Dendrocopos Major Research Articles

The requirements of three co-existing woodpecker species Picidae in relation to forests' features in the agricultural landscape of SE Poland

The occurrence of woodpeckers in European forests depends on many forest stand characteristics. During the study conducted in 2013 in the agricultural landscape of SE Poland (in an extremely deforested area with a 5% share of forest area), the habitat requirements of Middle Spotted Woodpecker Dendrocoptes medius, Great Spotted Woodpecker Dendrocopos major and Syrian Woodpecker Dendrocopos syriacus were described. For this purpose, the degree of occupation by individual species of 73 forest patches was assessed over an area of 355 km2. To determine the habitat requirements of the woodpecker species, a set of 7 parameters characterizing the studied forests and their surroundings were determined, viz. forest patch area, average age of the tree stand, etc.). Generally, the Syrian Woodpecker inhabited small forest patches surrounded by a significantly larger proportion (2.3–5.6%) of orchards, compared to forests uninhabited by this species. The most important factors that positively influenced the occurrence of the Middle and Great Spotted Woodpeckers were the forest patch size, average age of the forest patch stand, and area of forest stands aged older than 80 years. The Great Spotted Woodpecker preferred forest patches with an area exceeding 15 ha, but the Middle Spotted Woodpecker occurred only in forest patches over 42 ha. Such minimum forest patch areas should be considered essential for protecting the two mentioned species in a heavily deforested landscape. Small-sized forest patches should also be protected, enabling refuge for the Syrian Woodpecker. Keywords: bird conservation strategy, forest management, habitat selection, primary cavity nesters, rural landscape, woods, woodpeckers, SE Poland

The first case of a successful brood from a double hybrid mixed pair (Dendrocopos syriacus × Dendrocopos major (Picidae))

Hybridization occurs between numerous bird species, with some of them capable of producing backcrosses. However, little information is available concerning mating between pairs of hybrids. In this case study, a mixed pairing is reported between hybrids of Syrian and Great Spotted Woodpeckers, Dendrocopos syriacus and Dendrocopos major, respectively. Mixed phenotypic and genotypic traits were found in the male, the female and their offspring. The possible consequences of hybridization and its effect on the Syrian Woodpecker, which is protected under the Bird Directive of the European Union, are discussed.

Сравнительный эколого-географический анализ кузниц большого пёстрого дятла Dendrocopos major (Aves: Piciformes) на севере и юге европейской части России

Сравнительный эколого-географический анализ кузниц большого пёстрого дятла Dendrocopos major (Aves: Piciformes) на севере и юге европейской части России

Observations of a communal roost of Black Woodpeckers Dryocopus martius and Great Spotted Woodpeckers Dendrocopos major in two autumn-winter seasons 2018/2020 in Koszęcin Forest District (Lublinieckie Forests, Upper Silesia)

Observations of a communal roost of Black Woodpeckers Dryocopus martius and Great Spotted Woodpeckers Dendrocopos major in two autumn-winter seasons 2018/2020 in Koszęcin Forest District (Lublinieckie Forests, Upper Silesia)

Evaluation of genotyping by sequencing for population genetics of sibling and hybridizing birds: an example using Syrian and Great Spotted Woodpeckers

Recent high-throughput genotyping technologies allow for comprehensive genomic analyses on an unprecedented scale. However the advantages of the most commonly used tools are strongly limited in non-model organisms, including wild birds. In this study we attempt to test the utility of genotyping by sequencing (GBS) without relying on the reference genome sequence in selected pairs of sibling bird species that are known to hybridize (Syrian and Great Spotted Woodpeckers). We found that GBS is able to produce a satisfying number of polymorphisms and can be successfully applied to the population genetics of these species. The results also suggest that urban populations of these woodpeckers, especially phenotypic Syrian Woodpeckers, consist of individuals that harbor genotypes assigned to Great Spotted Woodpeckers, which suggests intensive hybridization and introgression.

