Colaptes Auratus Research Articles

Anatomy and Immunohistochemistry of Woodpecker Tail Muscles.

Woodpeckers (Order Piciformes) belong to a group of birds characterized by their hammering capabilities in which the bill is utilized as a tool to probe for food and to excavate nest cavities. They have numerous specializations for this behavior, including their bill and tongue, feet for gripping vertical tree trunks, and tail feathers with thickened shafts to provide stability as a postural appendage. We hypothesized that (1) woodpecker tail musculature is also modified for clinging behaviors with a heterogeneous distribution of fast and slow muscle fibers, and that (2) the tree-trunk foraging Hairy Woodpeckers would have more slow muscle fibers in their M. depressor caudae than Northern Flickers, which forage on the ground where they probe the substrate for insects. We performed immunohistochemistry to identify the fiber type distributions for tail muscles Mm. caudofemoralis pars caudalis, lateralis caudae, levator caudae, and depressor caudae in four Hairy Woodpeckers and five Northern Flickers. Our results show that these tail muscles in the two woodpecker species are comprised of a majority of fast muscle fibers common among dynamic locomotor muscles. Interestingly, we report a functionally-significant distribution of slow muscle fibers in M. depressor caudae predicted to be utilized in propping of the tail during tree climbing and support. Further, we found more slow fibers (13.80% ± 4.49%) in the trunk-foraging Hairy Woodpeckers compared with the ground-foraging Northern Flicker (7.40% ± 4.95%), which we interpret to be related to the trunk-foraging habits of Hairy Woodpeckers.

Persistence, changes and robustness of nest webs along a latitudinal gradient in the Canadian boreal forest

IntroductionIn eastern Canada, the boreal forest is associated with an important latitudinal shift in forest composition and structure, which occurs in the transition between the mixed southern boreal forest and the coniferous northern boreal forest. Along this transition, upland mixedwood stands with large deciduous trees (important for cavity-dependent vertebrate species) are gradually replaced by forests with smaller conifer trees, primarily black spruce (Picea mariana). Concomitantly, the availability of lowland forests flooded by the American beaver (Castor canadensis), which can provide adequate conditions for tree-cavity users, is also decreasing.MethodsWe hypothesized that this latitudinal gradient would bring important changes in the functional diversity and network structure of vertebrate cavity-using communities. Along this latitudinal gradient we used a nest web approach to analyze the structure and robustness of networks of cavity users in upland forests and in lowland forests flooded by beavers.ResultsDespite their low availability in the northern forest region, we found that mixedwood stands persisted throughout the boreal forest in being the main drivers of nest webs network structure of upland forests whereas old black spruce stands contribution was low. In lowland forests, beaver ponds harbored nest webs with a rich and complex structure in both forest regions. Species removal simulations revealed that across our latitudinal gradient upland and lowland forest nest webs responded differently. In upland forests, the removal of trembling aspen and the Pileated Woodpecker (Dryocopus pileatus) caused the highest proportions of secondary extinctions, showing low robustness of nest webs given that these two species were highly connected to the other species. Contrastingly, nest webs in beaver ponds were more robust mainly because excavator species used a higher diversity of tree species despite the removal of the Northern Flicker (Colaptes auratus) which induced numerous secondary extinctions. The Pileated Woodpecker remained the pivotal species across the two forest regions in upland forests whereas the Northern Flicker became the main large cavity provider in beaver ponds across the latitudinal gradient.DiscussionWe discuss how mixedwood forests and beaver ponds, which are key habitat types for the cavity-using vertebrate community across our latitudinal gradient, should be maintained and protected in landscapes under industrial timber harvesting.

