Habitat Generalists Research Articles

African Herald snakes,Crotaphopeltis, show population structure for a widespread generalist but deep genetic divergence for forest specialists

The African colubrid snake genus Crotaphopeltis currently comprises six species and occurs throughout sub-Saharan Africa. The most widespread of these, Crotaphopeltis hotamboeia, inhabits most biomes, aside from rainforest and hyper-arid regions, and its catholic niche has presumably facilitated substantial gene flow. Despite this, the geographical range is large enough that ecological or physical barriers might exist, facilitating allopatric diversification. In contrast, most of the other species are habitat specialists with limited distributions (e.g., Crotaphopeltis tornieri) and would be expected to show strong genetic structure. We therefore examined species boundaries within Crotaphopeltis in a phylogenetic context using five markers (16S, cyt b, ND4, c-mos, and RAG-1) for four of the six species. Species delimitation methods included two coalescent-based and one barcoding approach. Widespread geographical sampling of C. hotamboeia allowed examination of genetic structuring across its range. The species status of Crotaphopeltis barotseensis, C. degeni, and C. hotamboeia was confirmed, whereas the Afromontane species C. tornieri comprised two candidate species. Crotaphopeltis hotamboeia did not show cryptic speciation, although its phylogeographic structure corresponded with the spatiotemporal pattern of the African savanna. Our results show how the heterogeneous African environment could influence genetic partitioning of habitat specialist and generalist species at broad geographical scales.

Habitat of the endangered salt marsh harvest mouse (Reithrodontomys raviventris) in San Francisco Bay.

Understanding habitat associations is vital for conservation of at‐risk marsh‐endemic wildlife species, particularly those under threat from sea level rise. We modeled environmental and habitat associations of the marsh‐endemic, Federally endangered salt marsh harvest mouse (Reithrodontomys raviventris, RERA) and co‐occurrence with eight associated small mammal species from annual trap data, 1998–2014, in six estuarine marshes in North San Francisco Bay, California. Covariates included microhabitat metrics of elevation and vegetation species and cover; and landscape metrics of latitude–longitude, distance to anthropogenic features, and habitat patch size. The dominant cover was pickleweed (Salicornia pacifica) with 86% mean cover and 37 cm mean height, and bare ground with about 10% mean cover. We tested 38 variants of Bayesian network (BN) models to determine covariates that best account for presence of RERA and of all nine small mammal species. Best models had lowest complexity and highest classification accuracy. Among RERA presence models, three best BN models used covariates of latitude–longitude, distance to paved roads, and habitat patch size, with 0% error of false presence, 20% error of false nonpresence, and 20% overall error. The all‐species presence models suggested that within the pickleweed marsh environment, RERA are mostly habitat generalists. Accounting for presence of other species did not improve prediction of RERA. Habitat attributes compared between RERA and the next most frequently captured species, California vole (Microtus californicus), suggested substantial habitat overlap, with RERA habitat being somewhat higher in marsh elevation, greater in percent cover of the dominant plant species, closer to urban areas, further from agricultural areas, and, perhaps most significant, larger in continuous size of marsh patch. Findings will inform conservation management of the marsh environment for RERA by identifying best microhabitat elements, landscape attributes, and adverse interspecific interactions.

Urban coyotes are genetically distinct from coyotes in natural habitats

AbstractUrbanization is increasing throughout the world, transforming natural habitats. Coyotes (Canis latrans) are found in highly urban, suburban, rural and undeveloped mountainous habitats, making them an exemplary model organism to investigate the effects of urbanization on animals. We hypothesized that coyotes in natural habitats are more genetically related to distant coyotes in similar natural habitats and less related to coyotes in urban areas due to natal habitat-biased dispersal. We also hypothesized that increasing urbanization would result in decreased genetic diversity due to habitat fragmentation, dispersal barriers and genetic drift. We analyzed 10 microsatellite genetic markers from 125 individual coyotes sampled across a spectrum of highly urban to highly natural areas in southern California. Most coyotes clustered into four distinct genetic populations, whereas others appeared to have admixed ancestry. Three genetic populations were associated primarily with urban habitats in Los Angeles and Orange Counties. In contrast, the remaining population was associated with more naturally vegetated land near the surrounding mountains. Coyotes living in natural areas formed a genetically distinct cluster despite long geographic distances separating them. Genetic diversity was negatively associated with urban/suburban land cover and local road density, and positively associated with the relative amount of natural vegetation. These results indicate that genetic differentiation and loss of genetic diversity coincided with the extremely rapid expansion of Greater Los Angeles throughout the 1900s. Thus, urbanization reduces gene flow and erodes genetic diversity even in a habitat generalist thought to be minimally impacted by land development.

