Relative forelimb–hindlimb investment is associated with flight style, foraging strategy, and nestling period, but not nest type

We investigated Dial’s 2003 hypothesis that birds that rely more heavily on flight as their primary mode of locomotion and thus invest more in their forelimbs than hindlimbs will experience selection for smaller body sizes, greater altriciality, and more complex nests. To test this hypothesis, we examined the skeletons of over 2,000 individuals from 313 species representing the majority of avian families and all major branches of the avian tree. We used the lengths of the sternal keel and long bones of the wing relative to the lengths of the leg long bones as an index of relative locomotor investment. We found that locomotor investment was predicted by flight style, foraging method, and length of nestling period, supporting Dial’s hypothesis. Soaring birds and birds with more acrobatic flight styles, birds whose foraging methods were heavily reliant upon flight, and birds whose young spent more time in the nest tended to invest more in their forelimbs relative to hindlimbs. Nest type and body size were not significant predictors of relative forelimb–hindlimb investment, however, suggesting that the relationships among flight style, locomotor investment, and life history are not as tightly intertwined as Dial originally hypothesized.

Conspicuous female plumage is common among open cup-nesting passerine birds

Alfred Russel Wallace hypothesized that the use of cavity or dome nests releases incubating birds from predation risk, and that this allows the evolution of conspicuous coloration in females. By this hypothesis, females that use open nests are subject to strong selection for crypsis. Here, we test the validity of Wallace’s proposed evolutionary correlation between nest type and conspicuous coloration in females across the largest avian radiation, the Passeriformes, using phylogenetic comparative methods. We also test an alternate hypothesis that cavity-nesting results in greater conspicuousness because competition for cavities is stronger than for other nest sites, and such competition can drive social selection on female plumage. By this hypothesis, dome-nesting females should generally be less conspicuous than cavity-nesting species. We found no support for Wallace’s hypothesis that concealed nests yield conspicuous plumage while open nests yield dull plumage, and some support for the social selection hypothesis in smaller-bodied, gregarious species. While our analyses do not support the core part of Wallace’s hypothesis, they corroborate his contention that evolutionary transitions in nest type are rare, indicating that nest types may influence macroevolutionary selective regimes for other traits.

Nest-boxes alter the reproductive ecology of urban cavity-nesters in a species-dependent way

To mitigate the shortage of natural breeding sites in cities, nest-boxes are provided for cavity-nesters. However, these are not the breeding sites these animals originally evolved in and optimised their breeding performance to. It thus remains inconclusive if nest-boxes can provide adequate substitutes, ensuring equivalent fitness returns for breeding animals. Additionally, the majority of knowledge on the ecology of urban birds comes from nest-box populations, but no study to date directly compared fitness consequences of breeding inside nest-boxes in relation to natural-cavities in an urban context. This limits our understanding of the urban ecology of cavity-nesters and addressing its functional meaning. We investigate fitness consequences and life-history trait variation according to the nesting site type to provide a comprehensive understanding of conservation potential of nest-boxes in cities and to support/question generalisations stemming from nest-box studies on urbanization. We directly compare the reproductive performance of two small passerines, blue tits and great tits, breeding in nest-boxes as opposed to natural-cavities in a seminatural forest of a capital city using a quasi-experimental setting. We show that the effects of nest type vary between species: in blue tits, fitness proxies were negatively affected by nest-boxes (lower fledging success and fledgling numbers, longer time spent in nest and later fledging date in comparison to natural-cavities), while great tit performance appeared to be unaffected by nest type. We detected that both species breeding in nest-boxes accelerated incubation onset, but since there were no major differences in pre-hatching traits (lay date, clutch size, hatching rates) between the nest types, we attribute the fitness deterioration to post-hatching effects. Interestingly, overall breeding density of tits in urban natural-cavities was higher than observed in a primeval habitat. Nest-boxes may become an ecological trap for some species and the unaffected species can consequently outcompete them, decreasing overall biodiversity in cities. We highlight the ecological importance of old-growth tree stands, providing natural tree cavities for city-breeding animals. Due to the detected nest type-dependent variation in reproductive performance, we support the criticism regarding the unconditional extrapolation of evolutionary and ecological interpretations of nest-box studies to general populations.

