Foraging ecology

This essay theorizes venatic taste as a mode of rhetorical invention: phronesis exercised as perceptual acuity, situated judgment, and ecological responsiveness. Modern Industrial Agriculture preempts three topoi-place, edibility, and quantity-that any food system must address, foreclosing the situated judgments such questions invite. Against this molar foreclosure, we trace a genealogy of foraging molecularity through Epicurus, Cicero, Erasmus, and Carolyn Miller, illuminating taste as moderating, reflexive, discerning, and provisional. Alexis Nikole Nelson's "Black Forager" videos enact the phronimos/taster in (urban/civic) practice, weaving situated discovery, Black foodway reclamation, and phronetic restraint into a repeatable public pedagogy. This molecular disposition is what we call venatic taste.

To study the foraging ecology of elephant seals in relation to oceanographic conditions, Satellite-Relayed Data Loggers (SRDL) with an integrated Conductivity-Temperature-Depth (CTD) have been developped by the Sea Mammal Research Unit (University of St Andrews), which autonomously collect and transmit hydrographic profiles (temperature/salinity) in near-real time via Argos satellites. These devices have the potential to provide detailed oceanographic information in logistically difficult areas at comparatively low cost, being therefore highly interesting for the oceanographic community as well. Large efforts for calibrating and validating the huge amount of collected hydrographic data have been constantly made since the first deployments in 2004, as a necessary step to produce data useful for oceanography. When possible, at-sea experiments were performed on ships of opportunity before deployments on seals, consisting in comparing hydrographic profiles from SRDLs with reference prof...

The Holocene archaeology of the South African west coast is arguably the most studied among other coastal stretches in this country. It has helped to understand the shifts in the lifeways and technology of coastal hunter-gatherers in relation to their environment, climate changes and cultural contact with herder groups. Among the momentous and varied records, the appearance of very large shell middens known as ‘megamiddens’ stands out. They are discontinuously distributed along a ~125 km long stretch of coastline from Lamberts Bay and Elands Bay to Paternoster, and date to ca. 3200-2200 cal. BP. Megamiddens around Paternoster are less studied than the two former. The Fisheries Factory Midden in Paternoster is contemporary with two megamiddens in this locality and is the subject of this paper. This site was excavated by Pete Robertshaw in 1975, and here we expand on his observations to make them directly relevant to the megamidden period. New radiocarbon dates position this site a few centuries before 3265 cal. BP to ca. 2760 cal. BP, with last visits happening from ca. 1990 cal. BP to ca. 625 cal. BP. This study reveals a decrease in bovid foraging efficiency and a concomitant and dramatic increase in the procurement of a number of marine resources from the onset of the site occupation until ca. 2760 cal. BP. Several proxy indicators suggest an increasing occupational intensity at this site as group mobility and foraging range shrank to the coastal margin and adjacent plain during this period. This trend was largely reversed soon after ca. 2000 cal. BP.

Wildlife species exhibit changes in behavior, population dynamics, and abundance after disturbances to forests. In western North America, large swathes of dead trees have resulted from unusually large outbreaks of bark beetles (Dendroctonus spp.) over recent decades. For bats, these tree mortality events could be either negative or positive, depending on whether cavities and crevices for roosting increase in response to beetle outbreaks and how the food supply is affected. It is therefore important to determine bat presence and activity in areas with many beetlekilled trees. We examined bat species richness in the southern interior of British Columbia, Canada, in areas with light and severe beetle-kill. We identified six bat species from acoustic recorders; the federally endangered little brown myotis (Myotis lucifugus) had the most detections. Although we surveyed stand-level vegetation, we found no systematic difference between areas identified from government aerial surveys as having had high or low beetle-kill within the previous decade. Neither beetle-kill severity nor the fine-scale vegetation that we measured correlated with bat presence or activity. We conclude that bats in this region use beetle-killed forests and that the severity of beetle-killed trees is neither adversely affecting bat presence or activity, nor enabling increased use by bats of affected forest stands in comparison to activity levels found in other high elevation forests.

Wildlife species exhibit changes in behavior, population dynamics, and abundance after disturbances to forests. In western North America, large swathes of dead trees have resulted from unusually large outbreaks of bark beetles (Dendroctonus spp.) over recent decades. For bats, these tree mortality events could be either negative or positive, depending on whether cavities and crevices for roosting increase in response to beetle outbreaks and how the food supply is affected. It is therefore important to determine bat presence and activity in areas with many beetlekilled trees. We examined bat species richness in the southern interior of British Columbia, Canada, in areas with light and severe beetle-kill. We identified six bat species from acoustic recorders; the federally endangered little brown myotis (Myotis lucifugus) had the most detections. Although we surveyed stand-level vegetation, we found no systematic difference between areas identified from government aerial surveys as having had high or low beetle-kill within the previous decade. Neither beetle-kill severity nor the fine-scale vegetation that we measured correlated with bat presence or activity. We conclude that bats in this region use beetle-killed forests and that the severity of beetle-killed trees is neither adversely affecting bat presence or activity, nor enabling increased use by bats of affected forest stands in comparison to activity levels found in other high elevation forests.

