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Trends in Threat Status and Priorities in Conservation of the Woodpeckers of the World

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Taking the first IUCN Red List from 1988 as a starting point, I review trends in the threat status of the woodpecker species of the world, the geographical distribution of (near-) threatened woodpecker species, threat factors affecting these species, and the research output about them. Between 1988 and 2013 the number of genuinely Red Listed woodpeckers (categories Near Threatened and up) increased from 20 to 28 species and the number of species in the categories Vulnerable and up from 8 to 12. As percentage of recognised woodpecker species in the different years, the increase in Red Listed woodpecker species was even sharper. The geographical distribution of Red Listed woodpeckers stayed constant between 1988 and 2013, with over half of the species in Latin America, about one quarter in Asia, and none in Europe. A taxonomic reappraisal adopted by IUCN in 2014 raised the total number of recognised woodpecker species to 254 and of Red Listed woodpecker species to 42, of which 40% occur in Asia. Nearly all Red Listed woodpecker species on the 2013 list are threatened by deforestation. Out of 28 species, 10 are also threatened by selective logging, and these 10 are in higher threat categories. Woodpecker conservation research should focus in particular on the species sensitive to selective logging, to assess their within-habitat requirements and thresholds. The output of research on Red Listed woodpeckers in the past 25 years was heavily skewed to three North American species: Red-headed Woodpecker Melanerpes erythrocephalus, Red-cockaded Woodpecker Picoides borealis and Ivory-billed Woodpecker Campephilus principalis. I identify 10 priority species to focus woodpecker conservation research on, four from Latin America: Speckle-chested Piculet Picumnus steindachneri, Fernandina's Flicker Colaptes fernandinae, Black-bodied Woodpecker Dryocopus schulzi, Helmeted Woodpecker Dryocopus galeatus; and six from Asia: Okinawa Woodpecker Dendrocopos noguchii, Korean White-bellied Woodpecker Dryocopus richardsi, Great Slaty Woodpecker Mulleripicus pulverulentus, Red-collared Woodpecker Picus rabieri, Yellow-faced Flameback Chrysocolaptes xanthocephalus and White-rumped Woodpecker Meiglyptes tristis.
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... Within forest ecosystems, woodpeckers are known to be especially vulnerable to deforestation and forest degradation because of their high degree of specialization on old growth trees, which they use both to search for food and to build their nests (Lammertink 2014). Research shows that the global species richness of woodpeckers is strongly linked with tree cover, precipitation (Ilsøe et al. 2017), and presence of deadwood at the early decay stage (Tremblay et al. 2009); therefore, events that modify these conditions, such as climate change and human activities, have a strong impact on the woodpeckers' persistence (Billerman et al. 2016). ...
... principalis Linnaeus 1758) and the Imperial Woodpecker (C. imperialis Gould 1832), both old-forest specialists driven to extinction as a result of habitat loss (Lammertink andEstrada 1995, Fitzpatrick et al. 2006). Likewise, research on other woodpeckers shows that habitat loss and fragmentation reduced genetic diversity, increased inbreeding, and lowered effective population sizes, e.g., Red-cockaded Woodpecker (Picoides borealis; Reed et al. 1988, Stangel et al. 1992, Haig et al. 1993, Blackwell et al. 1995, Schiegg et al. 2006, Bruggeman et al. 2010, White-backed Woodpecker (Dendrocopos leucotos; Ellegren et al. 1999), and Wryneck (Jynx torquilla; Mermod et al. 2009;Assandri et al. 2018). ...
... Research on the movement behavior of Magellanic Woodpeckers shows that dominant males determine their movement trajectory and patch residence times according to observable and memorized information of local habitat quality (Vergara et al. 2015, suggesting that individuals avoid the use of a hostile matrix to perform dispersal, similarly to other woodpecker species (e.g., Pasinelli andWalters 2002, Trainor et al. 2013). Hence, evidence suggests that lower genetic variability values observed in Nahuelbuta may be a consequence of the open matrix surrounding this area, which would limit the ability of the forest-dependent woodpeckers to disperse (Gorman 2014, Lammertink 2014). Although we did not find evidence for inbreeding (FIS > 0) in these populations (Table 1), it is important to note that inbreeding is a gradual phenomenon and likely to increase over time in small and/or closed populations in which mating individuals will have, eventually, some degree of kinship (Ralls et al. 2014, Chen et al. 2016. ...