Winter nest trees of sympatric northern and southern flying squirrels: a test of reinforcement in a hybrid zone

Shifting range boundaries can lead to secondary contact of closely related species, which might in turn lead to hybridization when the evolution of reproductive isolation is incomplete. We examined winter nest use of northern (Glaucomys sabrinus Shaw, 1801) and southern flying squirrels (G. volans Linnaeus, 1758) in an area of recent secondary contact and known hybridization in Ontario, Canada to test for evidence of reinforcement due to different and diverging nesting behaviours. We radio-collared 26 flying squirrels (12 G. sabrinus and 14 G. volans) between two survey periods (winters of 2008-9 and 2019-20) and identified all nest trees used by individuals throughout each winter. For each nest tree we identified the nest type and collected tree classification information to compare differences in nest use between species. We also present a novel application of habitat suitability modelling to test for evidence of divergence in nest use through time, which would suggest reinforcement. We found southern flying squirrels used a higher proportion of cavities in large, hardwood trees, whereas northern flying squirrels used more external nests and softwood trees. Conditional probabilities provided some evidence for increased differentiation in nest use by flying squirrels through time. Overall, we found relatively little overlap in winter nest use between flying squirrel species, despite evidence for hybridization at this site, and some weak evidence for increased divergence between species in nest use over 11 years

Isolation and Identification of Cellulolytic Bacteria Symbiont from Various Termites on Different Nest Type in Bukit Baka Bukit Raya National Park, West Kalimantan, Indonesia

The microbial symbiotic community in the digestive tract of termites is reportedly influenced by the taxonomy and feeding habit of the host. Both factors are strongly correlated with the nest type. This study aimed to isolate the cellulolytic bacteria from termite’s digestive tract on different nest types and characterize and identify the potential isolates. The research methods included termite sampling conducted in Bukit Baka Bukit Raya National Park (BBBRNP), Melawi, West Kalimantan, isolation of cellulolytic bacteria from termites’ gut, endoglucanase activity test, biochemical characterization, and DNA analysis based on the amplification of 16S rRNA gene. Thirty isolates from 6 different species of termites on three different nest types were successfully isolated. Sixteen potential endoglucanase bacterial isolates were tested in terms of their endoglucanase activity. The cellulolytic index measured from those isolates ranged from 1.162 - 4.894. Three isolates (MRH.13.S, MRH.13.AF, and MRH.13.O2) with the highest cellulolytic index on each nest type were identified. The analysis of 16S rRNA gene using BLAST (Basic Local Alignment Search Tool for Nucleotides) revealed that isolate MRH.13.S had the closest relationship with Bacillus tequilensis (99 % homology). Based on biochemical characterization, MRH.13.AF and MRH.13.O2 isolates were related to Bacillus spp. HIGHLIGHTS Potential cellulolytic bacteria from termite intestinal tract from different nests (i.e., soil, wood, and arboreal) were isolated and compared Termites were obtained from a lowland dipterocarp primary forest ecosystem in Bukit Baka Bukit Raya National Park, West Kalimantan Province, Indonesia Termite species collected were Termes comis, Dicuspiditermes garthwaitei, Synhamitermes quadriceps, Havilanditermes proatripennis, Bulbitermes borneensis, and Bulbitermes parapusillus Potential cellulolytic bacteria acquired were closely related with Bacillus tequilensis and Bacillus spp GRAPHICAL ABSTRACT

The Functional Traits of Breeding Bird Communities at Traditional Folk Villages in Korea

Interaction between nature and human has formulated unique biodiversity in temperate regions. People have conserved and maintained traditional folk villages (TFVs) dominated with houses made of natural materials, arable land and surrounding elements of landscape. Until now, little attention has been given to understand the traits of breeding birds in TFVs of Korea. The aim of this study was to reveal traits of breeding birds in TFVs and get conservative implications for biodiversity. We selected five TFVs: Hahoe maeul (HA), Wanggok maeul (WG), Nagan maeul (NA), Yangdong maeul (YD), and Hangae maeul (HG). We surveyed breeding birds with line transect methods, and analyzed functional traits (diet type and nest type) of birds in TFVs. Among 60 species recorded, Passer montanus (PM), Streptopelia orientalis (SO), Hirundo rustica (HR), Pica pica (PP), Phoenicuros auroreus (PA), Paradoxornis webbiana (PW), Microscelis amaurotis (MA), Carduelis sinica (CA) and Oriolus chinensis (OC) could be potential breeding birds that prefer diverse habitats of TFVs in Korea. Compared to the breeding birds of rural, urban and forest environments, the diversity of nesting types for birds was high in TFVs. The diverse nest types of breeding birds can be linked with habitat heterogeneity influenced by sustainable interaction between nature and human in TFVs in Korea.

