A study of composition and diversity variation of avifauna along with different types of agroforestry system in Kibet town, Southern Ethiopia

Background Agroforestry is an integrated land-use system that plays a great role in the conservation of landscape biodiversity. The study aimed to assess the composition and diversity of avian species along with different habitat types of agroforestry in Kibet Town, Southern Ethiopia. Methods Four habitat types of agroforestry system which are home gardens, live fences, parkland, and eucalyptus woodlot were identified. Line transects were used for bird surveys. The Shannon diversity index (H′) and species evenness index (E) were used to compare diversity among habitat types. A similarity percentages (SIMPER) test was carried out to identify the main species and feeding guild that typified each habitat type. The overall significance was assessed with the ANOSIM test using PAST (version 4.03). Results A total of 50 bird species belonging to 28 families and 10 orders were recorded. Order Passeriformes (67.3%) had the highest number of species. Bird community composition differed among habitat types. The dissimilarity was mainly due to White-browed robin-chat (Cossypha heuglini), Streaky seed-eater (Serinus striolatus), Village Weaver (Ploceus cucullatus), African Paradise-Flycatcher (Terpsiphone viridis), and Black-Headed Paradise Flycatcher (T. rufiventer). The finding also revealed that insectivore was the dominant feeding guild. Conclusions The present study shows evidence that more insectivore bird species use different types of agroforestry as habitat and foraging sites. So, any concerned bodies who have engaged in avian conservation should give special consideration to this modified landscape.

Population density and structure of a breeding bird community in a suburban habitat in the Cuvelai drainage system, northern Namibia

In a suburb (c. 100 ha) of Ongwediva, a total of 30 breeding bird species were recorded in 2018. Shannon’s Diversity Index was 2.01. Passer domesticus comprised almost half of all breeding pairs (36.4 pairs / 10 ha). Granivores were by far the most numerous feeding guild, comprising 77.5 % of all birds breeding. Birds nesting on/in buildings were represented by two species only, but they comprised almost half (49.9 %) of all breeding birds. In comparison with other southern African towns, the number of bird species breeding in Ongwediva was low. This was compensated by high population densities of some species.

Herbivory on the pedunculate oak along urbanization range in Europe: effects of local forest cover and insect feeding guild

Urbanization is recognized as an important driver of the diversity and abundance of tree associated insect herbivores, but its consequences for insect herbivory are controversial. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effect of urbanization and local canopy cover on insect herbivory in the pedunculate oak (Quercus robur) throughout most of its geographic range in Europe. The damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing urbanization around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of urbanization. In contrast, an increase in local canopy cover buffered the negative effect of urbanization on leaf-miners and strengthened its effect on gall-inducers. These results show the complexity of plant-herbivore interactions in urbanized areas, highlighting that the presence of local canopy cover within cities has the potential to attenuate or modify the effect of urbanization on biotic interactions.

Plasticity in induced resistance to sequential attack by multiple herbivores in Brassica nigra

In nature, plants interact with multiple insect herbivores that may arrive simultaneously or sequentially. There is extensive knowledge on how plants defend themselves against single or dual attack. However, we lack information on how plants defend against the attack of multiple herbivores that arrive sequentially. In this study, we investigated whether Brassica nigra L. plants are able to defend themselves against caterpillars of the late-arriving herbivore Plutella xylostella L., when plants had been previously exposed to sequential attack by four other herbivores (P. xylostella, Athalia rosae, Myzus persicae and Brevicoryne brassicae). We manipulated the order of arrival and the history of attack by four herbivores to investigate which patterns in sequential herbivory determine resistance against the fifth attacker. We recorded that history of sequential herbivore attack differentially affected the capability of B. nigra plants to defend themselves against caterpillars of P. xylostella. Caterpillars gained less weight on plants attacked by a sequence of four episodes of attack by P. xylostella compared to performance on plants that were not previously damaged by herbivores. The number of times the plant was attacked by herbivores of the same feeding guild, the identity of the first attacker, the identity and the guild of the last attacker as well as the order of attackers within the sequence of multiple herbivores influenced the growth of the subsequent herbivory. In conclusion, this study shows that history of sequential attack is an important factor determining plant resistance to herbivores.

Ecological patterns of polychaete assemblages associated with the Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767): a comparison of sites in two biogeographic zones (Adriatic and Aegean Sea)

The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) is a well-known habitat builder, and as such hosts a diversified faunal assemblage. Although polychaetes are one of the most abundant and diverse macrobenthic groups associated with C. caespitosa colonies, our knowledge of their ecological features in this association is still limited. The aim of this paper was to gather and compare the most comprehensive data available on polychaetes associated with C. caespitosa in the Adriatic and the Aegean Seas, and to test for differences between these geographic areas. To this end, differences were tested in terms of: (i) richness and structure of polychaete assemblages; (ii) feeding and functional traits of assemblages; (iii) the main factors influencing those aspects, (iv) the relationship between polychaete assemblages richness and Cladocora colony size, and estimate richness. Differences were observed between the Adriatic and the Aegean Seas, in terms of richness, species composition and relative proportion of the dominant feeding guild (filter feeders most abundant in the Aegean and carnivores in the Adriatic) and motility mode (sessile most abundant in the Aegean and motile in the Adriatic). Conversely, cosmopolitan and Atlanto-Mediterranean species dominated the assemblages in both geographic areas, and the same Species-Area Relation model proved to be effective for richness estimation in both geographic areas.