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One important landscape-scale consequence of deforestation is reduced connectivity, which has the potential to isolate populations in ways that affect genetic diversity and population structure. Among the many regions of the world where this scenario has played out is the South American temperate forest (SATF) in southern Chile, and there is now strong concern about the population viability of forest taxa. We studied one such species, the Magellanic Woodpecker (Campephilus magellanicus), a forest specialist that is now listed as vulnerable in parts of its range in Chile. We characterized genetic variability and population structure from 33 samples of Magellanic Woodpeckers from two large but isolated populations in Nahuelbuta National Park in the Coastal mountain range and the Conguillío National Park in the Andes using ddRAD-seq method. We found lower genetic variability in Nahuelbuta than Conguillío, but inbreeding values (FIS) did not show evidence for inbreeding depression. Results suggest the presence of two genetic clusters, with an average FST value of 0.04. Phylogenetic analysis showed that the Nahuelbuta population forms a clade that is nested within the individuals from Conguillío, suggesting limited gene flow between these populations. Our results support the idea that extensive deforestation has played a role in shaping the genetic patterns that we have identified. Because of this, we emphasize the need for regional planning to increase the structural connectivity between fragments of mature native forests, to provide an opportunity for the persistence of Magellanic Woodpeckers in this region.
... Woodpeckers are globally distributed birds, absent only from Australasia, Antarctica, Madagascar, remote islands, and treeless environments (Mikusiński 2006;Ilsøe et al. 2017). The tropics have the greatest richness of woodpecker species, as well as the greatest richness of imperiled woodpecker species (Mikusiński 2006;Lammertink 2014). Woodpeckers are considered keystone species due to their role in excavating holes, creating breeding habitat for secondary cavity users (Martin et al. 2004;Blanc and Walters 2008;Roberge et al. 2008;Robles and Martin 2013;Cockle and Martin 2015). ...
... Woodpeckers are considered keystone species due to their role in excavating holes, creating breeding habitat for secondary cavity users (Martin et al. 2004;Blanc and Walters 2008;Roberge et al. 2008;Robles and Martin 2013;Cockle and Martin 2015). Despite the great threats to conservation in the tropics, most research on imperiled woodpeckers have focused on three temperate North American species, the Red-headed (Melanerpes erythrocephalus), Red-cockaded (Picoides borealis) and Ivory-billed Woodpeckers (Campephilus principalis) (Lammertink 2014). Woodpecker conservation is needed in tropical regions, where deforestation and urbanization follow rapid population growth (Meyer and Turner 1992;Cincotta et al. 2000). ...
... Researchers project low elevation coastal zones in these countries to grow by up to 20 million people by 2060 over 2000 baseline populations (Neumann et al. 2015). Half of the woodpecker species red-listed by IUCN occur in Latin America (Lammertink 2014). ...
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Critical resources for birds nesting in cities can support populations in spite of the challenges imposed by urbanization, and the identification of such resources can shed light on how species are able to adapt to novel environments. In the case of woodpeckers, these resources also support the conservation of secondary cavity-nesters. Woodpecker nesting has been well-studied in temperate regions, including within urban areas, but in subtropical and tropical regions, less is known. Here we ask what types of trees and what habitats woodpeckers use most, and which species of woodpeckers create the most nest cavities. We recorded information from 967 woodpecker nest trees in the region surrounding Miami, Florida, USA, which contained 1864 nest cavities excavated by four woodpecker species. Palm trees were used more than all other tree categories, and royal palms (Roystonea regia) were the most-used species overall. Woodpeckers preferentially excavated palm snags in every habitat where they were available and three of the four woodpecker species used palms snags over all other categories of trees. Red-bellied Woodpeckers (Melanerpes carolinus) were the most prolific cavity excavators, creating 78.1% of holes. Remnant patches of two native forest types contained the highest densities of woodpecker nest trees. We found a higher density of nest trees in moderately-developed suburban areas than either rural, agricultural areas or in the highly-developed urban core. We consider how these results can inform conservation efforts in the developing tropics, and especially within similar urbanizing environments in the nearby Caribbean.