Nesting behaviour and breeding success of Willow Tits Poecile montanus in north-west England

ABSTRACTThe British Willow Tit Poecile montanus has undergone a substantial decline in abundance and a severe contraction in range since the 1970s, for reasons that are poorly understood. Breeding failure, due to nest-site competition and predation, has been suggested as a potential factor in the decline, but limited data exist for the nesting ecology and breeding productivity of the species in Britain. We studied a sample of 128 Willow Tit nests in a habitat mosaic of early successional woodland, scrub and wetland in a post-industrial landscape in north-west England, which is increasingly becoming a key refuge for the species in Britain. Results showed that nesting began in April, with standing deadwood of silver birch Betula pendula, common elder Sambucus nigra and black alder Alnus glutinosa being the most frequent nest sites, and the characteristics of nest sites are described. Daily survival rates and overall probability of nest survival are calculated, and details are given for the timing of breeding, clutch size, nestling survival and number of fledglings produced. Overall, 55% of nesting attempts were successful, although many first breeding attempts failed due to Willow Tits being evicted from their nest cavity by Blue Tits Cyanistes caeruleus, or nests being predated by Great Spotted Woodpeckers Dendrocopos major and, potentially, grey squirrels Sciurus carolinensis. Repeat breeding attempts were relatively more successful, but produced fewer fledglings on average. The results are discussed in the context of other studies of Willow Tits and some related species, and also the implications for the conservation of Willow Tits in Britain.

Dynamics of Woodpecker – Common Starling interactions: a comparison of Old World and New World species and populations

Abstract Woodpecker species whose cavities are most usurped by Common Starlings (Sturnus vulgaris) are widespread and generalists in their use of habitats. These include primarily woodpeckers that are similar in size to or slightly larger than the starling - such as the Great-spotted Woodpecker (Dendrocopos major) of Eurasia and the Northern Flicker (Colaptes auratus) and Red-bellied (Melanerpes carolinus) and Red-headed (M. erythrocephalus) Woodpeckers of North America. Usurpation occurs primarily in human-dominated urban, suburban and exurban habitats with pastures, sports fields and other open areas that serve as prime feeding habitats for starlings. Starlings prefer high, more exposed cavities with a minimal entrance diameter relative to their body size. Usurpation success depends on timing - optimally just as a cavity is completed and before egg-laying by the woodpeckers. Starlings likely reduce woodpecker populations in more open, human-dominated habitats. Woodpecker habitat losses and fragmentation are more serious problems that enhance habitat quality for starlings and reduce habitat quality for most woodpeckers. The only woodpeckers that might become in danger of extinction as a primary result of starling cavity usurpation are likely island species with small populations. Conservation of rare species limited to islands, such as Fernandina’s Flicker (Colaptes fernandinae) of Cuba, may depend on our ability to prevent the establishment of the Common Starling or other aggressive cavity competitors on their island. Understanding and interpreting impacts of woodpecker cavity usurpation must include consideration of past woodpecker and Common Starling population fluctuations, breadth of habitats used by woodpecker species, and habitat limitations of Common Starlings. Conservation efforts for woodpeckers and other primary and secondary cavity-nesting species must focus on changes in tree, forest and ecosystem management to encourage maintenance of dead wood, large contiguous tracts that include diverse tree species and old growth, and forested linkages among such areas.

Nest site characteristics of the Great-spotted Woodpecker in a bottomland riparian forest in the presence of invasive tree species

Abstract This study was carried out in Hungary, in an old unmanaged riparian poplar-willow forest during the breeding seasons of 2014 and 2015. The occurrence of two invasive tree species, the green ash and boxelder, is significant in the study area, which influences negatively the populations of native riparian tree species in Central Europe. We studied Great-spotted Woodpecker nest sites in the presence of these invasive species. Throughout the study period, eight and twelve nesting cavity trees were mapped. Trees were recorded in 20-20 circular plots of 0.05 ha both for each mapped nest trees and random plots as well. Species, diameter at breast height and condition were recorded for each tree. Composition and diversity of nest site and random plots were compared. Distributions and preferences were calculated for nest tree use. Most of the recorded trees were invasive. Nest site plots had more native trees compared to random plots. Nest site showed higher diversity in terms of all three variables. Decayed and dead willow and white poplar hybrid trees were preferred for nesting. Diameter at breast height of nest trees was between 30-90 cm. Studies about cavity excavators in transformed habitats have high importance for nature conservation of riparian forests.

