Species Feeding Research Articles

Desert landscape features influencing the microgeographic genetic structure of Nelson's pocket mouse Chaetodipus nelsoni.

Elucidating the factors that drive the genetic patterns of natural populations is key in evolutionary biology, ecology and conservation. Hence, it is crucial to understand the role that environmental features play in species genetic diversity and structure. Landscape genetics measures functional connectivity and evaluates the effects of landscape composition, configuration, and heterogeneity on microevolutionary processes. Deserts constitute one of the world's most widespread biomes and exhibit a striking heterogeneity of microhabitats, yet few landscape genetics studies have been performed with rodents in deserts. We evaluated the relationship between landscape and functional connectivity, at a microgeographic scale, of the Nelson's pocket mouse Chaetodipus nelsoni in the Mapimí Biosphere Reserve (Chihuahuan desert). We used single-nucleotide polymorphisms and characterized the landscape based on on-site environmental data and from Landsat satellite images. We identified two distinct genetic clusters shaped by elevation, vegetation and soil. High elevation group showed higher connectivity in the elevated zones (1250-1350 m), with scarce vegetation and predominantly rocky soils; whereas that of Low elevation group was at <1200 m, with denser vegetation and sandy soils. These genetic patterns are likely associated with the species' locomotion type, feeding strategy and building of burrows. Interestingly, we also identified morphological differences, where hind foot size was significantly smaller in individuals from High elevation compared to Low elevation, suggesting the possibility of ecomorphs associated with habitat differences and potential local adaptation processes, which should be explored further. These findings improve our understanding of the genetics and ecology of C. nelsoni and other desert rodents.

Capybara (Hydrochoerus hydrochaeris) Salivary Glands Morphology.

Morphological studies concerning salivary glands have emerged as an exciting tool to understand feeding habits. In this sense, this study aimed to describe capybara salivary glands morphology to understand potential morphological associations to this species feeding habits. Macroscopic dissections and microscopic analyses were performed on eight specimens. The findings indicate that capybaras have three pairs of major (parotid, mandibular and sublingual) and two pairs of minors (dorsal and ventral buccal) salivary glands. The parotid gland, the largest, is irregularly shaped, forming small macroscopic lobes. The mandibular gland is rounded and found syntopically alongside the mandible angle and arranged medially to the ventral projection of the parotid gland. The sublingual gland is a compact elongated and semicircular mass. The dorsal and ventral buccal glands are located in the buccal portion of the buccinator muscle. Histologically, the parotid and mandibular glands are composed of serous acini, while the sublingual and buccal (dorsal and ventral) glands consist of mucous tubules containing serous demi-lunes at their periphery. Capybara salivary glands reveal morphological associations with a predominantly herbivorous diet. The parotid gland, for example, notably developed in size and volume, suggests a specialisation for increased saliva production, necessary for chewing, forming the food bolus, swallowing fibrous foods, and protecting the oral cavity ecosystem.

The Influence of Habitat Diversity on Bat Species Richness and Feeding Behavior in Chilean Vineyards: Implications for Agroecological Practices

Agriculture is a leading cause of biodiversity loss, making the transition to sustainable agroecological practices crucial. Insectivorous bats play a crucial role as biological controllers in regard to agricultural crops, serving as important insect predators. The purpose of this study is to assess bat communities in three distinct habitats, namely the interior of a vineyard, native vegetation, and the transitional edge between them, by analyzing the echolocation patterns of different species. Generalized linear mixed models were used to evaluate the influence of landscape characteristics on bat communities and at the species level, allowing the incorporation of variables at different scales (at 10 m, 100 m, and 1000 m radius) from each sampling site. Our results show that edges enhance bat richness, their general activity, and feeding patterns, and are of particular benefit to certain species: Tadarida brasiliensis, Myotis chiloensis, and Lasiurus varius. Implementing agroecological practices, such as the maintenance of tree hedgerows at the landscape scale, along with native vegetation at the landscape scale, can amplify feeding activity in vineyards, thereby enhancing the provision of ecosystem services in agroecosystems. The edges of vineyards and natural vegetation are crucial for providing habitats for bats and increasing their foraging activity, as well as providing a way to enhance agroecological practices in vineyards to bolster ecosystem services.