ABSTRACTAim  Tracking technologies are often proposed as a method to elucidate the complex migratory life histories of migratory marine vertebrates, allowing spatially explicit threats to be identified and mitigated. We conducted a global analysis of foraging areas of adult green turtles (Chelonia mydas) subject to satellite tracking (n= 145) and the conservation designation of these areas according to International Union for Conservation of Nature criteria.Location  The green turtle has a largely circumtropical distribution, with adults migrating up to thousands of kilometres between nesting beaches and foraging areas, typically in neritic seagrass or algal beds.Methods  We undertook an assessment of satellite tracking projects that followed the movements of green turtles in tropical and subtropical habitats. This approach was facilitated by the use of the Satellite Tracking and Analysis Tool (http://www.seaturtle.org) and the integration of publicly available data on Marine Protec...

This study examines the extralimital movements of Antarctic seals reaching South America. Through the analysis of records (laboratory databases, published and web sources), we explore the geographic distribution, frequency of each seal species through time and annually, and abundance. The presence of Antarctic seals in South America represents a biologically and ecologically significant phenomenon, with an increasing frequency of documented records in recent decades. This growing pattern of occurrence emphasizes the high dispersal capabilities and extralimital presence of these species, which may be driven by behavioral and ecological differences rather than population abundance. The presence of Antarctic seals raises important considerations for the management of pinniped populations in South America. One critical concern is the potential for pathogen transmission, particularly in the context of emerging infectious diseases such as avian influenza (HPAI), which has recently affected pinnipeds worldwide. Changes in oceanographic conditions, sea ice dynamics, and prey availability due to climate change may alter the non-breeding distribution of Antarctic seals, potentially increasing their contact with South America. Such changes could increase the frequency of occurrences of Antarctic pinnipeds in temperate zones, with broader implications for local food webs, competition, and ecosystem health. The records summarized in this work provide the first comprehensive picture of Antarctic seals in South America and serve as a critical reference point for future studies of spatial and temporal distributions of Antarctic seals. Our contribution also makes this knowledge more accessible for Antarctic seal conservation efforts.

Successful conservation of rare species requires detailed knowledge of the species' distribution. Modeling spatial distribution is an efficient means of locating potential habitats. Cerulean Warbler (Dendroica cerulea, Parulidae) was listed as a Vulnerable Species by the International Union for the Conservation of Nature and Natural Resources in 2004. These neotropical migratory birds breed in eastern North America. The entire population migrates to the northern Andes in South America to spend the nonbreeding period. As part of a larger international conservation effort, we developed spatial hypotheses of the bird's occurrence in South America. We summarized physical, climatic, and recent land-cover data for the northern Andes using ESRI software, ArcGIS. We developed five hypothetical distributions based on Mahalanobis D, GARP, Biomapper, MAXENT, and Domain models. Combining results of the different models on the same map allowed us to design a rigorous strategy to ground-truth the map and thus to identify sites for protection of the species in South America.

In regulated rivers, hydropeaking may create abrupt sub-daily changes in discharge that can rapidly alter fish habitat. Although hydropeaking impacts on juvenile salmonids have been widely studied, short-term effects on foraging by early life stages remain poorly documented. We used a laboratory flume experiment to test how a downramping flow regime and substrate heterogeneity affect the foraging performance of brown trout (Salmo trutta) fry. We exposed fry to four treatments, combining two flow conditions (stable vs. downramping) and two substrates (gravel vs. gravel with cobbles). We quantified individual total prey intake, assessed from stomach contents, and drift-feeding activity from video analyses. Our results showed that the flow treatment had no detectable effect on total prey intake, indicating that both stable and rapid flow reductions did not disrupt shortterm feeding under an adequate food supply. The number of drift-feeding attempts was similar across all treatments. In contrast, the presence of cobbles increased total prey intake, suggesting that structural complexity enhanced intake by providing hydraulic refuges and additional feeding opportunities. Prey intake showed a general size-dependent pattern, with larger fry consuming more prey. Our findings indicate that adding or maintaining fine-scale substrate complexity is a potent enhancer of fry feeding and should be considered as a restoration measure for habitat mitigation in hydropeaking rivers.

