Human-altered Habitats Research Articles

Shark shuffle: segregated co-occurrence of multiple dusky and sandbar lineages at a human-altered habitat in the eastern Mediterranean Sea

Requiem sharks (genus Carcharhinus) have previously been reported to form large aggregations around marine infrastructures in the eastern Mediterranean Sea. While this behaviour may offer fitness advantages at the individual level, the implications of extended residency at human-altered habitats for population persistence have yet to be assessed. In this work, we investigated the phylogeographic and demographic composition of sharks near a coal-fired power and desalination station in Israel. Our aim was to infer habitat use and the mechanisms underlying the aggregation behaviour, and to highlight potential conservation impacts. We sampled, measured, and released 70 individuals between 2016 and 2022 to assess genetic variability within the cytochrome C oxidase I (COI) region and to analyse the aggregation’s structure based on the sharks’ size and sex distribution. In addition, we performed meristic counts on a reference specimen collected dead at another power station in Israel to supplement species identification using the abovementioned techniques. Our findings indicate size-based sex segregation of adult female dusky and male sandbar sharks (Carcharhinusobscurus and Carcharhinusplumbeus, respectively), with each species comprising two COI haplotypes. In the dusky shark, one haplotype corresponded to an Indo-Pacific lineage, and the other matched an Atlantic lineage. In the sandbar shark, we observed a haplotype previously sampled in the Mediterranean Sea, the Red Sea, the Northwest Indian Ocean, and South Africa, and another haplotype that was unique to our study site and genetically closer to the former than to sequences sampled in other ocean basins. This study provides the first indication of sympatric aggregation amongst phylogeographically distinct dusky and sandbar shark lineages, suggesting that human-altered habitats in the eastern Mediterranean Sea may influence the distribution of these species. Based on the observed segregation pattern, we conclude that the site does not function as a nursery, parturition, or mating area, and discuss other plausible explanations that warrant further research. Finally, we highlight important directions for future research and the implications of our findings for management and conservation.

Edge effects and social behavior in three platyrrhines.

Social behavior is a key adaptation for group-living primates. It is important to assess changes to social behavior in human-impacted landscape zones to better understand the impact of anthropogenic disturbance on primate species. We investigated social behavior rate and type in three species of platyrrhines across 100 m anthropogenic edge and interior zones of a fragmented forest in Costa Rica, La Suerte Biological Research Station (LSBRS). Following results from other sites, we predicted that spider monkeys (Ateles geoffroyi), capuchin monkeys (Cebus imitator) and howler monkeys (Alouatta palliata) would show lower rates and fewer types of social behavior in forest edge compared to interior. We collected 1341 h of instantaneous focal data from 2017 to 2023 across the three monkey species. We found mixed support for our predictions, with spider and capuchin monkeys modifying some but not all aspects of social behavior across forest zones at LSBRS. Spider monkeys had lower rates of social behavior and capuchin monkeys performed different types of social behaviors in forest edge compared to interior at LSBRS. In contrast, howler monkeys did not modify social behavior. Two out of three platyrrhine species altered their social behavior when in anthropogenic edges, indicating behavioral adjustment when in human-altered habitat areas at LSBRS.

Ground beetles (Coleoptera: Carabidae) of Akimiski Island, Nunavut, Canada

Abstract In many regions of Canada, knowledge of the distribution of insect species is far from complete. This knowledge gap, known as the Wallacean Shortfall, is often manifest by species records separated by large, often remote areas with no records. Paradoxically, these difficult-to-access areas offer the best opportunity to study unaltered native community assemblages. Such gaps in knowledge are exemplified by ground beetles, a well-known group, yet with record gaps in many unstudied areas of Canada, including Akimiski Island, Nunavut. This postglacial rebound island, located in James Bay, has no permanently occupied human dwellings and almost no human-altered habitat. Using a combination of pitfall-malaise traps, pitfall traps, and hand captures during 2008–2014, we collected 1368 ground beetles (Coleoptera: Carabidae) as part of a larger biodiversity survey. We identified 31 species, 29 of which were first territorial records for Nunavut. Our results almost double the number of Carabidae known from Nunavut and extend the known range of eight other species. Seventeen of the species that we caught cannot fly, evidence for colonists arriving on Akimiski on floating debris. Our study fills substantial range gaps and serves as baseline information to detect future change.

