Vagrant Species Research Articles

Assessing the role of competitive processes in mediating the range expansions of tropical vagrant fish

AbstractClimate change is promoting fast poleward expansion in many tropical marine fish species. With projected increases in sea surface temperatures, there is significant scope for increased range expansions in the future. However, the strength and consequences of density‐driven competitive interactions between vagrant and resident fishes are largely unknown. Here, we investigate how the density effects resulting from the addition of tropical fishes to temperate assemblages may alter patterns of habitat and behaviour usage by both tropical vagrant and temperate resident species. We explore these impacts for two ecologically similar (diet, habitat and behaviour) pairs of vagrant and resident species (the territorial species Stegastes gascoynei and Parma microlepis, and the shoaling species Abudefduf vaigiensis and Atypichthys strigatus, respectively). We compare situations where the other member of each of these ecological pairs was present or absent. There was a shift in the type and structural complexity of habitat occupied, with all species displaying some characteristics of occupying seemingly less‐preferred habitats in the presence of their pair species than without them. Behavioural effects were only apparent for the territorial species, which had altered feeding and vigilance patterns in the presence of their pair. These data indicate that the increased density of ecologically similar fish which results from the annual arrival of vagrant fishes is likely driving shifts away from optimal habitat usage and alterations in activity of both residents and vagrants, suggesting resource competition. The degree to which this competition was evident depended on the life history of the species, being stronger for the more territorial species. While similar research on additional species would be required to determine to what degree these results could be generalised to other territorial or shoaling species, this work suggests to highlight the important role that competition will play in determining both the ability of the vagrant species to become established within temperate communities, as well as the impact they may have once they have done so.

History and Modern Status of the Black-eared Wheatear, Oenanthe hispanica (L.) (Passeriformes, Muscicapidae), in Ukraine

Th e history of research of the Black-eared Wheatear Oenanthe hispanica (L.) in Ukraine in XIX–XXI centuries is presented. Th e Black-eared Wheatear is now a rare breeding bird in the coastal area of the Crimean peninsula, and a very rare vagrant species on the other territory of Ukraine. Four breeding regions of the Black-eared Wheatear are found in the Crimean peninsula: seacoast between Sudak and Th eodosia cities; neighbourhood of Sevastopol City; Tarkhankut peninsula; Kerch peninsula. Th e fi rst two breeding regions have been known since the middle of XIX century. In the breeding regions, the breeding areas of the Black-eared Wheatear are not constant: the birds almost never nest in a place for a number of years. Oenanthe hispanica breeds in Crimea in the same biotopes as its sibling species, the Pied Wheatear, Oenanthe pleschanka, which is essentially more abundant there. Th e breeding of single Black-eared Wheatears with the numerous Pied Wheatears increases their interspecies hybridization, which is rather common on the Crimean peninsula. Th ree out of fi ve individuals of Oenanthe hispanica collected in Crimea and stored in various museums turned out to be hybrids with Oenanthe pleschanka. Th e Black-eared and Pied Wheatears have hybridized in the Crimean peninsula for a long time: the hybrids have been recorded in XX and in XXI centuries. Th e hybrids do not occur in a specifi c breeding region, and can be found in any of those.

Rare birds in Nepal

This paper aimed to fulfil the knowledge gap on the status of vagrants and rare birds of Nepal. Records of all Nepal’s bird species that were previously considered vagrants by the National Red List of Nepal’s Birds (2016) were collated and detailed with localities, dates and observers. Species recorded since 2016, including vagrant species, were also covered. A total of 92 species was assessed to determine if they were vagrants, that is species that had a total of 10 or less records. It was concluded that six species are no longer vagrant and we recommend these for national red list assessment. Nepal currently has a total of 71 vagrant species. In addition, four vagrant species have still to be accepted by the Nepal Rare Birds Committee before they can be officially included on the Nepal bird list. Nine species have so far only been recorded in the 19th century. Red-faced liocichla Liocichla phoenicea, was previously one of these, but was re-found In Nepal after the National Red List was published in 2016; it is a very rare and very local resident. Himalayan grasshopper-warbler Locustella kashmirensis is a recent split and now considered a full species (instead of a subspecies); it is probably an altitudinal migrant in Nepal. Despite great advances in our ornithological knowledge of Nepal, there is still high potential to find new species, especially of passerine birds and in the less explored parts of the country.