Wild Bird Species Structure and Feeding Guilds in Agricultural Area at Zagazig District, Sharkia Governorate, Egypt

Wild Bird Species Structure and Feeding Guilds in Agricultural Area at Zagazig District, Sharkia Governorate, Egypt

Feeding of the crab Eriphia gonagra (Fabricius, 1781) (Decapoda: Brachyura: Eriphiidae) as a tool to assess the impacts of oil spills

ABSTRACT This study aimed to observe changes in the diet of crab Eriphia gonagra due to the oil spill that occurred in 2019 on two beaches on the Pernambuco coast (Gaibu and Carneiros Beach) Northeastern, Brazil. Changes in the species feeding were investigated considering the periods before, during, and after of the spill and correlated with the analysis of sediment contamination Polycyclic Aromatic Hydrocarbons (PAHs) and Trace Metals (TM). 160 specimens were analysed. 24 food items were found, with a prevalence of Mollusca (fragment) and Macroalgae in the diet. There was no detection of oil fragments in the stomachs of animals, however, different patterns were observed in the feeding of the species studied in the BEF, DUR, and AFT periods of the spill. A generalist habit, it was possible to observe changes in captured items, thus we observed a diet with low nutritional levels caused mainly in impacted environments. Two factors may be prevalent in explaining the impacts caused by the feeding of E. gonagra in Carneiros Beach. The first was the decrease in prey that died after the arrival of the oil, the second was the lasting effects of contaminants on the predation capacity of the species.

How do global forest pests respond to increasing temperatures? – a meta‐analysis

Biotic disturbances caused by insects and pathogens have a major impact on forests in the Northern Hemisphere. Knowledge of the effects of increasing temperature on the performance of these forest pests will thus be crucial for predicting future disturbance risks. Here, we systematically review the direct effects of increasing temperatures on four functional subgroups of forest pests, including leaf chewers, sap suckers, bark and wood borers, and pathogens. We considered 118 studies (2003–2022) representing 72 pest species feeding on 33 host genera from sub‐tropical, temperate and boreal forests in Asia, Europe and North America. Based on a subset of 89 studies reporting the required data, we conducted a meta‐analysis 1) distinguishing the functional subgroups, and 2) considering the main life‐history traits, i.e. development, fitness and survival. A temperature corresponding to the expected mean temperature during the growing season in the years 2081–2100 had a significant positive effect on the overall performance of leaf chewers (+18%) and bark and wood borers (+10%), while sap suckers and pathogens remained unaffected. In contrast, performance was not or even significantly negatively affected when a more pronounced temperature increase, i.e. corresponding to the temperature maxima in 2081–2100, was considered. This finding reflects the non‐linear temperature–performance relationship beyond currently evolved temperature optima in insects and pathogens. Furthermore, we showed that differential responses of life‐history traits to increased temperatures may counterbalance each other (e.g. development versus survival), highlighting the importance of a multi‐trait approach to assessing the impact of global warming on pest performance. By quantifying the effects of increasing temperatures on forest pest performance, our results facilitate the prediction of biotic disturbance impacts in a future climate. For instance, they could provide a valuable contribution to the parameterization of large‐scale ecosystem models, which often do not explicitly consider the response of biotic disturbances to climate change.

Still waters and deep: Habitat characteristics, density and distribution of a lake-dwelling population of the freshwater pearl mussel Margaritifera margaritifera

The freshwater pearl mussel, Margaritifera margaritifera is widely considered to be confined to fast-flowing, near-pristine rivers, and is highly endangered throughout its Holartic range. Here we describe a large population of some 150–200,000 individuals of the freshwater pearl mussel living in an oligotrophic Irish lake.Employing underwater photographic techniques and snorkel diving, mussels were found in two separate locations in the lake. In the first location, 200 m from the shore, mussels were found at a maximum density of 43 m−2, in a largely random distribution in the sandy bed substrate of the lake, up to 9.5 m deep. In the second shoreline location, mussels were observed in dense aggregations up to 118 individuals m−2, in sandy pockets in between boulders and bedrock, in waters 1–2 m deep. In both locations, mussels were found associated with macrophytes – the charophyte Nitella sp. in the deeper location and the quillwort Isoetes lacustris in the shallower shoreline location. Juvenile mussels (>1.5 cm length) were observed lying exposed on the sediment surface in the shallow littoral location, indicating that recruitment occurs in this population, although no estimates of juvenile density were obtained.The discovery of a large population of lentic Margaritifera margaritifera has significant implications for the species’ conservation and indicates that there may be substantial lentic populations of the species elsewhere. The environmental envelope of the species is clearly much wider than thought and our discovery challenges assumptions about the fundamental feeding and reproductive biology of this endangered species.

