Negative interactions between people and crocodilians have increased worldwide, but in Mexico there have been few systematic reports and no rigorous evaluation of this problem. We compiled information on negative interactions between people and the spectacled caiman Caiman crocodilus and American crocodile Crocodylus acutus from the Worldwide Crocodilian Attack Database for 1993–2018, and we investigated interactions in greater depth, through interviews with people in La Encrucijada Biosphere Reserve. We examined the relationship between the occurrence of negative interactions between people and C. acutus and the species' nesting season and abundance, and presence records. In Mexico, the frequency of negative interactions increases when anthropogenic activities occur close to nesting sites (< 30 km) and during the nesting season (February–September). In La Encrucijada, following negative interactions with crocodiles, the local inhabitants killed 30 crocodiles measuring > 2.5 m long in 2011–2012. The frequency of negative human–crocodilian interactions was not correlated with the abundance of crocodilians but was correlated with the number of presence records of crocodiles. Strategies to minimize these interactions include warnings at nesting sites, increased monitoring of anthropogenic activities during the nesting season, and management of nests to prevent them being destroyed by people.

Pelagic seabird populations have declined strongly worldwide. In the North Atlantic there was a huge reduction in seabird populations following the European colonization of the Azores, Madeira and Canary archipelagos but information on seabird status and distribution for the subtropical region of Cabo Verde is scarce, unavailable or dispersed in grey literature. We compiled and compared the historical and current distribution of all seabird species breeding in the Cabo Verde archipelago, updated their relative abundance, investigated their inland habitat preferences, and reviewed their threats. Currently, the breeding seabird community in Cabo Verde is composed of Bulwer’s Petrel Bulweria bulwerii, White-faced Storm-petrel Pelagodroma marina aedesorum, Cape Verde Shearwater Calonectris edwardsii, Cape Verde Storm-petrel Hydrobates jabejabe, Cape Verde Petrel Pterodroma feae, Boyd's Shearwater Puffinus lherminieri boydi, Brown Booby Sula leucogaster, and Red-billed Tropicbird Phaethon aethereus. One breeding species is currently extinct, the Magnificent Frigatebird Fregata magnificens. The relative abundance of Cape Verde Shearwater, Boyd’s Shearwater, Cape Verde Petrel, and Cape Verde Storm-petrel was determined from counts of their nocturnal calls in Santo Antão, São Vicente, Santa Luzia, Branco, Raso and São Nicolau. Cape Verde Petrel occurred only on mountainous islands (Santo Antão, São Nicolau, Santiago, and Fogo) from mid-to high elevations. Larger species such as the Cape Verde Shearwater and Boyd’s Shearwater exhibited a wider distribution in the archipelago, occurring close to the coastline but at lower densities on populated islands. Small procellariforms such as the Cape Verde Storm-petrel occurred at high densities only on rat-free islets and in steep areas of main islands where introduced cats and rats are unlikely to occur. The main threats to seabird populations in Cabo Verde range from predation by introduced predators, habitat alteration or destruction, and some residual human persecution.

The coastal waters of east Lewis from the Butt of Lewis to Loch Erisort are a proposed Marine Protected Area (MPA) for Risso's dolphins (Grampus griseus). A total of 100.4 h (2006.4 km) of active search effort (Beaufort sea states ≤3) was collected during 72 dedicated boat surveys between 2010 and 2017 (primarily in August and September) in the southern part of the MPA and south to the Shiant Isles. Forty Risso's dolphin sightings and 24.1 h of encounter effort were recorded, predominantly along the southern and eastern Eye Peninsula in 20–40 m water depths and at distances <1 km from shore. Group size ranged from one to 50 animals (mean = 11.8 dolphins) and calves occurred in 37.5% of sightings. A total of 2404 shore-based scans (Beaufort sea states ≤3) carried out from Tiumpan Head between September 2011 and December 2017 resulted in 271 (11.3%) ‘dolphin-present’ scans. Dolphins were present year-round, with a seasonal increase between May and October. ‘Calf-present’ scans only occurred between April and October. Photo-identification images from 28 boat surveys produced a minimum population size of 117 animals. There was evidence of high inter- and intra-annual site fidelity, with individual dolphins photographically captured in up to six of the eight survey years, and between two and seven capture dates being recorded for over 45% of individuals within most years. The combined datasets support the importance of east Lewis for Risso's dolphins, and recommendations are made for ongoing monitoring of dolphin occurrence throughout the wider MPA.

