Arboreal Birds Research Articles

Intelligent Rock-Climbing Robot Capable of Multimodal Locomotion and Hybrid Bioinspired Attachment.

Rock-climbing robots have significant potential in fieldwork and planetary exploration. However, they currently face limitations such as a lack of stability and adaptability on extreme terrains, slow locomotion, and single functionality. This study introduces a novel multimodal and adaptive rock-climbing robot (MARCBot), which addresses these limitations through spiny grippers that draw inspiration from morpho-functionalities observed in beetles, arboreal birds, and hoofed animals. This hybrid bioinspired design enables high attachment strength, passive adaptability to different terrains, and quick attachment on rock surfaces. The multimodal functionality of the gripper allows for attachment during climbing and support during walking. A novel control strategy using dynamics and quadratic programming (QP) optimizes attachment wrench distribution, reducing cost-of-transport by 20.03% and 6.05% compared to closed-loop inverse kinematic (CLIK) and virtual model control (VMC) methods, respectively. MARCBot achieved climbing speeds of 0.15mmin-1 on a vertical discrete rock surface under gravity and trotting speeds of up to 0.21ms-1 on various complex terrains. It is the first robot capable of climbing on rock surfaces and trotting in complex terrains without the need for switching end-effectors. This study highlights significant advancements in climbing and multimodal locomotion for robots in extreme environments.

Blue-green infrastructure and biodiversity: Urbanization and forestation have an important influence on bird diversity in water habitats

Water and forest habitats are an indispensable part of the blue-green infrastructure, a network that provides solutions for urban climatic challenges by building with nature. We were interested in the effect of water areas and the surrounding environment on bird species richness; specifically, we studied the influence of different levels of urbanization and related forestation. We focused on water, arboreal and ground bird assemblages in forested and nonforested water habitats in a 2000 km2 lowland area of Polabí in the Czech Republic at three urbanization levels: (i) urban, (ii) rural and (iii) open landscapes. The results revealed that ground birds were positively influenced by urban areas, while arboreal birds benefitted from surrounding forestation and tree vegetation on water banks. Overall, the results for native bird assemblages were not different, except that native water birds appeared to thrive in no settlement. The positive relationship between ground birds and urbanization and the weak negative relationship or lack of relationship between urbanization and the other groups were somewhat unexpected. The most likely reason is that water habitats are not as homogenized as other urban habitats. Surrounding forests could also help buffer the influences of urbanized areas. We conclude that blue-green infrastructure is also an essential environment for many birds.

Consumption of stamens of buds and flowers by the Hoatzin, <i>Opisthocomus hoazin</i>, in the Brazilian Amazon, based on citizen science data

The Hoatzin, Opisthocomus hoazin, is an arboreal bird species considered to be primarily folivore, with the eventual consumption of other vegetal parts, such as shoots and flowers. I report here the consumption of floral resources by the Hoatzin in Brazil, using citizen science data. I present four records of Hoatzins feeding on stamens of flowers and buds of Pseudobombax munguba (Malvaceae) during the dry season. These are new items in the Hoatzin’s diet. Further studies are necessary to investigate how Hoatzins rely on this tree species and to quantify their role in causing damage to its reproductive parts.

The Halcyornithidae from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK): A species complex of Paleogene arboreal birds

We report fossils of the Halcyornithidae from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). The material includes remains of nine individuals of these small zygodactyl birds, which belong to at least seven different species, two of which are newly described. This documents a high species richness of halcyornithids in the London Clay, and these birds apparently underwent a significant radiation in the early Paleogene. One of the specimens includes a skull with a proportionally much smaller neurocranium than in Pseudasturides macrocephalus from Messel, suggesting an increased encephalization of halcyornithids towards the middle Eocene. A previously undescribed variation in sternum morphology of halcyornithids distinguishes the fossils we assign to the taxa Pulchrapollia and Cyrilavis and indicates that halcyornithids occupied disparate ecological niches. Furthermore, sternum morphology supports a sister group relationship between the halcyornithid taxa Pulchrapollia and Pseudasturides. The closest extant relatives of the Halcyornithidae remain elusive, but our new osteological data substantiate the hypothesis of a sister group relationship to the Messelasturidae, another group of Eocene birds with zygodactyl feet.[http://zoobank.org/urn:lsid:zoobank.org:pub:DDC1768F-1389-4F36-92F6-46DA318A0C19].