... Although the foraging and nesting preferences of Magellanic woodpeckers are well known (e.g., Espinosa et al., 2016;Ojeda and Chazarreta, 2006;Vergara et al., 2019Vergara et al., , 2016, the mechanisms for which forest attributes influence the fitness of territorial individuals remain poorly understood. Disentangling the association of breeding success and forest attributes may become important to explain the decline of Magellanic woodpecker populations in some conservation areas of southern Chile (Vergara et al., 2017b), also found in other large woodpecker species worldwide (Lammertink, 2014;Vergara-Tabares et al., 2018). Magellanic woodpeckers live in small social groups composed of an adult pair and accompanying juveniles, whose dispersal can be delayed by more than two years (Ojeda, 2004;Schlatter and Vergara, 2005). ...
... Here we have presented an example of how remote sensing indices can be considered as reliable proxies of the habitat quality for Magellanic woodpeckers through influencing their reproductive success. Considering the threatened status of large-sized woodpeckers, with some extinct species of the genus Campephilus (Lammertink, 2014), our study may be further replicated in other forest ecosystems where woodpeckers live in social groups. Larger woodpeckers are known to provide large tree cavities to forest-dwelling species (Mikusiński et al., 2001;Martin, 2014, 2013), so the conservation of these woodpeckers offers an opportunity to maintain multiple species assemblages. ...
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Bridging remote-sensing ecosystem indices with biodiversity conservation implies converting these indices into habitat quality indicators for species playing an important role in communities and ecosystems , such as woodpeckers. However, an ecologically reliable estimation of habitat quality necessarily involves an assessment of fitness components ultimately responsible for population persistence. Here, we assessed the relationship be tween remote-sensing indices of forest structure, dynamics and composition with the breeding performance of Magellanic woodpeckers in conservation areas of southern Chile. We used a Bayesian-spatial model based on age and sex information from woodpecker's social group data collected seasonally in seven years. The probability of a young remaining in the group decreased with the me an group size du ring the previous year, with group size fluctuating temporally in all conservation areas. Tree senescence had a positive effect on the pairing probability of woodpeckers, but this effect be came more marked in sites of higher altitude. Paired woodpeckers were more likely to be observed in sites supporting more than 69 % of forest cover. The probability of the young remaining in the territory was positively affected by the interaction be tween forest canopy continuity and altitude, with retention of the young being more likely in sites located higher than 10 00 ma sl. Social groups were larger in sites where the continuity of canopy increased over time. Those findings suggest that remote sensing indices representing the structure and dynamics of forest ecosystems are important indicators of the habitat quality for woodpeckers. Thus, forest biodiversity that depend s on the woodpecker's engineering function ma y be conserved through the retention of senescent trees and the maintaining of critical levels of forest cover ensuring high habitat-quality for breeding woodpeckers.
... Black-bodied Woodpecker (Dryocopus schulzi): this woodpecker (Fig. 5F) is endemic to the Chaco region, and it is considered "Nearly Threatened" (López-Lanúz et al. 2008, Lammertink 2014, Winkler & Christie 2016. Despite its wide distribution across the Chaco region, this species is generally rare on a local scale (Madroño & Pearman 1992). ...
... However, Yzurieta (1995) has stated that this woodpecker is rare in Córdoba, contrary to our observations in the study area. Big woodpeckers, such as D. schulzi, are sensitive to logging and deforestation, as trees are required to build their nests (Lammertink 2014). Therefore, urbanization of pristine mountain forests may present a new threat for these locally abundant populations of D. schulzi. ...
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Between 1970 and 1980, many ornithological prospections were made in central Argentina. With this work we intend to fill some of the existing gaps regarding such knowledge. We conducted bird surveys in the central-western region of Córdoba province. We identified 240 bird species (63% of province's avifauna) belonging to 48 families: 10 of which are considered under some threat category, 37 are migrants, and two are endemic to the region. Throughout a qualitative analysis of ordination, we identified three clusters of environments that share similar bird composition. Among those, the most dissimilar group was composed of aquatic environments, whereas the two other groups included wooded and anthropized environments and high altitude environments, respectively. The high bird richness recorded in a relatively small region, encompassing a variety of environments, place upon this area a high bird conservation value. The inclusion of this area in the system of “Important Bird Areas” (IBAs) may prompt protection actions.
