Parasitic infection patterns in Coleodactylus meridionalis (Squamata: Sphaerodactylidae) from Atlantic Forest fragments, northeast of the Neotropical Region

Summary Studies that seek to understand which factors influence the patterns of infection in the lizard Coleodactylus meridionalis are non-existent. In this way, we recorded the infection rates for these lizards from three different sized fragments of the Atlantic rainforest and investigated if there is influence of the size, mass and sex of the host regarding the endoparasite abundance. In addition, we investigated if there were possible associations between the host’s diet and parasitism, by calculating the diet niche breadth (based on the prey number of pooled stomachs) for each host population and comparing the diet between fragments and sexes (from the three sampled fragments). We collected 38 lizards across the three sampled forest fragments. We only found parasites in the lizards sampled from the smallest of the three forest fragments which included: Physaloptera lutzi, Haplometroides odhneri and Oligacanthorhynchus sp. For this population, lizards with greater length and body mass have a greater endoparasite abundance. In addition, based on the results obtained in our study, the diet of the lizards varies in food composition between sampled populations. Finally, knowing that among the infected lizards there is no sexual dimorphism in relation to size and body mass and that the stomach sampling for this population is insufficient to calculate the indexes related to the food niche; we used the number of prey lizards from all populations, thus we were able to associate the fact that female lizards have a greater endoparasite abundance due to variations in food composition between sexes.

KOMPOSISI DAN LUAS RELUNG MAKANAN IKAN PALUNG (Hampala macrolepidota C.V.1823) DI WADUK PB. SOEDIRMAN BANJARNEGARA, JAWA TENGAH

This study aims to determine the composition and value of the natural feed niche of trough fish caught from the waters of the PB Reservoir. Sudirman. The research method used is a survey method with a sampling technique using purposive random sampling. The research location was divided into three stations, namely I (Karang Kemiri), II (Wanadadi), and III (Karang Jambe). Sampling was carried out three times (19 February, 07 March, and 2 August 2020). Data were analyzed descriptively comparatively. The results showed that the composition of the trough fish diet was dominated by Chlorophyta and plant debris. Based on the selectivity index and the most significant part of trough fish, including omnivorous fish. Large trough fish have a high food niche area. Small, medium and large trough fish have stiff competition for food in the waters

Winter diet of Long-eared Owls (Asio otus) in the southern Pannonian Plain (Serbia, Vojvodina)

Owl diets undergo qualitative changes across the different regions of their area of distribution. During the four winters (from 2014–15 to 2017–18), Long-eared Owls’ pellets were collected at three winterroosts located at the southern part of Pannonian Plain, in the Serbian province of Vojvodina. In 8070 prey items from pellets, we identified 16 mammal and 32 bird species. The Common Vole was the dominant prey species with a proportion in a range from 27.4% to 71.6%. The Muridae family formed a supplementary part of the diet: Mus sp., wood mouse and harvest mouse, during all winters. Birds were also a major supplementary prey during winter 2014–15, comprising 10.6%. A comparison of our results with the diet of Long-eared Owls wintering at the northern Pannonian plain (southwestern Slovakia) indicated an increase the proportion of some species in the southern part. How different land uses in agriculture and environmental conditions may be reflected in the food supply are discussed in relation to the diet composition of Long-eared Owls and an environment whose is richer provides both growing diversity in the diet of these owls and an expansion of their food niche. Our study described the Long-eared Owl as opportunistic predators expanding their food niche in the presence of diversified prey.