The effectiveness of protected area management is a major concern. In Taï National Park, Côte d'Ivoire, recurrent human pressure challenges the ability of law enforcement authorities to protect wildlife. During 2010–2015 we studied the implementation of law enforcement in the Park to determine (1) the potential for improvement of the protection of large mammals and (2) the minimum patrolling effort needed to obtain increases in their populations. We recorded presence of large mammals and illegal activities in two areas within the Park, the research area (210 km2) and the rest of the Park (5,150 km2), and compiled data about patrolling efforts from the Park authorities. Using a generalized linear mixed model we identified a relationship between increased patrolling effort and the relative abundance of large mammals, especially for monkey groups, pygmy hippopotamuses Choeropsis liberiensis and duikers. At low patrolling efforts duiker encounter rates remained stable, whereas rates of encounter with monkey groups and pygmy hippopotamuses decreased. Chimpanzee Pan troglodytes verus encounter rates were slower to respond and remained stable at higher patrolling effort, but decreased at low patrolling effort. Our findings suggest that a minimum of 1.32 patrol days per km2 over 2 years is required for chimpanzee and monkey populations to increase, whereas a patrolling effort of 0.48 days per km2 over 2 years would lead to an increase in duiker and pygmy hippopotamus populations. We maintain that the patrolling effort required to ensure an increase in wildlife can be estimated relatively precisely from multi-year biomonitoring programmes.

The diet–microbiota–metabolism relationships during pregnancy are mostly unknown. We explored the effect of the habitual diet and adherence to the dietary reference values on gut microbiota composition and diversity. Further, the association of gut microbiota with serum lipidomics and low-grade inflammation was evaluated. Overweight and obese women (BMI 30·7 (sd 4·4) kg/m2, n 100) were studied at early pregnancy (≤17 weeks). Intakes of nutrients were calculated from 3-d food diaries. Faecal microbiota composition was analysed using 16S rRNA gene sequencing. Fasting serum lipidomic profiles were determined by NMR. High-sensitivity C-reactive protein, glycoprotein acetylation (GlycA) and lipopolysaccharide activity were used as markers for low-grade inflammation. The recommended dietary intake of fibre and fat was related to higher gut microbiota richness and lower abundance of Bacteroidaceae. Correlations were observed between gut microbiota richness and GlycA and between a few microbiota genera and serum lipoprotein particles. As a conclusion, adherence to the dietary reference intake of fat and fibre was associated with beneficial gut microbiota composition, which again contributed to lipidomic profile. Higher gut microbiota richness and nutrient intakes were linked to a lower level of low-grade inflammation marker GlycA. This finding offers novel insights and opportunities for dietary modification during pregnancy with potential of improving the health of the mother and the child.

The ability of Medicago sativa to suppress weed growth may provide a viable alternative to chemical weed control and allow crop producers to reduce herbicide inputs. Quantitative information regarding the suppressive effect of M. sativa on weed populations in current cropping systems is lacking. A survey was conducted in Manitoba, Canada, in 1993 and 1994 to investigate weed populations in commercial cereal fields that had been preceded by either M. sativa hay or cereal grain crops. A total of 117 fields were surveyed; approximately half from each field type. Principle component analysis indicated that the inclusion of M. sativa in crop rotations resulted in weed communities different from those of continuous cereal fields. Naturally occurring populations of Avena fatua, Cirsium arvense, Brassica kaber, and Galium aparine were lower in cereal fields that had previously contained M. sativa than in cereal fields that had been preceded by a cereal crop. Lower field uniformity values for C. arvense and Avena fatua indicated that these weeds were also more patchy in the M. sativa rotations. Population differences between field types were nonsignificant for Amaranthus retroflexus, Chenopodium album, and Polygonum convolvulus, and although populations of Taraxacum officinale and Thlaspi arvense were greater in M. sativa/cereal fields than in continuous cereal crops. No consistent effect of field type on Setaria viridis populations was observed. These results show that M. sativa effectively suppressed some, but not all, of the weeds found in the study area. Including M. sativa hay crops in crop rotations can be part of an integrated weed management strategy for weeds such as A. fatua, B. kaber, and C. arvense.