Successional Changes in Vegetation Communities near Mine Pits

This study investigates demutational changes in plant communities of phosphorite mines between 2005 and 2021. A total of 23 plant species were initially found in the surveyed areas in 2005, while 68 species were identified in spring 2021. The plant communities were categorized into five different groups, with the older communities (No. I and II) exhibiting richer vegetation and greater diversity. Community No. III comprised various cereals, legumes, orchid plants, and mosses. Dominant species in community No. I included Betula pubescens, Carpinus betulus, Quercus robur, and Picea obovata, while community No. II featured Juniperus communis, Larix sibirica, Pinus sylvestris, and Abies sibirica. Erosion was observed in community No. V on slopes of different ages. The study also found changes in physicochemical indices, such as increased organic matter concentration and decreased pH value (4.9). The basal respiration rate of the pit soil was low (around 0.4 mg CO2/m2/h), and carbonate content ranged from 0.06 to 0.9%. This study presents novel data on the dynamics of species composition, plant community structure, and physicochemical soil parameters in human-altered habitats, thereby contributing to the expansion of our knowledge of vegetation recovery and evolution in such environments.

Diversity and abundance of avifauna in the Suba Forest area, central Ethiopia

Birds are one of the best-described taxa, but detailed knowledge about most bird species in Ethiopia remains rare, which hinders the development and evaluation of conservation strategies in the region. In this study, we estimated bird species diversity and abundance in the Suba Forest area (comprising natural forest and adjacent plantation forest and farmland) in central Ethiopia, during the dry and wet seasons in 2021. Bird data were collected using line transects or point counts in each habitat type. Two-way ANOVA was applied to evaluate the effect of habitat and season on bird species richness and abundance. A total of 132 bird species belonging to 51 families were recorded during the study. Of these, 124 are residents, 4 are endemic to Ethiopia, 11 are endemic to Ethiopia and Eritrea, and 4 are near endemics (one largely confined to Ethiopia and the others with their core populations in Ethiopia and Eritrea). Habitat type and season both had significant effects on species abundance and richness. Species diversity was highest in natural forest during the wet season, and lowest in farmland during the dry season. Plantation forest and farmland shared similar avian communities, with both being human-altered habitats in close proximity to each other. Native forest supported the highest number of bird species, which confirms the Suba Forest area’s great potential for biodiversity conservation and sustainable wildlife tourism. Continuous monitoring of this area and effective implementation of conservation measures will provide beneficial outcomes for not only avifauna but other taxa.

Factors Affecting Nest Site Selection by Freshwater Turtles: A Systematic Review

Nest site selection is an important behavior, particularly in species that lack parental care, as nest microclimate can greatly impact embryos’ survival and offspring phenotype. Understanding which factors influence oviposition decisions is critical to identifying priority areas for conservation. This systematic review aimed to synthesize the factors that affect nest site selection by freshwater turtles. The search was conducted in the Web of Science database. In total, 35 publications met the eligibility criteria. The first study on the topic was published more than three decades ago, but only within the last ten years have studies started to be published annually. More than half of the studies were conducted in the United States and the most studied species was Chrysemys picta. Environmental factors, mainly vegetation characteristics, but also soil properties and beach morphology, are the most studied. Anthropogenic factors have been increasingly studied, especially residential areas and agricultural fields. Some studies suggest that human-altered habitats may act as ecological traps, emphasizing the need for further research on this topic. More studies are also needed on the influence of predation risk, co-species cues, female size, and offspring phenotype on nest site selection by freshwater turtles. We highlight that understanding the factors affecting nest site selection is important for identifying the habitat needs of nesting females, predicting possible ecological implications of nest site choice, assessing the adaptive potential of species to environmental change, and determining the vulnerability of populations to different threats.

The role of climate change and niche shifts in divergent range dynamics of a sister-species pair.

Species ranges are set by limitations in factors including climate tolerances, habitat use, and dispersal abilities. Understanding the factors governing species range dynamics remains a challenge that is ever more important in our rapidly changing world. Species ranges can shift if environmental changes affect available habitat, or if the niche or habitat connectivity of a species changes. We tested how changes in habitat availability, niche, or habitat connectivity could contribute to divergent range dynamics in a sister-species pair. The great-tailed grackle (Quiscalus mexicanus) has expanded its range northward from Texas to Nebraska in the past 40 years, while its closest relative, the boattailed grackle (Quiscalus major), has remained tied to the coasts of the Atlantic Ocean and the Gulf of Mexico as well as the interior of Florida. We created species distribution and connectivity models trained on citizen science data from 1970-1979 and 2010-2019 to determine how the availability of habitat, the types of habitat occupied, and range-wide connectivity have changed for both species. We found that the two species occupy distinct habitats and that the great-tailed grackle has shifted to occupy a larger breadth of urban, arid environments farther from natural water sources. Meanwhile, the boattailed grackle has remained limited to warm, wet, coastal environments. We found no evidence that changes in habitat connectivity affected the ranges of either species. Overall, our results suggest that the great-tailed grackle has shifted its realized niche as part of its rapid range expansion, while the range dynamics of the boat-tailed grackle may be shaped more by climate change. The expansion in habitats occupied by the great-tailed grackle is consistent with observations that species with high behavioral flexibility can rapidly expand their geographic range by using human-altered habitat. This investigation identifies how opposite responses to anthropogenic change could drive divergent range dynamics, elucidating the factors that have and will continue to shape species ranges.

