Allen's Hummingbirds Research Articles

Sampling affects population genetic inference: A case study of the Allen's (Selasphorus sasin) and rufous hummingbird (Selasphorus rufus).

Gene flow can affect evolutionary inference when species are undersampled. Here, we evaluate the effects of gene flow and geographic sampling on demographic inference of 2 hummingbirds that hybridize, Allen's hummingbird (Selasphorus sasin) and rufous hummingbird (Selasphorus rufus). Using whole-genome data and extensive geographic sampling, we find widespread connectivity, with introgression far beyond the Allen's × rufous hybrid zone, although the Z chromosome resists introgression beyond the hybrid zone. We test alternative hypotheses of speciation history of Allen's, rufous, and Calliope (S. calliope) hummingbird and find that rufous hummingbird is the sister taxon to Allen's hummingbird, and Calliope hummingbird is the outgroup. A model treating the 2 subspecies of Allen's hummingbird as a single panmictic population fit observed genetic data better than models treating the subspecies as distinct populations, in contrast to morphological and behavioral differences and analyses of spatial population structure. With additional sampling, our study builds upon recent studies that came to conflicting conclusions regarding the evolutionary histories of these 2 species. Our results stress the importance of thorough geographic sampling when assessing demographic history in the presence of gene flow.

K-mer analysis shows hybrid hummingbirds perform variable, transgressive courtship sequences

Behaviours are challenging to describe. Here, we apply k-mer analysis to characterize complex courtship behaviours at four hierarchical levels: elements, displays, bouts and repertoires, on two species of hummingbirds and their hybrids. During courtship, male rufous hummingbirds, Selasphorus rufus, perform three types of displays: shuttles (S), half pendulums (H) and rufous dives (R), while Allen's hummingbirds, Selasphorus sasin, perform four displays: S, H, Allen's dives (A) and the pendulum (P). Here we explore the behavioural sequences expressed by their hybrids, on a sample of displays from 35 Allen's hummingbirds and 46 rufous hummingbirds sampled far from their hybrid zone, compared against 306 wild male birds from a hybrid zone in Oregon and California, U.S.A. Among Allen's hummingbirds, hybrids and rufous hummingbirds, there was almost no variation in the kinematic elements that comprised displays. By contrast, the displays themselves, display sequences and repertoires varied substantially among these three groups. Some hybrids performed transgressive display variants in which kinematic elements of typical displays were missing or duplicated. This transgressive segregation implies the displays are under oligogenic control. We analysed display sequences using k-mer analysis, in which we binned display sequences into 3-mers (sequences of three). Typical 3-mers for Allen's hummingbirds included sequences PPP, PPA and SHP while typical 3-mers for rufous hummingbirds included SHR and RRR. The most defining characteristic of certain hybrids was their sequence variability: the display repertoire of some hybrids encompassed the repertoire of both parent species (e.g. performed both PPA and RRR) as well as 3-mer sequences never observed in either parent such as PRA. Such high within-individual variability in hybrid phenotype differs from how modular morphological traits (such as flowers, feathers or hair) are expressed in hybrids. This within-individual variability may be unique to behaviour.

A second decade of overwintering hummingbirds in Florida and Alabama

For a second decade, from November 2008 to March 2018, we examined the species diversity, return rate, longevity, and migration routes of hummingbirds overwintering in southern Alabama and the panhandle, northern peninsula, and central peninsula of Florida. We captured and banded 11 species of hummingbirds (n= 1,870 individuals), including 931 Rufous Hummingbirds (Selasphorus rufus; 49%), 583 Ruby-throated Hummingbirds (Archilochus colubris; 31%), 219 Black-chinned Hummingbirds (A. alexandri; 12%), 49 Buff-bellied Hummingbirds (Amazilia yucatanensis), 49 Calliope Hummingbirds (S. calliope), 19 Allen's Hummingbirds (S. sasin), 11 Broad-tailed Hummingbirds (S. platycercus), 6 Broad-billed Hummingbirds (Cynanthus latriostris), 1 Anna's Hummingbird (Calypte anna), 1 Costa's Hummingbird (Calypte costae), and 1 White-eared Hummingbird (Hylocharis leucotis). Site fidelity was high, with 299 hummingbirds of 5 species returning at least once. Two Rufous Hummingbirds migrated to our study area in the autumn from the West (Oklahoma and Texas). One Ruby-throated Hummingbird banded in Lakeland, Florida, was recovered in Utopia, New Brunswick, Canada, suggesting the overwintering Ruby-throated Hummingbirds in our study area are migratory and not sedentary.