Frequent Agonistic Interactions among Arboreal Birds in Savannahs But Not in Humid Forests of Africa

Frequent Agonistic Interactions among Arboreal Birds in Savannahs But Not in Humid Forests of Africa

Distribution and Numbers of Arboreal Birds between the Hyper-Arid Sahara and the Hyper-Humid Guinea Forests

Distribution and Numbers of Arboreal Birds between the Hyper-Arid Sahara and the Hyper-Humid Guinea Forests

Flock size increases with the diversity and abundance of local predators in an avian family.

Group living has long been viewed as an adaptation to reduce predation risk. Earlier comparative analyses provided support for the hypothesis but typically ignored variation in group size at the local scale and included proxies of predation risk rather than more direct estimates. Here, we related variation in group size at the scale of a study site in various species with the diversity and abundance of local predators. If larger groups provide protection against predators, we expected larger groups to evolve in species facing locally more diverse and abundant predators. We examined this hypothesis in one avian family, the Paridae, which are small arboreal birds that include some of the better studied species in ecology. From the literature, we gathered 275 flock size estimates from 34 species. In a phylogenetic framework and controlling for the potential confounding effect of latitude, we found that flock size increased with predation risk but only in flocks that included more than one species. We suggest that competition sets an upper limit to the size of flocks including conspecifics only. Joining flocks with other species, thus, allows individuals to increase flock size in response to higher predation risk without a substantial increase in competition. Overall, our results based on more direct estimates of predation risk provide further comparative evidence for an association between predation and the evolution of flocking in birds.

Canopy cover mediates the effects of a decadal increase in time since fire on arboreal birds

Wildfires impact animal populations directly, and indirectly through alteration of forest habitats. Recovery of populations and habitat structure occurs over time since fire, but knowledge is lacking about the relative importance of these processes as drivers of the occurrence of birds in fire-prone forests. We aimed to determine the extent to which canopy cover mediates the effects of a decadal increase in time since fire on the richness and occurrence of canopy bird species. We established sites at either short (5 years) or mid-range (16 years) time since fire in montane dry sclerophyll forests of south-eastern Australia. Canopy cover estimates were derived from airborne LiDAR data. Birds were surveyed using acoustic recorders, with the resulting data analyzed using Bayesian mediation models to partition direct (population processes) and indirect (canopy cover) effects of time since fire on canopy birds. The predictive accuracy of models representing partial mediation (direct and indirect effects) and complete mediation (indirect effects only) were then compared. The direct effects of wildfire on birds were minimal between five and 16 years since fire. Instead, indirect effects prevailed, with species richness and the occurrence of most canopy species increasing as canopy cover regenerated over time since fire. As these forests transition from short to mid-range time since fire, ongoing increases in canopy cover are of primary importance for birds. We recommend an approach to managing avian diversity that incorporates canopy cover in fire planning to optimize the retention of dwindling amounts of older forest under climate change.

A tarsometatarsus from the upper Eocene Na Duong Basin—the first Palaeogene fossil bird from Vietnam

Knowledge of the Palaeogene avifauna of East Asia is scarce, and only a few fossils have been described thus far. A tarsometatarsus from the upper Eocene Na Duong Basin represents the first Palaeogene fossil bird from Vietnam. The fossiliferous sediments in the Na Duong Basin originated from an aquatic ecosystem but also yielded terrestrial animal and plant remains suggesting a dense forest habitat surrounding an ancient lake. In accordance, the Na Duong Basin tarsometatarsus is compared with extant aquatic, terrestrial and arboreal bird species, but because of diagenetic compression and fragmentary preservation, it is difficult to classify the bone. Nevertheless, the specimen exhibits a distinctive morphology and is potentially referable to an endemic neognath unknown from other Palaeogene localities outside of Vietnam.

Diversity and abundance of water birds in the mangrove area of south coast of Bangkalan, Madura Island, Indonesia

