The status and conservation of the Asiatic black bear in Nikshahr County,Baluchistan District of Iran

Little information exists on the Asiatic black bear (Ursus thibetanus gerdrosianus) in the western part of its distribution. This study investigated the status of this species in the Baluchistan district of Iran, from April 2004 to February 2006. Sign surveys and interviews with elderly local‐born people revealed that although this bear was commonly seen by locals in many areas 20–30 years ago, at present, it only exists in four localities in Nikshahr County (Aband, Kushad, Shoshin and the Pozak Protected Area). Each of these four areas appears to be occupied by only a few individual bears. It seems that the largest number of black bear live in the Aband Mountains, followed by the Kushad Mountains, Shoshin and the Pozak Protected Area. Habitat fragmentation as the result of human habitation, livestock grazing and a continuous severe drought has caused insularization of these small bear populations in Nikshahr. The Asiatic black bear in Nikshahr is endangered in the entire area and is in need of urgent conservation action. The education and co‐operation of local people, and active management to restore habitat, are vital if this species is to persist in this region.     

Biogeography of amphipods (Crustacea: Amphipoda: Gammaridae) from the central Zagros Mountains,Iran, with descriptions of two new species

Seven species of gammarid amphipods were studied in the relatively small province of Charmahal-Va-Bakhteyari in the central Zagros Mountains, Iran. Of these, four are previously known (Gammarus proiectus, G. komareki, G. syriacus and G. balutchi), one is a new record for the region (G. pseudosyriacus) and two are new species (G. lordeganensis and G. bakhteyaricus). From the taxonomic point of view, head microsculpturing characters were found to be reliable as discriminating sets of characters useful in species identification. Habitat diversification and climatic fluctuations appear to be the main factors for species diversity of the area, and the Zagros Mountains act as a geographical barrier to species distribution.     

Orb‐web spiders (Araneae: Araneomorphae; Orbiculariae) captured by hunting‐wasps (Hymenoptera: Sphecidae) in an area of Atlantic Forest in south‐eastern Brazil

Members of two hunting‐wasp families, Pompilidae and Sphecidae, are among the major predators of orb‐web spiders. In this study, we collected paralysed spiders from natural nests and trap‐nests provisioned by sphecids in an area of Brazilian Atlantic Forest, and compared these data with the composition of species collected by visual searching during one year. Prey preferences were analysed based on the relative abundance of spider species, their size and web characteristics. We also compiled a list of orb‐weavers captured by four sphecid genera reported in 40 other studies. A large number of prey was obtained from natural nests of Trypoxylon (Trypargilum) albonigrum in Parque Estadual Intervales, especially species of Eustala, Parawixia, and Araneus (Araneidae). Other prey, stored in trap‐nests by T. lactitarse and unidentified hunting‐wasp species, included Nephila (Tetragnathidae), Parawixia, Ocrepeira, Mecynogea, Acacesia (Araneidae), and other spider species that were less abundant. All the species that were heavily preyed upon had a relatively lower abundance in our samples of prey availability. The range of body sizes of spiders captured by Trypoxylon in our study area include the size of some abundant orb‐weavers always absent in their nests. These results indicate that factors other than abundance in the field and the spider's size influence prey selection or susceptibility to attack.     

Mosquito fauna (Diptera: Culicidae) of the Iranian islands in the Persian Gulf II. Greater Tonb,Lesser Tonb and Kish Islands

Mosquitoes of five Iranian islands in the Persian Gulf (Abu-Musa, Greater Tonb, Lesser Tonb, Kish and Qeshm), Hormozgan Province of southern Iran, were studied during 2009 (February and March) and 2010 (April, May and November). Adult mosquitoes were obtained by hand catch, total catch and night landing catch using aspirators and light traps. Larvae were collected by dipping with a 350-ml dipper. In total, 963 adults and 114 third-instar and fourth-instar larvae representing seven species belonging to four genera were collected and identified, including Anopheles stephensi Liston, Culex perexiguus Theobald, Cx. quinquefasciatus Say, Cx. sitiens Wiedemann, Cx. tritaeniorhynchus Giles, Culiseta longiareolata (Macquart) and Ochlerotatus caspius (Pallas) s.l. This is the first record of mosquitoes on the Greater Tonb, Lesser Tonb and Kish Islands.     