The population genetics of nonmigratory Allen's Hummingbird (Selasphorus sasin sedentarius) following a recent mainland colonization.

Allen's Hummingbird comprises two subspecies, one migratory (Selasphorus sasin sasin) and one nonmigratory (S. s. sedentarius). The nonmigratory subspecies, previously endemic to the California Channel Islands, apparently colonized the California mainland on the Palos Verdes Peninsula some time before 1970 and now breeds throughout coastal southern California. We sequenced and compared populations of mainland nonmigratory Allen's Hummingbird to Channel Island populations from Santa Catalina, San Clemente, and Santa Cruz Island. We found no evidence of founder effects on the mainland population. Values of nucleotide diversity on the mainland were higher than on the Channel Islands. There were low levels of divergence between the Channel Islands and the mainland, and Santa Cruz Island was the most genetically distinct. Ecological niche models showed that rainfall and temperature variables on the Channel Islands are similar in the Los Angeles basin and predicted continued expansion of nonmigratory Allen's Hummingbird north along the coast and inland. We also reviewed previous genetic studies of vertebrate species found on the Channel Islands and mainland and showed that broad conclusions regarding island–mainland patterns remain elusive. Challenges include the idiosyncratic nature of colonization itself as well as the lack of a comprehensive approach that incorporates similar markers and sampling strategies across taxa, which, within the context of a comparative study of island–mainland relationships, may lead to inconsistent results.

Novel hybrid finds a peri-urban niche: Allen’s Hummingbirds in southern California

Species range expansions and contractions can have ecological and genetic consequences, and thus are important areas of study for conservation. Hybridization and introgression are not uncommon in closely related populations that experience secondary contact during a range expansion. Allen’s Hummingbird (Selasphorus sasin) in California comprises two subspecies: the migratory S. s. sasin, which winters in central Mexico and breeds in central and northern California, and the resident S. s. sedentarius, which lives and breeds year-round on several of the Channel Islands off the California coast. Within recent decades, Allen’s Hummingbirds have been found living and breeding year-round in the southern California peri-urban mainland near Los Angeles. Ornithologists assumed that the L.A. birds were an expansion of the island subspecies, S. s. sedentarius due to similar but very subtle morphological characteristics. However, the genetic relationships among the three putative populations of Allen's hummingbird—migratory, southern California mainland, and island—are unknown. We investigated these relationships by analyzing variation of single nucleotide polymorphisms from the three geographic regions where S. sasin are present. Our population genomic analyses indicate that S. sasin hummingbirds inhabiting mainland southern California are a hybrid population resulting from admixture between S. s. sasin and S. s. sedentarius. From one perspective, these results may be interpreted as a positive development for S. s. sasin as the growing population represent an overall increase in the S. sasin population, and the expanding population contains a significant representation of S. s. sasin alleles.

Evidence of linked selection on the Z chromosome of hybridizing hummingbirds.

Levels of genetic differentiation vary widely along the genomes of recently diverged species. What processes cause this variation? Here, I analyze geographic population structure and genome-wide patterns of variation in the Rufous, Allen's, and Calliope Hummingbirds (Selasphorus rufus/Selasphorus sasin/Selasphorus calliope) and assess evidence that linked selection on the Z chromosome drives patterns of genetic differentiation in a pair of hybridizing species. Demographic models, introgression tests, and genotype clustering analyses support a reticulate evolutionary history consistent with divergence during the late Pleistocene followed by gene flow across migrant Rufous and Allen's Hummingbirds during the Holocene. Relative genetic differentiation ( ) is elevated, and within-population diversity (π) is depressed on the Z chromosome in all interspecific comparisons. The ratio of Z to autosomal within-population diversity is much lower than that expected from population size effects alone, and Tajima's D is depressed on the Z chromosome in S. rufus and S. calliope. These results suggest that conserved structural features of the genome play a prominent role in shaping genetic differentiation through the early stages of speciation in northern Selasphorus hummingbirds, and that the Z chromosome is a likely site of genes underlying behavioral and morphological variation in thegroup.