Abstract. Ramadhani A, Ambarwati R, Gumilang RS. 2022. Diversity and abundance of water birds in the mangrove area of south coast of Bangkalan, Madura Island, Indonesia. Biodiversitas 23: 3277-3284. The southern coastal mangrove area of ??Bangkalan, Madura Island, Indonesia, is an important bird habitat, especially for water birds. This study aimed to analyze the diversity and abundance of water birds in the southern coastal mangrove area of ??Bangkalan, Indonesia, as well as the environmental carrying capacity of this area as their habitat. Sampling was carried out using a birdwatching approach at four research stations. The diversity of water birds was analyzed using the Shannon-Wiener diversity index, while the abundance of water birds was calculated based on the abundance index. Environmental carrying capacity was analyzed descriptive-quantitatively based on the habitat profile. The results indicated that there were 15 species of water birds in the mangrove area belonging to five families in four orders, namely Charadriiformes, Ciconiiformes, Pelecaniformes, and Suliformes, with a diversity index of 1.547. There were three abundant species of water birds, namely the little egret (Egretta garzetta), Javan Pond-heron (Ardeola speciosa), and Great Egret (Ardea alba). In addition to water birds, there were nine species of arboreal birds in this area. The areas with dense mangroves provide better habitat carrying capacity for water birds compared to other coastal areas.

Investigating Avian Behaviour Using Opportunistic Camera-Trap Imagery Reveals an Untapped Data Source

Understanding the behavioural responses of bird species to their environments is important for effective conservation, especially in captive-management and resource-provisioning programs. Camera traps present a growing opportunity to research bird breeding and foraging behaviour in situ. Remotely triggered cameras are commonly deployed to study mammals and large terrestrial birds. They are rarely used to survey small or arboreal birds due to habitat constraints. However, a wealth of information about small or arboreal birds can be generated opportunistically from camera traps in the course of collecting data on other taxa. Here, we describe and quantify the types of behavioural information that can be so gleaned, based on over 1,700 small-bird images captured as “collateral” during a geographically extensive mammal-focused camera study in Tasmania, Australia in 2018–2020. Postural analysis of images revealed 10 distinct behaviours. Large- and medium-sized terrestrial bird species were most commonly observed (61.6% of behavioural images), but small and arboreal species were also photographed at high rates (18.4% and 29.5% of behavioural images respectively). Investigative activity was the most commonly observed behaviour in small and arboreal species (around half of all images), but feeding, mating and even very rare behaviours like fur plucking, were also captured photographically. This case study reveals the value of opportunistically analysing camera trap images for small or arboreal birds species, especially when they are of conservation interest, even for cases where deliberately targeting them would not be a cost-effective strategy.

Local colonization and extinction in forestry habitats: Assessing the effects of productive activities on the occupancy dynamics of bird populations

AbstractAssessing the impact of working landscapes on biodiversity and defining locally contextualized management guidelines for productive activities are key for sustainability. Occupancy dynamics provide information about sites in the landscape that are either avoided or preferred by populations through the estimation of extinction and colonization probabilities, respectively. We identified the habitat traits that affected colonization and extinction probabilities of target birds (forest‐dependent, endemic, or conservation concern species) within a Neotropical working landscape by using multi‐season occupancy models to point count data collected through a participatory monitoring approach and considering our imperfect detectability of species in the field. We provided colonization and extinction scenarios according to local land uses (forestry plots, urban‐cropfield areas, and conservation forests) to recommend management activities that could have a positive impact on bird conservation. Shrub cover was key for local colonization of most of our focal species. Increasing values of tree size and tree species richness can enhance microhabitat complexity, which in turn promotes the presence of arboreal birds. Selective forestry management, in which only the largest individuals of a few tree species are extracted, promoted high colonization rates of birds because the structure of the vegetation remains relatively unaffected. In contrast, intensive forestry management plots, in which most trees are removed, resulted detrimental for bird occupancy. Local management guidelines should pay special attention to maintaining shrub cover, tree size, and tree species richness above critical values (>50%, >30 cm, >7 tree species, respectively) to promote habitat use by birds in this type of working landscapes.Abstract in Spanish is available with online material.

Mass estimation of extinct taxa and phylogenetic hypotheses both influence analyses of character evolution in a large clade of birds (Telluraves).

Incorporating extinct taxa in phylogenetic comparative methods is rapidly becoming invaluable in studies of character evolution. An increasing number of studies have evaluated the effects of extinct taxa, and different numbers of extinct taxa, on model selection and parameter estimation. Body mass is a well-studied phenotype, but individual mass estimates may vary dramatically depending on the particular measurement used. Here, we perform an analysis of body mass evolution in a large clade of principally arboreal birds, incorporating 76 extinct species. We evaluate how different methods for estimating body mass of extinct taxa, and different phylogenetic hypotheses, affect our understanding of the rate and pattern of body mass evolution. Our results show that model selection can vary dramatically depending on the phenotypic and phylogenetic hypothesis used in the reconstruction. Even small changes in phenotype estimates can lead to different model selection and, as a result, affect the inferred evolutionary history. The best-fit models support an increase in the rate of evolution following the K-Pg boundary, with variation accumulating linearly through the Cenozoic. These results provide additional insight into the application of comparative models of evolution, as well as the evolutionary history of one of the most spectacular vertebrate radiations.