Isotopic Niches of Tropical Birds Reduced by Centenary Anthropogenic Impacts

Land use changes in tropical forests intensified during the 20th century, mainly caused by deforestation for agricultural uses, which had an overwhelming influence on bird communities. However, there is a knowledge gap on how these historical anthropogenic changes have impacted habitat use and diet of tropical birds. On this regard, isotopic analysis can be useful since δ13C and δ15N values provides information of habitat and food resource use, and also isotopic niche of species. Here, we aimed to evaluate whether changes in landscape composition caused by centenary anthropogenic impacts have influenced the isotopic signatures and niche widths of birds in a Neotropical biodiversity hotspot, the Atlantic Forest, in southeastern Brazil. Our results showed that all bird guilds (frugivore, granivore, insectivore, nectarivore, omnivore) presented a large reduction (28-70%) in niche width from the twentieth century until contemporary. These reductions are likely associated with historical impacts (e.g. fragmentation and habitat loss), which are responsible for a decrease in the availability of food resources. There was also a reduction in the mean values of δ15N over the years in all guilds, which might be related to the expansion of agricultural areas and the increment in use of synthetic nitrogen fertilizers. Albeit some of the analyzed species are considered diet and habitat generalists, all of them showed to have been strongly influenced by anthropogenic actions throughout the years. Since these birds perform ecological functions in fragmented areas, we suggest an increase in conservation actions that ensure they do not vanish in the near future.

Ground Beetle (Coleoptera: Carabidae) Response to Harvest Residue Retention: Implications for Sustainable Forest Bioenergy Production

Research Highlights: Our study adds to the scant literature on the effects of forest bioenergy on ground beetles (Coleoptera: Carabidae) and contributes new insights into the responses of ground beetle species and functional groups to operational harvest residue retention. We discovered that count of Harpalus pensylvanicus (DeGeer)—a habitat generalist—increased owing to clear-cut harvests but decreased due to harvest residue reductions; these observations uniquely allowed us to separate effects of additive forest disturbances to demonstrate that, contrarily to predictions, a generalist species considered to be adapted to disturbance may be negatively affected by altered habitat elements associated with disturbances from renewable energy development. Background and Objectives: Despite the potential environmental benefits of forest bioenergy, woody biomass harvests raise forest sustainability concerns for some stakeholders. Ground beetles are well established ecological indicators of forest ecosystem health and their life history characteristics are connected to habitat elements that are altered by forest harvesting. Thus, we evaluated the effects of harvest residue retention following woody biomass harvest for forest bioenergy on ground beetles in an operational field experiment. Materials and Methods: We sampled ground beetles using pitfall traps in harvest residue removal treatments representing variable woody biomass retention prescriptions, ranging from no retention to complete retention of all merchantable woody biomass. We replicated treatments in eight clear-cut stands in intensively managed loblolly pine (Pinus taeda L.) forests in North Carolina and Georgia. Results: Harvest residue retention had no effect on ground beetle richness and diversity. However, counts of H. pensylvanicus, Anisodactylus spp., and “burrower” and “fast runner” functional groups, among others, were greater in treatments with no woody biomass harvest than those with no harvest residue retention; all of these ground beetles may confer ecosystem services in forests. We suggest that H. pensylvanicus is a useful indicator species for burrowing and granivorous ground beetle response to harvest residue reductions in recently harvested stands. Lastly, we propose that retaining 15% retention of total harvest residues or more, depending on regional and operational variables, may support beneficial ground beetle populations.

