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Treecreeper

The treecreeper (Certhia familiaris), also known as the Eurasian treecreeper, is a small passerine bird in the family Certhiidae, renowned for its specialized adaptations for foraging on tree trunks, including a long, slender, downcurved bill for probing bark crevices and stiff tail feathers for support while climbing. Measuring 12–15 cm in length and weighing an average of 9–10 g, it features cryptic plumage with mottled brown upperparts streaked in white, a pale supercilium, and clean white underparts that provide effective camouflage against tree bark. Both sexes are similar in appearance, and the species is non-migratory in much of its range, though northern populations may move southward in winter. Treecreepers inhabit mature deciduous and coniferous woodlands across the Palearctic region, from (including the ) through to and south to the , preferring old-growth forests with large trees at elevations up to 2,135 m for breeding. They are diurnal and solitary or in pairs outside the breeding season, often forming small communal roosts of up to 15 individuals in tree crevices during cold nights. In the and , where it is the only widespread treecreeper species, populations are stable with approximately 225,000 territories recorded, though there has been a slight 4.4% contraction in breeding distribution since the 1980s. These exhibit distinctive mouse-like behavior, spiraling upward in short hops along trunks to glean , spiders, and arthropods from under , supplemented by seeds in winter; they rarely on the ground and drop to the base of another upon reaching the top. occurs from to , with monogamous pairs constructing domed nests of , , and feathers in crevices or behind loose , laying 5–6 eggs that the female incubates for 13–17 days, followed by fledging after 14–20 days; they typically raise two broods per season. The species faces no major global threats and is classified as Least Concern by the IUCN, benefiting from its adaptability to parks and gardens in addition to natural forests.

Taxonomy and systematics

Classification and evolution

The treecreepers comprise the Certhiidae, a group of small oscine passerines within the order Passeriformes. They are classified in the suboscines' sister clade Passeri, specifically under the parvorder Passerides, the clade Muscicapida, and the superfamily Certhioidea. The is monotypic at the level, containing only the Certhia, which includes nine extant distributed across wooded habitats in the . These are: (C. familiaris), Hodgson's Treecreeper (C. hodgsoni), (C. americana), (C. brachydactyla), Bar-tailed Treecreeper (C. himalayana), Rusty-flanked Treecreeper (C. nipalensis), Treecreeper (C. discolor), Hume's Treecreeper (C. manipurensis), and Treecreeper (C. tianquanensis). Recent taxonomic revisions, such as those in the IOC World Bird List version 15.1 (as of 2025, aligned with the unified AviList global checklist), have elevated the spotted creepers (genus Salpornis) to their own , Salpornithidae, based on molecular distinguishing their phylogenetic position within Certhioidea. Phylogenetically, Certhiidae form a well-supported clade within Certhioidea, closely related to families such as the wrens (Troglodytidae), nuthatches (Sittidae), and gnatcatchers and allies (Polioptilidae), as resolved by multi-locus analyses of nuclear and mitochondrial DNA. The genus Certhia exhibits low interspecific genetic divergence, reflecting a conserved morphology adapted for arboreal foraging, but molecular studies have revealed cryptic diversity and clarified relationships among subspecies. For instance, a phylogeny based on cytochrome b sequences affirmed the species status of all recognized Certhia taxa while identifying hidden lineages, such as distinct clades within C. discolor and C. himalayana, contributing to recent species splits like the Sichuan Treecreeper. This work underscores the role of incomplete lineage sorting and hybridization in shaping the genus's evolutionary patterns, particularly in Eurasian refugia during Pleistocene glaciations. The evolutionary history of Certhiidae traces back to the diversification of Certhioidea, which originated in during the early Miocene, approximately 20–25 million years ago, based on phylogenomic reconstructions using thousands of ultraconserved elements. From this Palearctic cradle, treecreepers underwent multiple dispersals into , with at least five independent colonization events across Certhioidea, including the ancestor of the (C. americana), which represents a Nearctic radiation. Diversification within Certhia accelerated in the to , driven by in temperate forests and climatic oscillations, leading to across and . Vocalizations and show correlated with phylogeny, with simpler songs in basal lineages and more complex repertoires in derived Asian species, as evidenced by comparative bioacoustic analyses integrated with molecular data. Ongoing genomic studies continue to refine these timelines, highlighting the family's to coniferous and woodlands as a key driver of its biogeographic success.