Survey of Leafminers on American Chestnut and other Castanea spp. (Fagales: Fagaceae) on Long Island, NY.

The effect of the 20th-century functional extinction of the American Chestnut (Fagaceae: Castanea dentata (Marshall) Borkh) on associated herbivorous insects is unknown. These insects include leafminers that spend at least part of their larval phase feeding between the epidermises of leaves. We surveyed leafminers on C. dentata, nonnative Castanea spp., and hybrids on Long Island, NY. We found 10 leafminer species feeding on Castanea spp. A first New York State record was documented for Stigmella castaneaefoliella (Chambers) (Lepidoptera: Nepticulidae). New host records are established for 6 lepidopterans, including a new host genus for Phyllonorycter basistrigella (Clemens) (Lepidoptera: Gracillariidae). We found no significant differences in the mean intensity of S. castaneaefoliella leaf mines on native and nonnative Castanea spp.; however, our sample size was small. Thus, we guardedly conclude that nonnative Castanea spp. can serve as refugia for C. dentata leafminers native to North America while acknowledging that the extent to which nonnative species are utilized requires further investigation.

Furostanol Saponins and Ecdysteroids from Plants of the Genus Helleborus as Phagostimulants and Predator Deterrents for Larvae of Two Monophadnus Sawfly Species.

Sawfly species of the genus Monophadnus are specialised on Ranunculaceae plants from which the larvae can sequester furostanol saponins into the haemolymph, mainly (25R)-26-[(α-L-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl-O-β-D-glucopyranosyl-(1→3)-O-[6-acetyl-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranoside (compound 1). In this work, TLC, GC-MS, and HPLC-DAD-ESI/MS analyses together with feeding, repeated simulated attacks, and ant deterrence bioassays were conducted to extend the chemoecological knowledge about two sawfly species specialised on H. foetidus L. (Monophadnus species A) and H. viridis L. (Monophadnus species B). Larvae of Monophadnus species B were mostly feeding on the squares treated with the n-butanol fraction from H. foetidus, compound 1 being its primary non-nutritional stimulant. In contrast, all H. viridis fractions stimulated feeding, with n-hexane marginally more active. β-sitosterol within n-hexane was determined as the nutritional stimulant. Quantitative analyses demonstrated that leaves of H. viridis but not H. foetidus contain the ecdysteroids 20-hydroxyecdysone and polypodine B. Moreover, the haemolymph of Monophadnus species B larvae reared on H. viridis contained the glycosides of polypodine B and 20-hydroxyecdysone at a concentration of 2.5 to 6.8 µmol/g fresh weight of haemolymph. This concentration is several thousand times higher than the concentration range of the aglycones in their host plant (3.63 × 10-4 to 2.23 × 10-4 µmol total ecdysteroids/g fresh weight of leaves), suggesting bioaccumulation. The larvae of both species fed on H. foetidus do not show any traces of ecdysteroids in their haemolymph, indicating a facultative role of these compounds in their defence as well as their inability to endogenously synthesise these compounds. The haemolymph containing ecdysteroids was a significant feeding deterrent against Myrmica rubra L. ant workers (one of their natural predators) at 0.8 mg/mL. The larvae kept effective deterrent levels of glycosylated ecdysteroids (≅175 mM) between simulated attacks on days 1 and 2, but the levels clearly decreased on day 3 (≅75 mM). Most larvae (89%) survived a first attack but only 23% a consecutive second one. As a conclusion, we report for the first time that two Monophadnus species feeding on H. viridis sequester phytoecdysteroids into the larval haemolymph in the form of glycosides. In addition, compound 1 possesses defensive and phagostimulant activities, and we present evidence for a combined effect of furostanol saponins and ecdysteroids as repellents against ants.