Antimicrobial-Resistant Bacteria Carriage in Rodents According to Habitat Anthropization.

It is increasingly suggested that the dynamics of antimicrobial-resistant bacteria in the wild are mostly anthropogenically driven, but the spatial and temporal scales at which these phenomena occur in landscapes are only partially understood. Here, we explore this topic by studying antimicrobial resistance in the commensal bacteria from micromammals sampled at 12 sites from a large heterogenous landscape (the Carmargue area, Rhone Delta) along a gradient of anthropization: natural reserves, rural areas, towns, and sewage-water treatment plants. There was a positive relationship between the frequency of antimicrobial-resistant bacteria and the level of habitat anthropization. Although low, antimicrobial resistance was also present in natural reserves, even in the oldest one, founded in 1954. This study is one of the first to support the idea that rodents in human-altered habitats are important components of the environmental pool of resistance to clinically relevant antimicrobials and also that a "One Health" approach is required to assess issues related to antimicrobial resistance dynamics in anthropized landscapes.

Evaluating the impact of caribou habitat restorationon predator and prey movement.

Fragmentation of the boreal forest by linear features, including seismic lines, has destabilized predator-prey dynamics, resulting in the decline of woodland caribou (Rangifer tarandus caribou) populations. Restoration of human-altered habitat has therefore been identified as a critical management tool for achieving self-sustaining woodland caribou populations. However, only recently has testing of the response of caribou and other wildlife to restoration activities been conducted. Early work has centered around assessing changes in wildlife use of restored seismic lines. We evaluated whether restoration reduces the movement rates of predators and their associated prey, which is expected to decrease predator hunting efficiency and ultimately reduce caribou mortality. We developed a new method for using cameras to measure fine-scale movement by measuring speed as animals traveled between cameras in an array. We used our method to quantify speed of caribou, moose (Alces alces), bears (Ursus americanus), and wolves (Canis lupus) on treated (restored) and untreated seismic lines. Restoration treatments reduced travel speeds along seismic lines of wolves by 1.38km/h, bears by 0.55km/h, and caribou by 1.57km/h, but did not reduce moose travel speeds. Reduced predator and caribou speeds on treated seismic lines are predicted to decrease encounter rates between predators and caribou and thus lower caribou kill rates. However, further work is needed to determine whether reduced movement rates result in reduced encounter rates with prey, and ultimately reduced caribou mortality.

Keeping it cool to take the heat: tropical lizards have greater thermal tolerance in less disturbed habitats.

Global climate change has profound effects on species, especially those in habitats already altered by humans. Tropical ectotherms are predicted to be at highrisk from global temperature increases, particularly those adapted to cooler temperatures at higher altitudes. We investigated how one such species, the water anole (Anolis aquaticus), is affected by temperature stress similar to that of a warming climate across a gradient of human-altered habitats at high elevation sites. We conducted a field survey on thermal traits and measured lizard critical thermal maxima across the sites. From the field survey, we found that (1) lizards from the least disturbed site and (2) operative temperature models of lizards placed in the least disturbed site had lower temperatures than those fromsites with histories of human disturbance. Individuals from the least disturbed site also demonstrated greater tolerance to high temperatures than those from the more disturbed sites, in both their critical thermal maxima and the time spent at high temperatures prior to reaching critical thermal maxima. Our results demonstrate within-species variability in responses to high temperatures, depending on habitat type, and provide insight into how tropical reptiles may fare in a warming world.