Woodpeckers in the city: Abundances are highest in large green spaces with complex understories

Abstract We documented occurrence and relative abundance (henceforth abundance) of five woodpecker species in 36 forested green spaces in Portland, Oregon (USA), to estimate minimum area requirements (MAR; 0.5 probability of occurrence) and to test for potential influences of green space area and type (heavily treed manicured green spaces vs. undeveloped natural forests), habitat features, and landscape composition on the abundance of woodpeckers. Abundances of all species increased with green space area. Manicured and natural green spaces did not differ in canopy cover or total basal area, but woodpecker abundances were greater in natural than manicured green spaces for all species except Northern Flickers (Colaptes auratus). Flickers and Downy Woodpeckers (Picoides pubescens) were most abundant, MAR of both were under 1.5 ha, and both were found in essentially all green spaces. Hairy (P. villosus) and Pileated (Dryocopus pileatus) woodpeckers were least abundant, and with MAR of 34 and 51 ha, respectively, exhibited pronounced area sensitivity. Red-breasted Sapsuckers (Sphyrapicus ruber) were intermediate in abundance and MAR to the 2 former and 2 latter species. The most important habitat variables associated with variation in abundance among green spaces were the contribution of deciduous trees to the canopy (Downy Woodpecker [+], Pileated Woodpecker [+], and Northern Flicker [–]), canopy cover (Hairy Woodpecker [+] and Northern Flicker [+]), and log density (Hairy Woodpecker [+], Red-breasted Sapsucker [–]). At the landscape level, lower woodpecker abundance was associated with increased urbanization (Red-breasted Sapsucker and Northern Flicker), while increasing forest cover influenced abundance of Northern Flicker (–) and Pileated Woodpecker (+). Highest woodpecker abundances were thus found in large green spaces with complex understories that were embedded in relatively undeveloped treed landscapes. Management of forested urban green spaces should prioritize needs of the area-sensitive species because ensuring their continued presence benefits the entire avian community.

Identifying Bird Species in River Yuman Oral Traditions

Identifying Bird Species in River Yuman Oral Traditions Jonathan A. Geary (bio) 1. Introduction Nearly 400 bird species occur along the lower Colorado River (Rosenberg et al. 1991), and Yuman communities that have historically lived along the lower Colorado surely knew and named many of them. However, judging from modern sources, this knowledge has been fading over time. For example, the ~6,700-entry Mojave dictionary (Munro et al. 1992; also spelled "Mohave") lists 105 unique bird names, and past speakers likely knew specific species referents for many of these, yet 53 are glossed as a "type of" something while many others are given generic definitions that preclude identifying an exact species referent (e.g., 'big bird', 'chickenhawk', 'eagle'). Studying such knowledge today is complicated by at least three factors: (1) changes to traditional ecological knowledge that have accompanied man-made changes to the lower Colorado River ecosystem, which has caused many species to decline while allowing other formerly-rare or new species to expand their use of the lower Colorado (Rosenberg et al. 1991: 14–28); (2) historical migrations away from the lower Colorado River and toward the Gila and Salt Rivers in central Arizona by the Piipaash (also spelled "Pee Posh", a.k.a. "Maricopa"; see Rea 1983, 2007 for changes to the Gila River ecosystem); and (3) the general decline in the intergenerational transmission of linguistic and cultural knowledge that Yuman communities have experienced. However, we can turn to the information that past speakers of these languages shared with early linguists and anthropologists about these birds, especially through their oral traditions, to identify exact referents for many such names, and thus reconstruct a small part of the rich ecological knowledge that they possessed. [End Page 538] In this paper, I analyze three bird names that recur in the oral traditions of the River Yuman languages: Mojave, Piipaash, and Quechan (a.k.a. "Yuma"). These bird names include (1) Mojave yaːlák, Piipaash yalák, and Quechan yaːlák; (2) Mojave humaθéː and Piipaash xomasé; and (3) Mojave hanavčíːp, Piipaash xnvčíːp, and Quechan xanavcíːp, which have been glossed as a range of different bird species across Yuman sources. I show that Yuman speakers maintained rich knowledge of these birds (e.g., about their appearance, hunting behaviors, and nests) which they incorporated into their traditions, and based on this information I identify these species as (1) Snow Goose (Anser caerulescens), (2) Ferruginous Hawk (Buteo regalis), and (3) Verdin (Auriparus flaviceps). To my knowledge, these names have not been identified as referring to these species in past sources. Further, the range of glosses that these names have received in more modern sources suggests that much of the ornithological knowledge contained in past sources has faded over time. This research stems from a larger effort to identify the bird species named in Piipaash and other Yuman languages (e.g., Geary 2022).1 Underpinning this work is the assumption that Yuman oral narratives contain valuable descriptive information about birds and bird characters that reflect the appearance and behavior of their natural-world counterparts, which I have found to be well supported in my work. Yuman oral traditions often explain how birds and other animal characters received their names as well as salient physical and behavioral characteristics during mythic times that their natural-world counterparts have exhibited since then until now. For example, versions of the creation story that were recorded in Mojave (Bourke 1889; Kroeber 1972: 9) and Havasupai (Smithson and Euler 1994: 38) describe how rising floodwaters stained the Red-shafted Northern Flicker's (Colaptes auratus) tail feathers, whose undersides are red with black tips, accounting for their current appearance. A Quechan version of the creation story (Halpern 1984: 322) similarly explains how floodwaters stained the tail of Mourning Dove (Zenaida macroura), which became white when the waters receded, explaining their current appearance. Mojave (Bourke 1889: 187) and Piipaash versions of the same story (Spier 1933: 391) further describe how Northern Flicker drank the blood of a murdered pair of twin brothers, staining its feathers and so accounting for the red malar stripes that are visible on male Red-shafted Northern Flickers. Finally, a Mojave...

