Population Densities and Community Structure of Birds Breeding in a Suburban Wooded Grassland in the Highveld of Lesotho

The mapping method was employed to study avian community structure in relation to rainfall in a town suburb in Highveld grassland in southern Africa. Studies were conducted in two breeding seasons: 1998, with dry spring; and 2001, with close to average spring rainfall. The total rainfall in 1998 was 1254 mm, while in 2001 it was 1445 mm, in both years much above the long-term annual average (866 mm). The avian community remained remarkably similar in both years, both in respect to the number of species (44 in 1998 and 53 in 2001), and dominance relationships. The Simpson’s Diversity Index was high and also very similar in 1998 and 2001 (D = 0.91; 0.93 respectively). In all years, dominant species included the Laughing Dove, Grey-headed Sparrow, Speckled Dove, Cape Turtle-Dove and Common Fiscal. The Southern Red Bishop in 2001 was also in the group of dominants. Significant differences were noted in the overall density of all birds, but contrary to expectation density was higher in 1998, with lower rainfall, than in 2001, with higher rainfall. The proportions of nesting and feeding guilds were similar in both years compared, except for the granivores, which were proportionally more common in 1998 than in 2001. This difference was mainly due to the Laughing Dove and Grey-headed Sparrow. Generally, it appears that the suburban avian community is more stable and more diverse than neighbouring communities in the natural habitats.

ESTRUCTURA DE LA COMUNIDAD DE AVIFAUNA ASOCIADA AL MANGLAR EL CONCHALITO, BCS, MÉXICO BAJO DIFERENTES CONDICIONES DE MAREA

RESUMEN. El estudio de la estructura de comunidades de aves está relacionado con su relevante papel en el ecosistema, y cobra mayor importancia cuando se hallan expuestas al daño colateral por actividades antropogénicas. Esta investigación tuvo por objetivo determinar la variación de la estructura en la comunidad de aves en el manglar de El Conchalito, BCS, mediante la aplicación de índices ecológicos como diversidad (H´), dominancia (D) e índice de valor biológico (IVB), durante abril-julio de 2016 en la temporada de transición primavera - verano. Para describir el marco ambiental, se realizaron mediciones de temperatura, nivel de ruido y clorofila a. Igualmente, se utilizaron datos climatológicos. Se registraron 15 especies de aves acuáticas, marinas y/o costeras (5 órdenes, 7 familias y 9 géneros) y 3 especies de aves terrestres (2 órdenes, 2 familias, 3 géneros). Las máximas abundancias de aves se registraron durante los primeros muestreos. La diversidad osciló entre H´= 1.1 y H´= 1.8, con máximos al inicio y final del periodo de estudio. Esto se relaciona con mareas bajas e incremento en la riqueza de especies, respectivamente. El nivel de ruido y concentración de clorofila a no se asociaron directamente con los cambios observados en la estructura de la comunidad. La riqueza específica se asoció de manera directa con el incremento de temperatura. Las especies de aves más importantes fueron: Egretta thula (96.9%), Zenaida asiatica (88.7%), Numenius phaeopus (86.8%) y Egretta rufescens (83.8); de menor importancia fue Ceryle alcyon (28.2). Se identificaron 3 especies sujetas a protección (NOM-059-SEMARNAT-2010). Avifaunal community structure associated to El Conchalito mangrove, BCS, Mexico under different tide conditionsABSTRACT. The importance in the study of avian community structure relates to their relevant role in the ecosystem. Specially, when they are exposed to collateral damage by anthropogenic activities. The goal of this research was to determine the variation of avian community structure in the mangrove forest El Conchalito, BCS through the use of ecological indices such as diversity (H’), dominance (D), and the biological value index (IVB) in April-June of 2016 during the seasonal transition from Spring-Summer. To describe the environmental frame, measurements of temperature, noise level, and chlorophyll a were made, and other climatological data were used. A total of 15 species of aquatic, marine or shore birds were recorded (5 orders, 7 families and 9 genera), and 3 species of terrestrial birds (2 orders, 2 families and 3 genera). Maximum bird abundances were observed during the first sampling. Diversity values varied between H´= 1.1 and H´= 1.8, with maxima at the beginning and at the end of the study period. This was related with the low tides and the increase of species richness, respectively. Noise level and chlorophyll a concentration, were not associated directly with the changes observed in the community structure. Species richness was associated directly with temperature increase. The most important bird species were: Egretta thula (96.9%), Zenaida asiatica (88.7%), Numenius phaeopus (86.8%), and Egretta rufescens (83.8); less important was Ceryle alcyon (28.2). Three species protected under NOM-059-SEMARNAT-2010

Avian community structure and habitat use ofPolylepisforests along an elevation gradient

BackgroundAs one of the highest forest ecosystems in the world,Polylepisforests are recognized both as center of endemism and diversity along the Andes and as an ecosystem under serious threat from habitat loss, fragmentation, and climate change due to human activities. Effective conservation efforts are limited, in part, by our poor understanding of the ecology and habitat needs of the ecosystem’s flora and fauna.MethodsIn 2014–2015, we studied bird communities and 19 associated local and landscape attributes within five forested glacial valleys within the Cordillera Blanca and Huascaran National Park, Peru. We surveyed birds during the dry (May–August) and wet (January–April) seasons at 130 points distributed along an elevational gradient (3,300–4,700 m) and analyzed our data using Canonical Correspondence Analysis (CCA).ResultsWe associated a total of 50 species of birds, including 13 species of high conservation concern, with four basic habitat types: (1)Polylepis sericeaforests at low elevations, (2)P. weberbaueriforests at high elevations, (3) Puna grassland and (4) shrublands. Four species of conservation priority (e.g., Microspingus alticola) were strongly associated with large forest patches (∼10-ha) ofP. sericeaat lower elevations (<3,800 m), whereas another four (e.g., Anairetes alpinus) were associated with less disturbed forests ofP. weberbaueriat higher elevations (>4,200 m).DiscussionResults suggest two key strategies form the cornerstones of conservation efforts: (a) protect large remnant (>10-ha)P. sericeaforests at lower elevations and (b) maintain all relicts ofP. weberbaueri, irrespective of size, at high elevations (>4,200 m).