Explore the vast range of titles available.

The Honey Badger Algorithm (HBA) is a new swarm intelligence optimization algorithm by simulating the foraging behavior of honey badgers in nature. To further improve its convergence speed and convergence accuracy, an improved HBA based on the density factors with the elementary functions and the mathematical spirals in the polar coordinate system was proposed. The algorithm proposes six density factors for attenuation states based on elementary functions, and introduces mathematical expressions of the polar diameters and angles of seven mathematical spirals (Fibonacci spiral, Butterfly curve, Rose spiral, Cycloid, Archimedean spiral, Hypotrochoid and Cardioid) in the polar coordinate system based on the density factors with the best synthesized effect to replace the foraging strategy of honey badger digging pattern in HBA. By using 23 benchmark test functions, the above improvements are sequentially compared with the original HBA, and the optimization algorithm with the best improvement, α4CycρHBA, is selected to be compared with SOA, MVO, DOA, CDO, MFO, SCA, BA, GWO and FFA. Finally, four engineering design problems (pressure vessel design, three-bar truss design, cantilever beam design and slotted bulkhead design) were solved. The simulation experiments results show that the proposed improved HBA based on the density factors with the elementary functions and the mathematical spirals of the polar coordinate system has the characteristics of balanced exploration and expiration, fast convergence and high accuracy, and is able to solve the function optimization and engineering optimization problems in a better way.

Context Mass-flowering crops have the potential to mitigate the negative effects of agricultural intensification on resource availability for pollinators, but their full utility also depends on pollinators providing consistent pollination services across the entire field. However, the spatial extent of pollination services in mass-flowering fields remains poorly understood, particularly within the landscape context. Objectives We evaluated bumblebee abundance and species richness along the gradient from field edge to center in mass-flowering red clover fields, while also accounting for the composition of the surrounding landscape and field size. Additionally, we examined within-field foraging patterns of individual bumblebee species. Methods Bumblebee species richness and abundance were assessed during peak flowering in 27 clover fields in Estonia, along transects extending from field edge to field center at equal distances. Results Nearly all true bumblebee species (20 of 21) of the national fauna were observed to forage on red clover fields. Contrary to our expectations, bumblebee foraging patterns in the studied fields did not show a negative edge-to-center gradient. While species richness did not change within fields, abundance even tended to increase toward the field interior. The responses of individual species varied, ranging from no edge-to-center change ( Bombus lucorum , B. terrestris ) to a decline ( B. pascuorum ). Neither field size nor the composition of surrounding landscape influenced the observed foraging patterns . Conclusions The absence of edge-to-center trends in bumblebee species richness and abundance cautiously suggests that pollination services may be relatively evenly distributed in moderately sized mass-flowering fields within a diverse landscape. Consequently, field size is unlikely to be a major limiting factor for effective pollination in this system.

Human-wildlife conflicts pose a growing threat to biodiversity, particularly when the targeted species plays an ecological keystone role. Mauritius has repeatedly mass-culled an endemic and threatened flying fox species (the Mauritian flying fox; Pteropus niger ) failing the intended objectives of crop protection and elevating the species’ extinction risks. In this context, the ecology of this species should be better understood to develop non-lethal management strategies. Here we investigated foraging patterns of vertebrate frugivores over 24 hour cycles in lychee orchards and backyard gardens. We assessed all agents of damage (mainly flying fox, alien bird, alien mammal) and the temporal variation of flying fox and bird foraging (take and amount eaten relative to fruit ripeness) on lychee trees. The most important frugivores foraging on lychees were flying foxes (78.3%) and birds (16.1%), namely ring-necked parakeets ( Alexandrinus krameri ), red-whiskered bulbuls ( Pycnonotus jocosus ), village weavers ( Ploceus cucullatus ) and common mynas ( Acridotheres tristis ) while damage by alien mammals was negligible (<1%). Flying foxes consumed more fruits in the early night (59%) compared to the late night and this was statistically significant in one orchard and backyards. However, the difference in damage was on average one to three fruits per tree per night. Bird damage at both orchards was highest during the first half of the day (64%). Flying foxes ate fewer fruits towards the end of the fruiting season while birds followed the opposite trend. As fruit ripeness increased from unripe to fully ripe, flying foxes ate 39–42% more lychee pulp per fruit at the two orchards. Parakeets ate 7% more fruit pulp with increasing ripeness at one orchard only. Deliberate disturbances involving smoke, noise or light to deter flying foxes were common in orchards. The weak difference in the extent of flying fox damage to fruits between early and late night suggested at best minor advantages of concentrating deliberate disturbances in early night, and that netting would be a better strategy as it would also protect against diurnal frugivores. Additionally, trees should be protected from the sixth week after fruit set as most damage occurred when fruits were unripe. Such an improved timing of crop protection should play an important role in reducing fruit losses and thereby alleviate the human-wildlife conflict around the flying fox’s diet.