Cellobiase Activity as an Indicator of Fungal Decay in the Wood of Woodpecker Nest Cavities in the Pacific Northwest.

Woodpeckers require trees and snags with decayed wood in order to excavate nest and roost cavities, and interior wood hardness is considered an important factor determining where a woodpecker can create a cavity. In most ecosystems, saprophytic fungi are responsible for the decay and softening of wood, and are thought to be important in providing soft wood for woodpecker cavity excavation. We conducted a study of cellulose-degrading enzymes in the wood surrounding woodpecker nest cavities. We measured wood hardness, percent wood density loss (PWDL), and activity of cellobiase (an extracellular fungal cellulase that degrades cellulose) within wood surrounding the nest cavities of the northern flicker (Colaptes auratus), black-backed woodpecker (Picoides arcticus), white-headed woodpecker (Dryobates albolarvatus), and hairy woodpecker (D. villosus) in Oregon and Washington. We found that mean wood hardness was significantly lower, and cellobiase and PWDL were significantly higher, at nest cavities than controls for each woodpecker species. Wood hardness was higher and cellobiase lower at nests of black-backed woodpecker than northern flicker, but did not differ among the other woodpecker species. Our results suggest that increased amounts of cellobiase result in softer wood due to the increased decay caused by higher fungal enzyme activity and that measuring cellobiase can be used to estimate wood decay without directly measuring wood hardness. All four woodpecker species selected nest substrates with softer wood and higher fungal enzyme activity than controls. This supports findings from previous studies of the importance of saprophytic fungi for woodpecker cavity excavation.

The First Isospora Species (Apicomplexa: Eimeriidae) Described from the Northern Yellow-Shafted Flicker (Colaptes auratus luteus) in Ontario, Canada.

Members of the genus Isospora commonly infect a wide variety of wild birds. By combining morphometric and genetic data, we are able to differentiate and describe a new apicomplexan parasite, Isospora picoflavae n. sp., from the Northern Yellow-shafted Flicker (Colaptes auratus luteus) in Ontario, Canada. Unsporulated oocysts were observed in intestinal contents obtained during necropsy; these oocysts completed exogenous sporulation within 7days at room temperature. Complete nuclear 18S rDNA and complete mitochondrial genome sequences were obtained from this previously undescribed Isospora sp. to compare with related coccidia. Sporulated oocysts were subspherical in shape measuring an average of 22.7 × 21.7μm (n = 53; mean shape index 1.05) containing a near-spherical polar granule. Sporocysts were ovoidal to ellipsoidal in shape, measuring an average size of 17.0 × 10.5μm (n = 9; mean shape index 1.62). Sporocyst residuum was concentrated in an irregular, spherical mass in the middle of each sporocyst. The isolated oocysts differed morphologically from other Isospora species reported to infect members of the family Picidae. Based on phylogenetic analyses using either combined nuclear 18S rDNA and mitochondrial cytochrome c oxidase I (COI) sequences or complete mitochondrial genome sequences, this Isospora sp. n. isolated from the Northern Flicker grouped within a clade containing Isospora species described from various passeriform hosts. Based on combined morphological and molecular data, the oocysts found in the gastrointestinal contents of Colaptes auratus luteus represent a new species of Isospora named herein as Isospora picoflavae n. sp.