<strong>Host plant discrimination through mobility parameters by eriophyoid mites</strong>

Eriophyoidea is a well-known mite taxon of economic importance. Due to their small size, elucidating many of their bio-ecological aspects becomes a challenge. These mites are obligatory plant feeders, with high host specificity and vagrant (free living) and non-vagrant (part or whole life cycle in a host) lifestyles. The mobility (distance walked - mm, resting time - s, and number of stops) of these mites on host and non-host plant species has been investigated. Eriophyoid species were submitted to walking tests on host and non-host plants using five vagrant species and five non-vagrant species. The walking was recorded with video tracking (ViewPoint) for ten minutes. Twenty replicates were performed for each treatment (eriophyoid species and plant). There was a difference in the behavioral response of the species studied in relation to the hosts. When the species were grouped by ecological lifestyle (vagrant and non-vagrant), non-vagrant eriophyoids presented a higher mobility (higher distance walked, less resting time) than vagrant eriophyoids on their respective hosts. There was no difference in the mobility of vagrant and non-vagrant species on non-host plants. The absence of a pattern of behavioral response among the species tested here indicates that more factors are involved in the host identification and acceptance process.

Cannot see the diversity for all the species: Evaluating inclusion criteria for local species lists when using abundant citizen science data.

Abundant citizen science data on species occurrences are becoming increasingly available and enable identifying composition of communities occurring at multiple sites with high temporal resolution. However, for species displaying temporary patterns of local occurrences that are transient to some sites, biodiversity measures are clearly dependent on the criteria used to include species into local species lists. Using abundant opportunistic citizen science data from frequently visited wetlands, we investigated the sensitivity of α‐ and β‐diversity estimates to the use raw versus detection‐corrected data and to the use of inclusion criteria for species presence reflecting alternative site use. We tested seven inclusion criteria (with varying number of days required to be present) on time series of daily occurrence status during a breeding season of 90 days for 77 wetland bird species. We show that even when opportunistic presence‐only observation data are abundant, raw data may not produce reliable local species richness estimates and rank sites very differently in terms of species richness. Furthermore, occupancy model based α‐ and β‐diversity estimates were sensitive to the inclusion criteria used. Total species lists (all species observed at least once during a season) may therefore mask diversity differences among sites in local communities of species, by including vagrant species on potentially breeding communities and change the relative rank order of sites in terms of species richness. Very high sampling effort does not necessarily free opportunistic data from its inherent bias and can produce a pattern in which many species are observed at least once almost everywhere, thus leading to a possible paradox: The large amount of biological information may hinder its usefulness. Therefore, when prioritizing among sites to manage or preserve species diversity estimates need to be carefully related to relevant inclusion criteria depending on the diversity estimate in focus.

An economic analysis of twitching behaviour and species rarity

ABSTRACT Avid birdwatchers, or ‘twitchers’, expend a considerable amount of money and time pursuing viewing experiences of rare or vagrant species. By vagrant species, we mean a species found outside its normal range/distribution. To enhance our understanding of this form of behaviour, we present results from a U.K. survey of twitchers. First, we examine the relationship between cost and rarity based on actual viewing experiences. Our statistical results reveal that the relationship between cost and rarity is positive and very inelastic. Second, we present results from a hypothetical Best-Worst Scaling exercise examining aspects of species rarity. We find that rarity is a more nuanced construct than simply the frequency with which a vagrant species has appeared. Our results provide insights into the meaning of rarity, as well as the economic value attach to it and why.

<p class="Body"><strong>A new phytoptid mite from iconic Gondwanan plant: description of <em>Solenocristus nothofagalis</em> n. sp. (Eriophyoidea, Phytoptidae) from Argentina supplemented with sequences of nuclear ribosomal genes of <em>Nothofagus pumilio</em> (Nothofagaceae)</strong></p>

Plants of the genus Nothofagus (Fagales, Nothofagaceae) has ancient South American-Australasian disjunctive distribution and represent a perspective model for biogeographical studies in Eriophyoidea. Among six currently known eriophyoid genera reported from Nothofagus (Acalitus, Aceria, Austracus, Cymoptus, Rectalox, and Nothacus) only genus Cymoptus was registered in western and eastern distribution areas of Nothofagus. In this paper we describe a new vagrant species, Solenocristus nothofagalis n. sp. (Phytoptidae, Sierraphytoptinae) collected from lower leaf surface of Nothofagus pumilio in Los Glaciares National Park (Patagonia, Argentina). Because all mite specimens in the sample were dead, amplification of three marker genes (COI, 18S, 28S) performed ten days after collecting data was unsuccessful. Morphological identification of the host plant was confirmed using PCR method and resulted in new sequences of 18S (MT164471) and ITS1‒5.8S‒ITS2 region (MT164174) of N. pumilio, deposited in GenBank.