On the high bird diversity in the non-protected regions of Trashiyangtse District in Bhutan

Birds are ecological indicators of ecosystem health. Baseline information on bird diversity are, therefore, important for ecological monitoring. Such information is, however, sorely lacking for many areas outside the protected areas. Here, we explore the avian diversity and present a comprehensive checklist for the non-protected regions of Trashiyangtse District in northeastern Bhutan. We also categorise the bird species by their residency pattern, feeding guilds, abundance, and IUCN Red List status. We conducted an avifauna exploration for a period of four years from 2017 to 2020, mostly through opportunistic encounters coinciding with regular field visits. We recorded a total of 273 bird species belonging to 173 genera, 69 families and 19 orders. Passeriformes was the most dominant order with 41 families and 174 species and Muscicapidae was the most dominant family with 12 genera and 32 species. Most birds were altitudinal migrants (39%), insectivorous (45%), and occasional (44%) in terms of residency pattern, feeding guild, and abundance, respectively. Only one species (Ardea insignis) was listed as Critically Endangered and one (Haliaeetus leucoryphus) as Endangered. Our study identified the non-protected regions of Trashiyangtse District as an important bird diversity area in Bhutan.

Mammal Species Richness at a Catena and Nearby Waterholes during a Drought, Kruger National Park, South Africa

Catenas are undulating hillslopes on a granite geology characterised by different soil types that create an environmental gradient from crest to bottom. The main aim was to determine mammal species (>mongoose) present on one catenal slope and its waterholes and group them by feeding guild and body size. Species richness was highest at waterholes (21 species), followed by midslope (19) and sodic patch (16) on the catena. Small differences observed in species presence between zones and waterholes and between survey periods were not significant (p = 0.5267 and p = 0.9139). In total, 33 species were observed with camera traps: 18 herbivore species, 10 carnivores, two insectivores and three omnivores. Eight small mammal species, two dwarf antelopes, 11 medium, six large and six mega-sized mammals were observed. Some species might not have been recorded because of drought, seasonal movement or because they travelled outside the view of cameras. Mammal presence is determined by food availability and accessibility, space, competition, distance to water, habitat preferences, predators, body size, social behaviour, bound to territories, etc. The variety in body size and feeding guilds possibly indicates a functioning catenal ecosystem. This knowledge can be beneficial in monitoring and conservation of species in the park.

The relationship between resource abundance and insect herbivory on islands

We examined the relationship between resource abundance and the feeding activity of phytophagous insects on three common island plants. The aim was to investigate the correlation between phytophagous insects’ abundance and availability of food and island geography. We collected 30,835 leaves from three tree species groups (Mallotus japonicus, Prunus species, and Quercus species) on 18 islands in southwest Korea. The number of plant resources for herbivores varied: the number of leaves per shoot was the highest in Mallotus, leaf weight and the water content per leaf was significantly lower in Quercus species. External feeding was higher for Prunus and Quercus species, whereas the internal feeding type was significantly higher for Quercus species. Geography (area and distance), elevation and food resource (elevation, number of plant species, and the forest cover rate) had a variable effect on phytophagous insects feeding activities: distance and the number of plant species were more explainable to the external feeding guild. In contrast, area and forest cover were more to the internal feeding guild.

Many More Consumers Not Always Induce Stronger Competition: Weaker Interspecific Competition Despite Higher Species Richness in Secondary Feeding Guild, as Compared to Primary

The species functional structuration (specifically in terms of species richness and average intensity of interspecific competition) is widely varying among species communities and this point is now very well documented in literature. But, what about the species functional structuration within the different feeding guilds that coexist in a same local community – in particular the primary and the secondary feeding guilds? Are there significant differences – or not – between them in this respect? This rather fundamental issue does not seem having been addressed yet, at least using appropriate investigative tools. However, a series of recently published case studies, precisely implementing such an adequate investigative approach, now deserves full consideration in this regard and makes the subject of the present review. Substantially, it results from this preliminary survey of the question that marked differences in the patterns of species functional structuration clearly singularize the secondary from the primary feeding guilds, within a same local community. More precisely, a consistent trend seems to arise, highlighting both: (i) a markedly greater species richness and, yet somewhat unexpectedly, (ii) a significantly reduced intensity in interspecific competition within secondary feeding guild as compared to primary. The point is discussed and interpreted as being the consequence of the fact that secondary feeders (typically carnivores) have obviously evolve quite more diversified feeding behaviors than did the primary feeders (typically herbivores).