Movement within and between prey patches can influence the fitness of a predator, and understanding such foraging decisions is an important topic in ecology. Most research has found sustained foraging in dense prey patches but has focused on the movement of raptorial predators that feed on single prey items, or suspension-feeders foraging on comparatively immobile zooplankton. The goal of this study was to investigate the fine-scale movement of a suspension-feeding marine vertebrate species while foraging for mobile prey. Using animal-borne tags and surface observations, we analyzed the movement of foraging humpback whales Megaptera novaeangliae within and among acoustically detected patches of sand lance Ammodytes spp. in the water column in the southern Gulf of Maine, USA. Analyzing data from 9 whales tagged between 2008 and 2012, we found hierarchical whale foraging movements that paralleled a complex, hierarchically structured prey landscape. For 7 out of 9 whales, feeding bout scales corresponded to prey patch scales. For 6 out of 9 whales, movement between sequential feeding events was not significantly different from distances between neighboring prey schools. Targeting neighboring schools during sequential feeding events, as opposed to sustained foraging in profitable patches, may increase foraging success in marine suspension-feeders targeting mobile prey, which confirms findings from many other marine predator taxa feeding on mobile prey species. Our study presents novel evidence for the high behavioral plasticity of an intermittent suspensionfeeder targeting mobile prey, adapting its movement to the behavior of its prey and the structure of its prey field.

Movement within and between prey patches can influence the fitness of a predator, and understanding such foraging decisions is an important topic in ecology. Most research has found sustained foraging in dense prey patches but has focused on the movement of raptorial predators that feed on single prey items, or suspension-feeders foraging on comparatively immobile zooplankton. The goal of this study was to investigate the fine-scale movement of a suspension-feeding marine vertebrate species while foraging for mobile prey. Using animal-borne tags and surface observations, we analyzed the movement of foraging humpback whales Megaptera novaeangliae within and among acoustically detected patches of sand lance Ammodytes spp. in the water column in the southern Gulf of Maine, USA. Analyzing data from 9 whales tagged between 2008 and 2012, we found hierarchical whale foraging movements that paralleled a complex, hierarchically structured prey landscape. For 7 out of 9 whales, feeding bout scales corresponded to prey patch scales. For 6 out of 9 whales, movement between sequential feeding events was not significantly different from distances between neighboring prey schools. Targeting neighboring schools during sequential feeding events, as opposed to sustained foraging in profitable patches, may increase foraging success in marine suspension-feeders targeting mobile prey, which confirms findings from many other marine predator taxa feeding on mobile prey species. Our study presents novel evidence for the high behavioral plasticity of an intermittent suspensionfeeder targeting mobile prey, adapting its movement to the behavior of its prey and the structure of its prey field.

Movement within and between prey patches can influence the fitness of a predator, and understanding such foraging decisions is an important topic in ecology. Most research has found sustained foraging in dense prey patches but has focused on the movement of raptorial predators that feed on single prey items, or suspension-feeders foraging on comparatively immobile zooplankton. The goal of this study was to investigate the fine-scale movement of a suspension-feeding marine vertebrate species while foraging for mobile prey. Using animal-borne tags and surface observations, we analyzed the movement of foraging humpback whales Megaptera novaeangliae within and among acoustically detected patches of sand lance Ammodytes spp. in the water column in the southern Gulf of Maine, USA. Analyzing data from 9 whales tagged between 2008 and 2012, we found hierarchical whale foraging movements that paralleled a complex, hierarchically structured prey landscape. For 7 out of 9 whales, feeding bout ...

The Smooth-billed Ani Crotophaga ani was introduced to the Galapagos archipelago in the 1960s, since when its population has grown signifi cantly. We studied the dietary items in the gizzards of 56 anis sampled on the island of Santa Cruz. We confi rmed that the diet of C. ani consists primarily of invertebrates and plant material, including native species and non-native invasives. The second most abundant seed in the anis' diet was that of the highly invasive plant, Rubus niveus. Our fi ndings suggest that C. ani poses a threat to the Galapagos ecosystem by dispersing seeds of non-native plants and by competing with other insectivorous species on the islands. Furthermore, the discovery of a Darwin's Finch nestling in the gizzard of one C. ani establishes direct predation by this species on native birds. Contenido de la molleja del Garrapatero aní Crotophaga ani en Santa Cruz, Galápagos, Ecuador. El Garrapatero aní Crotophaga ani fue introducido en el archipiélago de Galápagos en los años 60 y desde entonces su población ha crecido signifi cativamente. Estudiamos los elementos dietarios en las mollejas de 56 garrapateros colectados en la isla de Santa Cruz. Confi rmamos que la dieta de C. ani consiste principalmente de invertebrados y materia vegetal, incluyendo especies nativas e invasoras no-nativas. La segunda semilla más abundante en la dieta de los garrapateros fue la de la planta altamente invasora, Rubus niveus. Nuestras observaciones sugieren que C. ani representa una amenaza al ecosistema de Galápagos ya que dispersa semillas de plantas no-nativas y compite con otras especies insectivoras en las islas. Además, el hallazgo de un pichón de pinzón de Darwin en el gizzard de un C. ani establece la directa predación de esta especie sobre aves nativas. brought to you by CORE View metadata, citation and similar papers at core.ac.uk