The first fossil barbet (Aves, Ramphastidae) from Siberia

Barbets are arboreal birds, inhabiting mainly tropical forests west of the Wallace’s Line. Fossil remains of barbets are extremely scarce. Until recently, only two species of barbets were described from the early and middle Miocene of Europe and several other undescribed fragments were mentioned in the literature. Here I report the first finds of barbets from Eastern Siberia. ?Capitonides sp. is here described from the late early Miocene of Baikal Lake based on a distal part of the humerus, an omal part of the coracoid, and a distal part of the ulna. The morphology of the fossil specimen does not allow attributing it to any of the modern genera, and thus ?Capitonides sp. is apparently a stem representative of the group. This find documents a previously unrecognized broad geographical distribution of barbets during the warmest phase (climatic optimum) of the Miocene. The observed similarity between the early–middle Miocene arboreal avifaunas of Western Europe and Eastern Siberia suggests the presence of a wide belt of relatively humid forests connecting Europe and Asia.

Dew-bathing in the Atlantic Forest endemic Robust Woodpecker Campephilusrobustus(Lichtenstein, 1823) (Aves: Picidae)

The bathing behavior of woodpeckers (Picidae) is almost unknown and the paucity of reports of bathing in the family has led to suppositions that they may do so rarely. An unusual observation of the Atlantic Forest endemic Robust Woodpecker Campephilus robustus dew-bathing socially is reported from Paraguay and discussion of its significance follows. Dew-bathing has been reported for a small number of New World bird families and has often been linked to a shortage of water, but has never been previously reported in New World Picidae. Given the environmental conditions in this humid habitat it is considered that dew-bathing in this family is related to structure and ecological constraints and not to limited access to water. Picids are highly arboreal birds with structural modifications for arboreality that make them awkward and thus potentially vulnerable when on the ground. A propensity for dew-bathing in forest canopies at sunrise may be a factor in the rarity of such observations and contribute to the lack of published reports.

Skeletons from the early Oligocene of Poland fill a significant temporal gap in the fossil record of upupiform birds (hoopoes and allies)

ABSTRACT Upupiformes is the avian clade including extant hoopoes (Upupidae) and wood hoopoes (Phoeniculidae). Upupiform birds are abundantly represented in some Eocene fossil sites and are also known from early Miocene localities, but the fossil record in between is surprisingly scant. This gap of over 25 million years is bridged by two skeletons from the early Oligocene of Poland. One of the fossils is described as a new species, ?Laurillardia smoleni, sp. nov., the other is tentatively referred to Laurillardia munieri Flot, 1891. We detail that these stem group Upupiformes are more closely related to the crown group than are the Eocene Messelirrisoridae. The specimens show that very small upupiform birds coexisted with passerines (Passeriformes) for at least ten million years and challenge previous hypotheses that the arrival of passerines in Europe led to the demise of small non-passeriform arboreal birds. It remains elusive, why small upupiform birds became extinct in the Northern Hemisphere. Even though these insectivorous birds may not have found enough food after the emergence of cold Northern Hemispheric winters, it is an open question why very small-sized upupiform birds do not occur in the tropical regions of Asia but are today restricted to Africa south of the Sahara. http://www.zoobank.org/urn:lsid:zoobank.org:pub:A90B22E7-C3EC-4EAE-A757-F073EAF521F3

Tip-dating and the origin of Telluraves

Despite a relatively vast accumulation of molecular data, the timing of diversification of modern bird lineages remains elusive. Accurate dating of the origination of Telluraves—a clade of birds defined by their arboreality—is of particular interest, as it contains the most species-rich avian group, the passerines. Historically, neontological studies have estimated a Cretaceous origin for the group, but more recent studies have recovered Cenozoic dates, closer to the oldest known fossils for the group. We employ total-evidence dating to estimate divergence times that are expected to be both less sensitive to prior assumptions and more accurate. Specifically, we use a large collection of morphological character data from arboreal bird fossils, along with combined molecular sequence and morphological character data from extant taxa. Our analyses recover a Late Cretaceous origin for crown Telluraves, with a few lineages crossing the K-Pg boundary. Following the K-Pg boundary, our results show the group underwent rapid diversification, likely benefiting from increased ecological opportunities in the aftermath of the extinction event. We find very little confidence for the precise topological placement of many extinct taxa, possibly due to rapid diversification, paucity of character data, and rapid morphological differentiation during the early history of the group.