Habitat Preference of Great-Spotted Woodpecker (Dendrocopos major Linnaeus, 1758) and Lesser-Spotted Woodpecker (Dendrocopos minor Linnaeus, 1758) in the Presence of Invasive Plant Species - Preliminary Study

Abstract This study was carried out in Hungary, in an old, unmanaged, riparian poplar-willow forest, where two invasive tree species, the green ash and the boxelder maple are presented and reproduce more effectively therefore are more abundant than the native species in the study area. There are also invasive hybrid wild grapes to be found. These invasive plants cause widespread problems in floodplain forests in Central Europe. We studied Great-spotted and Lesser-spotted Woodpeckers. We investigated the following questions: Which tree species are preferred by the foraging birds? How are the foraging birds distributed spatially between the microhabitats? Are there any differences in terms of foraging niche utilization between the two studied species? We gathered our data through weekly standard observations throughout two whole years. Based on our findings we could determine that both species preferred the less abundant native trees rather than the invasive ash and maple trees, though Lesser-spotted Woodpeckers preferred hybrid wild grapes the most. Great-spotted Woodpeckers preferred the middle heights of the trees, they also moved mainly on trunks. Lesser-spotted Woodpeckers used the thinnest branches in the canopy. Based on our results we predict that the decrease of the native tree species may create a suboptimal habitat compared to the current situation. As the studied species are the major cavity excavators, the above mentioned changes will probably have significant effects on numerous cavity dependent species.

Relationship between vegetation structure and abundance of Great-spotted Woodpeckers (Dendrocopos major) in a mosaic habitat

AbstractThis study was made in a postglacial relic bog in the Ócsa Protected Landscape Area in Hungary. Secondary succession of vegetation began after peat extraction and a grove-like forest evolved. Among the eight woodpecker species that occur in this area, the Great-spotted Woodpecker is the most abundant with the largest amount of data, it is for this reason we chose this species to study. The aims of this work were to detect changes in the abundance of the study species in relation to forest succession; to examine the seasonal patterns of these changes in abundance, and to identify any relationship between the height of the trees near the nets and the number of captured birds. We used the data from 1411 mist-netted Great-spotted Woodpeckers (1984- 2010), which were captured at the Ócsa Bird Ringing Station (120 standard mist nets). The assessment of forest succession rates were based on aerial photos (1979-2010). We measured the height of the vegetation, at 12 points, near each 12 m long net. Population growth of Great-spotted Woodpeckers was significantly correlated with the rate of afforestation. The majority of birds occurred only during the dispersal period. The pattern of the captures correlated well with the vegetation structure, not just with height, but also with vegetation quality as well

Assessing breeding success in common woodland birds using a novel method

Capsule Repeated counts of fledged broods can provide a useful estimate of breeding success for most common woodland birds. Aims To assess the efficacy of comparing fledged-brood survey data with territory mapping using simple mark–recapture analysis techniques to provide an estimate of breeding success for common woodland birds that does not involve finding nests. Methods Three observers undertook territory mapping surveys of adults, followed by counts of fledged broods four times a week during May–July 2007 in two 15 ha woods each, both in southern England. Using known fledging to maturity periods, these counts were used to calculate daily detection probabilities for broods of ubiquitous species. These enabled fledged brood territory occupancy probabilities (i.e. brood to territory ratios) to be estimated that take account of the possibility that broods were present but missed by surveys. Results Of the 19 species found in all six woods, mean daily detection probability estimates for fledged broods of 17 species ranged from 0.17 to 0.50 with significant variation between woods for 12 species, but within region/observer for four species. The mean probability of detecting a brood at least once was over 75% using four visits per week and over 50% using two visits. Only for Great Spotted Woodpeckers Dendrocopos major and Garden Warblers Sylvia borin was the fledging period too short and the daily detection probability too low to provide a reasonable estimate of the territory occupancy probability. Conclusion Daily detection probabilities for fledged broods of most common woodland birds were sufficiently high to enable useable estimates of fledged-brood territory occupancy probabilities to be made based on a survey programme involving two or three visits per week between late May and the end June. The method used may have application as a means of providing a relatively easily derived productivity index for woodland bird monitoring programmes or for research studies.

The origins of Great Spotted Woodpeckers Dendrocopos major colonizing Ireland revealed by mitochondrial DNA

Capsule Although necessarily based on a small number of samples, comparisons of molecular data from the newly established Great Spotted Woodpecker populations in Ireland with those in Britain and continental Europe revealed that Britain was the more likely source area of the Irish populations.