Prey capture and feeding behaviour in an endemic land flatworm from São Tomé Island

ABSTRACT

Two specimens of the endemic land flatworm species Othelosoma impensum Sluys & Neumann, 2017 from the volcanic island São Tomé were observed in the wild in Obo-National Park while they were preying on ants that had descended on a tree trunk after their nuptial flight. A maximum of 41 ants were assembled in a cluster by one of the flatworms, the insects being immobilised by mucus secreted by the worms. A strong cephalic retractor muscle facilitated capture of the mobile prey. Presence or absence of similar cephalic adaptations in other species of Othelosoma and other genera of land flatworms is discussed, as well as the effectiveness of the sticky mucus secreted by the worms during prey capture.     

Predation on invasive land gastropods by a Neotropical land planarian

Studies on the predatory behaviour of land planarians have focused mainly on established invasive species, while the feeding habits of non-invasive planarians are poorly understood. We analyse the predatory behaviour of Obama ladislavii, a land planarian native to southern Brazil that is common in both natural and human-disturbed areas. Observations were performed in the laboratory. Several groups of invertebrates were offered as possible prey and interactions between these invertebrates and planarians were recorded. Obama ladislavii fed on the introduced land gastropods Bradybaena similaris, Helix aspersa and Deroceras laeve, ignoring other invertebrates. Once potential prey were identified, we tested the ability of O. ladislavii to recognize and follow slime trails, and demonstrated the planarian’s ability to follow chemical trails from prey in the environment. The consumption of exotic species indicates a flexible, generalist diet that is consistent with the ability of O. ladislavii to adapt to environments altered by human activities. Thus, this species may become invasive if introduced outside of its original distribution, but it also has the potential to be used in biological control programs for pest management in its native range.     

Observations on the nesting behaviour of seven species of Crabro (Hymenoptera,Sphecidae)

Summary

Data are presented on the nests and prey of seven species of Crabro from diverse localities in North America. In two instances (virgatus and largior) this is the first published report. Further information is provided for the following previously studied species: argusinus, advena, cribrellifer, latipes, and monticola. Behavioural differences among these species are not conspicuous. Most are rather general fly predators, but cribrellifer appears to show a strong preference for Asilidae. There are also differences in type of soil used for nesting and in antipredator behaviour such as approach flights and daily cycles of activity. Two species, largior and monticola, provision their nests early in the morning, before miltogrammine flies are active in numbers. All species probably make cells of two sizes, larger cells containing more prey and producing females, smaller cells males.     

Diet and feeding behaviour of the Neotropical parrot snake (Leptophis ahaetulla) in northern Brazil

Specimens (289) of Leptophis ahaetulla from northern Brazil and western Maranhão were examined for the composition of stomach contents. Most prey items were tree frogs, especially those of the family Hylidae (90%). Most of the anurans identified belong to the Scinax ruber species group (27%) and Scinax sp. (25%). Prey size was significantly related to snake length but not to head length. There was no significant difference related to sex in either case. Both sexes preyed on small to medium‐sized items (3–10% of snake snout–vent length). Leptophis ahaetulla seems to manipulate captured prey before ingestion since most of the prey items (83.6%) were swallowed head‐first. Leptophis ahaetulla is primarily diurnal and semi‐arboreal, inhabits disturbed and undisturbed forest, and forages primarily on the ground and in fallen vegetation, where its prey items are likely to be found at rest.     