Species diversity

The family Certhiidae, known as treecreepers, comprises nine in the single genus Certhia, reflecting a relatively low diversity within the Passeriformes order, with all adapted to arboreal in forested habitats. The genus Certhia is primarily distributed across the Holarctic and Oriental regions, where exhibit cryptic for on tree bark. These include the widespread (Certhia familiaris), which spans and Asia, and the (Certhia americana), the sole representative in the , ranging from to . Recent taxonomic revisions, based on vocalizations and genetic analyses, have elevated several Asian forms to full status, such as the Sichuan Treecreeper (Certhia tianquanensis) and Hodgson's Treecreeper (Certhia hodgsoni), increasing recognized diversity in montane Asian forests. The spotted creepers (genus Salpornis, now in the separate family Salpornithidae) include only two species, both characterized by barred and downcurved bills suited to and Asian woodlands. The Spotted Creeper (Salpornis salvadori) occurs in sub-Saharan savannas and woodlands, while the Spotted Creeper (Salpornis spilonota) inhabits dry forests of the . This bifurcation highlights the superfamily Certhioidea's evolutionary divergence, with Certhia species showing greater in temperate zones and Salpornis adapted to tropical environments. Overall, the limited species count in Certhiidae underscores the specialized niche of treecreepers, with no major radiations beyond the genus Certhia.

Description

Physical characteristics

The Eurasian treecreeper (Certhia familiaris) is a small, slender adapted for arboreal life, measuring 12 to 15 cm in length, with a of 19 to 22 cm and an average weight of 8 to 10 g. Its compact build includes a relatively large head and a slim body, facilitating maneuverability on vertical surfaces. Males and females are similar in size and show no in or morphology. The plumage provides excellent camouflage against tree bark, with upperparts mottled in shades of brown, tan, and black, accented by fine white streaks and scalloping for a cryptic . Underparts are unmarked whitish, sometimes with a subtle wash on the flanks and breast sides, while a broad white contrasts sharply with the darker crown and eyeline. Juveniles exhibit duller upperparts with more pronounced pale streaking. varies among ; for example, the nominate race has a bright rufous-brown crown and with narrow black fringes and white streaks, while some Asian subspecies, such as C. f. mandellii, are paler overall. A defining feature is the long, thin, decurved , which curves gently downward to probe crevices for without requiring forceful pecking. The is notably long and rigid, comprising 12 stiff, pointed rectrices that function as a third leg, pressing against the trunk to brace the body and reduce strain on the hindlimbs during spiral ascents up trees. Locomotor adaptations include short legs that flex to keep the body close to the , paired with weak feet that do not . Instead, strongly curved, needle-sharp claws—particularly the elongated hind claw, which extends the foot span to about 27 —hook into irregularities for purchase, while the toes remain closely appressed. These traits minimize energetic costs during , with the absorbing up to 50% of the supporting .

Vocalizations

The (Certhia familiaris) produces high-pitched vocalizations that are often thin and , adapted for communication in dense forest environments where visual cues are limited. These typically range from 3 to 8 kHz, making them faint and easily overlooked by human observers, yet they serve essential roles in territory defense, mate attraction, and alarm signaling. Songs are primarily delivered by males during the breeding season and are characterized by low intra-individual and intra-population variation, indicating a strong innate component with some learned s. Songs consist of organized s featuring repeated "sreeh" s (around 7-8 kHz, lasting 0.3 seconds) combined with shorter "tyt" notes (L-shaped , 0.2 seconds), forming complex phrases with diverse syntax and speeds. Geographic dialects occur across , with regional variations in speed and correlating with genetic distances. Discriminant analysis of parameters, including length, , and number, distinguishes C. familiaris from closely related species. Calls are simpler, innate, and used year-round by both sexes for and . The common call is a shrill, penetrating "tsree" or "sreeh," often with a quality, functioning in pair coordination and predator alerts. Call differentiation shows some geographic variation aligned with dialects.

