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Woodpeckers and certain passerine species secure encased food in the environment in various ways to facilitate the extraction of the contents with their bills. They do this by securing the food items in locations such as crevices and holes, newly defined in this paper as ‘vice-anvils’. Here I report that free-living New Caledonian crows (Corvus moneduloides) and rooks (Corvus frugilegus, in New Zealand) also use vice-anvils to process candlenuts and walnuts, respectively. New Caledonian crows placed candlenut sections in vice-anvils to aid kernel extraction, after the candlenuts had been dropped onto an anvil to break them open. In contrast, rooks used vice-anvils to secure walnuts while they broke the shell with their bills. Long-term use by rooks of a vice-anvil in a tree had produced a ‘purpose-made’ nut-cracking site. My findings extend the persistent use of specific vice-anvils to Corvus species and further demonstrate their innovative and flexible foraging behaviour. [ABSTRACT FROM PUBLISHER]

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In this paper we present the abundance, distribution, nest-site characteristics and habitat analysis of woodpecker species in managed forests. The studied territory is part of a Special Protection Area for bird species. We found breeding evidence of six of the eight sedentary woodpecker species from Romania: Greyheaded- (Picus canus), Green- (Picus viridis), Great Spotted- (Dendrocopos major), Middle Spotted- (Dendrocopos medius), White-backed- (Dendrocopos leucotos) and Black Woodpecker (Dryocopus martius). The most abundant was the Middle Spotted Woodpecker. Middle Spotted-, Green- and Great Spotted Woodpeckers excavated nest-holes most commonly in oak (Quercus petraea), Black Woodpeckers in beech (Fagus sylvatica), Greyheaded Woodpeckers in aspen (Populus tremula). White-backed Woodpeckers used only oaks as nest-trees. Weak excavators selected large trees, dead trees or soft woods for nesting, but most of the species used primarily live trees for excavation. The average diameter of nesting tree, tree height, nest height and relative nest height did not increase with the body size of the woodpecker species. Nearest neighbor analysis indicated that the local distribution of woodpecker species in most forest fragments differs from randomness. Great Spotted Woodpeckers and Black Woodpeckers presented uniform distributions, while Middle Spotted Woodpeckers aggregated distribution. Tree diameter and diversity, relative abundance of oak and aspen but also altitude affected woodpecker abundance. Black Woodpecker and Middle Spotted Woodpecker presence depends on large trees and diversity of trees. The results will contribute to forest restoration operations. [ABSTRACT FROM AUTHOR]

The Ivory-billed Woodpecker (Campephilus principalis) is an iconic species that has survived in barely detectable numbers for the past 100 years, during which it has been feared extinct only to be rediscovered several times. The most recent rediscovery was announced in an article that was featured on the cover of Science in 2005. The persistence of the Ivory-billed Woodpecker became controversial when ornithologists were unable to obtain a clear photo for documenting this ultra-elusive bird during multi-year searches at sites in Arkansas and Florida, where they had several sightings and were convinced these birds were present. Audio recordings of 'kent' calls and double knocks were obtained at both sites, but such recordings are not regarded as conclusive evidence of persistence. A debate on this issue that took place in Science and Nature focused on relatively weak video evidence obtained in Arkansas but excluded three videos obtained in Louisiana and Florida that show flights, field marks, and other behaviors and characteristics that are consistent with the Ivory-billed Woodpecker but no other species of the region. Kent calls were recorded in the 1930s, when other types of vocalizations were observed but not recorded, including a high-pitched alarm call. On two occasions in Louisiana, high-pitched calls were observed coming from the direction of an alarmed Ivory-billed Woodpecker, and several of them were recorded. The spectrograms of the high-pitched calls and all other known and putative vocalizations of the Ivory-billed Woodpecker consist of simultaneously excited harmonics. A harmonic oscillator model has been used to draw a connection between the drumming that is typical of most woodpeckers and the double knocks of the Ivory-billed Woodpecker and other Campephilus woodpeckers. Drumming corresponds to periodic forcing; double knocks correspond to impulsive forcing, and a single thrust of the body is sufficient to produce two impacts of the bill in rapid succession. The audio recordings from Arkansas and Florida were obtained with single microphones. A horizontal array of microphones would make it possible to detect weaker sounds and determine the directions of sources. This approach has the potential to lead to the discovery of a nest, and it might be more effective if the array is placed above the treetops, where sounds might propagate to longer ranges. [ABSTRACT FROM AUTHOR]