... Black-bodied Woodpecker (Dryocopus schulzi): this woodpecker (Fig. 5F) is endemic to the Chaco region, and it is considered "Nearly Threatened" (López-Lanúz et al. 2008, Lammertink 2014, Winkler & Christie 2016. Despite its wide distribution across the Chaco region, this species is generally rare on a local scale (Madroño & Pearman 1992). ...
... However, Yzurieta (1995) has stated that this woodpecker is rare in Córdoba, contrary to our observations in the study area. Big woodpeckers, such as D. schulzi, are sensitive to logging and deforestation, as trees are required to build their nests (Lammertink 2014). Therefore, urbanization of pristine mountain forests may present a new threat for these locally abundant populations of D. schulzi. ...
Article
Full-text available
Between 1970 and 1980, many ornithological prospections were made in central Argentina. With this work we intend to fill some of the existing gaps regarding such knowledge. We conducted bird surveys in the central-western region of Córdoba province. We identified 240 bird species (63% of province's avifauna) belonging to 48 families: 10 of which are considered under some threat category, 37 are migrants, and two are endemic to the region. Throughout a qualitative analysis of ordination, we identified three clusters of environments that share similar bird composition. Among those, the most dissimilar group was composed of aquatic environments, whereas the two other groups included wooded and anthropized environments and high altitude environments, respectively. The high bird richness recorded in a relatively small region, encompassing a variety of environments, place upon this area a high bird conservation value. The inclusion of this area in the system of “Important Bird Areas” (IBAs) may prompt protection actions.
... These ecological traits together with other attributes such as sedentariness and poor dispersal in most species (Mikusiński, 2006) result in woodpeckers being a group highly sensitive to forest cover change (Henle, Davies, Kleyer, Margules, & Settele, 2004;Ilsøe et al., 2017;Virkkala, 2006). Some woodpecker species are capable of maintaining populations in managed forests or in tree plantations, but even these species usually reach higher densities in extensive, natural forest areas (Lammertink, 2014;Winkler & Christie, 2017). Because of the strong association between traits of woodpeckers and forests environments (Ilsøe et al., 2017), woodpeckers have been used in the guiding of forest management and of forest biodiversity conservation (Lammertink, 2004;Nilsson, Hedin, & Niklasson, 2001;Uliczka, Angelstam, Roberge, & Uliczka, 2004;Virkkala, 2006). ...
... km 2 ( Figure 6 Lack of biological knowledge has been identified as one of the most important shortfalls for biodiversity conservation (Bini, Diniz-Filho, Rangel, Bastos, & Pinto, 2006;Diniz-Filho, Loyola, Raia, Mooers, & Bini, 2013;Hortal et al., 2015). Studies on woodpecker biology and/ or ecology in South America, Africa and Southeast Asia are scarce compared to Europe and North America (Lammertink, 2014;Mikusiński, 2006 The range maps provided by IUCN (2015) we worked with may have inaccuracies, but are considered to suffice for analyses at large spatial scales (Ficetola et al., 2013). We combined these maps with a fine resolution raster of land cover (300 m). ...
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Aim As a result of their ecological traits, woodpeckers (Picidae, Aves) are highly sensitive to forest cover change. We explored the current land cover in areas of high species richness of woodpeckers to determinate regions where urgent conservation actions are needed. In addition, we identified woodpecker species that are sensitive to forest loss and that have high levels of human habitat modification and low levels of protection (through protected areas) in their distribution ranges. Location Global. Methods We joined available range maps for all extant 254 woodpecker species with information of their conservation status and tolerances to human habitat modifications and generated a richness map of woodpecker species worldwide. Then, we associated this information (the richness pattern and individual species’ maps) with land cover and protected areas (PAs) maps. Result We found that the foremost woodpecker species richness hotspot is in Southeast Asia and is highly modified. At the second species richness hotspot in the eastern Andes, we observed a front of deforestation at its southern extreme and a greater deforested area in its northern extreme but most of its area remains with forest coverage. At the species level, 17 species that are sensitive to forest modification experience extensive deforestation and have low extents of PAs in their ranges. Main conclusions The most diverse woodpecker hotspots are mostly occupied by human-modified landscapes, and a large portion of the species there avoids anthropogenic environments. The level of representation of woodpecker species in PAs is low as a global general pattern, although slightly better in Asia. Our global analysis of threats to woodpecker from land use patterns reiterates the urgent conservation needs for Southeast Asian forests. Finally, based on our results, we recommend a re-evaluation for inclusion in the Red List of five woodpecker species.