Occurrence of Ants (Hymenoptera: Formicidae) in both Leaf Litter and Twigs in Atlantic Forest

Twigs in the litter derived from the fragmentation of tree branches form one microhabitat, where entire colonies of ants, both leaf litter and arboreal species, can be found. The objective was to survey ant species that are presente in both the leaf litter and twigs simultaneously. We describe the nest type, the social structure of the colonies and the trophic guild membership of these species. Samples were collected from 10 preserved fragments of Brazilian Atlantic forest. We used Berlese funnels to collect leaf litter ants and manual collection for twig ants. We recorded 80 ant species; 60 species were in leaf litter samples and 35 species were in twigs. Of the total species, only 15 (20%) occurred simultaneously in the leaf litter and in twigs. Of these species, Gnamptogenys striatula, Pheidole sarcina, P. sospes and Solenopsis sp. 2 were the most frequent among leaf litter dwellers, and Myrmelachista catharinae was the most common arboreal species. Most of these belonged to generalista and predator guilds, with “polydomous nests” and colonies monogynous.

Studi Karakteristik Sarang Orangutan (Pongo pygmaeus morio) di Resort Sangatta dan Resort Sangkima Taman Nasional Kutai

Orangutan (Pongo pygmaeus morio) merupakan satwa langka yang harus dikonservasi melalui pelestarian Taman Nasional Kutai (TNK). Studi karakteristik sarang orangutan merupakan bagian dari upaya pelestarian. Metode yang digunakan dalam penelitian ini adalah menggunakan jalur transek dengan menghitung sarang orangutan serta mencatat karakteristik sarang orangutan yang meliputi kelas sarang, posisi sarang, tinggi sarang, tinggi pohon, diameter pohon dan jenis pohon sarang. Pada lokasi penelitian ditemukan sebanyak 173 sarang orangutan yang terdiri dari 84 sarang di resort Sangatta dan 89 sarang di resort Sangkima. Jenis sarang didominasi oleh kelas sarang C dan D dengan posisi sarang sebagian besar terdapat pada ujung dahan (UD) di resort Sangatta, posisi sarang terbanyak ada pada ujung dahan (UD) dan pucuk pohon (PP) di resort Sangkima. Rata-rata tinggi sarang orangutan adalah 12,2 - 40,2 m, diameter pohon 17,4 - 110 cm, dan tinggi pohon 12,2 - 40,2 m di resort Sangatta. Pada resort Sangkima rata-rata tinggi sarang orangutan adalah 10,2 - 24,2 m dengan diameter pohon 20 - 109,4 cm dan rata-rata tinggi pohon 14-28,6 m. Karakteristik sarang orangutan menjadi indikator kondisi habitat orangutan yang ada di TNK. Orangutan (Pongo pygmaeus morio) is a rare animal that must be conserved through the preservation of the Kutai National Park (KNP). Study of orangutan nest characteristics is part of conservation efforts. The method used in this study is to use a transect line by counting orangutan nests and noting orangutan nest characteristics which include nest class, nest position, nest height, tree height, tree diameter and nest tree species. At the study site, 173 orangutan nests were found, consisting of 84 nests at Sangatta resort and 89 nests at Sangkima resort. The nest type is dominated by the nest classes C and D with the nest position mostly found at the tip of the branch (UD) at Sangatta resort, the position of most nests is at the tip of the branch (UD) and tree tops (PP) at the Sangkima resort. The average height of orangutan nests is 12.2 - 40.2 m, tree diameter 17.4 - 110 cm, and tree height 12.2 - 40.2 m at Sangatta resort. At Sangkima resort, the average height of orangutan nests is 10.2 - 24.2 m with a tree diameter of 20 - 109.4 cm and an average tree height of 14-28.6 m. The characteristics of orangutan nests are an indicator of the condition of orangutan habitat in KNP.