The Smooth-billed Ani Crotophaga ani was introduced to the Galapagos archipelago in the 1960s, since when its population has grown significantly. We studied the dietary items in the gizzards of 56 anis sampled on the island of Santa Cruz. We confirmed that the diet of C. ani consists primarily of invertebrates and plant material, including native species and non-native invasives. The second most abundant seed in the anis’ diet was that of the highly invasive plant, Rubus niveus. Our findings suggest that C. ani poses a threat to the Galapagos ecosystem by dispersing seeds of non-native plants and by competing with other insectivorous species on the islands. Furthermore, the discovery of a Darwin’s Finch nestling in the gizzard of one C. ani establishes direct predation by this species on native birds.

Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.

The residence time is the amount of time spent within a predefined circle surrounding each point along the movement path of an animal, reflecting its response to resource availability/quality. Two main residence time-based methods exist in the literature: (1) The variance of residence times along the path plotted against the radius of the circle was suggested to indicate the scale at which the animal perceives its resources; and (2) segments of the path with homogeneous residence times were suggested to indicate distinct behavioral modes, at a certain scale. Here, we modify and integrate these two methods to one framework with two steps of analysis: (1) identifying several distinct, nested scales of area-restricted search (ARS), providing an indication of how animals view complex resource landscapes, and also the resolutions at which the analysis should proceed; and (2) identifying places which the animal revisits multiple times and performs ARS; for these, we extract two scale-dependent statistical measures-the mean visit duration and the number of revisits in each place. The association between these measures is suggested as a signature of how animals utilize different habitats or resource types. The framework is validated through computer simulations combining different movement strategies and resource maps. We suggest that the framework provides information that is especially relevant when interpreting movement data in light of optimal behavior models, and which would have remained uncovered by either coarser or finer analyses. animal movement, movement path analysis, first passage time, foraging behavior.

The residence time is the amount of time spent within a predefined circle surrounding each point along the movement path of an animal, reflecting its response to resource availability/quality. Two main residence time-based methods exist in the literature: (1) The variance of residence times along the path plotted against the radius of the circle was suggested to indicate the scale at which the animal perceives its resources; and (2) segments of the path with homogeneous residence times were suggested to indicate distinct behavioral modes, at a certain scale. Here, we modify and integrate these two methods to one framework with two steps of analysis: (1) identifying several distinct, nested scales of area-restricted search (ARS), providing an indication of how animals view complex resource landscapes, and also the resolutions at which the analysis should proceed; and (2) identifying places which the animal revisits multiple times and performs ARS; for these, we extract two scale-dependent statistical measures-the mean visit duration and the number of revisits in each place. The association between these measures is suggested as a signature of how animals utilize different habitats or resource types. The framework is validated through computer simulations combining different movement strategies and resource maps. We suggest that the framework provides information that is especially relevant when interpreting movement data in light of optimal behavior models, and which would have remained uncovered by either coarser or finer analyses. animal movement, movement path analysis, first passage time, foraging behavior.

The residence time is the amount of time spent within a predefined circle surrounding each point along the movement path of an animal, reflecting its response to resource availability/quality. Two main residence time‐based methods exist in the literature: (1) The variance of residence times along the path plotted against the radius of the circle was suggested to indicate the scale at which the animal perceives its resources; and (2) segments of the path with homogeneous residence times were suggested to indicate distinct behavioral modes, at a certain scale. Here, we modify and integrate these two methods to one framework with two steps of analysis: (1) identifying several distinct, nested scales of area‐restricted search (ARS), providing an indication of how animals view complex resource landscapes, and also the resolutions at which the analysis should proceed; and (2) identifying places which the animal revisits multiple times and performs ARS; for these, we extract two scale‐depe...