Revisiting a classic hybrid zone: Movement of the northern flicker hybrid zone in contemporary times.

Natural hybrid zones have provided important insights into the evolutionary process, and their geographic dynamics over time can help to disentangle the underlying biological processes that maintain them. Here, we leverage replicated sampling of an identical transect across the hybrid zone between yellow-shafted and red-shafted flickers in the Great Plains to assess its stability over ∼60 years (1955-1957 to 2016-2018). We identify a ∼73-km westward shift in the hybrid zone center toward the range of the red-shafted flicker, but find no associated changes in width over our sampling period. In fact, the hybrid zone remains remarkably narrow, suggesting some kind of selective pressure maintains the zone. By comparing to previous work in the same geographic region, it appears likely that the movement in the hybrid zone has occurred in the years since the early 1980s. This recent movement may be related to changes in climate or land management practices that have allowed westward movement of yellow-shafted flickers into the Great Plains.

DNA metabarcoding reveals broad woodpecker diets in fire-maintained forests

Abstract Ecological disturbance is a key agent shaping the spatial and temporal landscape of food availability. In forests of western North America, disturbance from fire can lead to resource pulses of deadwood-associated arthropods that provide important prey for woodpeckers. Although the foraging strategies among woodpecker species often demonstrate pronounced differences, little is known about the ways in which woodpeckers exploit and partition prey in disturbed areas. In this study, we employed DNA metabarcoding to characterize and compare the arthropod diets of 4 woodpecker species in Washington and California, USA—Black-backed Woodpecker (Picoides arcticus), Hairy Woodpecker (Dryobates villosus), Northern Flicker (Colaptes auratus), and White-headed Woodpecker (Dryobates albolarvatus)—primarily using nestling fecal samples from burned forests 1–13 years postfire. Successful sequencing from 78 samples revealed the presence of over 600 operational taxonomic units (OTUs) spanning 32 arthropod orders. The nestling diets of two species in particular—Northern Flicker and Black-backed Woodpecker—proved to be much broader than previous observational studies suggest. Northern Flicker nestlings demonstrated significantly higher diet diversity compared to other focal species, all of which displayed considerable overlap in diversity. Wood-boring beetles, which colonize dead and dying trees after fire, were particularly important diet items for Black-backed, Hairy, and White-headed woodpeckers. Diet composition differed among species, and diets showed limited differences between newer (≤5 yr) and older (>5 yr) postfire forests. Our results show mixed evidence for dietary resource partitioning, with three of the four focal species exhibiting relatively high diet overlap, perhaps due to the pulsed subsidy of deadwood-associated arthropods in burned forests. Woodpeckers are frequently used as management indicator species for forest health, and our study provides one of the first applications of DNA metabarcoding to build a more complete picture of woodpecker diets.