... isms to climate-induced changes in forest processes are scarcely known (Della Rocca et al., 2019;Ulyshen, 2013). In this sense, large-bodied species with long generation times, occupying higher trophic levels, may be particularly sensitive to disturbances (Henle et al., 2004;Eklöf et al., 2012), as the case of large specialized woodpeckers (Schlatter and Vergara, 2005;Lammertink et al., 2009;Lammertink, 2014;Ojeda and Chazarreta, 2014). Woodpecker populations are considered to describe the conservation state of forest biodiversity (Drever et al., 2008;Walsh et al., 2019;Menon and Shahabuddin, 2021) but the linkage between climate change and woodpecker populations remains a challenge due to uncertainty arising from imperfect knowledge about the causal mechanisms involved (Walsh et al., 2019). ...
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Climate change-induced mortality of trees is a concerning phenomenon for global forest ecosystems. The rapid decay and death of long-lived trees can significantly impact forest dynamics, with effects that transmit through ecological networks, becoming more evident in organisms occupying high trophic levels, such as large and specialized woodpecker species. However, understanding how populations of high trophic level species respond to climate change is still a challenge. In this study it was analyzed 32-year data of social groups of the Magellanic Woodpecker (Campephilus magellanicus) in North Patagonia, a region facing increasingly frequent droughts and increased temperatures. A positive trend in the size of woodpecker social groups as a response to climate-induced tree senescence was tested. A causal structural equation model examining climate- tree senescence- woodpecker relationships was used. Increasing nonlinear trends and positive interannual growth rates (>10%) for tree senescence and group size were found. Lowland forest sites had higher levels of tree senescence and more numerous social groups. The causal model supported the positive effect of mean temperature on tree senescence and the positive association of woodpeckers with tree senescence. These results provide evidence of a climate-induced increase in tree senescence that causes an increase in the size of woodpecker social groups. It is suggested that accelerated decay and mortality of trees in the northern Patagonian forests will decrease the stocks of deadwood in the long term, threatening the persistence of this large woodpecker species.
... Numerous species depend on tree cavities; inter alia cavity-excavators provide nesting opportunities for other cavity-dwelling species (Bai et al. 2005). Woodpeckers can be examples of umbrella species since, through their protection, it is possible to protect other species (Roberge et al. 2008;Edman et al. 2011;Lammertink 2014;Robles and Pasinelli 2014). For these conservation purposes, it is crucial to study their ecological needs, specifically their habitat preferences. ...
Article
We investigated the pre-breeding intersexual foraging habitat references of the great spotted woodpecker Dendrocopos major in six old, unmanaged riparian forest stands in Central Hungary, which are composed mainly of the invasive North American green ash Fraxinus pennysylvanica and boxelder Acer negundo, and native poplar Populus sp. and willow Salix sp. trees in lower abundances. With the influence of river management, the two invasive species have usurped native tree species in numerous Central European riparian forests. We studied the intersexual utilization of tree species, tree condition, stem diameter, foraging height, horizontal sections, substrate diameter, substrate condition, and foraging technique. The birds showed intersexual segregation in numerous studied variables despite the high niche overlap between sexes. Similar patterns were also found in other woodpecker species as well. We think that the most important part of this segregation could be the difference revealed in the choice of tree species, as males tended to be more specialized for native softwood tree species with rougher bark structure. Despite the high abundance of invasive tree species, neither sex preferred them. The further population decrease of native tree species could increase within-species competition and negatively affect the studied bird species.
... As a consequence of human-induced habitat loss, fragmentation, and structural homogenization, many woodpecker species are threatened or have declining populations (Mikusiński 2006, Lammertink 2014, Vergara-Tabares et al. 2018). This especially concerns habitat specialists with strong affinity for old-growth forest or forest subjected to natural disturbances, e.g. ...