Feeding Practices in Rearing of Yak and its Bovine Crosses in Ladakh

Yak has been very closely associated with the culture, religion, and social fabric of the pastoral people in Ladakh. A study was carried out to document the feeding practices involved in rearing of yak and its bovine crosses in Ladakh. Results indicate that availability of fodder was seasonal with the fodder being available only between the months of April to October and had to be stored for harsh winters. Common property resources (CPRs) were found to be the primary and only fodder source and all the yak rearers were feeding a mixed feed including green, dry and home-grown concentrate depending on the availability. Usually, the animals were allowed to graze in the pastures (CPRs) for most of the time and were stall-fed with collected and stored grasses only during extremely harsh winters. During stall-feeding, animals were fed once a day and it was usually a group feeding of different animal species all together. Yak rearers in general lacked the knowledge regarding feed improvement and feeding of mineral mixture but were aware about feeding of salt to animals.

Maya Traditional Knowledge of Cnidoscolus spp. in the Yucatán Peninsula

The genus Cnidoscolus (Euphorbiaceae) contains some species with socioeconomic and cultural relevance in the Yucatán Peninsula, Mexico. There is little published information on the traditional knowledge of this genus, and the recent movements of younger people to more populated cities and towns risks this knowledge being forgotten. To preserve this knowledge, we wanted to answer the questions: what are the species or varieties of the plant with the generic name chaya that the contemporary Maya population uses in the Yucatan Peninsula, and in which agroecosystems are these species or varieties found? Nine local communities were selected for interviews in which the general population and healers shared their knowledge about the uses and management of Cnidoscolus spp. Through these interviews, we identified eight species or cultivars used by these communities: six cultivars of C. aconitifolius ( chay, makat chay, chay sin espinas, ch’inch’in chay, tsaj, and tsaj/ hoja de papaya), C. multilobus ( tsaj), and C. souzae ( tsaj). Within homegardens chay, makat chay and chay sin espinas are utilized for their feeding, medicinal and fodder value; while ch'inch'in chay and tsaj are utilized for their feeding, medicinal, and living-fence potential. In paddocks, ch’inch’in chay and tsaj are utilized as livestock feed. Tsaj is used for handcrafts, and tsaj/ hoja de papaya possesses spiritual-religious attributes. The feeding, medicinal, fodder, living-fence, spiritual-religious, and handcraft potential of species and cultivars of Cnidoscolus reflect their biocultural importance for Maya inhabiting the peninsula of Yucatan.

Chemical composition of muscle tissue of fish reared in the aquaculture of South Vietnam

To study the chemical composition of four species of valuable fish reared in aquaculture conditions in South Vietnam.Individuals of Channa striata, Channa gachua, Oreochromis niloticus, a hybrid of Clarias gariepinus and Clarias macrocephalus were purchased in markets from farmers of cage farms and directly in the farms of Khanh Hoa province. The fish were measured, weighed, and then muscle tissue was dissected for chemical analysis. The water content in the tissue was determined by a two‐stage method for determining moisture, while lipids were determined by the fat‐free residue method in a Soxhlet apparatus. The amount of protein was obtained according to the principle of the Kjeldahl method, using a semi‐automatic distillation unit UDK 139 (Velp Scientifica, Italy, 2011); minerals were determined by the gravimetric method, and carbohydrates – by calculation. The index of physiological state was calculated according to the standard method.Hybrid catfish muscles are characterised as having the greatest nutritional value. In terms of lipid content, the individuals studied belonged to fish with a low fat content, Channa striata, which belongs to the category of lean fish. A high index of physiological state in Oreochromis niloticus was found to be associated with increased water content in muscle tissue. No significant differences were found between the biochemical parameters in the muscles of fish with an increase in body size, and only in Channa striata did the proportion of minerals increase. The data obtained can be used in the organisation of rational feeding and maintenance of aquacultural species.