Disappearances

Disappearances Karin Lin-Greenberg (bio) i Every afternoon, my landlord, who owns the duplex we both live in, throws birdseed and unshelled peanuts off her back deck onto the lawn below. Moments later, birds appear. Some days there are blue jays. Some days there are sparrows. Some days there are mourning doves. And some days there are northern flickers, woodpeckers who, strangely, peck at the ground with their sharp beaks. Northern flickers usually eat ants and beetles dug from the earth, but perhaps they, like many of the animals who frequent the large, grassy backyard, can't resist the buffet of seeds and nuts. When I peer out the window, it looks as if the backyard is being overtaken by flocks of birds. Yet scientists say birds are disappearing. They say there are three billion fewer birds in North America than there were in 1970. The birds who've been disappearing—a euphemism, of course, for dying off—are common, ordinary, the kinds of birds that appear in the backyard to peck at my landlord's offerings. Because many species of birds seem so prevalent, people don't even realize the birds are disappearing; they don't realize there's a crisis at hand. After all, how often do we even notice what's not there? ii Several years ago, one of my English Department colleagues passed away. I can't honestly say we were friends, but perhaps we could have been if we'd had more time together. Some afternoons, during my office hours, she'd stop by my office and sit in one of the red chairs my students sit in during conferences. We'd talk for a while about ordinary things, like our pets or what we did over the weekend. I've always been nervous about stopping into other people's offices, worried I'm disturbing their work, so I rarely do. But I was always glad when my colleague came in and spent some time talking with me. [End Page 36] Now, there is always a reminder of her when I'm at work. When I press the scanner function on the copy machine in the faculty lounge, a grid of small boxes with last names in each box appears on the screen. Press one of the boxes, and the scanned material is sent to that person's e-mail inbox. The square with my name is next to the square with my colleague's name. No one has removed her name, even three years after her death, so every time I scan stories and essays and poems I see her name. Some nights, when I'm at work late and am the only one remaining on the hallway, I go to scan something for the next day's classes and see her last name next to mine and feel a small wave of sadness. Often, when I stand by the photocopier, the lights in the lounge—controlled by motion sensors—shut off, and I'm plunged into darkness. I stand still in the shadowy room, the only sound the copier churning, and think how a photocopier in a dark room is such a strange site of remembrance. iii Before my landlord started feeding the birds in the backyard, she fed other animals in our front yard. During the day, she put piles of cut-up apples on the lawn, and deer and wild turkeys came. Each night, she threw hot dogs and fluffy white buns onto the front lawn, and gray foxes and raccoons appeared. Often, my husband and I looked out an upstairs window and watched the animals below, lit by the dim porch lights. They ate the hot dogs and buns, a meal I could not help but think was so far removed from food actually found in nature. Sometimes the raccoons would hiss and threaten other raccoons, but the raccoons and foxes ignored each other, contentedly chewing like diners in a restaurant, strangers seated at adjacent tables. Then the baby raccoons, the kits, arrived. They were balls of fluff with tiny feet. The two kits would follow their mother toward the duplex, grab food in their jaws, and then, with pieces...

Description and molecular characterization of novel Leucocytozoon parasite (Apicomplexa: Haemosporida: Leucocytozoidae), Leucocytozoon polynuclearis n. sp. found in North American woodpeckers.

We describe Leucocytozoon polynuclearis n. sp. (Haemosporida: Leucocytozoidae) from two North American woodpeckers, the northern flicker (Colaptes auratus Linnaeus) and white-headed woodpecker (Dryobates albolarvatus Boie, 1826), based on the morphology of its blood stages and portions of the mitochondrial cytochrome b gene. The most distinctive features of Leucocytozoon polynuclearis n. sp. development are the triangular-shaped host cell nuclei and position of host cell nuclei above gametocytes. This parasite inhabits thrombocytes. Leucocytozoon squamatus Nandi, 1986, the only other Leucocytozoon species detected from Picidae birds, lacks features that are commonly found with L. polynuclearis n. sp. infections. Phylogenetic analysis identified DNA lineages associated with L. polynuclearis n. sp. and showed that this parasite is more closely related to other North American Leucocytozoon species than to L. squamatus, whose initial description was from infected Old World Picidae species. Although there are reports of L. squamatus in North American Picidae species, these detections were based only on microscopic examinations, remain genetically non-characterized, and might be misidentifications with regards to L. polynuclearis n. sp. Available parasite distribution data indicate that L. polynuclearis n. sp. infects Picidae species throughout North America and L. squamatus distribution probably is restricted to Old World Piciformes birds.