The genetic consequences of habitat specificity for fig trees in southern African fragmented forests

Theory predicts that fragmentation will lead to reduced gene flow between populations, with loss of genetic diversity and increased population differentiation. However, these predictions may not always hold true, especially for long-lived woody plants and some fig trees (Ficus species) may not be affected by fragmentation because their fig wasps can transfer pollen for distances of over 100 km. Here we contrast the extent of genetic isolation caused by fragmentation among three southern African Ficus species with different habitat dependencies and distributional ranges. Two of the species are restricted to forest environments, which have been fragmented since at least the Pleistocene, and provide an indication of the long-term genetic effects of forest fragmentation. The third species is less forest-dependent, with a more general habitat association and more continuous populations. We found significant population differentiation in all three species. Populations of F. bizanae, a forest specialist with a highly restricted distribution, displayed the most genetic structure, followed by the second forest specialist, F. craterostoma. Populations of the habitat-generalist F. sur were the least genetically structured. Forest specialist Ficus species are clearly not immune to habitat fragmentation, despite extensive pollen flow, and other southern African forest trees are likely to have experienced similar or greater effects of habitat fragmentation. The strong genetic structure of F. bizanae suggests a limited seed dispersal range and local dispersal by the fig wasp pollinator, a possible adaptation to the limited range of its host fig tree.

Potential distribution patterns of scorpions in north‐eastern Brazil under scenarios of future climate change

AbstractCurrent predictions about the responses of species to climate change strongly rely on projecting altered environmental conditions on their distributions. In this study, we investigated the effects of future climate change scenarios on the potential distribution of 10 species of scorpions in north‐eastern Brazil in the context of their degree of specialisation to closed (Atlantic and Amazon Forests) and open (Caatinga and Cerrado) habitats. Scorpion species were classified as habitat specialists or generalists according to the IndVal index, and present and future species distribution models were prepared using minimum volume ellipsoids. According to IndVal, four species were classified as closed‐forest specialists (Ananteris mauryi, Tityus brazilae, Tityus pusillus and Tityus neglectus), four as open‐forest specialists (Jaguajir agamemnon, Jaguajir rochae, Physoctonus debilis and Bothriurus rochai), and two as generalists (Tityus stigmurus and Bothriurus asper). All species presented a drastic reduction in potential distribution, ranging from 44% to 72%, when compared with their current distribution. In addition, we found a reduction in scorpion species richness under future climate change scenarios. This finding has implications for scorpion conservation. Further, the results show that climate change may impact the composition of scorpion assemblages in north‐eastern Brazil, revealing important implications for human–scorpion interactions.

Selection of aquaculture sites by using an ensemble model method: a case study of Ruditapes philippinarums in Moon Lake

Manila clam Ruditapes philippinarum is one of the most important bivalve species, with high commercial value, cultured in coastal areas around the world. However, few studies have attempted to model the suitable habitats of this species. For farming, knowledge of suitable habitat is critical information. Here, we use an ensemble-modelling approach implemented in the biomod2 platform to examine potential suitable habitats in Moon Lake. Initially, nine single-algorithm species distribution models (SDMs) were constructed by combining 96 Manila clam actual presence-and-absence data with oceanographic and sediment data. A weighted ensemble model was then derived from the different individual models. Results showed that the contribution of the six predictor variables differed among modelling techniques, in general, the substrate-related variables contributed the best at predicting habitat suitability. The performance of single-algorithm models ranged from poor to excellent, and the weighted ensemble model performed better than any individual modelling technique according to performance metrics. The use of an ensemble of predictions allowed us to identify potentially suitable areas for clam farming. The predicted suitable, secondary suitable and general suitable habitat for R. philippinarum accounted for 7.69%, 9.03% and 11.80% of the total area of Moon Lake, respectively. And both the average shell length and biomass of Manila clam displayed positive relationships with HSI value. This ensemble-modelling approach could be a useful tool to identify suitable aquaculture sites for Manila clam farming.

Comparative phylogeography of mainland and insular species of Neotropical molossid bats (Molossus).

