The Picidae family, commonly known as woodpeckers, is a group of birds belonging to the order Piciformes, characterized by a remarkable variety of species primarily distributed across temperate and tropical regions. The Picidae family includes around 200 species, divided into numerous genera, and stands out for its unique physiological adaptations, including a robust beak and specialized claws that allow them to excavate and feed in a highly specialized manner.
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Piciformes
Family: Picidae
Morphological Characteristics
Members of the Picidae family are generally characterized by a compact and elongated body, robust wings, and a strong, pointed beak, adapted for digging into tree bark. The size varies among species, but woodpeckers typically possess a long tongue adapted to extracting insects and other invertebrates from beneath tree bark. The body is often covered in plumage ranging from shades of green, brown, white, black, and red, frequently featuring distinctive facial masks or tail feathers.
Woodpeckers have serrated claws that help them maintain a firm grip on tree trunks, as well as a long, sticky tongue that they extend through the beak to collect insects hidden in crevices of the bark.
Behavioral Adaptations
A distinctive feature of the Picidae is their drumming behavior. Woodpeckers use their powerful beaks to strike against tree bark, producing a distinctive sound known as drumming. This behavior serves two main purposes: marking territory and foraging for food. The force with which woodpeckers strike trees is astonishing, and physiological adaptations, such as a skull structure that absorbs impacts, are crucial in preventing brain injuries.
Habitat and Distribution
Woodpeckers are birds of forests and wooded environments, though some species are adapted to live in mountainous habitats, savannas, and even urban areas, where they find trees and wooden structures to feed and nest in. Their geographic distribution is vast, with most species found in the Americas, Europe, and Asia. Some species, such as the European Green Woodpecker (Picus viridis), are common in Europe, while the Red-headed Woodpecker (Melanerpes erythrocephalus) is distributed in the Americas.
Feeding and Diet
Woodpeckers are primarily insectivorous, feeding on a variety of insects and invertebrates that live under the bark of trees or in decaying wood. Their preferred prey includes ants, termites, beetles, and larvae. Some species, however, are also frugivorous or granivorous, though this behavior is less common. Their long tongue, which can extend beyond the beak, is an evolutionary adaptation that allows them to reach insects deep within the wood.
Reproduction
The breeding season of woodpeckers is marked by the construction of nests in tree cavities. Woodpeckers excavate their own nests in the trunk or branches of decaying trees, creating a cavity where they lay their eggs. The female generally lays 3-5 eggs, which are incubated by both parents for a period ranging from 10 to 14 weeks. After hatching, the parents care for the young, feeding them insects and protecting them from predators.
Conservation
Many species of Picidae are stable in terms of population, but some are considered vulnerable or endangered, especially in areas where deforestation and habitat destruction pose a threat. The loss of forest habitats, reduction of mature woodlands, and the use of pesticides that eliminate their natural prey are among the primary risk factors for these species.
Conclusion
The Picidae family represents an extraordinary example of evolutionary adaptation to forested environments. Woodpeckers not only play an important ecological role as insect predators, but their habits of excavating tree bark also contribute to the health of forest ecosystems, promoting the decomposition of dead wood and creating habitats for other species. While many species remain abundant, the protection of forests and their natural habitats is crucial to ensuring the long-term survival of these remarkable creatures.
References__________________________________________________________________________
Alder, D., & Marsden, S. (2010). Characteristics of feeding‐site selection by breeding Green Woodpeckers Picus viridis in a UK agricultural landscape. Bird study, 57(1), 100-107.
Abstract. Capsule Green Woodpeckers exhibited strong feeding‐site preference, choosing areas based on abundance of ants with additional micro‐habitat effects. Aims To identify the habitat characteristics influencing feeding‐site selection across farmland. Methods A pair of Green Woodpeckers was radiotracked during a breeding season. Habitat and prey abundance variables were compared within the birds’ combined home‐ranges. canoco was used to identify ecological gradients, and logistic regression used to predict feeding‐site use based on ant abundance with resultant residuals correlated to identify habitat features that further influenced site selection. Results Most feeding was done in sheep‐grazed pastures and garden lawns with arable and cattle‐grazed land avoided. Green Woodpecker feeding sites were associated with areas of short grassland with high plant richness and high densities of ants, especially Lasius flavus. Logistic regression correctly classified 98% of cases from ant abundance. The woodpecker pair had a greater probability of feeding in areas with deep leaf litter, high plant species richness, and lower probability if the site had tall or dense vegetation, or heavily compacted soils. Conclusions Structural habitat characteristics were important, with this woodpecker pair foraging in short grazed and mown grasslands. If these results are replicated elsewhere then appropriate farm management may benefit Green Woodpeckers significantly.
Pons, J. M., Olioso, G., Cruaud, C., & Fuchs, J. (2011). Phylogeography of the Eurasian green woodpecker (Picus viridis). Journal of Biogeography, 38(2), 311-325.
Abstract. Aim In this paper we investigate the evolutionary history of the Eurasian green woodpecker (Picus viridis) using molecular markers. We specifically focus on the respective roles of Pleistocene climatic oscillations and geographical barriers in shaping the current population genetics within this species. In addition, we discuss the validity of current species and subspecies limits. Location Western Palaearctic: Europe to western Russia, and Africa north of the Sahara. Methods We sequenced two mitochondrial genes and five nuclear introns for 17 Eurasian green woodpeckers. Multilocus phylogenetic analyses were conducted using maximum likelihood and Bayesian algorithms. In addition, we sequenced a fragment of the cytochrome b gene (cyt b, 427 bp) and of the Z-linked BRM intron 15 for 113 and 85 individuals, respectively. The latter data set was analysed using population genetic methods. Results Our phylogenetic results support the monophyly of Picus viridis and suggest that this taxon comprises three allopatric/parapatric lineages distributed in North Africa, the Iberian Peninsula and Europe, respectively. The North African lineage split from the Iberian/European clade during the early Pleistocene (1.6–2.2 Ma). The divergence event between the Iberian and the European lineages occurred during the mid-Pleistocene (0.7–1.2 Ma). Our results also support a post-glacial range expansion of these two lineages from distinct refugia located in the Iberian Peninsula and possibly in eastern Europe or Anatolia, which led to the establishment of a secondary contact zone in southern France. Main conclusions Our results emphasize the crucial role of both Pleistocene climatic oscillations and geographical barriers (Strait of Gibraltar, Pyrenees chain) in shaping the current genetic structure of the Eurasian green woodpecker. Our molecular data, in combination with diagnosable plumage characters, suggest that the North African green woodpecker (Levaillant’s woodpecker) merits species rank as Picus vaillantii (Malherbe, 1847). The two European lineages could be distinguished by molecular and phenotypic characters over most of their respective geographical ranges, but they locally exchange genes in southern France. Consequently, we prefer to treat them as subspecies (P. viridis viridis, P. viridis sharpei) pending further studies.
Gorman, G. (2023). The Green Woodpecker: The Natural and Cultural History of Picus Viridis. Pelagic Publishing Ltd.