Neither sex appears to benefit from divorce within migratory Northern Flickers consistent with accidental loss and bet-hedging

AbstractDivorce is widespread among species of birds and may either be an adaptive strategy to secure a better mate or territory or be a nonadaptive result of a failure to maintain the pairbond. I examined the causes and consequences for divorce in the Northern Flicker (Colaptes auratus), a migratory woodpecker with a high annual mortality rate. In a long-term population study of 1,793 breeding pairs over 17 years, the within-season divorce rate was 4.6% and the between-season divorce rate was 15.5%. Retained pairs within a season initiated their renest 5 days faster than divorced birds that had no greater fledgling production, suggesting that within-season divorce was making the best of a bad job with severe time constraints. Poor performance in the year prior to divorce was not strongly associated with divorce, and analysis of multiple breeding stages revealed that divorcing individuals in the subsequent year had later laying dates, smaller clutches, and fewer fledglings than retained pairs but no better performance than widowed individuals. Analyzing the data separately by sex showed that neither males nor females benefitted from divorce. Thus, there is a reproductive cost linked to finding a new partner per se, but no reproductive advantage associated with divorce. New mates after divorce were usually not older (not higher quality) than previous mates, so intrasexual competition was probably not driving partnership splits. The most plausible explanation seems to be a “bet-hedging” hypothesis in which birds re-pair rapidly in spring if their previous mate does not quickly arrive during spring migration. Divorce in Northern Flickers does not appear to be adaptive and future studies on arrival and interactions of individuals in spring will elucidate proximate constraints on relocating the previous partner.

Migratory Seasonality and Phenology by Birds in a Temperate Forest with Two Disturbance Conditions

Objective: The objective was to infer the effect of the variables phenology (migration-non-migration), seasonal (rainfall-dry season), sex and forest condition on the abundances of birds (resident-migratory) in a semi-preserved and disturbed oak pine forest.
 Design/methodology/approach: It was carried out in Monte Tlaloc, State of Mexico, under two conditions of apparent disturbance, semi-preserved oak pine forest and disturbed oak pine forest. Ten bird samplings were carried out with "count on point" with a fixed radius of 25 m, covering the 4 seasons of the year and migratory periods. With the previous data, the Relative Abundance Index (RAI) was estimated. To infer the effect of the variables phenology, seasonality, sex and forest condition on the abundances of birds, generalized linear models were elaborated.
 Results: The IAR of the birds registered in the semi-considered pine forest indicates that the species with the lowest presence was Aphelocoma ultramarina (0.002) and with the highest frequency Empidonax sp. (0.13), unlike to that found in the disturbed pine forest where the lowest IAR corresponded to Colaptes auratus (0.003) and with the highest appearance was Ptiliogonys cinereus (0.23). The Generalized Linear Model suggested that forest condition and phenology are significantly related to the frequency of species.
 Limitations on study/implications: In this study it was found that the abundance of birds was affected by the condition of the forest and that the phenology (migration-non-migration), seasonal (rain-dry season), sex and condition of the forest were related to the abundance of birds. Four species classified as under Special Protection and two Threatened according to NOM-059 were registered as well as the presence of four endemic species which highlights the importance of conserving these ecosystems.
 Findings/conclusions: The fauna communities present in Monte Tláloc highlight the importance of conserving the pine-oak forests since this site is part of the Eje Neovolcanico Transversal.

Erratum to: Local recruitment in Northern Flickers is related to environmental factors at multiple scales and provides reproductive benefits to yearling breeders settling close to home

Erratum to: Local recruitment in Northern Flickers is related to environmental factors at multiple scales and provides reproductive benefits to yearling breeders settling close to home

A review of the woodpeckers (Aves: Piciformes) from the asphalt deposits of Rancho La Brea, California, with the description of three new species

A review of the piciform avifauna from the upper Pleistocene asphalt deposits of Rancho La Brea, Los Angeles, California, reveals that it comprises at least six species in five genera. We describe a new genus and species, Breacopus garretti, for the largest woodpecker, which was similar in size to the largest living North American species, Dryocopus pileatus. We recognise a new genus and species, Bitumenpicus minimus, for the smallest woodpecker in the palaeoavifauna of Rancho La Brea. We also recognise a new species of Melanerpes, M. shawi. The most common species present in the asphalt deposits is the Northern Flicker, Colaptes auratus, which is predictable because of its ground-foraging habits, which would bring it into contact with the surficial seeps of petroleum more often than those piciforms preferring an arboreal habitat. Habits of the extant species from Rancho La Brea suggest a primarily open environment, with the largest species suggesting the presence of at least scattered large trees. The piciform palaeoavifauna provides support for the hypothesis that southwestern California was a “biogeographic island,” or a region where the insular nature of the habitat promoted speciation during the late Pleistocene.