Food Niche Overlap of Avian Predators (Falconiformes, Strigiformes) in a Field and Forest Mosaic in Central Poland

Food niche overlap statistics are a common way to show competition for food resources in a group of animals. Niche breadths of various species are very variable and their diet composition changes reflecting prey availability. The aim of this study was to evidence the food niche overlap of the whole assemblage of avian predators (eight raptor and owl species, some of them reaching very high densities) in a field and forest mosaic of central Poland. The diet composition was assessed on the basis of pellet analyses and the identification of prey remains found under the nests in the breeding period. The extent of the niche overlap was calculated using a Pianka formula. The food niche overlap indices ranged from 0.02 to 0.93 (mostly below 0.5). The most separate food niche was that of the white-tailed eagle, who regularly preyed on fish. The highest niche overlap was recorded for the common buzzard and common kestrel, two species preying on field rodents, switching to soricomorphs when the former were scarce. Our results confirmed that the food niches of species coexisting in the same area were considerably separate, which is a result of preying on various prey species or searching for them in different habitats.

Breeding diets of the Little Eagle Hieraaetus morphnoides and Wedge-tailed Eagle Aquila audax in the Australian Capital Territory in 2011–2019

The diets of the Little Eagle Hieraaetus morphnoides and Wedge-tailed Eagle Aquila audax breeding sympatrically in the Australian Capital Territory during 2011–2019 were compared by analysis of pellets and prey remains (six Little Eagle territories and 13 Wedge-tailed Eagle territories; 69 and 49 collections for a total of 232 and 256 prey items, respectively). Little Eagles took 33% mammals (29% European Rabbits Oryctolagus cuniculus), 44% birds, 6% reptiles and 17% insects by number, and 65% mammals (62% Rabbits), 27% birds, 8% reptiles and <1% insects by biomass. Wedge-tailed Eagles took 59% mammals (23% Rabbits and 19% macropods), 38% birds, 1% reptiles, <1% fish and 1% insects by number, and 89% mammals (20% Rabbits, 38% macropods), 10% birds, and <1% reptiles, fish and insects by biomass. Indices of dietary diversity (Shannon Index and Standardised Food Niche Breadth) were 2.57 vs 3.07 and 0.19 vs 0.24, respectively; Geometric Mean Prey Weights (GMPW) were 164 vs 1392 g, but discounting a biased sample of insects in many pellets from two fledglings, Little Eagle GMPW was more like 340 g. Dietary proportions and some metrics for both species appear to have changed little since the preceding decade, although Wedge-tailed Eagle dietary diversity increased slightly and dietary overlap (80%) increased greatly, concomitantly with some pairs of Wedge-tailed Eagles replacing pairs of Little Eagles. Intraguild predation occurred, including Wedge-tailed Eagle predation on Little Eagles.

Diet Selection of Heteracris littoralis in a Cultivated Environment, Mzab Valley, Septentrional Sahara, Algeria

This paper presents the results of a study on the diet of Heteracris littoralis in an agro-ecosystem at Mzab valley, Ghardaïa Province, Northern Sahara, Algeria. The diet was determined by the analysis of plant fragments in the feces of H. littoralis sampled in the field. The studied grasshopper consumed 12 of the 30 plant species found in the cultivated environment. The results showed that the locust predominantly fed on a few plants, such as Lagenaria siceraria and Solanum lycopersicum, although their diet includes over 12 plant species. Its food niche breadth was narrow (0.51), with a selectivity index of 0.61 for females, 0.52 for males and 0.42 for larvae. The plants consumed by the two sexes and larvae were not significantly different. This study suggests that Eyprepocnemidinae is a polyphagous grasshopper species, in spite of pronounced preference towards Cucurbitaceae and Solanaceae. This property results in a low Berger-Parker index value (0.24). Results are of great significance, increasing the understanding of insect herbivore feeding behavior and how to control the damage caused by this Orthoptera.

Food niche of solitary and social bees (Hymenoptera: Apoidea) in a Neotropical Savanna

In this study we investigated the group of floral resources that support bee populations from a bee assemblage in a savanna, and the way in which bee species use these food resources, with an emphasis on the breadth and overlap of trophic niches. The interactions between 75 species of bees and 62 species of plants visited to obtain floral resources were recorded on a Brazilian savanna site. The bee species explored a diverse set of plant species, but concentrated the collection of resources in a few plant species. The distribution of the samples over a long period favored a robust characterization of the food niche of the bee populations. Byrsonima sericea, Serjania faveolata, and Stigmaphyllon paralias were the plant species with the highest number of links with bees. In general, the trophic niche overlap was low, with 75% of pairs of bee species having a niche overlap (NO) less than 0.33. Only four pairs showed high overlap (NO>0.70) and all cases were related to the exploitation of floral resources provided by B. sericea, a key resource for the maintenance of the local bee fauna, an oil and pollen provider.

