Mohammad Irham

Morphological variation within species may promote adaptation across ecological and geographic space, perhaps reflecting evolutionary plasticity and adaptability. Based on this concept, species with greater intraspecific variation in morphological traits may be expected to occupy broader ecological niches and larger geographic ranges. However, even in the age of global trait datasets, intraspecific morphological variation remains poorly quantified at broad taxonomic and geographic scales, limiting our understanding of how trait flexibility shapes ecological and biogeographic patterns. Focusing on 161 species of bulbuls, a widespread avian family containing some of the most abundant bird species in the world, along with some of the rarest and most restricted in range, we conducted global-scale sampling of morphological traits. These included beak shape, tarsus length and wing length, associated with dietary niche, foraging strategy and dispersal, respectively. Using phylogenetic models, we tested whether ecological niche breadth and geographical range size are predicted by intraspecific morphological variation quantified from 8,251 museum specimens and 5,627 live captures. Our results demonstrate that morphological trait variation predicts both ecological niche breadth and geographic range size. Furthermore, widespread species exhibit greater morphological variation than restricted-range species even when comparisons are constrained to equivalent geographic extents, consistent with the hypothesis that intraspecific trait variation facilitates range expansion rather than simply accumulating as a consequence of occupying a larger range. These results identify intraspecific morphological variation as a potentially important, yet largely overlooked, predictor of ecological traits and biogeographic distributions in birds.

New Guinea, the world’s largest tropical island, supports the planet’s richest insular avifauna. Large areas of New Guinea remain poorly surveyed, however, in part due to the island’s challenging terrain. In hard-to-access areas, like many mountainous parts of New Guinea, automated surveying tools, like camera traps, may be especially helpful to address the survey deficit. Here we present the results of a camera-trap survey of the avifauna of the Cyclops Mountains, a range in New Guinea’s western, Indonesian provinces (Indonesian Papua). To our knowledge, our results represent only the second published camera-trap survey of birds from Indonesian Papua. We deployed 73 camera traps along an elevation gradient (143–1963 m) of the Cyclops Mountains for 11,869 camera-trap nights, recording 22 bird species from 1696 independent detections. Our species list is, to our knowledge, the first to include observations from the upper northern slopes of the Cyclops Mountains. It documents the first record of Masked Bowerbird (Sericulus aureus) in the range and provides photographic rediscoveries of two ‘lost’ species: Mayr’s Honeyeater (Ptiloprora mayri) and Mayr’s Forest Rail (Rallicula mayri). We also report substantial elevation range extensions for several species, including numerous records of Northern Cassowary (Casuarius unappendiculatus) over 1000 m above its historically known elevation ceiling. These findings provide new insights into species distributions and ecological flexibility in New Guinea’s montane systems, highlighting the potential for previously undocumented biodiversity in under-surveyed regions. Although camera traps detected fewer species than traditional ornithological methods, they were effective in documenting several elusive, ground-dwelling bird species, highlighting their value as a complementary tool for ornithological research in challenging terrain like New Guinea. Finally, we use our data to publish an updated bird species checklist for the Cyclops Mountains.

We describe a new species ofZosteropswhite‐eye, which is restricted to Wangi‐wangi, a single island of roughly 155 km²in the Wakatobi Archipelago, Indonesia. Informally known as the Wangi‐wangi White‐eye, the new species is highly distinct both morphologically and genetically. It is considerably larger in body and bill size compared with other regionalZosteropsspecies. The Wangi‐wangi White‐eye remains locally common but its habitat is dwindling. Given its minute area of occupancy and the threat from the bird trade, we recommend the IUCN status Endangered.

To reveal the diversity of Indonesian bent-toed geckos, we pay attention to Kalimantan (Borneo)—an island which has received less attention than other Indonesian islands such as Sumatra, Java, Sulawesi, the Moluccas, and the Lesser Sunda archipelagos. About 30 years after Hikida (1990) described three new Cyrtodactylus from Borneo, four more species were described, namely C. limajalur and C. muluensis in 2019, and C. hantu and C. miriensis in 2021, all by Davis et al. Through examination of the collection at MZB and three addition specimens collected from Tawau, we found several undescribed species, one of which we describe here. This new species is easily differentiated from all other congeners by the combination of the following characters: maximum SVL of at least 65.8 mm; no tubercles on dorsal surface of upper arm; tubercles present in the ventrolateral body folds; 28–30 paravertebral tubercles; 17–20 longitudinal dorsal tubercle rows; 39–46 ventral scale rows at midbody; 17–19 subdigital lamellae on fourth toe; precloacal pit with 5–7 pores in males arranged in a wide Λ-shape but absent in females; no enlarged transverse median subcaudals; paired dark brown semilunar-shaped markings on the upper nape. Further study is needed to reveal its molecular phylogenetic position and biogeographical history.