Animals facing seasonal food shortage and habitat degradation may adjust their foraging behaviour to reduce intraspecific competition. In the harsh environment of the world's southernmost forests in the Magellanic sub-Antarctic ecoregion in Chile, we studied intersexual foraging differences in the largest South American woodpecker species, the Magellanic Woodpecker (Campephilus magellanicus). We assessed whether niche overlap between males and females decrease when food resources are less abundant or accessible, that is, during winter and in secondary forests, compared to summer and in old-growth forests, respectively. We analysed 421 foraging microhabitat observations from six males and six females during 2011 and 2012. As predicted, the amount of niche overlap between males and females decreased during winter, when provisioning is more difficult. During winter, males and females (i) used trees with different diameter at breast height (DBH); (ii) fed in trunk sections with different diameters; and (iii) fed at different heights on tree trunks or branches. Vertical niche partitioning between sexes was found in both old-growth and secondary forests. Such a niche partitioning during winter may be a seasonal strategy to avoid competition between sexes when prey resources are less abundant or accessible. Our results suggest that the conservation of this forest specialist, dimorphic and charismatic woodpecker species requires considering differences in habitat use between males and females. [ABSTRACT FROM AUTHOR]

Cavity-nesting birds can save time and energy by reusing old cavities. We studied cavity reuse and its connections to nesting success and timing in the three-toed woodpecker Picoides tridactylus in a 170-km2 area in southern Finland during 1987-2015. The data include 520 nest trees, 645 nest cavities and 833 nestings in 86 territory sites, including 211 cases of cavity reuse. Twenty-five percent of nestings was in previously used cavities. Twenty-eight percent of cavities and 25% of nest trees were used more than once. Reuse improved nesting success and facilitated early nesting in the year following first nesting. Reuse of nest trees with several cavities was observed in 15% of nest trees, and 62% of reused cavities were in those multi-cavity trees. Cavity reuse and multi-cavity trees were most abundant in long-term territories with stable habitats. In boreal forests, cavity and tree reuse can be an important adaptation allowing efficient nesting during a short breeding season. [ABSTRACT FROM AUTHOR]

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The emerald ash borer (EAB), Agrilus planipennis, is an invasive beetle that has killed millions of ash trees (Fraxinus spp.) since it was accidentally introduced to North America in the 1990s. Understanding how predators such as woodpeckers (Picidae) affect the population dynamics of EAB should enable us to more effectively manage the spread of this beetle, and toward this end we combined two experimental approaches to elucidate the relative importance of woodpecker predation on EAB populations. First, we examined wild populations of EAB in ash trees in New York, with each tree having a section screened to exclude woodpeckers. Second, we established experimental cohorts of EAB in ash trees in Maryland, and the cohorts on half of these trees were caged to exclude woodpeckers. The following spring these trees were debarked and the fates of the EAB larvae were determined. We found that trees from which woodpeckers were excluded consistently had significantly lower levels of predation, and that woodpecker predation comprised a greater source of mortality at sites with a more established wild infestation of EAB. Additionally, there was a considerable difference between New York and Maryland in the effect that woodpecker predation had on EAB population growth, suggesting that predation alone may not be a substantial factor in controlling EAB. In our experimental cohorts we also observed that trees from which woodpeckers were excluded had a significantly higher level of parasitism. The lower level of parasitism on EAB larvae found when exposed to woodpeckers has implications for EAB biological control, suggesting that it might be prudent to exclude woodpeckers from trees when attempting to establish parasitoid populations. Future studies may include utilizing EAB larval cohorts with a range of densities to explore the functional response of woodpeckers. [ABSTRACT FROM AUTHOR]

