initiated by their neighbours more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. In such high-risk areas, birds also were more often involved in between-pair cooperation. This study demonstrates the positive impact of predation risk on cooperation in breeding songbirds, which might help in explaining the emergence and evolution of cooperation.
Avian Mobbing Response is Restricted by Territory Boundaries: Experimental Evidence from Two Species of Forest Warblers
Ethology, 2005
Predator mobbing has been viewed as an adaptation to reduce the risk of predation, however, factors influencing mobbing behaviour are still debated. We report on the results of an experiment with Dendroica caerulescens and Dendroica virens designed to determine (1) whether mobbing response by forest songbirds during the breeding season is restricted by territory boundaries, (2) the distance songbirds will move in response to anti-predator mobbing calls, and (3) whether reproductive status, age, and time of the breeding season determine the distance moved to mob. We did not detect an effect of reproductive status, age, or time of breeding season on the distance moved by birds to mob. All birds responded to the mobbing playback within their territory (defined by territorial defence in relation to specific song playbacks). The maximum distance moved within a territory to engage in mobbing ranged from 25 to 175 m ( x ¼ 72 ± 6 m). Three of 37 birds responded to playbacks outside their territory boundaries. In all three cases, maximum movement distances outside territories were short (25 m). Thus, for two species of warblers, mobbing is highly constrained by territory boundaries during the breeding season. This finding is congruent with arguments that mobbing is primarily a selfish behaviour, at least with respect to conspecifics. Our results also provide support for the Ômove-onÕ hypothesis.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.