A weed survey system methodology was developed and used annually for 4 yr in the province of Saskatchewan. Based on a stratified random sampling procedure, fields were selected in wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oat (Avena sativa L.), rye (Secale cereale L.), rape (Brassica napus L., Brassica campestris L.), and flax (Linum usitatissimum L.) crops. The boundaries of the 43 agricultural extension districts in the province formed the strata. The provincial agricultural extension service provided staff to conduct the survey. Computer processing of the data enabled reports, containing summary tables and distribution maps, to be distributed to extension, research, and industry personnel within 3 months after completion of the field survey. The field surveys were conducted late in the growing season before harvest commenced; hence, the weed populations consisted of species that had been present during the early part of the growing season and may have contributed to yield losses. During the 4 yr of the survey, weeds were counted in 4423 fields. Of the 164 species recorded, 97 species occurred in more than three fields. Only 29 species were encountered frequently in the fields. Green foxtail [Setaria viridis (L.) Beauv. # SETVI), wild buckwheat (Polygonum convolvulus L. # POLCO), and wild oat (Avena fatua L. # AVEFA) were the top three species based on a ranking system using a measure called relative abundance.

A weed survey of 115 Nova Scotia lowbush blueberry fields was conducted during the summers of 1984 and 1985 to determine the most common and prevalent weeds associated with blueberry production. A total of 119 weed species were observed within the surveyed blueberry fields. The most common weed species were bunchberry, colonial bentgrass, poverty oatgrass, sheep sorrel, and false lily-of-the-valley. Weeds with low relative abundance in this study, but which may become more widespread, include three-toothed cinquefoil, Kentucky bluegrass, hair fescue, canker-root, and Canadian St. Johnswort.

Knowledge of weed community structure in vegetable crops of the north central region (NCR) is poor. To characterize weed species composition present at harvest (hereafter called residual weeds) in processing sweet corn, 175 fields were surveyed in Illinois, Minnesota, and Wisconsin from 2005 to 2007. Weed density was enumerated by species in thirty 1-m2 quadrats placed randomly along a 300- to 500-m loop through the field, and additional species observed outside quadrats were also recorded. Based on weed community composition, population density, and mean plant size, overall weed interference level was rated. A total of 56 residual weed species were observed and no single species dominated the community of NCR processing sweet corn. Several of the most abundant species, such as common lambsquarters and velvetleaf, have been problems for many years, while other species, like wild-proso millet, have become problematic in only the last 20 yr. Compared to a survey of weeds in sweet corn more than 40 yr ago, greater use of herbicides is associated with reductions in weed density by approximately an order of magnitude; however, 57% of fields appeared to suffer yield loss due to weeds. Sweet corn harvest in the NCR ranges from July into early October. Earlier harvests were characterized by some of the highest weed densities, while late-emerging weeds such as eastern black nightshade occurred in fields harvested after August. Fall panicum, giant foxtail, wild-proso millet, common lambsquarters, and velvetleaf were the most abundant species across the NCR, yet each state had some unique dominant weeds.

With increased reliance on glyphosate for weed control, weed species composition shifts are likely. Changes in relative abundance could arise from differential tolerance or resistance to, or avoidance of, glyphosate. This study characterized the potential changes in seedbank composition of a mixed population of summer annual weeds due to glyphosate application timing. Seven weeds common in soybean fields in the Midwest were introduced at known densities and treated with glyphosate at several treatment timings. Common lambsquarters, common sunflower, common waterhemp, eastern black nightshade, ivyleaf morningglory, shattercane, and woolly cupgrass were selected to represent a range of emergence patterns and tolerances to glyphosate. Seedling emergence and seed production were monitored. Differences in herbicide tolerance and avoidance, through markedly different weed emergence patterns, were strong contributors to projected changes in weed species composition. Lessened sensitivity to glyphosate allowed some emerged species, such as ivyleaf morningglory, to better survive the herbicide. Late emergence allowed others, such as shattercane and ivyleaf morningglory, to avoid glyphosate applications. Such mechanisms may allow specific species to increase in a continuous glyphosate system.