Historical events, habitat preferences, and geographic barriers might result in distinct genetic patterns in insular versus mainland populations. Comparison between these two biogeographic systems provides an opportunity to investigate the relative role of isolation in phylogeographic patterns and to elucidate the importance of evolution and demographic history in population structure. Herein, we use a genotype‐by‐sequencing approach (GBS) to explore population structure within three species of mastiff bats (Molossus molossus, M. coibensis, and M. milleri), which represent different ecological histories and geographical distributions in the genus. We tested the hypotheses that oceanic straits serve as barriers to dispersal in Caribbean bats and that isolated island populations are more likely to experience genetic drift and bottlenecks in comparison with highly connected ones, thus leading to different phylogeographic patterns. We show that population structures vary according to general habitat preferences, levels of population isolation, and historical fluctuations in climate. In our dataset, mainland geographic barriers played only a small role in isolation of lineages. However, oceanic straits posed a partial barrier to the dispersal for some populations within some species (M. milleri), but do not seem to disrupt gene flow in others (M. molossus). Lineages on distant islands undergo genetic bottlenecks more frequently than island lineages closer to the mainland, which have a greater exchange of haplotypes.

Vascular Plant Flora of Stone Mountain Park, DeKalb County, Georgia, Based on Digitized Specimens in the University of Georgia Herbarium (GA)

Stone Mountain in DeKalb County, Georgia, is a large exposed granite monolith, 514 m (1,686 ft) above sea level and covering 230 ha (560 ac). This monadnock is located in the southwestern portion of Stone Mountain Park, comprising 1,300 ha (3,212 ac) owned by the state of Georgia. Recent specimen digitization efforts at the University of Georgia Herbarium (GA) have greatly facilitated capture of data from historic vouchers collected from this park. Based on these newly available data, the goals of this project were to (1) prepare a vouchered species list for the park, (2) produce a vegetation map based on georeferenced label data, and (3) identify all plant collectors and track collection activities through time and taxon focus. Eighty-one individuals and teams collected 1,207 vouchers (709 species) dated 1846–2011. The largest families were Asteraceae (96 spp.), Poaceae (70 spp.), Fabaceae (49 spp.), Cyperaceae (33 spp.), Rosaceae (21 spp.), and Lamiaceae (20 spp.). Approximately 17.5% of the species were exotic. Eighteen species are listed as rare in Georgia with state protection status conferred on five species; Gratiola amphiantha (threatened) and Isoetes melanospora (endangered) are also federally ranked. Specimen label data and various map resources were used to plot the locality of each specimen. Habitat data were recorded on 808 specimen labels, allowing assignment of 612 taxa to at least one of five general habitat types. GPS coordinates, assigned through GeoLocate, were combined with habitat data and infrared imagery to create a general vegetation map of Stone Mountain Park.

Marine Biodiversity and Geographic Distributions Are Independent on Large Scales

Fundamental ecological and evolutionary theories, such as community saturation and diversity-dependent diversification, assume that biotic competition restricts resource use, and thus limits realized niche breadth and geographic range size [1-3]. This principle is called competitive exclusion. The corollary (ecological release) posits that, after competitors disappear from a region, species that were previously excluded will invade. Hundreds of field experiments have demonstrated ecological release in living populations. However, few of these studies were conducted in marine environments, and almost no work extended beyond 10 years and 1,000km2 [4,5]. In limited investigation of marine taxa at larger spatiotemporal scales, macroecologists and paleobiologists have observed little evidence of competitive exclusion [6-9]. Here, we quantified spatial trends in the rich and densely sampled fossil history of brachiopods and bivalves, while accounting for inconsistent sampling coverage through time using a new method of spatial standardization. The number of potential competitors in a region did not explain the geographic distribution of constituent species or genera. Furthermore, although ecological release predicts species to expand after extinction events, survivors of intervals with net species loss expanded as rarely as species in other intervals. Regression model estimates indicated different spatial responses of brachiopods and bivalves, and of habitat specialists and generalists, but no effect from changes in number of potential competitors. Biotic competition may control the distribution of populations, but, on larger spatiotemporal scales, non-competitive factors may have driven biogeographic patterns of brachiopods and bivalves.