Distribution and habitat

Geographic range

The (Certhia familiaris) has a broad Palearctic distribution, breeding from western Europe, including the , across northern and , , and Asia to and northern . It occurs in coniferous and mixed forests from to high elevations. Its extend into the , northern , and the , among other regions. Key include C. f. britannica in Ireland and ; C. f. macrodactyla in western and ; C. f. familiaris in and eastern Europe to western ; C. f. daurica in to northeastern ; C. f. orientalis in the , , and ; C. f. japonica in southern ; C. f. persica in the , , , and northern ; C. f. tianschanica in southeastern to northwestern ; and C. f. bianchii in northern .

Habitat preferences

The Eurasian (Certhia familiaris) is a specialized inhabitant of forested and environments, relying on the vertical surfaces of trunks and branches for , nesting, and roosting. It favors mature woodlands with large, old trees that provide rough, fissured rich in such as and spiders hidden in crevices. Habitat selection is driven by the need for structural complexity in the bark, which supports its spiral-climbing foraging behavior and offers protection from predators. This species occupies a of and forests but shows a strong preference for breeding in (Pinus) and (Picea) stands, where breeding densities can be three times higher in old-growth forests compared to managed woodlands. It thrives in mature forests or urban parks with high densities of large trees suitable for climbing, occurring at elevations from to 2,135 meters above . It particularly selects older stands for nesting, placing hammock-like nests behind loose bark or in crevices up to 16 meters high, lined with materials like feathers and .

Behavior

Foraging and diet

Treecreepers in the family Certhiidae are specialized bark-foragers, primarily the trunks and branches of in a spiral or helical pattern using short hops, supported by their stiffened tail feathers as a prop and strong, curved claws for grip. They probe crevices and flaking with their long, decurved bills to extract hidden prey, typically moving upward from the base of a before flying to the bottom of another to repeat the process. This foraging method allows them to access food sources inaccessible to many other , though they may occasionally descend to the ground or walls, especially in winter. Their diet consists mainly of small , including such as , , and earwigs, along with their larvae, spiders, and , which they glean from fissures. During the breeding season, this arthropod-focused diet supports high energy demands for reproduction. In winter, when invertebrate availability declines, treecreepers supplement with seeds and occasionally fruits, sometimes on the ground or visiting bird feeders. Species like the (Certhia familiaris) avoid ant-heavy trunks due to competition, optimizing their search efficiency. This strategy contributes to in forest ecosystems by reducing arboreal insect populations, though treecreepers themselves face predation risks while climbing exposed trunks. Across the , solitary or paired is common, but winter flocks with other enhance detection of food patches.