Characteristics of woods used recently and historically by Lesser Spotted Woodpeckers Dendrocopos minor in England

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.

Great Spotted WoodpeckersDendrocopos majorDetect Variation in Wood Hardness before Excavating Nest Holes

Great Spotted Woodpeckers Dendrocopos major typically excavate nest holes in trees with specific physical characteristics, namely with harder outer and softer inner wood. They excavate trial holes before excavating their nest holes, occasionally expanding old trial holes into nest holes. If trees with trial holes always share the same physical characteristics with nest trees, then Great Spotted Woodpeckers should be able to detect these characteristics before excavating trial holes and nest holes. I measured wood hardness and compared it among trees with trial holes, trees with nest holes, and sound trees. The physical characteristics of sound trees, which varied little in hardness, differed markedly from those of trees with trial holes and nest holes, Many trees with trial holes showed the same pattern of wood hardness as nest trees, although one showed the reverse pattern that is with softer outer and harder inner wood. The results of this study suggest that Great Spotted Woodpeckers are able to detect trees and positions on those trees with considerable wood hardness variation, but are unable to sense whether the hardness variation is suitable for nest excavation before they excavate trial holes. Thus, Great Spotted Woodpeckers excavate trial holes and then judge whether the positions where trial holes are excavated are appropriate for nest hole excavation.

Diversity and plasticity in branch-side use by birds in mixed-species flocks: niche differentiation or competitive hierarchy

ABSTRACT Two models of mechanisms have been proposed to account for resource partitioning between species with overlapping niches, i.e., niche differentiation and competitive hierarchy. I examined branch-side uses by color-marked individuals of eight canopy-foraging species (Long-tailed Tit Aegithalos caudatus, Marsh Tit Parus palustris, Great Tit P. major, Eurasian Nuthatch Sitta europaea, Japanese Pygmy Woodpecker Dendrocopos kizuki, Great-spotted Woodpecker D. major, White-backed Woodpecker D. leucotos and Grey-headed Woodpecker Picus canus) in mixed-species flocks on artificial feeding trees for three years. The three tit species and the Nuthatch used the upper sides of branches most frequently whereas the four woodpecker species used the lateral sides of the branches most frequently, as expected from the niche differentiation model. Among the three tit species and among the four woodpecker species, small-subordinate species foraged on a wider range of branches than large-dominant species, as expected...

Factors influencing Willow Tit Poecile montanus site occupancy: a comparison of abandoned and occupied woods

The British Willow Tit Poecile montanus kleinschmidti underwent a decline of 85% between 1970 and 2003. The cause of this decline is unknown. However, several hypotheses have been put forward to account for it: competition from other tit species, predation by Great Spotted Woodpeckers Dendrocopos major and habitat change. In order to test these, woods that are currently occupied by Willow Tits were paired with woods (within 50 km) that had been abandoned by Willow Tits five or more years previously. Point counts for other tit species (potential competitors) and woodpecker species (potential predators) were carried out at ten evenly spaced points throughout each wood. Habitat variables were collected within a 50‐m radius of where a Willow Tit was located (in the occupied woods) or where maps showed a Willow Tit had been located (for abandoned woods). No evidence was found for differences in numbers of potential competitor or potential predator species in abandoned and occupied woods. Soil water content was found to be higher at occupied sites. No other habitat features differed between the two categories of site. The drying up of British woods could therefore be implicated in the Willow Tit decline and this warrants further investigation.

Remote monitoring of nests using digital camera technology

ABSTRACT Although cameras have been used for many years to collect data at birds' nests, recent advances in digital technology have led to increased storage capacity, faster and easier review of data, and reduced power consumption. The development of sophisticated triggering mechanisms, such as video motion detection, herald a new era of portable, energy-efficient systems that require less frequent maintenance. We used a digital infrared camera system to monitor predation events at the nests of ground-nesting Lapwings (Vanellus vanellus; N= 40) and tree-nesting Spotted Flycatchers (Muscicapa striata; N= 17). Eight predator species were recorded taking eggs or chicks at Lapwing (N= 10) and Spotted Flycatcher (N= 7) nests, including red fox (Vulpes vulpes), badger (Meles meles), sheep (Ovis aries), and Carrion Crow (Corvus corone) at Lapwing nests and Eurasian Jay (Garrulus glandarius), European Buzzard (Buteo buteo), Great-spotted Woodpecker (Dendrocopus major), and domestic cat (Felis catus) at flycatcher nests. We tested three system configurations in an attempt to minimize power requirements and maximize predation-event recording capability. We found that the use of a passive-infrared sensor to awaken the system from standby mode did not compromise reliability and reduced power consumption. With this system, a 38-A h battery operated the system for 120 h with no maintenance at a cost per unit of about $800 (US; or £400 UK Sterling). Further modifications would permit adaptation of the system for a wide range of scientific and nest surveillance operations.