A 6-yr project comparing four cash grain–farming systems relevant to the mid-Atlantic region of the United States was conducted from 1993 to 1999. A wide range of parameters was sampled including soil health, nutrient and agrichemical movement, economic viability, and insect and weed communities. The systems and their approaches to weed management were: continuous no-till corn without (System A1) or with (System A2) rye cover crop and preplanned herbicides based on expected weed infestations; System B was a 2-yr corn–soybean rotation with conventionally tilled corn and no-tillage soybean, with preplanned herbicides based on expected weed infestations; System C was a 2-yr rotation with no-till corn, conventionally tilled wheat, and no-till double-cropped soybean, using postemergence (POST) herbicides on the basis of field scouting; and System D was a 3-yr rotation of corn-soybean-winter wheat with rye and hairy vetch cover crops, using cultivation and reduced rates of POST herbicides based on field scouting. Spring weed assessment in 1999 was similar for species evenness (Shannon's E) and diversity (Shannon's H′) indices. Weed density was lowest in System C because wheat in this system received a spring herbicide application. In the final fall assessment, Shannon's H′ was greater in System D than System C. Common lambsquarters, eastern black nightshade, and jimsonweed were more abundant in System D than Systems A1, A2, and C. Fall 1999 assessment also indicated Canada thistle was more prevalent in Systems A1 and A2 than the other three systems. During the 6-yr period, densities of jimsonweed, eastern black nightshade, morningglory species, crabgrass, and fall panicum dramatically increased in a particular system for 1 to 2 yr, then declined to levels similar to other systems. Overall, weed communities were quite stable and effective weed management did not result in dramatic changes in the weed community, regardless of the approach to cropping systems or weed management.

Approximately 50% of the genetically modified herbicide-resistant corn hectares in the United States are treated only with POST-applied herbicides for weed management. Although a high degree of efficacy can be obtained with POST-applied herbicides, delayed timing of application may result in substantial corn yield loss. Our goal was to characterize on-farm corn–weed communities prior to POST herbicide application and estimate potential corn-yield loss associated with early-season corn–weed competition. In 2008 and 2009, field surveys were conducted across 95 site-years in southern Wisconsin and recorded weed species, density, and height in addition to crop height, growth stage, and row spacing. WeedSOFT® was used to predict corn yield loss. Common lambsquarters, velvetleaf, dandelion, common ragweed, and Amaranthus species were the five most abundant broadleaf weed species across site-years, present in 92, 86, 59, 45, and 44% of all fields, respectively, at mean densities of 19, 3, 3, 4, and 3 plants m−2, respectively. Mean plant heights among these species were 17 cm or less. Grass and sedge species occurred in 96% of fields at a mean density of 25 plants m−2 and height of 7 cm. The mean and median of total weed density across site-years were 96 and 52 plants m−2, with heights of 14 and 13 cm, respectively. Mean predicted corn yield loss was 4.5% with a mean economic loss of $62 ha−1. However, predicted yield loss was greater than 5% on one-third of the site-years, with a maximum of 26%. These results indicate that delayed application of POST herbicides has led to corn yield loss due to early-season weed-crop competition on a substantial number of fields across southern Wisconsin, and suggest that management tactics need to be improved to protect corn yield potential fully.

The Peña Larga site, a rock shelter on the southern slopes of the Cantabrian cordillera (north Spain), is an archeological deposit covering nearly 4000 years, from the early Neolithic to the middle Bronze Age (Atlantic/Subboreal chronozones). It was used both as a household and as a stable, with a hiatus in the Chalcolithic when it was used as a collective sepulcher. Nearly twenty-eight thousand small vertebrate elements were recovered from its seven stratigraphic units, of which 2553 items were identified to the genus and/or species levels. The assemblage is composed of mammals, birds, reptiles, and amphibians. Of these, small mammals were used for paleoenvironmental reconstruction since they are very sensitive to climatic conditions, the sample sizes are large, and their preservation is good. Their distributions over time, measured in terms of relative abundance, serve as reliable proxies of habitat and climate change. The reconstruction of Peña Larga's past environments based on small mammals roughly coincides with the pollen and the amphibian/reptile records on the local scale, and with that of an ice core from Central Greenland on the global scale. This makes it a valuable tool for comparative purposes both in the regional and continental scales.