Reproduction

Treecreepers in the Certhiidae are generally , with males using high-pitched songs and calls to attract mates and establish breeding territories. form in late winter or early spring, and both sexes participate in territory defense, though the duration of monogamy varies by and may last only for a single breeding season. In like the (Certhia familiaris), courtship involves mutual chasing and displays, while the male often provides food to the female to strengthen the . Breeding occurs seasonally in spring and early summer, typically from March to June in the Palearctic for Eurasian and short-toed treecreepers (Certhia brachydactyla), and from April to July in for the (Certhia americana). Nests are constructed primarily by the in cryptic locations such as crevices in trunks, behind loose on or dying trees, or occasionally in rock fissures and nest boxes; materials include , twigs, strips, and grass, lined with feathers, hair, or wood chips for . Nest height ranges from ground level to over 15 meters, depending on suitable sites. Clutch sizes vary by species but typically range from 4 to 7 eggs, laid daily by the ; for example, the lays 2–9 (typically 5–6) white eggs speckled with pink or reddish-brown spots, while the produces 3–7 similar eggs. Incubation begins after the clutch is complete and is performed solely by the for 13–17 days, during which the male supplies her with food to sustain her. Hatchlings are altricial, naked, and blind, requiring intensive care; both parents feed the chicks a diet of and spiders, with the female initially brooding them while the male delivers most food items. fledge after 13–18 days, remaining dependent on parents for 2–3 weeks post-fledging, during which family groups together. Many pairs raise two broods per season, with replacement clutches possible if the first fails, though second broods are often smaller. Juveniles reach at one year and disperse to establish their own territories.

Migration and movements

Treecreepers (family Certhiidae) are generally sedentary with limited migratory behavior across most , though patterns vary by and population. The majority remain within their breeding territories year-round, undertaking only short-distance movements or altitudinal shifts to access food resources during harsh winters. These movements are often localized, influenced by availability and severity, rather than involving long-distance travel. The (Certhia familiaris), the most widespread species in the Palearctic, is primarily resident throughout its range from to eastern . In and , ringing data reveal small-scale dispersals, with foreign recoveries indicating seasonal presence but no large-scale ; populations fluctuate due to winter mortality rather than exodus. Northern subpopulations may exhibit partial southward movements in response to cold weather, though these are irregular and short-ranged. Similarly, the (Certhia brachydactyla) is strictly resident in its European and North African range, with post-breeding dispersal confined to distances of several kilometers and occasional altitudinal adjustments in mountainous areas. This species shows no evidence of migratory flights, maintaining stable local populations. In the , the (Certhia americana) follows a comparable pattern but with more pronounced partial . Southern and lowland populations are year-round residents in coniferous and mixed forests, while those breeding in northern latitudes or high elevations migrate short distances southward or downslope during winter to milder habitats across the . These shifts typically span hundreds of kilometers, allowing access to prey under bark in deciduous woodlands.

Ecology and conservation

Ecological interactions

Treecreepers, particularly the (Certhia familiaris), primarily function as predators in forest ecosystems, foraging on small s such as and spiders found in crevices. Their spiraling ascent along trunks allows them to access and consume prey that other overlook, leading to significant depletion of populations on frequented trees. Studies have shown that treecreepers can reduce abundance on trunks by 30–50% on trunks near the nest during the , demonstrating their role in local and influencing community dynamics. A key ecological interaction involves exploitative with wood ants ( group) for shared resources on tree trunks. Treecreepers actively avoid ant-occupied trunks, spending less time foraging there and recovering fewer food items compared to ant-free areas; experimental reductions in populations increased foraging duration and efficiency within days. This competition reduces overall food availability in ant territories, resulting in delayed (by approximately 2.5 days for second clutches), smaller clutch sizes (decreased by about 0.36 eggs when adjusted for laying date), lower nestling body mass, higher nestling mortality (90.5% survival in ant territories vs. 98.9% in ant-free ones for first broods), and reduced fledgling production (2.3 fewer fledglings per double-brooded pair). Interspecific interactions with other birds are generally limited but include participation in mixed-species foraging flocks during winter, where treecreepers benefit from enhanced predator detection through collective vigilance and alarm calls, allowing increased pecking rates (correlated positively with flock size, r_s = 0.42 to 0.58). Flocking frequency rises in colder conditions, and treecreepers narrow their foraging niche (e.g., focusing more on trunks) in larger groups, primarily for anti-predator advantages rather than resource sharing. Competition with closely related species, such as the short-toed treecreeper (C. brachydactyla), involves occasional aggressive encounters due to mistaken identity rather than resource overlap. Treecreepers face predation pressure from various woodland species, with the (Dendrocopos major) being a significant nest predator that consumes eggs and nestlings, prompting defensive behaviors from parents. Adult treecreepers are vulnerable to raptors like sparrowhawks (Accipiter nisus) and tawny owls (Strix aluco), while nest sites may be raided by small mammals such as pine martens (in ) or deer mice (Peromyscus maniculatus) (in ). These threats contribute to their cryptic and flocking tendencies as adaptive responses.