Kinematic control of male Allen's Hummingbird wing trill over a range of flight speeds

Wing trills are pulsed sounds produced by modified wing feathers at one or more specific points in time during a wingbeat. Male Allen's hummingbirds (Selasphorus sasin) produce a sexually dimorphic 9 kHz wing trill in flight. Here, we investigated the kinematic basis for trill production. The wingtip velocity hypothesis posits that trill production is modulated by the airspeed of the wingtip at some point during the wingbeat, whereas the wing rotation hypothesis posits that trill production is instead modulated by wing rotation kinematics. To test these hypotheses, we flew six male Allen's hummingbirds in an open-jet wind tunnel at flight speeds of 0, 3, 6, 9, 12 and 14 m s-1, and recorded their flight with two 'acoustic cameras' placed below and behind, or below and lateral to the flying bird. The acoustic cameras are phased arrays of 40 microphones that used beamforming to spatially locate sound sources within a camera image. Trill sound pressure level (SPL) exhibited a U-shaped relationship with flight speed in all three camera positions. SPL was greatest perpendicular to the stroke plane. Acoustic camera videos suggest that the trill is produced during supination. The trill was up to 20 dB louder during maneuvers than it was during steady-state flight in the wind tunnel, across all airspeeds tested. These data provide partial support for the wing rotation hypothesis. Altered wing rotation kinematics could allow male Allen's hummingbirds to modulate trill production in social contexts such as courtship displays.

EBird records show substantial growth of the Allen's Hummingbird (Selasphorus sasin sedentarius) population in urban Southern California

ABSTRACT The sedentary subspecies of Allen's Hummingbird (Selasphorus sasin sedentarius) was originally endemic to the Channel Islands off the coast of Southern California, but it colonized the mainland at the Palos Verdes Peninsula sometime before 1966. In the decades since, its population has expanded in Southern California. I tracked its growth using eBird checklists. The mainland range of S. s. sedentarius has grown from ∼70 km2 in 1970 to ∼13,000 km2 today, representing an increase of ≤23% in the total range of the species as a whole. Its main habitat within Los Angeles, Orange, San Diego, and western Riverside counties is urban parks, gardens, and campuses. The range expansion of S. s. sedentarius seems to be driven by food availability—although, given that it is found in urban habitats that the other subspecies, S. s. sasin, does not seem to utilize, a subtle change in the ecology of the 2 subspecies is also implied. Analysis of eBird data suggests that breeding S. s. sedentarius met S. s. sasin ne...

Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers.

Models of character evolution often assume a single mode of evolutionary change, such as continuous, or discrete. Here I provide an example in which a character exhibits both types of change. Hummingbirds in the genus Selasphorus produce sound with fluttering tail-feathers during courtship. The ancestral character state within Selasphorus is production of sound with an inner tail-feather, R2, in which the sound usually evolves gradually. Calliope and Allen's Hummingbirds have evolved autapomorphic acoustic mechanisms that involve feather-feather interactions. I develop a source-filter model of these interactions. The ‘source’ comprises feather(s) that are both necessary and sufficient for sound production, and are aerodynamically coupled to neighboring feathers, which act as filters. Filters are unnecessary or insufficient for sound production, but may evolve to become sources. Allen's Hummingbird has evolved to produce sound with two sources, one with feather R3, another frequency-modulated sound with R4, and their interaction frequencies. Allen's R2 retains the ancestral character state, a ∼1 kHz “ghost” fundamental frequency masked by R3, which is revealed when R3 is experimentally removed. In the ancestor to Allen's Hummingbird, the dominant frequency has ‘hopped’ to the second harmonic without passing through intermediate frequencies. This demonstrates that although the fundamental frequency of a communication sound may usually evolve gradually, occasional jumps from one character state to another can occur in a discrete fashion. Accordingly, mapping acoustic characters on a phylogeny may produce misleading results if the physical mechanism of production is not known.