A Guide to Helminth Parasites Reported from Shorebirds (Charadriidae) from the Americas

The shorebird family Charadriidae in the Americas consists of 21 native and 7 vagrant species. Members of the family occupy a diversity of open habitats, ranging from Arctic tundra during nesting, coastal sands, and mudflats to inland prairies, savannas, and wetlands. Some native plovers migrate from nesting grounds in North America to wintering grounds in South America (Hayman et al., 1986; Paulson, 2005; Winkler et al., 2020). Our search of the literature revealed the following: 17 of 28 host species infected with helminth parasites, 153 helminth species, and 199 infections involving 13 geographic areas. The purpose of this guide is to provide easy access to this data and information relevant to helminth infections in charadriids from the Americas. Information is summarized in Tables I–VI. Table I lists in sequence host, parasite, geographic location, and attenuated citation. Common names are given for each host. Host names are listed alphabetically, and older scientific names used in the literature search are in parentheses. Host geographic distribution is abbreviated as follows: NA = North America, M = Mexico, CA = Central America, SA = South America, A = Americas (NA + M + CA + SA). If present, parasite species are listed in the following order: trematode, cestode, nematode, and acanthocephala. The helminth species names are listed as they were given in the cited literature. Tables II–V are parasite-host lists for trematode, cestode, nematode, and acanthocephalan species and host of the species associated with the parasite. Table VI is a summary of information extracted from the tables and literature cited section.

Genome-scale data reveal the role of hybridization in lichen-forming fungi

Advancements in molecular genetics have revealed that hybridization may be common among plants, animals, and fungi, playing a role in evolutionary dynamics and speciation. While hybridization has been well-documented in pathogenic fungi, the effects of these processes on speciation in fungal lineages with different life histories and ecological niches are largely unexplored. Here we investigated the potential influence of hybridization on the emergence of morphologically and reproductively distinct asexual lichens. We focused on vagrant forms (growing obligately unattached to substrates) within a clade of rock-dwelling, sexually reproducing species in the Rhizoplaca melanophthalma (Lecanoraceae, Ascomycota) species complex. We used phylogenomic data from both mitochondrial and nuclear genomes to infer evolutionary relationships and potential patterns of introgression. We observed multiple instances of discordance between the mitochondrial and nuclear trees, including the clade comprising the asexual vagrant species R. arbuscula, R. haydenii, R. idahoensis, and a closely related rock-dwelling lineage. Despite well-supported phylogenies, we recovered strong evidence of a reticulated evolutionary history using a network approach that incorporates both incomplete lineage sorting and hybridization. These data suggest that the rock-dwelling western North American subalpine endemic R. shushanii is potentially the result of a hybrid speciation event, and introgression may have also played a role in other taxa, including vagrant species R. arbuscula, R. haydenii and R. idahoensis. We discuss the potential roles of hybridization in terms of generating asexuality and novel morphological traits in lichens. Furthermore, our results highlight the need for additional study of reticulate phylogenies when investigating species boundaries and evolutionary history, even in cases with well-supported topologies inferred from genome-scale data.

Falco lanarius: the contorted history of a poetical archetype and a taxonomic puzzle

Among true falcons (Falco sp.), the lanner falcon (F. biarmicus), due to its rarity, has always been viewed as an ‘oddity’, even the name has a contorted history, with both common and scientific names being subject to debate. Unfortunately, the Latinisation of the common name for taxonomic purposes (F. lanarius) produced further confusion. Indeed, the old falconry term Lanier evolved independently from lanarius indicating the falcon species. In addition, the lanner falcon was often considered a very rare and possibly vagrant species in Europe. As a consequence of this scarcity, many controversial taxonomic issues arose due to the low number of occurrences in private collections and museums. Numerous sources originally published in the nineteenth century, as well as those published more recently in the twentieth century, should be very helpful in understanding many of the anomalies that have been inherited from the past, many of which remain with us today. From this historical analysis, it is possible to deduce some constraints that have strongly influenced and driven the current taxonomic position of this large falcon. In fact, in spite of the discontinuous process of classification, only a few peculiar morphological features persist today to justify the subspecies level. Thus, further in-depth morphological and genetical analyses are needed on lanner falcon subspecies.

