Population status and distribution of the critically endangered Indian Courser (Cursorius coromandelicus) on Delft Island, Sri Lanka

The critically endangered Indian Courser ( Cursorius coromandelicus) is a rare resident bird species in Sri Lanka. This bird species is restricted to the northern avifaunal region of Sri Lanka, and even there it has been recorded from only a few locations. Thus, it is identified as one of the rarest birds in Sri Lanka. A 1-year study was conducted to investigate Indian Courser population and their distribution within the Delft Island from 5th of January to 20th of December 2020. Ten (10) randomly selected points were investigated in this study. Of the 10 sampling points, the Indian Courser was observed within three (03) sampling points year around while several sightings were recorded in points 8, and 9 during 3 months of the year. Their abundance significantly varied among sampling locations (one-way ANOVA, F = 15.04, p < .05). The maximum number of individuals recorded was 18 ± 4.64 in December and the minimum number was 4 ± 4.64 during the non-migrant season. Although most of the area in the island is covered with dry grasslands, their distribution in Delft is largely confined to a few grassland patches where human activities are minimum. Hunting, egg collection, and trampling of their nest by the Delft ponies (feral horses) can be identified as the main threats of this species. It is of utmost importance to immediately implement holistic conservation measures to save this critically endangered bird as Delft is the only known location where a viable resident population of Indian Courser is found.

Bird diversity, composition and response during COVID-19 in an urban landscape, Jamalpur, Bangladesh

The world has been encountering a COVID-19 pandemic since late 2019. The world’s people have also witnessed the free movement of wildlife, even in many urban areas in some countries during the imposed lockdown. We conducted research on the birds in the urban landscape of Jamalpur Sadar upazila from March 2020 to October 2020 during this pandemic situation. A total of 134 species of birds with 4338 individuals were recorded during the study period. The number of resident bird species was the maximum (115 species, 85.82%) compared to migrants. The highest number of birds was observed (120 species, 89.55%) and counted 2278 individual birds 52.51%) in the summer season. It was observed that the highest diversity of birds (89 species, 65.92%) was in March. The tree was the most (94 species, n = 2502) used microhabitat by birds in the study area. Among all birds, Pycnonotus cafer was the most abundant bird species with the highest relative abundance (6.11%). Some bird species (e.g. Metopidius indicus, Anastomus oscitans, Amaurornis phoenicurus, Streptopelia tranquebarica, Lonchura malacca) were frequently observed in the urban landscape of the study area during the pandemic. Proper management and awareness creation are essential for the conservation of the bird species in this area. Dhaka Univ. J. Biol. Sci. 30(2): 261-274, 2021 (July)

Prevalence and Genetic Diversity of Avian Haemosporidian Parasites in Southern Iran

Avian haemosporidians are widespread and diverse and are classified in the genera Plasmodium, Haemoproteus, Leucocytozoon, and Fallisia. These species are known to cause haemosporidiosis and decreased fitness of their hosts. Despite the high diversity of habitats and animal species in Iran, only few studies have addressed avian haemosporidians in this geographic area. This study was performed in the south and southeast of Iran during the bird breeding seasons in 2017 and 2018, with the aim to partly fill in this gap. Blood samples of 237 passerine birds belonging to 41 species and 20 families were collected. Parasite infections were identified using a nested PCR protocol targeting a 479-base-pair fragment of the mitochondrial cytochrome b (cytb) gene of Haemoproteus, Plasmodium and Leucocytozoon species. The overall prevalence of haemosporidian parasites was 51.1%, and 55 different lineages were identified, of which 15 cytb lineages were new globally. The lineages of Haemoproteus predominated (63.6% of all detected lineages), followed by Leucocytozoon and Plasmodium. Nineteen new host records of haemosporidian cytb lineages were identified, and the majority of them were found in resident bird species, indicating local transmission. Thirteen co-infections (9.8% of infected individuals) of Haemoproteus and Leucocytozoon parasites in seven host species were observed. This study shows the presence of active local transmission of parasites to resident bird species in the southeast of Iran and contributes to the knowledge on haemosporidian parasite biodiversity in this poorly studied region of the world.

Suitability of open digital species records for assessing biodiversity patterns in cities: a case study using avian records

Openly available species observation records on various online platforms achieve good coverage in urban areas. Thus, such digital data could provide a basis for biodiversity assessments in cities. Here, we investigated suitability of open digital species occurrence data, compared with systematically field surveyed data, in Freiburg, Germany (a Western city) and Dhaka, Bangladesh (a global-South city). We focused on resident bird species richness as an indicator of local biodiversity. We collected avian records for urban areas from ‘ornitho.de’ in Freiburg and ‘gbif.org’ in Dhaka. Additionally, we conducted point count surveys at several urban locations in both cities. Using these records, we prepared three grid (cell size 250 m × 250 m) based datasets—open digital dataset (i.e. records compiled from well-surveyed grid cells), field surveyed dataset (i.e. records of systematic bird surveys) and combined dataset (i.e. digital data and field data combined). We compared the relationship of resident bird richness with different habitat factors by applying linear regression models, separately using each of the three datasets. We assessed suitability of data from online platforms by comparing the variables retained after model selection based on digital data versus field surveyed data. We found that field surveyed data and combined data did not alter general understanding of the key driving factors of bird richness patterns we obtained from open digital data. This held for both case examples, Freiburg vs. Dhaka, respectively. This suggests that open digital data from well-surveyed urban locations can provide a suitable basis to assess drivers of biodiversity patterns within cities.

Redrawing Wallace’s Line based on the fauna of Christmas Island, eastern Indian Ocean

Based on a comprehensive literature survey, we determined the sources of the terrestrial vertebrate species on Christmas Island, asking where they originated relative to Wallace’s Line (the southern end of the divide lies 1100 km to the east, where the Lombok Strait adjoins the eastern Indian Ocean). The two bats, Pipistrellus murrayi and Pteropus natalis, are from the west. Concerning the endemic and ‘resident’ bird species, one is from the west (Collocalia natalis), four are from the east (Accipiter fasciatus, Egretta novaehollandiae, Falco cenchroides and Ninox natalis) and the other 15 are ambiguous or indeterminate. Most of the land-locked species are also from the east: rodents Rattus macleari and Rattus nativitatis, and squamates Cryptoblepharus egeriae, Emoia nativitatis and Lepidodactylus listeria. Additionally, two have westerly origins (Crocidura trichura and Cyrtodactylus sadleiri), one is ambiguous (Emoia atrocostata) and another is unknown (Ramphotyphlops exocoeti). West-directed surface currents that flow across the eastern Indian Ocean towards Christmas Island would have facilitated most of the land-animal colonizations. We therefore suggest that Wallace’s Line be redrawn such that the landmass is placed on the Australasian side of this fundamental biogeographical boundary.