A field survey was conducted in 2007 to characterize weed populations in different turfgrass sites throughout the Klang Valley of western Peninsular Malaysia. Sites included golf course putting greens, athletic fields, sod farms, and residential lawns. Weeds present in each site were identified and the data were used to calculate frequency, distribution uniformity, density, relative abundance, and community coefficient values for each species. Seventy-nine weed species, belonging to 16 families, were found. The most species were found on residential lawns, and the fewest were found on golf course putting greens; athletic fields and sod farms ranked intermediately. A total of 19 different weed species were classified as major (relative abundance ≥ 15), and abundance rankings varied by turfgrass area. Greater kyllinga had the highest relative abundance values on athletic fields (45.5) and golf course putting greens (71.5), and the second highest value (21.7) on residential lawns. Forked fringerush and annual sedge had the greatest relative abundance values on residential lawns and sod farms, respectively. Cogongrass was reported on 15% of the residential lawns evaluated. The heterogeneity of weed species composition suggests that control strategies will vary by turfgrass use area. Quantifying weed population dynamics will help researchers delineate integrated weed management strategies to turfgrass managers in Malaysia.

The bush dog Speothos venaticus is a medium-sized Neotropical canid. It is considered to be rare and its biology and population parameters are still poorly understood. The Amazon is one of the main strongholds of this species and is important for maintaining viable populations, as the region still holds extensive tracts of pristine habitat. We gathered field data from camera-trap studies throughout the Brazilian Amazon to estimate the relative abundance of the species and gain an understanding of its rarity, and how this compares with estimates from other vegetative formations and for sympatric hypercarnivores. We focused on three pristine or partially disturbed sites and one fragmented site. The estimated relative abundance of the species was 0.060–0.185 individuals per 100 trap-days, confirming that the species is rare. The bush dog's abundance in the Amazon is equivalent to that in all other areas outside the Basin. The mean group size recorded was c. 2.5 individuals. There were no differences in group sizes between forests in the Amazon and in other regions of Central America; however, there were significant differences between forests and open habitats. A combination of competition/predation, habitat structure/integrity, and disease may be acting synergistically in determining the abundance and rarity of bush dogs.

Despite the potential for phenological and abundance data to improve the reliability of species niche models, they are seldom used. The aim of this study was to combine information on the distribution, relative abundance and seasonal phenology of Natal fruit fly, Ceratitis rosa Karsch (Diptera: Tephritidae), in South Africa to model its potential global distribution. Bucket traps, baited with Biolure, were used to trap C. rosa in different climatic regions of South Africa over a two-year period. A CLIMEX niche model of the potential global distribution of C. rosa was fitted using the collected trapping data and other distribution records from South Africa. Independent distribution records for elsewhere in Africa were reserved for model validation. The CLIMEX model results conformed well to the South African trapping data, including information on relative abundance and seasonal phenology, as well as to the pattern of presence records of the species elsewhere in Africa. The model suggests that under recent historical conditions a large part of South America, Central America, Mexico and southern USA may be climatically suitable for establishment of C. rosa. In Europe, climatically suitable habitat is restricted to coastal regions of the Mediterranean, in Asia, mostly to the southern and south eastern countries, and in Australia mostly to the wetter south and east. The independent cross-validation provided by South African relative abundance and seasonal phenology data, central African distribution data and relevant species specific biological information provides greater confidence in the modelled potential distribution of C. rosa.