Habitat-Patch Occupancy of Western Screech-Owls in Suburban Southern California

Many predators can adapt to human-altered habitats, but varying responses to human activity mean that the findings of studies of a species in one region may not apply even to related species at other locations. The Eastern Screech-Owl (Megascops asio) has been extensively studied in suburban environments, but comparatively little research has investigated to what extent the closely related Western Screech-Owl (M. kennicottii) persists in developed areas. I studied Western Screech-Owl occupancy in the town of Alpine in the foothills of San Diego County, California, finding the species at the majority of sites sampled, more likely in larger wooded patches and in those adjacent to undeveloped chaparral. The distance to and size of nearby wooded patches did not statistically influence occupancy. This study confirmed that the Western Screech-Owl can persist in suburban residential areas as does its eastern relative. Ensuring that patches of woodland remain larger than the minimum modeled threshold for the Western Screech-Owl’s occupancy, 4.2 ha, will be important for its persistence in the suburban sprawl of Alpine.

Does Living in Human-Altered Environments Affect Life-History and Personality of Wild Mice?

In urban habitats, animals are faced with different and often challenging environmental conditions compared to their native habitats. Behavior is the fastest response to environmental change and therefore a very important component to adjust to human-altered environments. Behaviors such as novelty responses and innovativeness which allow animals to cope with novel stimuli are often altered in urban populations. The mechanisms producing such adaptations are currently not well understood. In this study, we investigate whether urban living has an impact on the microevolution of mouse behavioral and life-history traits including boldness, stress-coping, growth, longevity, and emphasis on reproduction. We hypothesized that animals living together with humans for longer show increased novelty-seeking and boldness characteristics at the species and subspecies level. We, therefore, compared behavior and life history characteristics among Mus musculus, a commensal rodent, Mus spicilegus as a synanthropic but not commensal, and Apodemus uralensis as a strictly rural species. In addition, we compared three subspecies of M. musculus (in total six populations) that differ in the time living together with humans. Behavioral and life history differences are stronger between populations even of the same subspecies rather than showing a structural trend with the time animals have spent with humans. In addition, species differ in behavior and life history, albeit not in a pattern that suggests an evolutionary adaptation to living in human-altered habitats. We, therefore, suggest that behavioral adaptations of wild mice are geared toward environmental differences such as geographic origin or habitat specifics but not necessarily directly evolve by living together with humans.

The Eurasian badger-generated seed rain drives the natural (re)colonization of vacant human-altered areas by a keystone pioneer palm

Seed dispersal is an essential ecological process for plant (re)colonization, especially in intensively human-altered habitats such as old-fields (i.e. abandoned farmlands) where seed arrival is often limited. Assessment of spatial patterns of mammal-generated seed rain and their matching with the spatial distribution of adult plants provides essential information on the patterns and pace of the (re)colonization processes. For instance, increased seedling survival far from adult plants could indicate density-dependent mortality (Janzen-Connell) effects whereas increased survival close to adult plants could suggest facilitative effects. Here, we characterized during two dispersal seasons the spatial distribution of feces from four frugivorous mammals and quantified its spatial association with the distribution of adult plants of the pioneer Mediterranean dwarf palm (Chamaerops humilis) in two old-fields in southwestern Spain. We also estimated the dispersal kernels of both emerged and surviving seedlings and assessed potential evidence for Janzen-Connell and/or facilitative effects. Using a spatially explicit approach, we revealed strong differences between study sites in the strength and scale of spatial associations between mammal feces with C. humilis seeds and adult dwarf palms, being strongly positive at small scales in one site and slightly positive at larger scales in the other one. Further, we found some evidence of both Janzen-Connell and facilitative effects depending on the study site. Altogether, our results emphasize the central role as seed disperser of the Eurasian badger (Meles meles) in the natural (re)colonization of Mediterranean old-fields and the spatial variations of the underlying mechanisms and demographic consequences for plant populations.

Pollen use by the solitary bee Osmia caerulescens in cherry orchard agroecosystems in Spain

Osmia caerulescens is a solitary bee species commonly found in the Iberian Peninsula that seems well-adapted to altered anthropogenic habitats. Using the post-emergence residues present in 965 brood cells coming from 453 nests (reed stems) from 36 cherry orchards in western Spain, we identified the collected pollen, and studied the diet of the species. We evaluated whether there are differences in the diet over the nest construction and between the developmental stages reached by the offspring, and we tested whether the offspring's body size is influenced by the pollen diet. The pollen from Fabaceae species predominated in the samples, followed by Jasione (Campanulaceae) and Echium (Boraginaceae). We did not find differences in pollen richness and diversity between inner and outer cells nor among the developmental stages reached. However different proportions of Echium and Jasione pollen in individuals at different developmental stages and a positive relationship between pollen diversity and female body size were detected. The results suggest that the availability of flower resources, together with different morphological and chemical pollen traits, play a key role in diet composition and offspring development. Pollen analysis, which provides knowledge about diet breadth, is a useful tool in the study of species adapted to human-altered habitats.