<p class="Body"><strong>Three new vagrant eriophyoid species (Acari: Trombidiformes: Eriophyoidea) associated to Rosaceae species from South Khorasan province, East Iran</strong></p>

During the field surveys on eriophyoid mites associated with plant species of the Rosaceae family in semi-arid and arid environments in East Iran (Birjand, South Khorasan, Iran 2016-2017), three new vagrant species (Acari: Eriophyoidea) were found. They are Epitrimerus vulgarubi sp. nov. on Rubus vulgaris Weihe & Nees, Phyllocoptes trilobos sp. nov. on Rosa persica Michx. ex Juss., Rhyncaphytoptus birrosa sp. nov. on Rosa canina L. which are described and illustrated herein. No symptom was observed on their infested host plants.

Off-host survival of Eriophyoidea and remarks on their dispersal modes.

Dispersal of eriophyoid mites is crucial for the successful colonization of new plants. Literature suggests that their long-distance dispersal is through aerial transfer. During dispersal, eriophyoids might be captured in vapor or fine drops of water (perhaps most likely in clouds) where they might be protected against water loss and desiccation, but where they would have no food and be exposed to low temperatures and oxygen concentrations. Considerable resistance of these mites to these stressful environmental conditions is expected and has only partly been confirmed experimentally. The aim of the bioassays conducted here was to assess the survival of five eriophyoid species off their host plants, with poor oxygen availability under two temperature regimes. The bioassays were carried out on live mites dipped into two media used as microenvironments: (1) vaseline oil (used also as control treatment), and (2) water solution of Tween 80 (0.2%) and cycloheximide (50mg/l). The bioassays were performed at 5 ± 1and 25 ± 1°C. The survival of mites was assessed weekly (5°C) or daily (25°C) by counting live and active specimens. The following species were subjected to the bioassays: Aceria caulobia (a stem gall mite), Aceria ficus (a vagrant mite), Cecidophyopsis hendersoni (a vagrant mite), Colomerus vitis (protogyne/male population and deutogyne morphs; a leaf gall mite) and Phytoptus avellanae (a bud gall mite). The survival rate of the mites was higher at 5°C than at 25°C under both experimental conditions. At 5°C, the survival of almost all species was higher in the water solution (up to 6-7weeks) than in vaseline oil (3-5weeks). Longer survival was found for A. caulobia and P. avellanae (gall-making species) than for C. hendersoni and A. ficus (vagrant species). As expected, the deutogynes of C. vitis survived longer than its protogynes. The current results suggest that individuals of some of the tested species are well suited for withstanding cold, starvation and low oxygen rates, which could be found at higher atmospheric layers, within the clouds, allowing them an effective long-distance dispersal.

Current Status of Anserinae Wintering in Azov-Black Sea Region of Ukraine

Abstract In the article is analyzed own field data of the authors and scientific publications on the wintering of Anserinae in the Azov-Black Sea region of Ukraine in 1900–2017, but the main data was obtained in frame of international mid-winter counts (IWC) in 2005–2017. It was found that 9 species of Anserinae occur in this region during the different seasons of the year: Anser anser — nesting, wintering and migrating; Rufibrenta ruficollis, A. albifrons, A. erythropus, A. fabalis — migrating and wintering; Branta canadensis, Branta leucopsis, Branta bernicla, Chen caerulescens — vagrant or birds which flew away from captivity (zoo etc.). Eulabeia indica — is possible vagrant species. The most numerous wintering species is A. albifrons, common — Rufibrenta ruficollis, not numerous — Anser anser, the other species are not met annually and registered in a very small number. There was almost tenfold drop in number of wintering geese in the Azov-Black Sea region of Ukraine during the period of counts. The main reasons of such reducing of geese amount are the followwing: weather and climate conditions, changes in the forage acessibility, hunting and poaching pressure, poisoning as a result of deratization of agricultural lands, and from 2014 — the militarization of the Syvash area and stop of water supplying of Crimea through the North Crimean channell. It is likely that the factors mentioned above led to relocating of wintering areas of Anserinae, and resulted in decreasing of their amount in this region.

