The composition of haypiles of Turuchan pika (Preliminary analysis)

The species composition and abundance of plants in the Turuchan pika habitat and in its haypiles were studied in the talus surrounded by taiga on the Primorsky ridge. With the Ivlev’s Electivity Index, it was found that the pika was selective in collecting food: Veratrum nigrum and Urtica dioica, being relatively rare in the habitat, were highly preferred and abundant in the haypiles. The bulk of the haypiles also consisted of 4 species (Rubus matsumuranus, Sambucus sibirica, Populus tremula, Spiraea media) with a high abundance in the habitat and collected proportionally with their abundance. Many plant species being abundant in the habitat were not stored by pikas.

Feeding of Barbus cyclolepis Heckel, 1837 (Teleostei: Cyprinidae) and its relationship with benthic macroinvertebrate fauna in the Istranca Stream (İstanbul, Turkey)

The aims of the study are to determine what the organisms Barbus cyclolepis consume as food in its feeding environments and to compare prey consumption with prey abundance in the environment. The study was conducted in the Istranca Stream located in Istanbul (Turkey) during the spring and summer of 2012. A total of 142 B. cyclolepis specimens were captured and it is determined that 94 of them had full digestive tracts. Diet analyses of B. cyclolepis showed that its food spectrum consisted of 11 different food types, and the species was found to feed on insects, mainly Diptera (IRI%= 92.26%). The most abundant macroinvertebrate organisms in the environment were Diptera and Gastropoda. The electivity index of B. cyclolepis was positive for Diptera in the spring (E= 0.49), but the value was below the expected value of 0.6 for high selectivity. The electivity values for other macroinvertebrate groups, consumed in low proportions, were negative. In summer, the fish fed on Diptera, Plecoptera, and Trichoptera, but a high electivity index value was found only for Trichoptera (E= 0.87). Results showed that B. cyclolepis mainly consumed Diptera as food and did not consume Gastropoda, although it is the second most abundant macroinvertebrate group in the environment. A relationship was determined between the proportion of food groups consumed in the digestive tracts of fish and the ratios of macroinvertebrates in the environment, and as a result, it was specified that the fish was selective on Diptera.

Which Index Should I Use? A Comparison of Indices for Enclosure Use Studies

Enclosure use assessments have gained popularity as one of the tools for animal welfare assessments and Post Occupancy Evaluations. There are now a plethora of studies and enclosure use indices available in published literature, and identification of the most appropriate index for each research question is often challenging. The benefits and limitations of four different enclosure use indices; Original and Modified Spread of Participation Index, Entropy, and Electivity Index were compared. Three artificial data sets were developed to represent the challenges commonly found in animal exhibits, and these indices were applied to these contrived enclosure settings. Three of the indices (Original SPI, Modified SPI, and Entropy) were used to assess a single measure of enclosure use variability. When zones within an exhibit were comparable in size, all three indices performed similarly. However, with less equal zone sizes, Modified SPI outperformed Original SPI and Entropy, suggesting that the Modified formula was more useful for assessing overall enclosure use variability under such conditions. Electivity Index assessed the use of individual zones, rather than the variability of use across the entire exhibit, and therefore could not be compared directly to the other three indices. This index is therefore most valuable for assessing individual resources, especially after exhibit modifications.

The bitter end: primate avoidance of caterpillar-infested trees in a central Amazon flooded forest

Animal–plant interactions are often mediated by chemical compounds. It has been widely reported that herbivore damage to plants induces chemical defenses which may then affect subsequent interactions with both invertebrate and vertebrate herbivores. Our study investigated the effects of the interaction between larvae of an unidentified nymphalid butterfly and the tanimbuca tree (Buchenavia ochroprumna Eichl.; Combretaceae) on subsequent folivory by a primate, the golden-backed uacari (Cacajao ouakary (Spix, 1823); Pitheciidae). Primate-feeding observations, records of the extent of nymphalid – B. ochroprumna interactions, and tree distribution occurred in Jaú National Park, Amazonas State, Brazil. The values of Ivlev’s electivity index showed that C. ouakary strongly rejected trees infested by caterpillars (−0.68), whereas non-infested trees were highly selected by them (+0.84). Given this behavior, we suggest that C. ouakary may be deterred by (i) caterpillars, (ii) change in leaf chemical composition induced by caterpillars, or (iii) a combination of both.

Feeding ecology and food preferences of Cherok Paloh, Pahang horseshoe crab, Tachypleus gigas

Intensive previous studies on horseshoe crabs feeding ecology were mostly focus on Limulus polyphemus. Their food preference might be different depend on the availability and abundance of feeds in the particular environment. This paper aims to investigate the feeding ecology and food preferences of Cherok Paloh, Pahang Tachypleus gigas. Ten samples of male and female horseshoe crabs, Tachypleus gigas were trapped in fishing net during the incoming high tide and 20 samples of male and female were hand-harvested at the spawning beach; 10 samples during pre-mating and 10 samples during post-mating. Their gut content was analysed by the Electivity Index. Results showed that Tachypleus gigas coming to spawn with full gut content. Echinoderm served as a main food composition in the gut of males (50%) and females (51.94%) during the open sea migration phase. The main composition was substituted by macrophyte (males: 59.51% to 65.15%; females: 36.36% to 58.10%) as they arrived to shore. Based on Electivity Index, male crabs showed positive preference toward polychaete (EI: 0.04) and macrophyte (EI: 0.19) at the spawning site while, the females showed positive preference toward bivalve (EI: 0.46). Further study on feeding ecology is needed in order to improve the population of Tachypleus gigas in Malaysia.