Disentangling prey-handling efficiency of larval newts through multivariate prey trait analysis

Multivariate prey trait analysis is a functional approach to understand predator–prey relationships. In the present study, six prey macroinvertebrate ecological traits were used to identify several key factors in the handling efficiency of seven predatory larval newt species. The results revealed a remarkable similarity in the feeding behaviour among species, suggesting a foraging behaviour convergence among species in the prey-handling efficiency of larval newts. Nevertheless, larvae of some newt species showed clear preferences for particular categories of ecological trait; for example, Lissotriton vulgaris tended to feed on macroinvertebrate taxa with random trajectory, and Calotriton asper fed on macroinvertebrate taxa with high agility. In contrast, Mesotriton alpestris showed a clear ability to feed on prey with movable accessories (cases/tubes) and patterned concealment. This study shows how multivariate approaches can complement traditional diet analyses, and the method has wide applicability across life-stages and species.     

The green June beetle (Cotinis nitida) (Coleoptera: Scarabaeidae): local variation in the beetle’s major avian predators and in the competition for mates

The green June beetle (Cotinis nitida) was observed in northern Virginia for a second and third flight season. The study yielded some results that were consistent with earlier findings, namely that mate-locating beetles were vulnerable to attack by avian predators and matings occurred primarily early in the flight season. Novel findings included the following: (1) blue jays (Cyanocitta cristata) were the major predators, not common grackles (Quiscalus quiscala), (2) some jays appeared to selectively prey on female beetles, (3) competition for mates among male beetles could be so intense that some males attempted to copulate with already mated (unreceptive) females, and (4) the sex ratio of the beetle population feeding on wild blackberries remained near equality late in the flight season despite the fact that the sex ratio of the population of beetles at the emergence site became highly female-biased over time.     

Foraging by the flower-dwelling spider,Misumenops argenteus (Thomisidae), at high prey density sites

In this study, the foraging sites of the crab spider Misumenops argenteus on Trichogoniopsis adenantha (Asteraceae) were investigated over a 2-year period. The choice of sites was examined in relation to prey density in rainy and dry seasons, in leaves versus stems, reproductive branches versus vegetative branches, and in flowerheads in different phenophases. Misumenops argenteus generally occupied sites where the prey frequency was high, indicating that this species was able to evaluate the quality of the foraging sites, as predicted by optimal foraging theory. One exception to the rule was that adult males occurred at all sites, independently of prey density, as also observed in other spider species in which males search for females and not for prey. In addition, young (third and fourth instar) spiders occupied flowerheads with few prey, but which provided shelter.     

Camera traps reveal use of caves by Asiatic black bears (Ursus thibetanus gedrosianus) (Mammalia: Ursidae) in southeastern Iran

The Baluchistan region of Iran and Pakistan is inhabited by one of the most threatened populations of Asiatic black bears (Ursus thibetanus gedrosianus) in Asia. The first camera-trapping survey of these so-called Baluchistan bears was conducted in Bahr-e Asman Mountain, southeastern Iran. Fourteen camera traps were installed in the entrances of caves from April to December, 2009. A total of 32 bear photographs were obtained from three caves. Data analysis of photographs showed the presence of at least seven different individuals: two lone bears, and two family groups, with one and two cubs. Despite being very marginal habitat, affected both by human use and drought, the area supports a reproducing population of bears. This study suggests that caves may be important in the life history of these bears, and should be protected for their conservation.     

Patterns of prey use in four sympatric species of Philanthus (Hymenoptera: Sphecidae) with a review of prey selection in the genus

Summary

Observations were made on four sympatric species of sphecid wasps of the genus Philanthus that nest in late summer and prey upon Hymenoptera. All four species nest in a restricted locale, but with little overlap in nesting areas. Comparison of nest contents of females demonstrated limited overlap in prey utilization among the four species, but only when both size and taxonomic category of prey were considered. The ultimate cause of this resource partitioning is unknown. Review of 30 populations of 16 species of North American Philanthus reveals varying degrees of specialization on prey types. Although populations of one species, separated in either time or space, tend to have similar niche breadths, this is not always the case. Intra-and inter-populational comparisons of prey records suggest behavioural plasticity allowing response to variations in prey availability. Some of the divergence in prey use among species is due to differences in predator size.     