In winter 2013/2014 a roost of longeared owls in Bojnice Spa (central Slovakia) was formed by two subgroups situated 12 meters apart from each other. The diets of both subgroups and the direction of the owls' departure from the roost were studied at monthly intervals. Owls of the Pinussubgroup left the roost in a significantly different direction compared with the owls in the Piceasubgroup. The common vole was the most hunted prey in both subgroups. However, comparing the alternative prey of the two subgroups, the wood mouse and other mammals were found significantly more often in pellets of the Piceasubgroup, whereas birds were more frequent in pellets of the Pinussubgroup. Our results suggest that the different prey hunted by the two subgroups may be a consequence of diverging hunting areas with different availability of alternative prey species. Abstrakt: V priebehu zimy 2013/2014 bolo zimovisko myšiarok ušatých na lokalite Bojnice kúpele (stredné Slovensko) rozdelené na dve časti, situované 12 metrov od seba. Potrava z oboch častí zimoviska a smer opúšťania zimovísk boli sledované v mesačných intervaloch. Myšiarky z časti zimoviska Pinus opúšťali zimovisko preukazne odlišným smerom ako myšiarky z časti zimoviska Picea. Hraboš poľný bol najčastejšie loveným druhom koristi v oboch častiachzimoviska. Každopádne porovnanie alternatívnej koristi medzi jednotlivými časťami zimoviska ukázalo, že ryšavka krovinná a ostatné cicavce boli preukazne viac lovené v časti Picea, kým vtáky boli preukazne častejšie zastúpene v potrave z časti Pinus. Naše výsledky naznačujú, že rozdielne zloženie koristi medzi dvoma sledovanými časťami zimoviska je prejavom využívania odlišných lovných habitatov s odlišnou dostupnosťou alternatívnych druhov koristi.

In winter 2013/2014 a roost of longeared owls in Bojnice Spa (central Slovakia) was formed by two subgroups situated 12 meters apart from each other. The diets of both subgroups and the direction of the owls' departure from the roost were studied at monthly intervals. Owls of the Pinussubgroup left the roost in a significantly different direction compared with the owls in the Piceasubgroup. The common vole was the most hunted prey in both subgroups. However, comparing the alternative prey of the two subgroups, the wood mouse and other mammals were found significantly more often in pellets of the Piceasubgroup, whereas birds were more frequent in pellets of the Pinussubgroup. Our results suggest that the different prey hunted by the two subgroups may be a consequence of diverging hunting areas with different availability of alternative prey species. Abstrakt: V priebehu zimy 2013/2014 bolo zimovisko myšiarok ušatých na lokalite Bojnice kúpele (stredné Slovensko) rozdelené na dve časti, situované 12 metrov od seba. Potrava z oboch častí zimoviska a smer opúšťania zimovísk boli sledované v mesačných intervaloch. Myšiarky z časti zimoviska Pinus opúšťali zimovisko preukazne odlišným smerom ako myšiarky z časti zimoviska Picea. Hraboš poľný bol najčastejšie loveným druhom koristi v oboch častiachzimoviska. Každopádne porovnanie alternatívnej koristi medzi jednotlivými časťami zimoviska ukázalo, že ryšavka krovinná a ostatné cicavce boli preukazne viac lovené v časti Picea, kým vtáky boli preukazne častejšie zastúpene v potrave z časti Pinus. Naše výsledky naznačujú, že rozdielne zloženie koristi medzi dvoma sledovanými časťami zimoviska je prejavom využívania odlišných lovných habitatov s odlišnou dostupnosťou alternatívnych druhov koristi.

In winter 2013/2014 a roost of long-eared owls in Bojnice Spa (central Slovakia) was formed by two subgroups situated 12 meters apart from each other. The diets of both subgroups and the direction of the owls’ departure from the roost were studied at monthly intervals. Owls of the Pinus-subgroup left the roost in a significantly different direction compared with the owls in the Picea-subgroup. The common vole was the most hunted prey in both subgroups. However, comparing the alternative prey of the two subgroups, the wood mouse and other mammals were found significantly more often in pellets of the Picea-sub-group, whereas birds were more frequent in pellets of the Pinus-subgroup. Our results suggest that the different prey hunted by the two subgroups may be a consequence of diverging hunting areas with different availability of alternative prey species.