Extensive hybridization reveals multiple coloration genes underlying a complex plumage phenotype.

Coloration is an important target of both natural and sexual selection. Discovering the genetic basis of colour differences can help us to understand how this visually striking phenotype evolves. Hybridizing taxa with both clear colour differences and shallow genomic divergences are unusually tractable for associating coloration phenotypes with their causal genotypes. Here, we leverage the extensive admixture between two common North American woodpeckers-yellow-shafted and red-shafted flickers-to identify the genomic bases of six distinct plumage patches involving both melanin and carotenoid pigments. Comparisons between flickers across approximately 7.25 million genome-wide SNPs show that these two forms differ at only a small proportion of the genome (mean FST = 0.008). Within the few highly differentiated genomic regions, we identify 368 SNPs significantly associated with four of the six plumage patches. These SNPs are linked to multiple genes known to be involved in melanin and carotenoid pigmentation. For example, a gene (CYP2J19) known to cause yellow to red colour transitions in other birds is strongly associated with the yellow versus red differences in the wing and tail feathers of these flickers. Additionally, our analyses suggest novel links between known melanin genes and carotenoid coloration. Our finding of patch-specific control of plumage coloration adds to the growing body of literature suggesting colour diversity in animals could be created through selection acting on novel combinations of coloration genes.

De novo assembly of a chromosome-scale reference genome for the northern flicker Colaptes auratus.

The northern flicker, Colaptes auratus, is a widely distributed North American woodpecker and a long-standing focal species for the study of ecology, behavior, phenotypic differentiation, and hybridization. We present here a highly contiguous de novo genome assembly of C. auratus, the first such assembly for the species and the first published chromosome-level assembly for woodpeckers (Picidae). The assembly was generated using a combination of short-read Chromium 10× and long-read PacBio sequencing, and further scaffolded with chromatin conformation capture (Hi-C) reads. The resulting genome assembly is 1.378 Gb in size, with a scaffold N50 of 11 and a scaffold L50 of 43.948 Mb. This assembly contains 87.4–91.7% of genes present across four sets of universal single-copy orthologs found in tetrapods and birds. We annotated the assembly both for genes and repetitive content, identifying 18,745 genes and a prevalence of ∼28.0% repetitive elements. Lastly, we used fourfold degenerate sites from neutrally evolving genes to estimate a mutation rate for C. auratus, which we estimated to be 4.007 × 10−9 substitutions/site/year, about 1.5× times faster than an earlier mutation rate estimate of the family. The highly contiguous assembly and annotations we report will serve as a resource for future studies on the genomics of C. auratus and comparative evolution of woodpeckers.

Disruptions of feather carotenoid pigmentation in a subset of hybrid northern flickers (Colaptes auratus) may be linked to genetic incompatibilities.

Hybridization can bring in single individuals alleles that were never designed to work together, which can result in unexpected or transgressive phenotypes. The Yellow-shafted (auratus group) and Red-shafted (cafer group) subspecies groups of the Northern Flicker (Colaptes auratus) differ conspicuously in the coloration of their flight feathers, but hybridize freely where their ranges overlap in western North America. The difference in color is largely the result of the Red-shafted form harboring ketolated products at C4(4') of the carotenoids found in the Yellow-shafted form. Characterizing the carotenoid pigments in a series of birds of intermediate color (presumed hybrids) revealed that most accumulated a product of β-cryptoxanthin with a keto group on its hydroxylated ring (3-hydroxy-echinenone), while a few accumulated the product with a keto group on the unhydroxylated ring (3'-hydroxy-echinenone). Surprisingly, the latter group also had feather barbs that were noticeably yellower than the associated rachis, corresponding to a lower level of ketolation at C4(4'). We assessed possible biochemical explanations for the differences by probing the relative carotenoid concentration data in individuals of varying color. The difference between the hybrids could not be explained by the general level of ketolation of carotenoids or a particular selectivity of the 4-ketolase involved. We present a testable genetic explanation that invokes incompatibilities between divergent alleles of the two parental forms at interacting loci. Because the idiosyncrasies affect oxidation, they may be the product of mitonuclear incompatibilities.