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Detailed studies of parental care of woodpeckers are restricted to a handful of species in the northern hemisphere. The Magellanic Woodpecker Campephilus magellanicus is the largest Neotropical picid and the southernmost distributed woodpecker worldwide. We investigated sex-specific parental care behaviour of Magellanic Woodpeckers at 11 nests by dawn to dusk monitoring, once a week throughout the nesting season. Behavioural observations were complemented with frequent inspections of all nests and video recordings at 3 nests. One or two hatchlings were produced; when two, the second-born was soon left to die from starvation, so a single young was reared at any nest. Observed parental care included incubation, brooding, nest sanitation and feeding of nestlings. Parental care was divided almost equally between partners for most activities except nest sanitation and night care, where males dominated. Contributions of the two sexes to parental care changed during progress of the breeding period. Feeding rates were similar between parents, but males delivered larger prey. Parental care in the Magellanic Woodpecker seems to be in accordance with the breeding behaviour exhibited by the majority of woodpecker species, nevertheless some differences may derive from particularities of the Austral temperate forest (i.e. food availability) and features of the species like one nestling brood size along with behavioural constraints on juvenile dispersal. [ABSTRACT FROM AUTHOR]

Lesser Spotted Woodpecker Dendrocopos minor numbers have declined greatly in England since the early 1980s for reasons that are not yet fully understood. It has been suggested that the species’ decline may be linked to the increase in Great Spotted Woodpeckers Dendrocopos major, changes in woodland habitat quality (such as deadwood abundance) and landscape-scale changes in tree abundance. We tested some of these hypotheses by comparing the characteristics of woods in southern England where the species is still relatively numerous with those of woods used in the 1980s before the major decline. In each time period, habitat, predator and landscape information from woods known to be occupied by Lesser Spotted Woodpeckers was compared with those found to be unoccupied during surveys. Before the main period of decline, Lesser Spotted Woodpeckers used oak-dominated, mature, open woods with a large amount of standing deadwood. Habitat use assessed from recent data was very similar, the species being present in mature, open, oak-dominated woodlands. There was a strong relationship between wood use probability and the extent of woodland within a 3-km radius, suggesting selection for more heavily wooded landscapes. In recent surveys, there was no difference in deadwood abundance or potential predator densities between occupied and unoccupied woods. Habitat management should focus on creating and maintaining networks of connected woodlands in areas of mature, open woods. Finer-scale habitat selection by Lesser Spotted Woodpecker within woodlands should be assessed to aid development of beneficial management actions. [ABSTRACT FROM AUTHOR]

The article presents a study on postfire woodpecker foraging in salvage-logged and unlogged Sierra Nevada forests. The study location includes the 2001 fire area which covers an approximate of 6,750 hectares on Tahoe and Eldorado National forests. The study examines the differences in presence between habitat conditions for every species with a nonparametric Kruskal-Wallis one-way variance analysis using SAS because the data were commonly not distributed. The result shows that the Black-backed woodpecker foraged in high amount of severity and unlogged patches.

Abstract Insects, mammals and birds are known to use tools, but empirical evidence of the ecological importance of tool-use is scarce. Here, we present the first ecological study of tool-use by a bird species. Woodpecker finches use twigs or cactus spines to pry arthropods out of tree-holes. We compared tool-use during wet and dry seasons in two different vegetation zones: the Arid Zone and the humid Scalesia Zone. In the Scalesia Zone, where food was abundant and easily accessible, woodpecker finches rarely used tools. In contrast, in the Arid Zone, where food was limited and hard to access, they obtained half of their prey using tools during the dry season. Tool-use enabled the birds to reach particularly large and otherwise inaccessible prey hidden in tree-holes. Our data suggest that tool-use in the woodpecker finch has evolved in response to the dry and unpredictable conditions in the coastal zone of the Galápagos Islands. [ABSTRACT FROM AUTHOR]