Birds of the Entella river (Genoa, Italy): a qualitative assessment of bird diversity in an urbanizing biotope, with implications for management and conservation

This work presents the first assessment of the birds of the Entella river (Genoa, Liguria), a small wetland embedded in an urbanized matrix. Data were collected through standardized in situ censuses from April 2012 to June 2017 and integrated with historical and recent data from other verified sources. A total of 278 species are known from the site; 53 species (19.06%) breed in the area, whereas 62 (22.30%) species are vagrant and 81 species (29.14%) are included in the Annex I of the Birds Directive (79/409/CEE). We determined the following indices: NP/P ratio = 1.48, O.V.I. (Ornithological Value Index) = 20.53. In-depth data are provided for vagrant species and for species of conservation concern, to prioritize conservation efforts. The results underline the importance of the Entella river as a local biodiversity hotspot and suggest a possible role of the area as a stepping stone in the regional ecological network. The study highlights a dichotomy between urbanization and high bird diversity in the area and acts as a first step towards its conservation and implementation.

Evidence of large‐scale range shift in the distribution of a Palaearctic migrant in Africa

AbstractAimLong‐distance Palaearctic migrant birds are declining at a faster rate than short‐distance migrant or resident species. This is often attributed to changes on their non‐breeding grounds and along their migratory routes. The European honey buzzard (Pernis apivorus) is a scarce migrant in southern Africa that is declining globally. This study assessed the distribution and abundance of honey buzzards in southern Africa over the past four decades and compared it to trends in the East African population to examine possible drivers of population expansion in southern Africa.LocationSouthern and East Africa.MethodsEuropean honey buzzard reporting data were collected from a variety of sources including citizen science databases (1983–2017). In addition, records of all other southern African vagrants (including ten other regularly occurring species) were gathered to account for changes in birdwatching effort in the subregion. To assess the effect of forest loss on honey buzzard abundance, rolling correlations were performed using forest cover in East Africa and number of honey buzzard records in both subregions.ResultsEuropean honey buzzard records in southern Africa have increased over five times more than other regularly occurring vagrant species and almost 40 times more than honey buzzard in Tanzania, where the population has remained stable. Loss of forested area in East Africa was correlated with an increase in European honey buzzard records in southern Africa.Main conclusionsWe suggest that the European honey buzzard shift in wintering range may be driven by a decline in suitable habitat further north in Africa amongst other possible reasons. This effect may have been amplified by an increase in appropriate habitat across southern Africa brought about by anthropogenic changes to vegetation such as increased tree cover in urban areas. This study further highlights the importance of using African distributional data banks to understand the effects of global change on Palaearctic migrant bird species.

Two new eriophyoid mite species (Acari: Trombidiformes: Eriophyoidea) on Quercus castaneifolia in Iran

Two new vagrant species of eriophyoid mites, Brevulacus cornifrontis sp. nov. and Cecidophyes aliabadi sp. nov., living on the under surface of the leaves of Quercus castaneifolia (Fagaceae) in Iran are described and illustrated. It is also the first record of a species belonging to the genus Cecidophyes found in Iran. Keys to the World Brevulacus and Quercus-related Cecidophyes species are provided. As a consequence of species comparison, Rhyncaphytoptus dichromae was assigned to Brevulacus.

New species and records of phytoptids (Eriophyoidea, Phytoptidae) from cinquefoils (Rosaceae, Potentilla) from Serbia and southern Russia

Two new vagrant species of the genus Phytoptus Dujardin (Eriophyoidea, Phytoptidae, Phytoptinae) from Serbia are described: Phytoptus argenteus n. sp. from Potentilla argentea and P. serbicus n. sp. from Potentilla tommasiniana. Remarks on morphology of Phytoptus alchemillae Jočić et al. 2011 collected from Alchemilla plicata in Serbia and supplementary description of infrequently encountered species Phytoptus potentillae Chen et al. 2005 from Potentilla bifurca (Poaceae) based on mummies recovered from dry plant material from southern Russia are given. Sequences of mtCOI barcode region (658 bp) of three Phytoptus species (P. alchemillae, P. argenteus n. sp., and P. serbicus n. sp.) are provided. A brief comparison of pairwise genetic distances between congeneric eriophyoid mites across taxa of Eriophyoidea (including genus Phytoptus) indicates that COI sequences of congeneric eriophyoid mites do not precisely reflect phylogenetic relations of their hosts. This fact may be explained by (a) different rate of the COI evolution in different mite clades associated with phylogenetically related and unrelated hosts or by (b) similar timing of the associations between mites and plants (while having the same rate of COI evolution).