Exploring motion using geometric morphometrics in microscopic aquatic invertebrates: ‘modes’ and movement patterns during feeding in a bdelloid rotifer model species

BackgroundMovement is a defining aspect of animals, but it is rarely studied using quantitative methods in microscopic invertebrates. Bdelloid rotifers are a cosmopolitan class of aquatic invertebrates of great scientific interest because of their ability to survive in very harsh environment and also because they represent a rare example of an ancient lineage that only includes asexually reproducing species. In this class, Adineta ricciae has become a model species as it is unusually easy to culture. Yet, relatively little is known of its ethology and almost nothing on how it behaves during feeding.MethodsTo explore feeding behaviour in A. ricciae, as well as to provide an example of application of computational ethology in a microscopic invertebrate, we apply Procrustes motion analysis in combination with ordination and clustering methods to a laboratory bred sample of individuals recorded during feeding.ResultsWe demonstrate that movement during feeding can be accurately described in a simple two-dimensional shape space with three main ‘modes’ of motion. Foot telescoping, with the body kept straight, is the most frequent ‘mode’, but it is accompanied by periodic rotations of the foot together with bending while the foot is mostly retracted.ConclusionsProcrustes motion analysis is a relatively simple but effective tool for describing motion during feeding in A. ricciae. The application of this method generates quantitative data that could be analysed in relation to genetic and ecological differences in a variety of experimental settings. The study provides an example that is easy to replicate in other invertebrates, including other microscopic animals whose behavioural ecology is often poorly known.

When the predator becomes the prey: new records of intraguild predation among Central American and Caribbean arachnids (Arachnida: Amblypygi, Araneae, Scorpiones)

ABSTRACT Intraguild predation occurs when an organism preys on a competitor. This ecological interaction can have considerable consequences on the population dynamics of predators and indirectly affect their prey. In arachnids, it is a quite common phenomenon, but it has been poorly documented in the Neotropical region. Here, we present records of 16 species feeding on other 14 species of arachnids. The most common families that acted as predators were Buthidae (Scorpiones) and Salticidae (Araneae), while the most common prey were members of the families Araneidae and Ctenidae (Araneae). In our survey, Drake Bay, in Costa Rica, is overrepresented due to years of systematic observations by two of the coauthors.

Species Composition and Feeding Behaviors of Vector Mosquitoes of Avian Infectious Diseases at a Wild Bird Rehabilitation Facility in Japan.

Although wild bird rehabilitation facilities are important for the conservation of wild species, individuals may be kept within the facilities for long periods, consequently posing a risk for the bird to be infected with pathogens to which they are not naturally exposed. In turn, novel pathogens may be introduced through rescued migratory species. Avian malaria and West Nile fever are important avian diseases transmitted by mosquitoes. To understand the transmission dynamics of such diseases at rehabilitation facilities, the ecology of vector mosquitoes, including species composition, seasonality, and feeding behaviors, were explored. Mosquitoes were collected at a wild bird rehabilitation facility and wildlife sanctuary in Japan from 2019 to 2020 using mouth aspirators, sweep nets, and light traps. A total of 2,819 mosquitoes of 6 species were captured, all of which are potential vectors of avian diseases. Culex pipiens pallens and Cx. pipiens form molestus were the dominant species (82.9% of all collected mosquitoes). Density and seasonality differed between sampling locations, presumably because of differences in mosquito behaviors including feeding preferences and responses to climatic factors. Blood-fed Culex mosquitoes fed solely on birds, and many mosquito species are thought to have fed on birds within the facility. Particularly, Cx. pipiens group probably fed on both rescued and free-living birds. The rehabilitation facility may be an important site for the introduction and spread of pathogens because 1) numerous mosquitoes inhabit the hospital and its surroundings; 2) blood-fed mosquitoes are caught within the hospital; 3) there is direct contact between birds and mosquitoes; 4) both birds within the hospital and wild birds are fed upon. Furthermore, blood-fed Cx. pipiens form molestus were observed in the winter, suggesting that pathogens might be transmitted even during the winter when other mosquito species are inactive.