Describir el crecimiento estatural de una muestra de niños y jóvenes de ambos sexos mediante el modelo 1 de Preece-Baines (PB1) para obtener valores percentilares suavizados que sirvan de referencia. Asimismo, aplicar el PB1 a una serie de muestras históricas, con rangos de edad variables, recopiladas de la bibliografía entre 1896 y 1983, para estimar los cambios seculares. La muestra constaba de 1.525 escolares entre 6 y 18 años. El PB1 se ajustó a las curvas percentilares que se corrigieron para las desviaciones de la normalidad mediante el modelo LMS. Después de aplicar el PB1 a las muestras históricas se han comparado los parámetros que describen el estirón y la talla adulta. La edad del pico del estirón ha resultado de 13,73 años en varones y de 11,02 años en mujeres y la estatura adulta estimada, según el modelo, de 176,22 cm en varones y de 163,53 cm en mujeres. La velocidad promedio de cambio secular en la talla adulta de los varones resultó de 1,2 cm/década. La edad del pico del estirón presenta un adelanto de 0,2 años/década. Al elaborar referencias poblacionales de talla para la edad, el PB1 por sí mismo no logra suavizar los percentiles finales. Pero la aplicación del LMS consigue eliminar la asimetría derecha de la distribución. Sin embargo, el PB1 se adapta al estudio del secular trend para la talla.

The ocellated eagle ray Aetobatus ocellatus is a large elasmobranch that is widely spread in the tropical Indo-West Pacific, and Somalia is the westward limit of its distribution. It is a benthic mesopredator that inhabits shallow waters in coastal ecosystems (i.e., coral reefs, seagrass meadows, lagoons and mangrove-proximate bays) in which it controls invertebrate populations, as well as providing sediment turnover, nutrient cycling and ecosystem engineering. It has K-selected characteristics in life-history such as low fecundity (26 pups per litter), late sexual maturity (15-m disc width), and a short lifespan (15 20 years). A. ocellatus is sometimes taken in artisanal fisheries along the Somali coast, and populations are susceptible to overfishing, habitat degradation, and environmental changes caused by climate change. It is also Vulnerable in the IUCN Red List, which indicates that the management interventions are urgently required. It is suggested that habitat protection, seasonal closures, bycatch mitigation, community-based monitoring, and genetic research to determine population connectivity should be recommended. Preservation of A. ocellatus is consistent with Sustainable Development Goals, especially SDG 14 (Life Below Water), because it focuses on sustainable fisheries, protection of marine biodiversity, and coastal livelihoods. The ecological, genetic and socioeconomic conservation measures should be long-term in conservation to ensure the ecological processes and survival of this endangered ray in Somali waters.

We studied the diet and foraging ecology of a community of six psittacines in western Costa Rica. All had a varied diet with clear seasonal changes in preferred food items, mostly due to changes in plant phenology. There was a significant relationship between parrot mass and food types: larger-bodied parrots consumed more seeds and smaller-bodied parakeets consumed more fruit pulp. Leaves, bark, and lichen were also consumed by most psittacines. Most parrots consumed more plant species in the dry season when food availability was at its peak. Levins' niche breath showed varying levels of diet specialization among species and, for some species, variation among seasons. There was less similarity in seasonal psittacine diets when compared to overall diets. Scarlet Macaws (Ara macao) under study were captive raised and released which may have contributed to their narrow diet breadth as they may have lacked the knowledge or experience to exploit additional food sources. Non-native and cultivated species comprised 76% of the diet of Scarlet Macaws, and averaged 28% for all other species. This suggests that foraging parrots may have increased conflicts with humans as landscapes become increasingly modified. Forest restoration strategies should augment the abundance of food species consumed when overall food supply is at its annual low.

Few data are available that describe the roosting and foraging ecology of the Hoary Bat (Lasiurus cinereus), and no such data are available for the northeastern United States. We captured a juvenile Hoary Bat in south-central New Hampshire during July of 2007 and monitored its roosting behavior for ten days and its foraging behavior for one night. The bat roosted

Citation: Busby, GBJ, D. Gottelli, S. Durant, T. Wacher, L. Marker, F. Belbachir, K. De Smet, A. Belbachir-Bazi, A. Fellous & M. Belghoul. 2006. A Report from the Sahelo Saharan Interest Group – Office du Parc National de l'Ahaggar Survey, Algeria (March 2005) - Part 5: Using ...