Ecology and distribution patterns of Chara connivens (Charophyta, Characeae) on the Canary Islands – the first record from Fuerteventura

Abstract The paper presents the first record of a Chara connivens (Characeae) stand from Fuerteventura (Canary Islands, Spain). The species was previously recorded only on Tenerife and Lanzarote, mostly in marine and artificial habitats. Physicochemical parameters of water and morphological features of the thalli and plant community were analyzed. General habitat requirements of C. connivens populations located in Europe, North Africa, and South-West Asia were reviewed. The newly described stand was located in a natural rock crevice that was part of a riverbed in El Barranco de las Peñitas (Penitas Canyon). This habitat was unshaded and filled with brackish water. C. connivens co-occurred with Cladophora glomerata and Ruppia maritima. Our report on the presence of C. connivens in the Spanish territory of the Atlantic Ocean is the first in almost 40 years. The distribution of C. connivens and its plant associations on the Canary Archipelago are poorly explored, which is why this topic requires further research.

Management of Forest-Dwelling and Urban Species: Case Studies of the Lion-Tailed Macaque (Macaca silenus) and the Bonnet Macaque (M. radiata)

Species conservation depends on the needs of the species concerned. For example, obligatory forest-dwelling and typically urban primate species require different conservation approaches. Here, I compare the ecology, life history, and behavior of two species of macaques in southern India; review what we know about the conservation challenges for each; and propose conservation measures. Lion-tailed macaques (Macaca silenus) are endemic to the rainforests of the Western Ghats and are endangered as a result of fragmentation of their habitats and low population growth. I recommend identification of contiguous forest habitats for viable lion-tailed macaque populations, improving the quality of their degraded habitats, and the linking of forest fragments with native vegetation as management measures for their conservation. In contrast, the bonnet macaque (M. radiata) is a habitat generalist endemic to southern India, but is losing its range to the relatively larger bodied and more aggressive rhesus macaque (M. mulatta). It is not a typically forest-dwelling species, and its populations are declining drastically in its traditional habitats that include Hindu temples, tourist spots, and roadsides with fruit-bearing trees and agricultural crops. The population has remained stable only where the habitat allows the macaques to forage in scrub jungle and includes a temple where the monkeys can obtain food from visitors. India is dotted with small hillocks with natural scrub or deciduous forest vegetation with one or two Hindu temples, and it appears that such habitats are the most suitable places for the long-term conservation of this species. These two case studies serve as examples of the different approaches needed to conserve forest-dwelling and urban primates, and with appropriate modifications, may inform the conservation of many other species.

Environmental Filtering Drives the Assembly of Habitat Generalists and Specialists in the Coastal Sand Microbial Communities of Southern China.

Coastal sands harbor diverse microbial assemblages that play a critical role in the biogeochemical cycling of beach ecosystems. However, little is known about the relative importance of the different ecological processes underlying the assembly of communities of sand microbiota. Here, we employed 16S rDNA amplicon sequencing to investigate the sand microbiota of two coastal beaches, in southern China. The results showed that sand microbial assemblages at intertidal and supratidal zones exhibited contrasting compositions that can be attributed to environmental filtering by electric conductivity. A consistent pattern of habitat generalists and specialists of sand microbiota was observed among different beach zones. Null and neutral model analyses indicated that the environmental filtering was mainly responsible for supratidal microbial communities, while the neutral processes could partially influence the assembly of intertidal communities. Moreover, environmental filtering was found to shape the habitat specialists, while random dispersal played a major role in shaping generalists. The neutral model analysis revealed that the habitat generalists exceeding the neutral prediction harbored a relatively higher proportion of microbial taxa than the specialist counterparts. An opposite pattern was observed for taxa falling below the neutral prediction. Collectively, these findings offer a novel insight into the assembly mechanisms of coastal sand microbiota.