Conservation status

Treecreepers in the family Certhiidae are generally not considered threatened, with all species classified as Least Concern on the as of the 2024 assessment. The (Certhia familiaris) has a large global population estimated at 27.3–48 million mature individuals as of 2018, which is considered stable, though regional declines may occur due to and loss of mature woodlands from intensive forestry practices. In , its breeding population is similarly stable at around 10.9–19.2 million mature individuals as of 2021. The (Certhia brachydactyla) also holds Least Concern status, with a of 11.2–18.7 million mature individuals as of 2018 and populations increasing in as of 2021, despite potential vulnerabilities to woodland degradation. The (Certhia americana), the sole New World representative, maintains an increasing (0.6% per year as of 2018; estimated at 11 million mature individuals as of 2019) across its North American range and is likewise Least Concern. No targeted measures are currently implemented for treecreepers in or , as their widespread distribution and adaptability reduce immediate risks; however, broader practices that preserve old-growth trees and reduce fragmentation would support their populations. through bird surveys continues to track trends, particularly in response to and events that can affect survival in northern ranges.

References

  1. [1]
    Treecreeper Bird Facts | Certhia Familiaris - RSPB
    The Treecreeper is a small, very active bird that lives in trees. It has a long, slender, downcurved bill, which it uses to pluck insects from underneath bark.
  2. [2]
    Certhia familiaris (Eurasian tree-creeper) - Animal Diversity Web
    Eurasian treecreepers are 12 to 15 cm in length and weigh an average of 10 g. Male and female treecreepers are similar in appearance.
  3. [3]
    Treecreeper - BTO
    Creeping up the bark of a tree in search of food, the Treecreeper's cryptic brown, white and yellow-gold plumage gives it the perfect camouflage.
  4. [4]
    Certhiidae - Systematic classification - Oiseaux.net - birds
    Systematic classification of species in the family Certhiidae - 9 species listed ... IOC World Bird List (v14.2) doi : 10.14344/IOC.ML.14.2. Avibase (ioc v14.2) ...
  5. [5]
  6. [6]
    IOC BIRD LIST V14.2 RELEASED - All the World's Birds
    Aug 31, 2024 · Genus Salpornis of Spotted Creepers within Family: Certhiidae – Treecreepers has been moved to new Family: Salpornithidae – Spotted Creepers.
  7. [7]
    Molecular Phylogenetics of the Wrens and Allies (Passeriformes
    Dec 8, 2017 · This study reports the first nearly genus-level sampling of certhioids, based on concatenated and species tree analyses of 8520 bases of DNA sequence data from ...
  8. [8]
    Molecular phylogeny of treecreepers (Certhia) detects hidden diversity
    Jul 7, 2006 · We sequenced a part of the mitochondrial cytochrome-b gene from the seven treecreeper species, including 18 subspecies, to reconstruct the ...Missing: history | Show results with:history
  9. [9]
    Diversification and dispersal in the Americas revealed by new ...
    Feb 6, 2024 · We found that Certhioidea originated largely in Eurasia and dispersed into North America five times in the last 20 million years.
  10. [10]
    Evolutionary history of treecreeper vocalisations (Aves: Certhia)
    Oct 31, 2008 · Treecreepers (Certhia) comprise a morphologically and genetically clearly defined group of passerine birds characterised by a suite of ...
  11. [11]
  12. [12]
    African Spotted Creeper Salpornis salvadori - eBird
    This species has typical creeper structure and behavior. The intricately spotted and barred plumage is gray-brown and white. Generally uncommon and local.
  13. [13]