Prey Availability or Electivity in the Diet of some Amphibians from Olinlin- Uzea, Esan North East, Edo State, Nigeria

The diet of four species of frogs, Hoplobatrachus occipitalis, Ptychadena bibroni, Amietophrynus maculatus and Leptopelis sp. from Olinlin -Uzea, Esan North East Local Government Area in Edo State, Nigeria was studied between July and November 2014. Specimens were stomach-flushed and a total of 166 prey items from 13 prey categories recorded. Hoplobatrachus occipitalis had the highest niche breadth (6.04) indicating a rich diversity of prey while Leptopelis sp. an arboreal frog had the least (2.67). Hoplobatrachus occipitalis and P. bibroni had a niche overlap of 0.79 indicating a common use of the microhabitat while no overlap was recorded between Leptopelis sp. and Amietophrynus maculatus and P. bibroni. The low electivity indices observed in Hoplobatrachus occipitalis, Ptychadena bibroni, and Amietophrynus maculatus is an indication that feeding was based more on the availability of prey rather than preference. Although a high electivity index was recorded for Leptopelis sp, it is most likely due to its restricted microhabitat and the corresponding available prey. Caution should, however, be employed with electivity indices as results could be affected by inadequate sampling.

Habitat use by Astyanax taeniatus (Jenyns, 1842) (Characiformes: Characidae) in a coastal stream from Southeast Brazil

The habitat use of a stream-dwelling Astyanax taeniatus from the State of Rio de Janeiro was investigated. We performed 12 h of underwater observation in a 200 m long stretch in the upper Roncador stream and quantified the following microhabitat descriptors: (i) water velocity, (ii) distance from the stream bank, (iii) substratum, and (iv) water column depth. Microhabitat selectivity was analyzed by comparing the microhabitat used by fish and the microhabitat available in the study site as well as by applying the Ivlev Electivity Index to the microhabitat use data. Differences in the use and availability of the various microhabitats revealed non-stochastic patterns of spatial occupation by A. taeniatus, which was selective for two of the four analyzed microhabitats. Our findings indicated that A. taeniatusis associated with habitats that have higher depths, low water velocity, and sand and bedrock substratum.

Microhabitat use by Phalloceros harpagos Lucinda (Cyprinodontiformes: Poeciliidae) from a coastal stream from Southeast Brazil

The size-related microhabitat use of Phalloceros harpagos Lucinda, 2008 from Mato Grosso stream (Saquarema - RJ) was examined. We analyzed, during 8.3 h of underwater observation, a 200 m long reach in the upper Mato Grosso stream, quantifying the following microhabitat descriptors: (i) distance from the stream bank, (ii) water column depth, (iii) occurrence on riffle, pool or run mesohabitat, (iv) water velocity, (v) substratum, and (vi) subaquatic vegetal cover. Microhabitat selectivity was analyzed by comparing the microhabitat used by fish and the microhabitat available in the study site. Complementary analyses, based in the Ivlev Electivity Index were applied in order to test selectivity for the microhabitat use. We did not found differences in the microhabitat used by juvenile and adult individuals. Phalloceros harpagos was selective for five among the six analyzed microhabitat descriptors. The occurrence of Phalloceros in the studied stream was limited to shallow pools, close to the river bank, with low water velocities and mud substratum. Vegetal cover was not an important factor in the occurrence of the studied species.

Sources of bycatch of loggerhead sea turtles in the western Mediterranean other than drifting longlines

Álvarez de Quevedo, I., Cardona, L., De Haro, A., Pubill, E., and Aguilar, A. 2010. Sources of bycatch of loggerhead sea turtles in the western Mediterranean other than drifting longlines. – ICES Journal of Marine Science, 67: 677–685. A survey, including questionnaires to fishers and observers on board fishing vessels, was conducted to assess turtle bycatch in the waters off Catalonia (northeastern Spain), a region inhabited mainly by loggerhead sea turtles (Caretta caretta) from the highly endangered eastern Mediterranean rookeries. Observer reports confirmed that the data produced by the interviewees were reliable, so interview results were used to estimate turtle bycatch. The number of turtles caught monthly per vessel was estimated at 0.01 for bottom longlines, 0.02 for trammelnets, 0.07 for bottom trawling, and 1.2 for drifting longlines. From these values, 481 (95% CI: 472–491) turtles were estimated to be taken annually as bycatch by the whole fleet. Bottom trawling and trammelnets were the most widely used fishing gears (33 and 31% of the total 11 237 fishing months), but most turtles were caught either by bottom trawlers (249; 95% CI 83–415) or by drifting longlines (124; 95% CI: 40–199). Ivlev's electivity index revealed that bottom trawler bycatch was higher than expected in areas with a wide continental shelf. Given the heavy turtle mortality associated with bottom trawling and the fact that, in southern Catalonia, the fleet mainly takes turtles from western Mediterranean rookeries, it is suggested that the fishery be regulated through winter fishing restrictions, reducing the number of bottom trawlers working in the area, reducing the time the net is in the water to prevent turtle suffocation, or being obliged to use turtle excluder devices.