Long-term variation in white-tailed deer abundance shapes landscape-scale population dynamics of forest-breeding birds

Over-browsing by white-tailed deer impedes forest regeneration, alters floristic and structural attributes of stands, and reduces biodiversity. Although numerous exclosure experiments have demonstrated negative impacts of deer on songbirds at small spatial scales, the effects of deer on avian communities at large spatial and temporal scales remains poorly understood. We integrated data from the Breeding Bird Survey with historic information on deer abundance in a multi-species hierarchical model to assess spatio-temporal relationships between deer and bird abundances across the state of Pennsylvania between 1981 and 2015. Our results provide evidence of strong links between deer and both avian functional groups and individual species, depending upon the extent each relied upon particular forest strata. Specifically, species that forage or nest near the ground were more negatively affected by deer than canopy-associated species. Likewise, mature-forest species were more sensitive to deer than successional-forest species or habitat generalists. With only a few exceptions, species-level responses to deer were consistent with group-level effects. Given the diverse suite of spatio-temporal stressors impacting migratory songbirds throughout their annual cycle, it was not surprising that long-term population trends of focal species were not significantly associated with deer abundance. Our findings, however, provide evidence that deer play an important role in songbird community structure, as mediated by the reliance of individual species upon particular forest strata and, as such, should be considered within the context of forest bird conservation.

A reconnaissance survey for Collared Pika (<i>Ochotona collaris</i>) in northern Yukon

Collared Pika (Ochotona collaris) is a cold-adapted Beringian species that occurs on talus slopes and is sensitive to climate warming. Collared Pikas are patchily distributed throughout the sub-Arctic mountains of northwestern Canada and Alaska; however, information on their occurrence in the northern part of their distributional range is limited. In particular, no survey information is known from the southern Richardson Mountains and the Nahoni Mountains. We conducted aerial- and ground-based surveys to document Collared Pika occurrence and general habitat suitability in northern Yukon. We flew 505 km of aerial survey (not including ferrying to targetted survey areas) and performed ground surveys at 22 sites within the Richardson Mountains (including a portion of Dàadzàii Vàn Territorial Park) and the Nahoni Mountains in and adjacent to Ni’iinlii Njik (Fishing Branch) Territorial Park. Overall, suitable habitat for Collared Pikas was patchy in the mountains of northern Yukon—talus was sparse and many patches of talus appeared to be unsuitable. Collared Pikas were detected at eight of 22 (36%) sites visited, representing important new records for the species in the northern portion of their range. Our reconnaissance provides a first approximation of habitat suitability for Collared Pikas of the mountains of northern Yukon, as well as new records for the species in the region. These data are useful in better determining the contemporary distribution of Collared Pika through species distribution modelling, and may serve to identify areas for more detailed survey and monitoring initiatives for this climate-sensitive mammal.

Ecological Attributes of Carnivore-Livestock Conflict

Mitigation of carnivore-human conflict due to domestic animal predation represents an imperative challenge. Although livestock management strategies aimed at reducing predation have recently received attention by wildlife managers and producers, the information regarding ecological attributes of studied predators and environmental characteristics of the areas where conflicts occur is largely missing. We conducted a global review to characterize the literature of carnivore-livestock conflict, identifying the set of reported predators, and assessing the ecological attributes of these species and areas where predation has occurred. A total of 391 published peer-reviewed research papers on carnivore-livestock conflict containing 783 predation study cases were evaluated. Carnivore-livestock conflict research was largely conducted in Asian and African countries (80% of published studies). Fifty-two carnivores were reported in conflict-related studies being Felidae and Canidae the most frequently studied groups (80% of study cases). Carnivores more often reported to prey on domestic animals exhibit larger home ranges and body masses, and are also subject to larger reductions in their distribution ranges. They also show a generalist habitat behavior, a strictly carnivore diet, and cathemeral activity. Predation of domestic animals consistently increased with vegetation cover, decreased with distance from human settlement and was higher in young animals. The analysis conducted separately for large and meso carnivores showed that predation on domestic animals by large carnivores (> 21.5 kg) increased near protected areas and far from human settlements. Current information regarding conflicts exhibits a notable variation in research effort towards some regions and large-bodied and broadly distributed species. This asymmetry could reflect the role of human perspectives in research based on species-level traits, research facilities and funding opportunities, though also underlies ecological processes induced by land transformation occurring in some regions across the globe. As encroached habitat increases, species with restricted distributions and behaviors, or smaller home ranges such as meso carnivores, will roam into human-dominated landscapes, increasing their probability of interacting with livestock activity. Identifying ecological attributes that distinguish carnivores and areas as “conflict-prone” may contribute to set evidence-based management approaches in frameworks ready to anticipate, reduce or prevent human-carnivore conflict, complementing the use of other strategies.