The feeding strategy of the predatory Gyrineum natator (Gastropoda: Neotaenioglossa: Ranellidae) in the Cape d’Aguilar Marine Reserve,Hong Kong,with a review of sulphuric acid use in prey access by the Tonnoidea and experimentally derived estimates of consumption

Under conditions of otherwise enforced starvation in filtered seawater and with only oysters (Saccostrea mordax) to feed on, an individual of Gyrineum natator consumed > 98%, on average, of its body weight of oyster tissues each week (> 14% per day). When other potential food, such as sediment, organic debris and other newly settled sessile organisms, was available to a similar-sized conspecific living in conditions of unfiltered seawater (in addition to oysters), the oysters only accounted for 1.52% of its average weekly diet (0.21% per day). This was because of the 12 proffered oysters, only four were consumed in contrast to the 12 eaten by the individual in filtered seawater. All the oysters were accessed through large holes made in their shells. It is generally understood that the salivary glands of confamilial ranellids produce secretions of sulphuric acid from greatly enlarged salivary glands and this is demonstrated herein for G. natator also. It is believed that it was these secretions that made the holes in the oyster shells. It, therefore, seems that G. natator uses sulphuric acid to attack prey only when more easily obtained food is not available. It may also be used in defence. A comparison of consumption rates for a range of scavenging and predatory gastropod taxa shows that representatives of the Nassariidae consume (much) more than predators because of their opportunistic lifestyles. Gyrineum natator generally eats similar amounts to other predators, although the increased difference in estimated consumption (~10%) between this species and another similar-sized ranellid, Linatella caudata, might be because the latter did not use sulphuric acid to access its prey. Its enforced use in this study of G. natator, therefore, might represent the increased costs of using the acid to access the proffered oyster prey.     

An investigation of predator‐induced defence responses in ciliated protozoa

Predator‐induced defence responses have been reported in 15 species of ciliates representing three subclasses: Hypotrichia, Stichotrichia and Hymenostomia. However, the discovery of this phenomenon in such distantly related groups suggests that it could be more widespread within the Ciliophora. In laboratory experiments, we tested 23 potential prey species with a range of potential predators including other ciliates (12 spp.), amoebae (two spp.), rotifers (two spp.), a turbellarian worm (Stenostomum sphagnetorum), and an oligochaete worm (Chaetogaster sp.). In each experiment, one predator species was incubated for 24?h with one potential prey species and the latter was examined for evidence of a defence response. One new example of predator‐induced morphological change was recorded (Euplotes viridis) and detailed observations were made for one poorly known example (E. eurystomus). Both species significantly increased their width (by about 35% and 23%, respectively) in the presence of the turbellarian worm S. sphagnetorum. An induced life cycle change was recorded for the first time among hypotrichs with E. muscorum exhibiting significantly increased rates of encystation in the presence of the ciliate predators Dileptus anser and Spathidium sp. Finally, Euplotes patella, Euplotes sp. and Stylonychia pustulata, which are usually regarded as omnivorous rather than predatory ciliates, all induced morphological change in Colpidium kleini, the C. kleini cells becoming significantly shorter and wider. No examples of induced defence response were found among groups other than hypotrichs and hymenostomes.     