Species traits to guide moth conservation in anthropogenic regions: A multi‐species approach using distribution trends in Flanders (northern Belgium)

Abstract Insect abundance and diversity appear to decline rapidly in recent decades, garnering significant media attention, and hence raising public awareness. Macro‐moths—a species‐rich and ecologically diverse insect group—face severe declines, particularly in urbanised and intensively farmed areas in NW Europe. Flanders is a highly anthropogenic region, serving as a case study where the impact on macro‐moths of stressors like intensive agriculture, industrialisation and urbanisation has been quantified through a recently compiled Red List. Here, for 717 macro‐moth species, we calculated relative changes in distribution area between a reference period (1980–2012) and the subsequent period (2013–2022). By correlating these species‐specific trends with 10 key ecological and life history traits, we calculated more general Multi‐Species Change Indices (MSCIs). These MSCIs showed that species associated with wet biotopes and heathlands declined on average by 20%–25%, while (sub)urban species increased by more than 60%. Species feeding on lichens or mosses increased by 31%, while grass‐feeding species decreased by 20%. Both very small (+34%) and very large species (+15%) increased, whereas medium‐sized species decreased by 5%. Monophagous (+17%), migrant (+88%) and colour‐invariable species (+5%) increased, while colour‐variable species decreased (−8%). Finally, Holarctic (−21%) and Palaearctic species (−5%) decreased, while Mediterranean (+27%) and Western‐Palaearctic species (+9%) increased. Our trait‐based approach identifies key threats and mitigation strategies for moths in anthropogenic regions, offering evidence‐based insights for crafting efficient management recommendations and informed conservation policies to safeguard moth communities.

Influence of host plant on the wing shape of Bactrocera cucurbitae and Bactrocera tau (Diptera: Tephritidae)

ABSTRACT Bactrocera fruit flies are a significant pest of fruits and vegetables. Some of them are polyphagous and show rapid reproduction. Our study evaluated the impact of three host plants: bottle gourd (Lagenaria siceraria), ridge gourd (Luffa acutangula), and cucumber (Cucumis sativus) on the shape and size of the wings of Bactrocera cucurbitae and B. tau by using geometric morphometrics. The wings of females were significantly larger than those of males, and the wings of B. cucurbitae were significantly smaller than those of B. tau. Individuals feeding on different host plants did not differ significantly in wing size. Wing shape differed significantly both between sexes and between species. Differences in wing shape between males and females were larger than differences between B. cucurbitae and B. tau. Wing shape can be used to identify males and females of the two species without errors. Wing shape differed significantly between males of the two species feeding on cucumber and bottle gourd. Wing shape can be used to identify males of B. cucurbitae and B. tau feeding on those two host plants without errors.

Does weed infestation alter the population density of harmful leafhopper species in second crop maize?

Weed-insect interaction has been studied for decades to determine the role of weeds in insect infestation. This study investigated the impact of weed density on the population density of important leafhopper species (Cicadellidae: Hemiptera) and their egg parasitoid Anagrus atomus (L.) (Hymenoptera: Chalcidoidea) in maize (Zea mays L.) planted as second crop in Şanlıurfa province, Türkiye during 2022 and 2023. Population densities of harmful leafhopper species, i.e., Zyginidia sohrab (Zachvatkin), Empoasca decipiens (Paoli), Asymmetrasca decedens (Paoli), Psammotettix striatus (Linnaeus), and their parasitoid, i.e. A. atomus were monitored by yellow sticky traps (RAL-1016) under weedy and weed-free conditions. Three traps were hung in each experimental unit and the densities of target species were recorded weekly. The population densities of leafhopper species feeding on Sorghum halepense (L.) (Johnsongrass) and the effect of A. atomus on their population density were also determined in weedy treatment. A total 15 maize leaves were taken from both weedy and weed-free treatments, and S. halepense leaf tissues containing leafhopper eggs parasitized by A. atomus were counted weekly. Weed density had non-significant effect on the population density of Z. sohrab during both years. Contrastingly, increasing weed density increased the population density of E. decipiens &amp;amp; A. decedens complex in 2022. Nevertheless, weed density had non-significant effect on the population density of E. decipiens &amp;amp; A. decedens complex during 2023. Weedy treatment recorded higher population density of P. striatus (140 and 100 adults, respectively); however, both weedy and weed-free treatments recorded similar density (125 and 97 adults) during 2023. Weed density proved a significant factor in increasing A. atomus density. A total of 2935 parasitized eggs were recorded from the weedy treatment, whereas 1609 parasitized eggs were recorded from weed-free treatment. Although direct relationship between leafhoppers and weed density remains uncertain, integrated pest management strategies must consider phytophagous insects feeding on weeds at field edges and within fields and the natural enemy complex.