Current phyto-scapes (plant populations in their geo-spatial context) are not exact replicas of past foraging potential, yet they provide valuable data about the carrying capacity or potential of a foraging-scape. Knowledge about contemporary micro-ecologies and ethno-historical plant use can inform on behavioral aspects, should such plants be found in archaeological deposits. It is in this context that we explore existing information (data and literature) to establish the current vegetation types and micro-ecologies around Holley Shelter, KwaZulu-Natal, South Africa, that contains Middle and Later Stone Age occupations. We present the first plant species inventory consisting of > 1500 taxa growing approximately a day’s foraging distance from the site, compiled from records provided by the South African National Biodiversity Institute and other sources. From this list, we generated separate checklists for foodplants ( n  = 450) and plants that have other uses ( n  = 337), to gain insight into the site’s current phyto-fitness potential. The resulting database is intended as a modern proxy for future work on the site’s archaeo-botany and palaeo-climatic reconstructions. The data is also applicable to other sites on the Savanna/Grassland Biomes of southern Africa with records of the same species. Here we use the foodplant checklist and what is known about the edible plant parts, their seasonality and the distribution of some species to speculate about land-use patterns. These hypotheses can be tested for the past with future archaeo-botanical work. We demonstrate that, compared to archaeological sites in the Eastern and Western Cape for which comparable data exist, Holley Shelter is rich in foodplants, and especially so in plant foods that are known to buffer against famine during the periodical droughts of inland South Africa.

Solitary bees build their nests by modifying the interior of natural cavities, and they provision them with food by importing collected pollen. As a result, the microbiota of the solitary bee nests may be highly dependent on introduced materials. In order to investigate how the collected pollen is associated with the nest microbiota, we used metabarcoding of the ITS2 rDNA and the 16S rDNA to simultaneously characterize the pollen composition and the bacterial communities of 100 solitary bee nest chambers belonging to seven megachilid species. We found a weak correlation between bacterial and pollen alpha diversity and significant associations between the composition of pollen and that of the nest microbiota, contributing to the understanding of the link between foraging and bacteria acquisition for solitary bees. Since solitary bees cannot establish bacterial transmission routes through eusociality, this link could be essential for obtaining bacterial symbionts for this group of valuable pollinators. Open Research Badges This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://www.ebi.ac.uk/ena/data/view/PRJEB27223, https://www.ebi.ac.uk/ena/data/view/PRJEB31610, and https://doi.org/10.5061/dryad.qk36k8q We investigated the importance of imported pollen for the solitary bee nest microbiomes, as its inclusion introduces a wide diversity of environmental and primarily floral bacteria. The simultaneous investigation of pollen composition and nest microbiota showed that both bacterial diversity and composition can be influenced by the foraging preferences of each bee species. Also, we were able to suggest associations with specific bacterial taxa as possibly secured through plant visitation. The present study contributes to the understanding of the complex relationships in the plant–pollinator–microbe triangle.

Not all individuals in a population use the same subset of dietary and habitat resources. Patterns of individual specialization have been documented in an increasing number of organisms, but often without an associated time scale over which niche specialization was observed. We examined the patterns in individual resource use through time and in relation to the population with metrics of temporal consistency and degree of individual specialization. We used stable isotope analysis of carbon and nitrogen in successive subsections of scute tissue from the carapace to compare foraging patterns in three successive life stages of the green turtle (Chelonia mydas). Temporal consistency was measured as the mean within-individual variation in stable isotope values through time, whereas the degree of individual specialization was a ratio of the individual variation to that of the population. The distinction between these two parameters is important, as the metric of temporal consistency quantifies the regularity of individual resource use, and the degree of individual specialization indicates what proportion of the population niche an average individual uses. The scute record retains a chronological history of resource use and was estimated to represent a minimum 0.8 years in juveniles to a maximum of 6.5 years in adults. Both temporal consistency and individual specialization varied significantly among life stages. Adults were highly consistent in resource use through time and formed a generalist population with individual specialists maintaining long-term patterns in resource use. Oceanic and neritic juvenile life stages exhibited less temporal consistency in resource use with less individual specialization than adults. These observations are important when considering the ecological roles filled by green turtles in each life stage; also, individual differences in resource use may result in differential fitness consequences.