Diet composition of an invasive population of Lithobates catesbeianus (American Bullfrog) from Argentina

The American bullfrog Lithobates catesbeianus has been introduced around the world, with invasive populations reported from almost all South American countries. A population of this species was introduced in the Calingasta department of San Juan province, which is an arid environment in western Argentina. This work provides information on the dietary composition of an invasive population of L. catesbeianus, and compares the degree of dietary overlap between adults and juveniles. Stomach contents of 169 bullfrogs (82 adults and 87 juveniles) were analysed. Adults consumed 40 prey taxa and Hymenoptera (Insecta) was the most numerous prey item (41.8%), followed by Araneae (13.6%) and Aeglidae (13.4%). Juveniles consumed 29 prey taxa and Hymenoptera constituted the highest percentage in prey number (77.2%). The trophic overlap niche index at the same level shows a value of 0.64 overlap in dietary community between adults and juveniles of this bullfrog. Aeglidae was volumetrically the most important trophic item (25.4%), followed by Anura (25.02%). Our results showed that cannibalism in bullfrogs is more common than the consumption of native anurans, coinciding with that reported in other populations of introduced bullfrogs. The high similarity in the diets of both size classes and the association between the size of the predator and prey suggest that the impact caused by bullfrogs throughout their ontogeny is high and probably has an impact on their prey. Freshwater crabs are the main items in the diet of Lithobates catesbeianus in other introduced populations and are usually the most conspicuous at our study site. The crabs in freshwater ecosystems are part of the lowest trophic level in the food chain. The major threats to the southern region’s freshwater crabs include deforestation, farming and exotic species. Lithobates catesbeianus has a generalist diet and high overlap between adults and juveniles.     

Foregut anatomy and predation by Charonia lampas (Gastropoda: Prosobranchia: Neotaenioglossa) attacking Ophidiaster ophidianus (Asteroidea: Ophidiasteridae) in the Açores,with a review of triton feeding behaviour

This paper is the first to describe, in detail, the process of feeding by a species of Charonia. As Charonia lampas commenced attacking its sea star prey, Ophidiaster ophidianus, the latter autotomized its trailing arm and escaped. The pursuing C. lampas ate this arm. The results of this study are not in accord with the established view of feeding by species of Charonia. Firstly, C. lampas did not inject either a venom into its prey to paralyse it nor an acid to access it and, second, nor did it pierce the skeleton of its prey and suck out the tissues, all as reported in the literature. Rather, in the case herein described, C. lampas held and manipulated its prey with the foot and used its taenioglossan radula located at the end of the extendible pleurembolic proboscis to scrape and ingest the soft tissues of the sea star and, subsequently, consume the remaining skeletal components again using the proboscis and contained radula. These two phases of consumption were followed by two matching phases of faeces production. Also described is the foregut anatomy of C. lampas, including, for the first time, the minute jaws and the histology of the salivary glands, and for which comparison is made with those of the known acid-producing structures of representatives of the Cassidae and other Ranellidae. As finally described, predator and prey clearly recognised each other signifying an identifiably intimate relationship. Charonia lampas consumed only the autotomised arm and it is argued that in such a case, as an anti-predation device, autotomy is of survival benefit to both predator and prey.     

The diet of the Eleonora’s falcon (Falco eleonorae) in the Aegean archipelago (Greece)

ABSTRACT

In the present study we investigated the diet of Eleonora’s falcons in Greece and assessed the regional dietary pattern of 16 breeding colonies of the Aegean. Overall 224 nests were visited and a total of 8067 prey items were collected which contained two mollusca classes, seven insect orders, one reptile family, two mammalian taxa and at least 54 avian species. Cicadas were the most common insects found in pellets (45.1%) followed by flying ants (34.8%) and beetles (15.8%) while just 20 species (33.3%) accounted for over 90% of the avian prey items identified in bird remains dominated (>50%) by the Willow Warbler (Phylloscopus trochilus), the Red-backed Shrike (Lanius collurio) and the Whitethroat (Sylvia communis). Insect feeding peaked in late August (39.8%) and late September (20.8%), whereas bird remains built up in falcon nests from mid-August onwards, culminating in late September (57.2%) and declined abruptly afterwards. Overall the falcons’ diet diversity increased as the breeding season progressed and from the north towards the south Aegean. The avian prey species richness was negatively influenced by the distance of the colonies from the mainland and the weather conditions during September which coincides with the fledgling period of the young and the autumn peak of passerine migration.