Temperature niche difference and interspecific competition determine the parapatric distribution of two congeneric species in Diaphanosoma

Background Diaphanosoma excisum and D. dubium are parapatrically distributed in tropical and subtropical waters, and rarely coexist at local communities in the transition between tropics and subtropics. According to Janzen’s hypothesis and the modern coexistence theory, the specific thermal adaptation and strong interspecific competition between the two congeneric species are assumed to result in their range limits. To explore the mechanisms underlying such parapatric distribution, we modeled their current geographic distribution, and compared temperature niche difference and fitness inequality in interspecific competition with their representative clones.Results The species distribution modeling showed that the two Diaphanosoma species had significantly divergent climate niches. Their life history parameters in monocultures also demonstrated as stable temperature niche difference, while D. excisum had higher fitness than D. dubium in dimension of food niche. The competition experiments revealed a strong exploitative competition between the two species, and D. excisum was the superior competitor, and excluded D. dubium in all the competition experiments within overlapping temperature niche regardless of food conditions.Conclusions Our results suggest that stable temperature niche difference overcoming interspecific competition for food plays a critical role in shaping Diaphanosoma species range.

Kebiasaan Makanan Belangkas, Tachypleus gigas (Müller 1785) dan Carcinoscorpius rotundicauda (Latreille 1802) di Perairan Pesisir Balikpapan, Kalimantan Timur

Horseshoe crabs are living fossils found in Indonesia. This study examined the food habit of horseshoe crabs (Carcinoscorpius rotundicauda and Tachypleus gigas) collected from Balikpapan coastal waters, East Kalimantan. Horseshoe crabs were captured using gill nets and picked by hand along the Balikpapan coast. The width of the prosoma and the body weight of each individual were measured, and the gut contents were analysed to determine the preponderance index, food niche breadth, and niche overlap. Carcinoscorpius rotundicauda prosoma widths ranged from 4.1 to 15.4 cm and those of Tachypleus gigas ranged from 2.8 to 24 cm. Eight food items were found in the gut of the horseshoe crabs, namely: bivalves, gastropods, scaphopoda, polychaetes, echinoderms, crustaceans, leaf litter and others. Based on the preponderance index, gastropods were the main food item of the two horseshoe crab species. In accordance to the food composition the horseshoe crabs inhabiting Balikpapan coastal waters are categorized as benthivores.

Diet of the Australian Hobby Falco longipennis breeding in Canberra, Australian Capital Territory, in 2002–2004 and 2005–2008

The diet of the Australian Hobby Falco longipennis was studied in Canberra (ACT), in the summers of 2002–2003 to 2004–2005 and 2005–2006 to 2008–2009 by analysis of prey remains and pellets (28 and 40 collections for a total of 229 and 132 prey items from six and four nests, respectively). The Hobbies’ breeding diet in the first period consisted of 73% birds, 1% microbats and 26% insects by number, and 98% birds, <1% microbats and 1% insects by biomass, mainly parrots (Psittaculidae), Common Starlings Sturnus vulgaris and sparrows Passer sp. In the second period, it consisted of 94% birds, 3% mammals (mostly microbats), 2% lizards and <1% insects by number, and was more dominated by Starlings and other introduced birds, with the change perhaps reflecting a recent decline in local insect abundance. The Hobby’s dietary metrics correspondingly shifted to a greater Geometric Mean Prey Weight and narrower food niche. The Hobby’s diet overlapped moderately (42%) with that of the similarly sized Collared Sparrowhawk Accipiter cirrocephalus in the ACT over the same timeframe, although the two are separated by foraging habitats and methods.