Southern elephant seal vagrants in Ecuador: a symptom of La Ni\xf1a events?

BackgroundExtralimital observations of pinnipeds are important to understand the effects of changing climates on our oceans and the distribution of these species. The southern elephant seal (Mirounga leonina) is a known vagrant species that moves over long distances. We report three new records of M. leonina in interior freshwater tributaries of the Guayas River Estuary Basin (Gulf of Guayaquil) and northern coast of Ecuador between October 2017 and January 2018 during a cold episode of La Nina event in the southeastern Pacific.ResultsThe elephant seals were identified according to their large size (~ 5 m for adult and 2–3 m for juveniles/subadults), the head to neck size ratio, and the size and external morphology of the proboscis, which was used as a key trait to differentiate M. leonina from the Northern elephant seal (M. angustirostris). The observations of M. leonina in Ecuador highlight an extreme movement covering an assumed total distance of approximately 8000 km from the circumpolar region. The cold event “La Niña” with sea surface temperature anomalies ranging − 1.5 °C to − 0.5 °C in October 2017 likely triggered the extralimital movements of these animals.ConclusionRecurring observations of M. leonina in the Guayaquil Gulf suggest the importance of this highly productive region and tropical estuarine-riverine habitats as temporary haulout sites for resting. These new findings indicate that vagrant individuals influenced by oceanographic events and eco-physiological processes are reaching this region more frequently than previously thought.

<span style="font-family: Times New Roman;">Eriophyoid mites associated with the blackberry in Brazil—a new species in the genus Diptacus Keifer 1951 (Diptilomiopidae) and first report and supplementary description of Acalitus orthomerus (Keifer, 1951) (Eriophyidae)</span>

A new vagrant species of Diptilomiopidae mite, in the Diptacus Keifer, 1951 genus, namely Diptacus rubuscolum sp. nov., living on the lower leaf surface of blackberry-Rubus sp. (Rosaceae) in South Brazil, is described and illustrated. In addition, Acalitus orthomerus Keifer, 1951, for the first time reported in Brazil and even in South America; a supplementary description of this species is presented based on females, males and immature specimens associated to the drupelets. Main morphological differences distinguishing the new Diptacus species and A. orthomerus species from those belonging to the same genera or morphologically similar also associated with Rubus are presented.

Biodiversity changes along the Algerian coast (Southwest Mediterranean basin): from 1834 to 2017: A first assessment of introduced species

“Introduced” species of the Algerian coast remains the most undocumented issue in the Mediterranean Sea. Only few studies were dedicated to Introduced species due to the lack of taxonomists. In-depth research on Introduced species along the Algerian coast should provide new data that could explain the spreading mechanisms in the southwestern part of the Mediterranean basin particularly near the Alboran Sea. Introduced species among other related research; of which the outcome is expected in the next few years, is in progress in the southwest Mediterranean basin. The aim of this work is to provide an inventory of available data pertaining to marine species “introduced” in Algerian waters, whether these species were introduced intentionally or accidentally. This large number of Introduced species records covers the period from 1834 to December 2017. Seventy “Introduced” species have been recorded along the Algerian coast, composed by 55.7% true aliens25.7 % range expanding species, 15.7% cryptogenic species and 2,9% vagrant species, with a clear domination of fish (38.57%) and macroalgae (30%). Approximately 348 introduction events have been reported; 64,9 % of them belong to macroalgae and one sighting out of two is done in the central region. The distribution and the status of introduced species in Algeria were evaluated. In total, 20% of the Introduced species can be considered as established along the Algerian coast, in particular the macrophyta, Codium fragile and Ulva lactuca as well as the cryptogenic species, Oculina patagonica, while Asparagopsis armata, A. taxiformis and Caulerpa cylindracea are considered as invasive.