The distribution of bloom-forming cyanobacteria in eutrophic to hypereutrophic ponds was studied in northern Taiwan in 2009. Eighty-four ponds were sampled in mid-summer, and the relationship between colony size and relative abundance of each cyanobacterial species was analyzed. Anabaena crassa and Cylindrospermopsis raciborskii were the dominant species in terms of frequency of appearance. The colony size of An. crassa increased significantly with its relative abundance. The relative abundance of C. raciborskii was usually below 10%, and its filament length was not correlated with its relative abundance. The colonies of Microcystis aeruginosa normally consisted of several tens of cells. However, when M. aeruginosa exclusively dominated the plankton community, the average number of cells in a colony reached several hundreds. The mean filament length of Planktothricoides raciborskii significantly increased with its relative abundance. The correlations between colony size and relative abundance of the ten cyanobacterial species were significantly positive for three species, insignificantly positive for five species and insignificantly negative for two species. Given the various ecological advantages of large colonies, the results of this study may suggest that the formation of large colonies of some cyanobacterial species is important to their dominance and/or bloom formation.

Information on cetaceans off Gabon in tropical West Africa is summarized from boat-based surveys carried out between 7 March and 7 August 2009. Thirteen cetacean species were positively identified comprising two baleen whale species, one sperm whale species and ten species of delphinid. Bryde's whale (Balaenoptera brydei) and humpback whale (Megaptera novaeangliae) were the most frequently encountered species. Cetaceans were found throughout a range of sea surface temperature between 20.5°C and 27.5°C and a wide range of depths with the majority of effort and sightings occurring seaward of the shelf break. Of particular interest from the study were the following: (1) Gabonese waters have a broad cetacean diversity, especially with a large and diversified delphinid community in the northern part of the study area; (2) the variations in oceanographic conditions within Gabonese waters are likely to result in a temporal variation in species composition; (3) the sightings of Atlantic spotted dolphin (Stenella frontalis) are the first at-sea sightings confirmed for these waters, although not unexpected given their distribution and abundant presence in surrounding waters; and (4) the poorly known Clymene dolphin (Stenella clymene) was sighted on four occasions in deep oceanic waters and was the most abundant cetacean. These are the first confirmed records of Clymene dolphins in Gabonese waters.

Sampling efficiency (p), estimated from the Zippin depletion model and the percentage of fish obtained during first runs (single-pass electrofishing), which is also named relative abundance (C1), calculated as the ratio of C1 to estimated density for a site (Ce), were analysed in five contiguous sites in a small lowland stream in Poland over 23 years. The sampled reach was unregulated during the first decade of the study period, but regulated by weirs and sluices in the latter 13 years. The sites were populated with 17 fish species during this period. Sampling efficiency p calculated for all species did not differ significantly between the five sites in any given year, between benthic and non-benthic species, or between the natural and regulated periods. Differences in p were only observed between some species. C1 differed significantly between large and small species and, except for roach, was not dependent on the number of runs. Results indicate a high stability of both sampling indices in this small stream, despite changes in channel morphology after regulation: information which could be useful for future sampling research in streams.

The oligarchy hypothesis proposes that large areas of Amazonian plant communities are dominated by limited sets of species. We tested this hypothesis by (1) quantifying dominance of the 10 most common species, genera and families in each region; and (2) assessing the consistency of relative abundance ranks between areas and across scales in dominance patterns for trees and lianas in two distant Amazonian regions (∼1900 km), the Yasuní and Madidi National Parks in Ecuador and Bolivia, respectively. The analyses were based on sixty-nine 0.1-ha plots in which all woody plants with a diameter at breast height (dbh) ≥2.5 cm were inventoried (19 775 individuals and 1729 species in total). The plots were located at two Yasuní and five Madidi sites, with an average of 10 plots per site. Overall, oligarchic dominance was pronounced at all the spatial scales investigated, although decreasing with increasing scale. Cross-scale relative abundance ranks were more consistent in Yasuní than in Madidi, while no such difference was apparent within single sites. Quantitative dominance and consistency of relative abundance ranks increased with taxonomic rank, being stronger at the family level than at genus and species levels. Species-level dominance was somewhat stronger within the 10 most common families in either region, than in other families. Dominance was similarly strong for canopy (dbh ≥10 cm) and understorey trees (dbh <10 cm), and less pronounced among lianas. In conclusion, our results provide strong evidence that western Amazonian forests can be dominated by limited oligarchies of species, genera and families over large expanses.