Dietary exposures to environmental food pollutants such as mycotoxins have gained enormous significance due to their adverse effects on production and reproduction in animal and human populations. The purpose of this review article is to summarize the most relevant and recent information available on mycotoxins. This includes information about their occurrence, toxicity, clinical signs, diagnosis, treatment and control as well as their significance in feed and food.

heritage have traditionally played a crucial role in the resilience of local communities, and their potentially significant role in addressing future challenges posed by the turbulent changes affecting food systems worldwide . Across millennia, coastal Mediterranean and Near Eastern landscapes have evolved as complex socio-ecological systems, shaped by traditional agroforestry, grazing, and small-scale polyculture, which not only support biodiversity but also facilitate the intergenerational transmission of place-based knowledge . However, the erosion of TEK has become a critical issue as the region faces a phenomenon known as the "Hysteresis Effect", the idea that, once knowledge systems are lost, they may be difficult or impossible to recover, even when conditions for their re-establishment return . The contemporary Mediterranean, however, is undergoing profound transformations. Since the mid-20th

Background: The juvenile stage of loggerhead sea turtles (Caretta caretta) can last for decades. In the North Pacific Ocean, much is known about their seasonal movements in relation to pelagic habitat, yet understanding their multi-year, basin-scale movements has proven more difficult. Here, we categorize the large-scale movements of 231 turtles satellite tracked from 1997 to 2013 and explore the influence of biological and environmental drivers on basin-scale movement. Results: Results show high residency of juvenile loggerheads within the Central North Pacific and a moderate influence of the Earth's magnetic field, but no real-time environmental driver to explain migratory behavior. We suggest the Central North Pacific acts as important developmental foraging grounds for young juvenile loggerhead sea turtles, rather than just a migratory corridor. We propose several hypotheses that may influence the connectivity between western and eastern juvenile loggerhead foraging grounds in the North Pacific Ocean.

ABSTRACT: Grass-feeding termites, Gnathamitermes sp., can be considered beneficial in pastureland, where they aerate topsoil, recycle nutrients from grasses and forbs, and excavate and redistribute soil. The primary objective of this report is to illustrate and determine the average physical dimensions of Gnathamitermes tubiformans soldiers by measuring key body parts, including left mandible length, as well as discuss observed foraging behavior. G. tubiformans soldiers have unique mandibles that can be used for accurate identification. Workers are morphologically similar compared with some other arid-land termite species, thus soldier characteristics are used for identification. The secondary objective is to describe observations of G. tubiformans foraging behavior. This report also provides detailed line drawings and a watercolor illustration for aid in identification. Termites were collected near Temple, Cotton County, Oklahoma, and measured with high precision microscopy. To ens...

Lay Summary Invasive rose-ringed parakeets caused behavioral changes in native garden birds that reduced their feeding rates. Understanding how invasive species impact native species can be complex, especially in urban environments where many other factors are also at play. We therefore used an experiment to disentangle these factors and demonstrate that parakeets are more disruptive than a dominant native competitor.

Aspectos biológicos y ecológicos de Limopsis hirtella (Mollusca; Bivalvia) en la plataforma profunda frente a Mar del Plata (Argentina). Resúmenes del VI Congreso Latinoamericano de Ciencias del Mar: 130. Mendez, J.D. y G.A. Mendez de Cabrera. 1987. Sobre la construcción de un centro de rehabilitación de mamíferos marinos en Argentina. Resumos da Segunda Reunião de Trabalho de Especialistas em Mamíferos Aquáticos da América do Sul: 20.

We studied the foraging ecology of the great grebe Podicephorus major through diet, prey energy return and foraging behaviour across three increasingly marine sites in the coastal lagoon of Mar Chiquita, Argentina. Grebes were followed by focal observations; we recorded dive duration, number of apparent successful and unsuccessful dives, size and type of captured prey and handling time above water.We analysed foraging effort as capture rate (i.e. number of prey eaten per minute) and capture success (i.e. number of successful dives per total dives made); and foraging efficiency as the number of captured prey per foraging time, the total biomass consumed and the energy intake obtained per time. We expected a piscivorous diet, but the most frequent prey were crabs, represented by Cyrtograpsus angulatus and Neohelice granulate, followed by diverse fish species. Diving time for different prey types and foraging sites did not differ. Handling time was higher for crabs. Foraging effort and...

This study investigated the importance of sand knobwood Zanthoxylum leprieurii (family Rutaceae) fruits as a food source for birds in the Tree Heritage Park, Ibadan, Nigeria. We conducted focal observations over three years (2018, 2019, and 2024) during peak fruiting periods, recording bird species foraging on fruits in the canopy and on the forest floor. A total of 4 452 birds from 30 species were observed, with the Red-eyed Dove Streptopelia semitorquata being the most frequent forager (48%). Foraging activity was higher in the morning than evening. Proximate analysis revealed that sand knobwood fruits contain 8.4% moisture, 6.7% ash, 3.5% fat, 11.2% protein, and 33.5% crude fiber, suggesting potential nutritional value for birds. These findings deepen our understanding of the intricate relationships between trees, birds, and ecosystems.