On the habitat use and foraging ecology of the Yellow-headed Brushfinch (Atlapetes flaviceps), an endemic species of conservation concern from Colombia

Natural history information is one of the major knowledge gaps in Neotropical ornithology. Several range-restricted and threatened species in the region are still poorly known, hindering the design of effective conservation programs. Here, we used direct observations collected at 7 localities throughout the Tropical Andes to describe habitat use and foraging ecology of the Yellow-headed Brushfinch (Atlapetes flaviceps), a species of conservation concern and endemic to Colombia. Our observational records (n = 174) indicate that this species mainly occurs in secondary forests and landscape mosaics that include patches of native vegetation and agricultural areas, but it seems to be frequently associated with the presence of regenerating vegetation in early successional stages. We found that the species' diet was mainly composed of fruits and invertebrates, although other items are occasionally included. Although our data suggest the possibility of an association between habitat type and the activity recorded, as well as temporal variation in foraging behavior, this requires more research. Our observations support the idea of this species being tolerant to human-altered habitats, but this needs to be confirmed by measuring habitat-specific productivity and survival. The results presented here not only increase knowledge of this poorly known endemic but can be useful for the subsequent implementation of management strategies aimed at increasing the availability of high-quality habitat.

Risk factors analysis for neglected human rickettsioses in rural communities in Nan province, Thailand: A community-based observational study along a landscape gradient

In this study, we estimated exposure for Scrub typhus (STG), Typhus (TG) and Spotted fever groups (SFG) rickettsia using serology at a fine scale (a whole sub-district administration level) of local communities in Nan Province, Thailand. Geographical characteristics of the sub-district were divided into two landscape types: lowland agricultural area in an urbanized setting (lowland-urbanized area) and upland agricultural area located close to a protected area of National Park (upland-forested area). This provided an ideal contrast between the two landscapes with low and high levels of human-altered habitats to study in differences in disease ecology. In total, 824 serum samples of participants residing in the eight villages were tested by screening IgG ELISA, and subsequently confirmed by the gold standard IgG Immunofluorescent Assay (IFA). STG and TG IgG positivity were highest with seroprevalence of 9.8% and 9.0%, respectively; whereas SFG positivity was lower at 6.9%. Inhabitants from the villages located in upland-forested area demonstrated significantly higher STG exposure, compared to those villages in the lowland-urbanized area (chi-square = 51.97, p < 0.0001). In contrast, TG exposure was significantly higher in those villagers living in lowland-urbanized area (chi-square = 28.26, p < 0.0001). In addition to the effect of landscape types, generalized linear model (GLM) analysis identified socio-demographic parameters, i.e., gender, occupation, age, educational level, domestic animal ownership (dog, cattle and poultry) as influential factors to explain the level of rickettsial exposure (antibody titers) in the communities. Our findings raise the public health awareness of rickettsiosis as a cause of undiagnosed febrile illness in the communities.

Indirect Hemagglutination Test in the Detection of Antibodies against Toxoplasma gondii in Venezuelan Felids

Current knowledge of Toxoplasma gondii infection in Venezuelan ecosystems is limited. Mammals and birds are intermediate hosts and felid species are definitive hosts. In most human-altered habitats, the domestic cat is the predominant definitive host. Cats are important in the epidemiology of T. gondii infection because they are the only hosts that can excrete the environmentally resistant oocysts. Other carnivores can be infected by the consumption of tissue cysts when feeding on infected animals and by incidental ingestion of oocysts from environmental contamination. This study aimed to quantify the values of antibodies for T. gondii in blood serum of some felids species employing the technique of indirect hemagglutination. In the present study, seropositivity of T. gondii was determined in serum of 35 animals (22 stray cats and 13 wild cats) from Venezuela, South America. Antibodies to T. gondii were found in 21 of 22 (95,45 %) stray cats’ titers of 1:64 in four, 1:128 in four, 1:256 in one, 1:512 in one, 1:1024 in three, and 1:2048 or higher in eight. In four of six (66,67 %) ocelots’ titers of 1:64 in one, 1:256 in one, 1:1024 in one, and one with titers 1:2048. In three of four (75,00 %) jaguars’ titers of 1:512 in one, and two with titers 1:2048. The Kruskal-Wallis test showed a statistically significant difference between species (H = 8,413, p = 0,015).