Resource manipulation reveals interactive phenotype-dependent foraging in free-ranging lizards.

Recent evidence suggests that individuals differ in foraging tactics and this variation is often linked to an individual's behavioural type (BT). Yet, while foraging typically comprises a series of search and handling steps, empirical investigations have rarely considered BT-dependent effects across multiple stages of the foraging process, particularly in natural settings. In our long-term sleepy lizard (Tiliqua rugosa) study system, individuals exhibit behavioural consistency in boldness (measured as an individual's willingness to approach a novel food item in the presence of a threat) and aggressiveness (measured as an individual's response to an 'attack' by a conspecific dummy). These BTs are only weakly correlated and have previously been shown to have interactive effects on lizard space use and movement, suggesting that they could also affect lizard foraging performance, particularly in their search behaviour for food. To investigate how lizards' BTs affect their foraging process in the wild, we supplemented food in 123 patches across a 120-ha study site with three food abundance treatments (high, low and no-food controls). Patches were replenished twice a week over the species' entire spring activity season and feeding behaviours were quantified with camera traps at these patches. We tracked lizards using GPS to determine their home range (HR) size and repeatedly assayed their aggressiveness and boldness in designated assays. We hypothesised that bolder lizards would be more efficient foragers while aggressive ones would be less attentive to the quality of foraging patches. We found an interactive BT effect on overall foraging performance. Individuals that were both bold and aggressive ate the highest number of food items from the foraging array. Further dissection of the foraging process showed that aggressive lizards in general ate the fewest food items in part because they visited foraging patches less regularly, and because they discriminated less between high and low-quality patches when revisiting them. Bolder lizards, in contrast, ate more tomatoes because they visited foraging patches more regularly, and ate a higher proportion of the available tomatoes at patches during visits. Our study demonstrates that BTs can interact to affect different search and handling components of the foraging process, leading to within-population variation in foraging success. Given that individual differences in foraging and movement will influence social and ecological interactions, our results highlight the potential role of BT's in shaping individual fitness strategies and population dynamics.

Hydro-ecological modelling of a hypersaline lagoon ecosystem (Pulicat) in Southeast coast of India

Climate change impacts the coastal lagoons and can affect various species reproductive cycles, feeding habits, and survival. Due to natural factors, the ecosystem habitat at Pulicat Lagoon on the east coast of India is under severe stress. This study assesses the ecosystem using a numerical model and field-collected physical, chemical, biological, and meteorological data for 2018 and 2019. A coupled hydro-ecological model was used to analyze circulation features, biological and chemical interactions, and transformation processes. The study indicates that high abnormalities in the lagoon ecosystem are caused by less exchange of fresh/coastal water from river sources and sea mouths due to less rainfall during the study period. The model output depicts the salinity variation from 15 to 58 PSU in different seasons of 2018 and 2019. Furthermore, high concentrations of Chl-a ranged from 50 μg/L to 95 μg/L during the monsoon and post-monsoon seasons, triggering phytoplankton C (70–350 mg/m3) and zooplankton C (9–43 mg/m3) at the Lagoon, resulting in an algal bloom. The monsoonal shift of Chlorophyte (9.52%–9.68%), Cyanobacteria (13.22%–14.95%), Diatoms (66.08%–63.87%), and Dinoflagellates (11.18%–11.51%) is observed in the biological field, with Diatom showing the highest abundance (65%). As a result, appropriate scenario-based model studies were conducted to conserve and strengthen the ecosystem during such extreme events. The model studies suggest that widening the lagoon inlet (800m) with a depth of 5 m (3 km length) increases the optimal tidal exchange to the ecosystem. The model output demonstrates the optimal exchange that normalizes the salinity from 12 to 34 PSU from the inner Lagoon to the mouth region. This study will support environmental authorities in conserving the ecosystem through proper management adaptations.