Understanding the botanical composition of herbivores’ diets and their nutritional quality is an important question in the development of sustainable strategies for the management of natural resources. In Chilean highland vicuña-grazed grasslands, there is little information in this regard and, therefore, this study aimed to determine the year-round profile of the diet’s botanical composition and quality. In highland grasslands, on an area of 21.9 ha, continuously grazed for 3.06 VU/ha/year (18°03′ S, 69°13′ W; 4425 m.o.s.l), twelve feces piles were sampled monthly and were analyzed through microhistology, and the nitrogen concentration [NF, OM basis] was determined. The botanical composition, diversity (J) and selectivity index (Ei) of the main species were estimated. Diets were composed of dry–grassland grasses (37.7%), wet–grassland grasses (36.6%), graminoids (14.3%) and forbs (10.2%). The diet diversity ranged from 0.79 (dry–winter) to 0.87 (wet–summer). The main dominant grass...

Dietary tannins are ubiquitous in woody plants and may have serious negative effects on herbivores by inducing a loss of dietary protein and producing toxins if they are hydrolyzed in the gut. Many herbivorous mammals counter the negative effects of tannins through tannin-binding salivary proteins (TBSPs) that inactivate tannins by forming insoluble complexes and prevent them from interacting with other more valuable proteins. Howlers are the most folivorous New World primates and ingest foods with varying tannin content. We studied the presence of TBSPs in six wild mantled howlers (Alouatta palliata mexicana) immediately after capture and in captivity when fed on two diets composed of natural ingredients: a mixture of fruit and leaves or only leaves. Protein concentration was determined in whole saliva samples, followed by gel electrophoresis. We identified two protein bands

The trophic relationships of both the benthic and pelagic communities in the Estuary and Gulf of St Lawrence regions were examined, with a special focus on the trophic position (TP) and relationship(s) among harbour, grey, hooded and harp seals and beluga whales. A multiple stable isotope and multiple tissue approach, used in conjunction with conventional dietary information, suggested that marine mammals occupied the highest trophic positions in the food webs of both communities and that they overlapped with one another to some extent trophically. Harbour seals Phoca vitulina and hooded seals Cystophora cristata occupied the highest TP, grey seals Halichoerus grypus, Gulf harp seals Phoca groenlandica, and male beluga whales Delphinapterus leucas were intermediate, and Estuary harp seals and female beluga whales were at the lowest TP. A general pattern of increasing enrichment of 13 C or 15 N with age was observed in marine mammals (as well as fishes), although yearlings showed a decreased enrichment compared to both younger and older age classes. Sex also influenced δ 15 N values. Males were more 15 N-enriched than females, with the difference between the sexes increasing with age, and being most pronounced in species that are sexually dimorphic with respect to body size. Geographical location also influenced isotope abundance. Estuary organisms were generally 13 C-enriched relative to Gulf animals. δ 13 C values were on average lower in short-term diet integrators (blood serum) than in longer-term diet integrators (red blood cells) of harbour seals captured in April to June in the Estuary, which suggests that they probably did not move outside the Lower Estuary during the winter. Grey seals captured in the Lower Estuary did, however, show evidence of having been in the Gulf region some weeks or months before capture.

Competition between co-existing species for limited resources is considered a main driving force of niche differentiation, including dietary specialization. Responses to interference competition vary, ranging from combat in dominant species to avoidance in submissive ones. Submissive species often show alternative strategies to avoid competition such as quick and efficient resource exploitation or shifts to less competitive resources. In the present study, we have evaluated the potential role of interference competition as driver of dietary specialisation in the mushroom-harvesting formicine ant Euprenolepis procera (Emery, 1900). This ant harvests a broad spectrum of wild-growing mushroom fruiting bodies -an exceptional diet among ants. We asked whether competition avoidance for more typical ant diets could explain the high degree of dietary specialization in E. procera. In baiting experiments at the Ulu Gombak field station, Malaysia, we first showed that E. procera also utilizes alternative food sources (tuna and honey) demonstrating that mushroom-harvesting is not a hard-wired foraging strategy. In contrast to expectations, E. procera's competitive ability for these resources was relatively high compared with other ants in the community. In a second experiment, we offered three resources (honey, tuna, mushroom) simultaneously and close to each other in baiting stations. In the absence of other ants, all three resources were exploited at similarly high rates by E. procera workers. However, E. procera avoided foraging on tuna and honey baits when those baits were utilized by other ants. This context-dependent food choice behaviour in E. procera suggests that the exceptional dietary specialization on wild-growing mushrooms represents a case of competition-induced niche differentiation. Finally, we provide new data about the geographic distribution and about variability in seasonal dietary preferences of E. procera.