Continental Great Spotted Woodpeckers in mainland Britain ‐ fact or fiction?

The wing lengths of Great Spotted Woodpeckers Dendrocopos major resident in Britain (subspecies anglicus) are more variable than had previously been realised, with one individual in a thousand reaching extremes of 123 mm and 140 mm. As a result, many of the past British records claiming to be of the larger continental subspecies major have probably been misidentified. There is no reliable evidence to indicate that continental Great Spotted Woodpeckers visit Britain annually. Rather, infrequent irruptions into Britain occur about once in 12 years. Birds arriving at Fair Isle are at the top end of the size range of this species, and probably originate from northern Russia and Scandinavia. The birds irrupting into the mainland of Britain are intermediate in size but, on average, have longer wings than the British residents, and so only the larger individuals with wing lengths beyond the British range can be identified as of continental origin. Woodpeckers originating from continental areas south of the Baltic have similar wing lengths to British birds and cannot be identified from wing length measurements. Currently, there are only two instances of Great Spotted Woodpeckers being ringed on the European continent and recovered in Britain, again indicating that immigrant birds are probably few.

Comparative reproductive biology of Middle Spotted Woodpeckers Dendrocopos medius and Great Spotted Woodpeckers D. major in a riverine forest

Capsule Nest success rate and survival probabilities of individuals are the same but clutch size and fledgling number are higher in the smaller species. Aims To examine the relevant reproductive features of the two co-occurring congeneric woodpecker species, to analyse the effect of timing of breeding, clutch size and weather conditions on survival time of nestlings, and to discuss life-history traits in relation to potential food limitation and mortality. Results The start of the breeding season in both species was highly synchronized and did not vary among species and years. Middle Spotted Woodpeckers laid larger clutches (6.5 eggs) than Great Spotted Woodpeckers (5.4 eggs). Daily survival rates and the proportion of nestlings that were surveyed to the end of the nesting period, as well as nesting success (83% and 88%, respectively) did not vary between species. Middle Spotted Woodpeckers reared more fledglings in successful nests (4.5 fledglings) compared to Great Spotted Woodpeckers (4.0 fledglings). In both species the survival time of nestlings was negatively correlated with the timing of laying and the amount of rainfall during the incubation and nestling phase. Moreover, among Great Spotted Woodpeckers there was positive correlation between the survival time and the clutch size. Conclusion The highly synchronized start of the breeding season is probably conditioned by food availability. The difference between annual fecundity was a likely result of the higher winter mortality of Middle Spotted Woodpeckers. The survival time of nestlings was determined to a large degree by the timing of breeding and weather conditions. The west–east climate gradient is a plausible factor for the explanation of the longitudinal differences regarding the annual fecundity of European Middle Spotted Woodpecker populations.

Resident males of small species dominate immigrants of large species in heterospecific, winter bird flocks

Dominant-subordinate relationship among eight species was investigated at the individual level in mixed, winter flocks of birds in Hokkaido, Japan. In five pairs of species, some individuals of averagely smaller species always dominated those of averagely larger species on average, large species. The characteristics of individuals causing dominance reversal were examined for body size, sex and residency for each pair of individuals. Among individuals of Nuthatch Sitta eurpaea and Japanese Pygmy Woodpecker Dendrocopos kizuki, in which body size largely overlapped and both were residents, their dominance was perfectly related to body size. Between species for which body size did not overlap, i.e., Marsh Tit Parus palustris and Great Tit P. major, and Great-spotted Woodpecker D. major and two larger woodpecker species (White-backed Woodpecker D. leucotos and Grey headed Woodpecker Picus canus), resident males of small species often dominated immigrants of large species. This result can be due to site- or sex-related aggressiveness of individuals.