    Treecreeper | The Wildlife Trusts
    A slim, tit-sized bird, the treecreeper has a long, pointed tail and a fine, downwards-curved bill. Treecreepers climb up trees in a spiral around the trunk.
  14. [14]
    [PDF] Treecreeper Climbing; Mechanics, Energetics, and Structural ...
    Certhia has a longer tail in relation to body size than have woodpeckers, a difference related to differences in locomotor habits. R. Ake Norberg, Dept. of ...
  15. [15]
    Sounds and Vocal Behavior - Brown Creeper - Certhia americana
    Vocalizations. Both song and calls are comprised of high, sibilant tsee notes that are easily missed. Song is high and thin, but surprisingly rich ...
  16. [16]
  17. [17]
    Brown Creeper Sounds, All About Birds, Cornell Lab of Ornithology
    Males and females make high, wavering call notes that sound like a small chain being dropped into a heap; these notes are noticeably longer than the very short ...
  18. [18]
    Certhiidae - Treecreepers - Birds of the World
    Oct 22, 2024 · Most diverse in the mountains of Asia, these forest birds are widespread throughout the forests of the north temperate zone. General Habitat.
  19. [19]
    Eurasian Tree-Creeper [persica or caucasica] - Avibase
    Certhia familiaris [persica or caucasica]: Crimean Peninsula, Türkiye, Caucasus, Transcaucasus, and northern Iran. Source: Clements checklist. English: Eurasian ...
  20. [20]
    Certhia brachydactyla (Short-toed Tree-Creeper) - Avibase
    Classification. Order: Passeriformes Family: Certhiidae Genus: Certhia Scientific: Certhia brachydactyla. Original description. Citation: Brehm, CL 1820.
  21. [21]
    Certhia americana (Brown Creeper) - Avibase
    List Birds Europe N. Amer. Protonym: Certhia americana. Type locality: eastern ... IOC World Bird Names, version 14.2: Brown Creeper ( Certhia americana) ...
  22. [22]
    Certhia himalayana (Bar-tailed Tree-Creeper) - Avibase
    Classification. Order: Passeriformes Family: Certhiidae Genus: Certhia Scientific: Certhia himalayana. Original description. Citation: Vigors, NA 1832.
  23. [23]
    Species - Certhiidae - Treecreepers - Birds of the World
    Oct 22, 2024 · Certhia 9 species ; Eurasian Treecreeper Certhia familiaris ; Hodgson's Treecreeper Certhia hodgsoni ; Sichuan Treecreeper Certhia tianquanensis ...Missing: IOC 14.2
  24. [24]
    Certhia nipalensis (Rusty-flanked Tree-Creeper) - Avibase
    The rusty-flanked treecreeper or the Nepal treecreeper is a species of bird in the family Certhiidae. It is found in northern India, Nepal, ...
  25. [25]
  26. [26]
    Salpornis salvadori (African Spotted Creeper) - Avibase
    The African spotted creeper is a small passerine bird, which is a member of the subfamily Salpornithinae of the treecreeper family Certhiidae.
  27. [27]
    Eurasian Treecreeper Certhia Familiaris Species Factsheet
    This species inhabits forest and woodland, generally requiring well-grown trees with many cracks and crevices in the bark for foraging, roosting and nesting.
  28. [28]
    Brown Creeper Overview, All About Birds, Cornell Lab of Ornithology
    Brown Creepers are tiny woodland birds with an affinity for the biggest trees they can find. Look for these little, long-tailed scraps of brown and white ...
  29. [29]
    [PDF] Life history account for Brown Creeper
    Prefers dense, mature stands of conifers, but also found in hardwood and hardwood-conifer habitats, especially in winter (Grinnell and Miller 1944, Garrett and ...Missing: preferences | Show results with:preferences
  30. [30]
    Treecreeper (Certhia familiaris) - British Birds - Woodland Trust
    The tiny treecreeper is a small and agile woodland bird. Find out what it eats ... Scientific name: Certhia familiaris. Family: Certhiidae (treecreepers).