Floodplain land cover affects biomass distribution of fish functional diversity in the Amazon River

Land-cover change often shifts the distribution of biomass in animal communities. However, the effects of land-cover changes on functional diversity remain poorly understood for many organisms and ecosystems, particularly, for floodplains. We hypothesize that the biomass distribution of fish functional diversity in floodplains is associated with land cover, which would imply that fish traits affect behavioral and/or demographic responses to gradients of land cover. Using data from surveys of 462 habitats covering a range of land-cover conditions in the Amazon River floodplain, we fitted statistical models to explain landscape-scale variation in functional diversity and biomass of all fish species as well as subsets of species possessing different functional traits. Forest cover was positively associated with fish biomass and the strength of this relationship varied according to functional groups defined by life history, trophic, migration, and swimming-performance/microhabitat-use traits. Forty-two percent of the functional groups, including those inferred to have enhanced feeding opportunities, growth, and/or reproductive success within forested habitats, had greater biomass where forest cover was greater. Conversely, the biomass of other functional groups, including habitat generalists and those that directly exploit autochthonous food resources, did not vary significantly in relation to forest cover. The niche space occupied by local assemblages (functional richness) and dispersion in trait abundances (functional dispersion) tended to increase with forest cover. Our study supports the expectation that deforestation in the Amazon River floodplain affects not only fish biomass but also functional diversity, with some functional groups being particularly vulnerable.

The Guard Coral Crabs of Familes Trapeziidae and Domeciidae (Superfamily Trapezoidea) from the Egyptian Red Sea Coasts, and Its Asscoiated Gulfs, Aqaba and Suez, Egypt

A total of 6 species belong to families Domciidae and Trapeziidae (superfamily Trapezoidea: Brachyura: Decapoda) live in symbionts with branching stony corals in the shallow waters of the Egyptian coasts of the Red Sea, Gulf of Aqaba and Gulf of Suez were recorded during this study. These species were carefully examined and revised. The first family (Domciidae) was represented by only one species, Domecia hispida; while family Trapeziidae has 5 species comprised: Trapezia bidentata, Tr. cymodoce, Tr. digitalis, Tr. guttata and Tr. tigrina. All 5 species of genus Trapezia are well represented in the Red Sea waters; while Gulf of Aqaba was inhabited with Tr. cymodoce, Tr. bidentata and Tr. tigrina, and Gulf of Suez was occupied with Tr. cymodoce and Tr. gutata, in addition to Domecia hisipida. A brief description on general character, size, localities, color, habitats, and distribution was given. Constructed keys for identification of genera and species were also given.

Habitat availability explains variation in climate-driven range shifts across multiple taxonomic groups

Range shifting is vital for species persistence, but there is little consensus on why individual species vary so greatly in the rates at which their ranges have shifted in response to recent climate warming. Here, using 40 years of distribution data for 291 species from 13 invertebrate taxa in Britain, we show that interactions between habitat availability and exposure to climate change at the range margins explain up to half of the variation in rates of range shift. Habitat generalists expanded faster than more specialised species, but this intrinsic trait explains less of the variation in range shifts than habitat availability, which additionally depends on extrinsic factors that may be rare or widespread at the range margin. Similarly, while climate change likely underlies polewards expansions, we find that more of the between-species variation is explained by differences in habitat availability than by changes in climatic suitability. A model that includes both habitat and climate, and their statistical interaction, explains the most variation in range shifts. We conclude that climate-change vulnerability assessments should focus as much on future habitat availability as on climate sensitivity and exposure, with the expectation that habitat restoration and protection will substantially improve species’ abilities to respond to uncertain future climates.