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Several studies have shown that the Three-toed Woodpecker (Picoides tridactylus) is strongly favored by large-scale disturbances, including forest fires. However, natural disturbances have largely disappeared from European boreal forests because of modern forestry practices and fire suppression. We currently lack knowledge on the foraging activity and resource use of the Eurasian Three-toed Woodpecker, especially in burned forests, and this restricts our ability to develop strategies for sustainable forest management and ecological restoration aiming at improving the situation of this woodpecker and associated species. In order to fill this knowledge gap, we studied the characteristics of selected foraging substrates and the foraging behavior of the Three-toed Woodpecker during the breeding season in unburned forests and forests that have been subjected to prescribed burning. We used instantaneous sampling during two consecutive springs (2016-2017), where we observed the woodpeckers’ foraging behavior during a total of 977 minutes in burned forest and 962 minutes in unburned forests. The preferred foraging substrate for Three-toed Woodpeckers in both burned and unburned forests can be characterized as freshly dead trees with a DBH > 15 cm. However, data on time spent foraging on different substrates suggest that also substrates in the 5-15 DBH range and living trees are important. Additionally, prescribed burnings led to less pronounced selection of tree species, which suggest that fire may reduce differences in abundance of saproxylic insect prey between tree species. This information on substrate selection and foraging time provide complementary knowledge and thus should be used simultaneously when management strategies for improved woodpecker habitat are developed. Our results suggest that both prescribed burning and protecting forests with high density and diversity of dead wood provides habitat opportunities for Three-toed Woodpeckers and using both in management may maximize conservation outcome
... Like other large woodpecker species, Magellanic Woodpeckers have relatively long parental care duration (two to three years), large territories (0.2 to 1.3 km²) and low densities (0.1 to 1.8 individuals/km²), which make them highly sensitive to forest loss and degradation caused by logging, wildfires, and natural disasters (Vergara and Schlatter 2004, Chazarreta et al. 2011, Soto et al. 2012, Ojeda and Chazarreta 2014, Vergara et al. 2014; see also Lammertink et al. 2009). Specifically, the loss of large, dying, or dead trees reduces availability of foraging, roosting, and nesting sites and, thus, induces population declines across multiple species of woodpeckers (Lammertink 2004, 2014, Mikusinski 2006, Bull et al. 2007, Pasinelli 2007, Lammertink et al. 2009, Kumar et al. 2014, Nappi et al. 2015. Remote sensing-based methods have proven to be effective in identifying trees with advanced decay stages, thus providing information on the quality of foraging habitat of Magellanic woodpeckers , Vergara et al. 2017. ...
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A major challenge for protected areas is providing wildlife with enough suitable habitat to cope with stochastic environment and increased pressure from the surrounding landscapes. In this study, we addressed changes in local populations of Magellanic Woodpeckers (Campephilus magellanicus) occupying three national parks of central-southern Chile. We compared the breeding and postbreeding abundance of woodpeckers during the 1990s with the present (2016) abundance (n = 4 years), and assessed the extent to which abundance was explained by forest type and quality of foraging habitat (as quantified through the plant senescence reflectance index; PSRI). Results show a distinctive temporal variation in woodpecker abundance at each park, with local populations of Magellanic Woodpeckers declining by 42.2% in Conguillío National Park, but increasing by 34.3% in Nahuelbuta National Park. Woodpeckers responded to forest conditions within each park such that their abundance increased with high quality of foraging habitat, i.e., large PSRI values, and the presence of old-growth Monkey puzzle (Araucaria araucana) - Nothofagus pumilio mixed forest. Anecdotal evidence suggests that populations of woodpeckers in Conguillío National Park might have responded negatively to large-scale disturbances from recent forest fires affecting part of the forest area within park. Because stochastic events seemed to strongly mediate population changes, our findings suggest that regional conservation of Magellanic Woodpeckers requires expanding the current conservation area network in central-southern Chile.
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The white-backed woodpecker (WbW) is a critically endangered species in Europe. The Białowieża Forest (BF) is of major importance for its conservation. Distribution of WbW in deciduous stands of the BF was studied in relation to habitat resources. In March-April 2005 we replicated a 1991 study where the WbW population was estimated using playback drumming techniques. Woodpeckers were recorded in only one-third of its former distribution area. A logistic regression model revealed that one variable (volume of dead wood) correctly classified 69.2% of habitat patches as occupied by the WbW, and 93.8% as missing the WbW. Plots with woodpeckers had six times more dead wood (54.2 m3 ha-1) than plots where WbWs were absent (8.9 m 3 ha-1). Our results demonstrate that reduction in the WbW population is causally linked to on-going logging and consequent removal of dead wood. The only way to prevent further WbW population decline is to protect the entire BF as a national park.