  31. [31]
    Bird Certhiidae - Treecreepers - Fat Birder
    The family contains just eleven species in two genera, Certhia and Salpornis. ... Number of Species. Number of bird species: 11. Species Links. Brown Creeper ...
  32. [32]
    Treecreepers (Certhiidae) - Encyclopedia.com
    Treecreepers are small, about 5–6 inches (12–15 cm) in length, and have a long, thin, curved bill, a slender tail, and streamlined, teardrop-shaped bodies.Missing: classification | Show results with:classification
  33. [33]
    Certhia americana (brown creeper) - Animal Diversity Web
    They have dark-brown upperparts that are heavily streaked with white on the head, back, scapulars (feathers covering the shoulder), and wings.Scientific Classification · Physical Description · Reproduction
  34. [34]
    Bird Migration Atlas
    Annual Movements for Eurasian Treecreeper​​ Based on data from S Finland, juveniles migrate earlier than adults (Saurola et al. 2013). Return migration take ...
  35. [35]
    Certhia brachydactyla - Bird Migration Atlas
    Annual Movements for Short-toed Treecreeper​​ The species is strictly resident. Post-breeding dispersal movements are extremely limited, usually within several ...Missing: patterns | Show results with:patterns
  36. [36]
    Short-toed Treecreeper Certhia Brachydactyla Species Factsheet
    This species has an extremely large range and the population size is extremely large, hence does not approach threatened thresholds for the range or ...
  37. [37]
    Brown Creeper Life History, All About Birds, Cornell Lab of Ornithology
    Brown Creeper Life History. Overview · ID info · Life History · Maps · Sounds. Habitat; Food; Nesting; Behavior; Conservation; Credits. Learn more at. Birds of ...
  38. [38]
    Prey depletion by the foraging of the Eurasian treecreeper, Certhia ...
    We examined to what extent breeding insectivorous treecreepers, Certhia familiaris, affect the abundance and the mean size of their prey population on the ...
  39. [39]
    (PDF) Behavioural responses of Eurasian treecreeper, Certhia ...
    Aug 8, 2025 · Competition was by far the most frequent interaction (48.91% of all interactions; figure 1a), the bulk of interactions coming from observational ...
  40. [40]
    (PDF) Reproductive Success of Eurasian Treecreepers, Certhia ...
    Aug 9, 2025 · Few studies have considered the effects of interspecific competition between distantly related taxa on the reproductive success of individuals.
  41. [41]
    The behaviour of Treecreepers Certhia familiaris in mixed-species ...
    We suggest that the main benefit to Treecreepers of joining mixed-species flocks is the avoidance of predation. Flocking behaviour is thought to have evolved as ...Missing: symbiosis | Show results with:symbiosis
  42. [42]
    Interactions between sibling species of treecreepers Certhia ...
    Jan 21, 2021 · Aggressive interactions between two treecreeper species were probably the result from misidentification of heterospecifics rather than resource competition.
  43. [43]
    Nest defence of Eurasian treecreeper Certhia familiaris against the ...
    Aug 6, 2025 · The Great Spotted Woodpecker is a genuine predator of the Treecreeper because it eats Treecreepers' eggs and nestlings. ... predators,. because.
  44. [44]
    Behavior - Brown Creeper - Certhia americana - Birds of the World
    Males with smaller territories tended to engage in more vocal defense. In one instance, 2 males sang back and forth 53 times in <10 min; countersang at ...
  45. [45]
    American Treecreeper Certhia Americana Species Factsheet
    American Treecreeper. Certhia americana. Certhiidae (Treecreepers) ... IUCN Red List assessment. Year of last assessment. 2021. IUCN Red List category.