Grazing improves habitat suitability for many ground foraging birds in Mediterranean wooded grasslands

Wooded grasslands, usually grazed, cover vast areas in Southern Europe and Northern Africa. They host rich resident bird communities and, in winter, receive large numbers of migrants from Central and Northern European woodlands. Many species are partly or entirely dependent on ground foraging and, since in winter food is often the most limiting factor for birds, maintaining suitable ground habitat is crucial.To study how grazing influences suitability of winter ground habitat for birds, we carried out an experiment in a wooded grassland in Southern Iberia, whereby grazing was controlled in 12 purposely fenced two-hectare plots (4 × 15 sheep/ha, 4 × 3 sheep/ha and 4 × no grazing). We quantified ground habitat features, food abundance and intensity of use by ground-foraging birds in each of these 12 plots. In addition, we made focal observations of birds feeding on the ground and compared the habitat of 1m2 foraging patches with those of nearby control patches.We found that virtually all birds prefer to forage in patches with short ground vegetation and high food abundance. Measurements of these parameters in the experimental plots showed that while grazing shortens vegetation it decreases food availability, and thus has opposing effects on important determinants of habitat suitability. Nevertheless, the numbers of birds foraging in the plots indicate that, overall, grazing benefits the assemblage of ground-feeding birds, presumably because for most species the advantages of foraging in less cluttered habitats more than compensate the lower abundance of prey. However, arboreal bird species that make short foraging forays to the ground had lower numbers in grazed plots.Most bird species that forage on the ground benefited from grazing, and although they can forage under a broad range of grazing levels, some showed clear preferences along the gradient of grazing intensity. Such preferences should be taken into consideration by managers. In general, grazing should be maintained at a level sufficient to open up ground vegetation, increasing the area occupied by patches of short vegetation, in which almost all bird species prefer to forage. At moderate levels, grazing is thus a valuable management tool to promote winter bird habitat quality in Mediterranean wooded grasslands, while increasing the economic value of these threatened landscapes.

Arboreal birds do not avoid scattered trees in West Africa

SummaryArboreal birds tend to remain in woody vegetation and avoid crossing open areas. Therefore, few tree-dwelling birds are to be expected in scattered trees. We tested this expectation with field data collected in the deserts, savannas and open agricultural parklands of West Africa where woody cover in 1,327 stratified random study sites varied between 0.2 and 29%. We found no evidence that scattered trees were avoided. Instead, bird density in trees was independent of trees occurring clumped or singly. The presence of birds in an individual tree was related to tree species and tree-related variables, but not to woody cover or species composition of the surrounding woody vegetation. We hypothesise that scattered trees are not avoided because (1) travel time between trees is too short to have a negative impact on foraging time, (2) predation risk of arboreal passerines is very low (bird-hunting raptors are scarce in the deserts and savannas of West Africa and mostly prey on ground-feeding, not arboreal, birds), and (3) the probability of being chased away by other arboreal birds is less when trees are more scattered. Scattered trees are ecologically important since hundreds of millions of migratory woodland birds, of which several species are in decline, spend the northern winter in Africa in open, often human-modified, landscapes where trees are well spaced.

New data on the anatomy and palaeobiology of sandcoleid mousebirds (Aves, Coliiformes) from the early Eocene of Messel

The Sandcoleidae are stem group representatives of the Coliiformes (mousebirds). These birds are among the most abundant medium-sized arboreal birds in some early and middle Eocene fossil sites of Europe and North America, and they are particularly well represented in the German locality Messel. Here, new sandcoleid fossils from Messel are reported. Most of these are tentatively assigned to Eoglaucidium pallas, which is the only named European sandcoleid species, but one specimen is likely to represent a new, unnamed species. Another fossil exhibits exceptionally well-preserved feather remains, which show that the tail of sandcoleids was not as greatly elongated and stiffened as that of extant mousebirds (Coliidae). It is hypothesised that these differences in the tail morphology of sandcoleids and coliids may have been due to changes in the habitual perching posture, which occurred early in the evolutionary history of the Coliidae.