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The polytypic species concept unites populations that theoretically could and would interbreed were the opportunity to arise-This concept places the burden of proof of reproductive in-capability and species status on those claiming species or higher rank. Advances in our understanding of the nature of reproductive isolation, the genetics of speciation, the limited role of gene flow, the power of directional selection, and the dynamics of hybridization support a different null hypothesis for taxonomic decisions, one that places the burden of proof on 'lumping' rather than on 'splitting' taxa at the species level. Switching the burden of proof provides an improved conceptual basis for the recognition of many allopatric island taxa and subspecies groups that merit species status. Taxonomic revisions based on these advances predictably confirm that distinct sister populations once lumped as polytypic species are independent evolutionary lineages that exhibit essential reproductive isolation. Release from the concerns about hybridization also positions proposed species for timely taxonomic decisions. The stage is set to proactively redefine polytypic species to separate component species for the 21' century. The improved species classification will better reflect phylogeny and evolutionary status, characterize biodiversity more accurately, guide improved sampling patterns of bird populations for systematic studies, and enable informed conservation decisions.
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Owing to its global decline, the Great Slaty Woodpecker Mulleripicus pulverulentus has been categorised as Vulnerable by IUCN. In India, the species is rare and occurs in the sub-Himalayan moist tropical forests from Uttarakhand in the west to Arunachal Pradesh in the east. Available records indicate that the Great Slaty Woodpecker (GSW) is dependent upon mature dipterocarp forests. However, there is very little scientific information on its distribution or habitat preferences in India. We surveyed the distribution of GSW and searched for its breeding sites in the Sal forests of western Uttarakhand. Using forest department records, we identified 50 sites having relatively mature Sal forests, which were likely to harbour GSW. At each site we carried out call playback surveys to detect the presence of GSW and qualitatively evaluated forest habitat structure. We detected GSW presence at seven sites, observed breeding at three, and found nesting trees at six sites. GSW was observed mainly in mature Sal-dominated forests in sloping terrain. Most trees in which cavities were found were deformed or diseased and had a median diameter at breast height (DBH) of 53.5 cm. For conserving GSW, it is important that mature Sal stands be retained, and silvicultural removal of deformed trees be discontinued.
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Piculus chrysochloros (Vieillot 1818) is a species of woodpecker that ranges from Argentina to Panama, occurring in lowland forests as well as Cerrado, Caatinga and Chaco vegetation. Currently, nine subspecies are accepted, but no study has evaluated individual variation within populations, so the status of these taxa remains uncertain. Here we review the taxonomy and distribution of this species, based on morphological and morphometric data from 267 specimens deposited in ornithological collections. Our results suggest the existence of six unambiguous taxonomic units that can be treated as phylogenetic species: Piculus xanthochloros (Sclater & Salvin 1875), from northwestern South America; Piculus capistratus (Malherbe 1862), from northern Amazonia west to the Branco River; Piculus laemostictus Todd 1937, from southern Amazonia; Piculus chrysochloros (Vieillot 1818), from the Cerrado, Caatinga and Chaco; Piculus paraensis (Snethlage 1907) from the Belém Center of Endemism; and Piculus polyzonus (Valenciennes 1826) from the Atlantic Forest. Both Brazilian endemics (P. polyzonus and P. paraensis) are threatened due to habitat loss. In addition, we found one undescribed form from the Tapajós-Tocantins interfluve, now under study, that may prove to be a valid species once more specimens and other data become available.
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Following the reported rediscovery of Campephilus principalis (Ivory-billed Woodpecker) in Arkansas, we initiated searches in South Carolina in February 2006, with additional searches in the winter and spring of 2006-2007 and 2007-2008, concentrating in the Congaree, Santee, and Pee Dee river basins. We accrued a cumulative total of 8893 survey hours. We found suggestive evidence in the form of visual and acoustic encounters, but failed to document conclusive evidence. Based on our search results, we believe it is unlikely that a population of Ivory-billed Woodpeckers persists in Congaree National Park and found limited evidence for their presence on other public lands in South Carolina. However, we cannot rule out the possibility that a small, nomadic population persists in the state.