Density-dependent winter survival of immatures in an irruptive raptor with pulsed breeding.

Highly mobile predators can show strong numerical responses to pulsed resources, sometimes resulting in irruptions where large numbers of young invade landscapes at a continental scale. High production of young in irruption years may have a strong influence on the population dynamics unless immature survival is reduced compared to non-irruption years. This could occur if subordinate individuals (mainly immatures) are forced into suboptimal habitats due to density-dependent effects in irruption years. To test whether irruptive individuals had lower survival than non-irruptive ones, we combined necropsy results (N = 365) with telemetry (N = 185) from more than 20years to record timing and causes of mortality in snowy owls (Bubo scandiacus), which irrupt into eastern North America during winter following high breeding output caused by lemming peaks in the Arctic. Mortality was more than four times higher in irruption years than non-irruption years, but only for immatures, and occurred disproportionately in early winter for immatures, but not adults. Mortality was also higher in eastern North America, where owl abundance fluctuates considerably between years, compared to core winter regions of the Arctic and Prairies where populations are more stable. Most mortality was not due to starvation, but rather associated with human activity, especially vehicle collisions. We conclude that immature snowy owls that irrupt into eastern North America are limited by density-dependent factors, such as increased competition forcing individuals to occupy risky human-altered habitats. For highly mobile, irruptive animals, resource pulses may have a limited impact on population dynamics due to low subsequent survival of breeding output during the nonbreeding season.

Leaf litter and rock bag surveys allow for detection and DNA barcoding characterization of diet composition of dusky salamanders

Salamanders are vital components of many aquatic ecosystems food webs and are often found in diverse habitats, including both urban and semi-rural environments. The northern dusky salamander, Desmognathus fuscus is a common salamander found throughout the southeastern United States and is an important predator of aquatic macroinvertebrates. However, very little is known about either diet or suitable survey techniques for this species in human altered habitats, which may vary based on level of urbanization (e.g., are either spring-fed, derived from ponds, modified ditches, etc.). Therefore, we used multiple survey methods (leaf litter bags, novel rock bags, and quadrat sampling) to quantify relative abundance of D. fuscus on Wingate University's campus, in Wingate, North Carolina. We also collected and identified aquatic invertebrates from bag sampling and diet items obtained from gastric lavage of adult salamanders from quadrat sampling. Leaf litter bags contained the highest relative abundance of salamanders (47) compared to rock bags (14), with quadrat sampling yielding primarily adult salamanders. We noted a significant difference among our two sites sampled in salamander relative abundance (Man-Whitney U test = 67.5, p < 0.001), possibly due to reduced water quality, canopy cover, or less available habitat. Aquatic worms represented the most frequent potential food item sampled from both bag types (61.9%), followed by Diptera nymphs (13.7%). Potential food items from leaf and rock bags as well as gastric lavage samples collected from Desmognathus were further identified using DNA barcoding. These food items included a variety of both aquatic and terrestrial invertebrates (annelid worms, springtails, chironomids, carpenter ants, shore flies, wasps, and wood lice). These results indicate urban salamanders may forage both in the stream and in the riparian zone or advantageously consume insects which fall into the stream. This study adds to our body of knowledge on the ecology of salamanders in urban stream environments.

Determination of Nectar Resources through Body Surface Pollen Analysis: A Study with the Stingless Bee Tetragonula iridipennis Smith (Apidae: Meliponini) in West Bengal, India

Knowledge about floral resources is essential for bee management and conservation. Pollen analysis of honey is the most traditional method for determining the nectar resources of a bee species. However, the collection of honey samples is difficult in cavity-nesting natural stingless bee colonies. Furthermore, it is detrimental to the wild bee’s colony and may threaten their survivability. We analyzed adhered body surface pollen of incoming nectar foragers (which were smeared incidentally during nectar foraging) as an alternative method to determine nectariferous flora of Tetragonula iridipennis in West Bengal, India. By this method, we have identified 75 pollen types. The number of obtained pollen types was lower in the human-altered habitats of Midnapore city (44 pollen types) than the semi-natural habitats of Garhbeta (71 pollen types). Excluding a few pollen types of non-nectariferous plants, most of the pollen types came from nectariferous plants of both crop and non-crop species. Non-crop flowering plants (viz. Ailanthus excelsa, Borassus flabellifer, Eucalyptus tereticornis, Lannea coromandelica, Peltophorum pterocarpum, and Tectona grandis) provided a significant amount of nectar to the bee species and, therefore, play an important role in the conservation of the bee species.