Gaps and Runs in Nest Cavity Occupancy: Cavity “Destroyers” and “Cleaners” Affect Reuse by Secondary Cavity Nesting Vertebrates

Many animals require tree cavities for breeding and these sites may be reused by a diversity of secondary nesters over a timespan of decades. It is unknown whether the reuse of holes changes their desirability as nest sites. We hypothesized that some species, cavity degraded the quality of holes by filling them with coarse nest material or waste whereas other species, cavity cleaners, might prolong the use of a hole by removing debris or enlarging the hole. Using data gathered during 22 years from a field study in central British Colombia, we analyzed long-term patterns of occupancy in relation to their sequential use by bird and mammal species, grouped by traits. Patterns of occupancy were variable with 49% of 875 large-sized holes (excavated by northern flickers Colaptes auratus and pileated woodpeckers Dryocopus pileatus) and 19% of 672 smaller-sized holes incorporating runs of sequential use that lasted up to 18 years. But 11-25% of cavities also had gaps of 3-13 years between occupancies. Mammals, raptors and European starlings, consistent with the hypothesis they were destroyers, occupied cavities as terminal users and before gaps more often than expected by chance. The pattern of occupancy by northern flickers was random in relation to gaps or prior use by other species so, although flickers did not target old holes to clean, neither did they avoid them. Small cavities that were renovated by flickers into larger cavities had double the reuse rate. Runs of occupancy that involved only cavity-destroying species were shorter than runs that involved periodic use by flickers, suggesting the woodpecker, through its cleaning and renovation, prolonged the use of such holes.

Camera Traps Detect Prey of Northern Carnivores

Use of camera traps for non-invasive data collection is increasingly common in wildlife studies. This technique presents a valuable, but generally unexploited, opportunity to learn about carnivore diet through direct observations of predators with prey. To highlight this potential, we present a collection of photographic observations from Michipicoten Island, ON, Canada, that improve our knowledge of the diets of northern carnivores. These include the first documentation of Vulpes vulpes (Red Fox) consumption of a Colaptes auratus (Northern Flicker) and the first photographic evidence of wintertime consumption of a Lithobates sp. (frog) by a Mustela erminea (Short-tailed Weasel). We discuss the implications of these observations and the use of camera traps to gather data on carnivore diets, including caveats to this technique.

Nest site characteristics of cavity-nesting birds on a small island, in Haida Gwaii, British Columbia, Canada

Many studies of cavity-nesting birds in North America are conducted in large continental forests and much less is known about them in island ecosystems. We describe a 29-year study of tree species, nest site characteristics, and fledge dates of cavity-nesting birds on a small island in Haida Gwaii, British Columbia (BC). Seven cavity-nesting bird species were documented on East Limestone Island and 463 nests were found in 173 different trees. Nest trees were significantly taller and had a greater diameter than a random sample of snags. Tree height did not differ among bird species but diameter at breast height was larger for trees used by Brown Creeper (Certhia americana) than for other species. Cavity-nesters selected tree decay classes 2–7 (all dead/near dead [snags]), with 85% in decay class 4 (35%) or 5 (50%), similar to the random snag sample (class 4, 32%; class 5, 42%). Cavity height ranged from 2.6 to 44.9 m and for all species, except Brown Creeper, the mean nest height was >60% of the mean tree height. Nest heights were generally greater than observed elsewhere in BC. Nest cavity orientation was random except for Red-breasted Sapsuckers (Sphyrapicus ruber), for which only 13% of the cavity entrances faced southeast. Median fledging dates ranged from 7 June (Chestnut-backed Chickadee [Poecile rufescens]) to 28 June (Northern Flicker [Colaptes auratus]). Estimated median dates of clutch completion were similar for all species. Our results show that large snags provide habitat for a high diversity of cavity-nesting birds on Haida Gwaii.