Diet plays a pivotal role in dictating behavioral patterns of herbivorous animals, particularly specialist species. The giant panda ( Ailuropoda melanoleuca ) is well-known as a bamboo specialist. In the present study, the response of giant pandas to spatiotemporal variation of bamboo shoots was explored using field surveys and GPS collar tracking. Results show the dynamics in panda-bamboo space-time relationships that have not been previously articulated. For instance, we found a higher bamboo stump height of foraged bamboo with increasing elevation, places where pandas foraged later in spring when bamboo shoots become more fibrous and woody. The time required for shoots to reach optimum height for foraging was significantly delayed as elevation increased, a pattern which corresponded with panda elevational migration patterns beginning from the lower elevational end of Fargesia robusta distribution and gradually shifting upward until the end of the shooting season. These results indicate that giant pandas can respond to spatiotemporal variation of bamboo resources, such as available shoots. Anthropogenic interference of low-elevation F. robusta habitat should be mitigated, and conservation attention and increased monitoring should be given to F. robusta areas at the low- and mid-elevation ranges, particularly in the spring shooting season.

The White-Tailed Eagle (WTE) Haliaeetus albicilla is a top avian predator that has rapidly increased in numbers and range in large parts of Europe in recent decades. In Poland, over the past 30 years, it has recolonized previously abandoned areas. In 1991, the first breeding pair in a large forest complex, the Augustów Forest (Northeast (NE) Poland), was recorded. In 2022, there were 13 breeding pairs. We analyzed changes in the diet composition of WTE in 2000–2023, divided into three periods: 2000–2005, 2009–2017, and 2018–2023. Throughout the 24 years of study, birds were the most frequently recorded food item, accounting for an average of 58% of food items, followed by fish (34%) and mammals (7%). During the study period, the most numerous food items were the Northern Pike Esox lucius, Coot Fulica atra, Common Bream Abramis brama, Mallard Anas platyrhynchos, and storks Ciconia sp. These species together accounted for 52% of food items. We recorded a long-term increasing share of Northern Pike, storks, and Great Crested Grebe Podiceps cristatus. Opposite changes, with declining frequency, were found for Coots and ducks. The share of the Coot, ducks, and Great Crested Grebe, as well as the total share of food connected with lakes in the WTE’s diet, increased along the growing area of lakes in the territory of the WTE. The proportion of fish in the food did not show a relationship with the increase in the area of lakes, while the most frequently eaten fish species changed. Observed changes in food composition appear related to the settlement of the habitat-diverse areas by individual breeding pairs and changes the availability of main food categories.

Kelp Gull (Larus dominicanus) foraging patterns were studied by deploying GPS loggers on 20 incubating individuals at their colony in the Bahía San Blas protected area, Argentina. Mean number of trips per day was 1.5 ± 0.5, and mean trip duration was 272.6 ± 165.2 min. Mean maximum distance from the colony was 19.6 ± 24.4 km. Incubating Kelp Gulls visited natural and anthropogenic environments. Individuals switched between two or three different habitat types 47% of the time during a given foraging trip. Kelp Gulls showed a differential use of feeding areas, with a significantly higher use of refuse dumps (75%; n = 151 trips) than coastal (47%), terrestrial (10%) and offshore (10%) habitats. In 72% of the recorded trips, Kelp Gulls targeted the dump located in the small town of Bahía San Blas, where waste generated by recreational fishing is regularly disposed. Moreover, most visited shoreline locations were those regularly used by recreational fishers. Despite showing plasticity in foraging habitat use, the local refuse dump and nearby shoreline sites where fish waste is regularly disposed were the main feeding habitats for incubating Kelp Gulls.

Several populations of Black Skimmers (Rynchops niger), colonial waterbirds with a tactile foraging strategy, are declining. Improving our limited knowledge of Black Skimmer foraging ecology has become critical to inform conservation decisions. Black Skimmers were GPS-tracked from the Isles Dernieres Barrier Island Refuge in coastal Louisiana, USA, from 27 June-1 July 2013 and 30 May-2 June 2016, to shed light on their foraging movements during the breeding season. Black Skimmers foraged almost exclusively at night, as far as 16 km from the colony in the coastal marshes of Louisiana, in a home range of 86-256 km2. Additional movement data are needed to identify areas of conservation need and provide a basis for future studies of skimmer response to environmental changes.