Hovering and Forward Flight Energetics in Anna's and Allen's Hummingbirds

Aerodynamic theory predicts that the mechanical costs of flight are lowest at intermediate flight speeds; metabolic costs of flight should trend similarly if muscle efficiency is constant. We measured metabolic rates for nine Anna's hummingbirds (Calypte anna) and two male Allen's hummingbirds (Selasphorus sasin) feeding during flight from a free-standing mask over a range of airspeeds. Ten of 11 birds exhibited higher metabolic costs during hovering than during flight at intermediate airspeeds, whereas one individual exhibited comparable costs at hovering and during forward flight up to speeds of approximately 7 m s(-1). Flight costs of all hummingbirds increased at higher airspeeds. Relative to Anna's hummingbirds, Allen's hummingbirds exhibited deeper minima in the power curve, possibly due to higher wing loadings and greater associated costs of induced drag. Although feeding at a mask in an airstream may reduce body drag and, thus, the contributions of parasite power to overall metabolic expenditure, these results suggest that hummingbird power curves are characterized by energetic minima at intermediate speeds relative to hovering costs.

Phenology, sex ratios, and population trends of Selasphorus hummingbirds in central coastal California

From 1980 to 2000, we mist-netted 2412 Allen's Hummingbirds (Selasphorus sasin) and 203 Rufous Hummingbirds (S. rufus) at a site in central coastal California. Adult Allen's occurred from late January to early August and juveniles from early April to early September. Overall ratios of female to male Allen's were 2.5:1 for adults, 1:1.1 for juveniles. The breeding season female-to-male ratio for adult Allen's of 6.2:1 probably reflected net placement at riparian edges between nests and feeding areas for females. Adult Rufous occurred as transients from mid-February to early May and late June to mid-August and juveniles from mid June to late September. Overall ratios of female to male Rufous were 2.3:1 for adults in spring, 1:1.1 for juveniles. For adults, there was little evidence for a spring migration peak in Allen's, but a fall migration peak was marked. In contrast, adult Rufous showed a spring migration peak but were rare in fall. The two species' main southbound routes in California (coastal for Allen's, interior for Rufous) may, in combination with temporal separation, help partition nectar resources. Capture rates for both age groups of Allen's Hummingbirds indicated a stable population. Juvenile Rufous showed a significant decline in capture rates, reasons for which are unknown.

Neural song control system of hummingbirds: Comparison to swifts, vocal learning (Songbirds) and nonlearning (Suboscines) passerines, and vocal learning (Budgerigars) and nonlearning (Dove, owl, gull, quail, chicken) nonpasserines

Males of certain hummingbird species such as Anna's hummingbirds (Calypte anna) learn their song during postnatal development. Here we report that male Anna's hummingbirds and male Amazilia hummingbirds (Amazilia amazilia), two singing hummingbird species, possess forebrain areas that are similar in morphological appearance, location, and connectivity to the song control areas RA (nucleus robustus archistriatalis), HVC (nucleus hyperstriatalis ventrale, pars caudale, or higher vocal center), and LMAN (lateral part of nucleus mangnocellularis anterioris) of oscine passerines (songbirds). The vocal control areas of songbirds are further defined by the expression of androgen receptors. Similarly, the singing hummingbird species express androgen receptors in the LMAN-like area and in the HVC-like area. The hummingbird RA projects to the medullary syringeal motonucleus nXIIts (nucleus hypoglossus pars tracheosyringealis) and the respiratory premotonucleus RAm (nucleus retroambigualis). The HVC-, RA-, and LMAN-like areas are rudimentary in adult male ruby-throated hummingbirds (Archilochus colubris) and Allen's hummingbirds (Selasphorus sasin) and not distinguishable in female hummingbirds, none of which sing. Vocal-area-like forebrain areas (delineated by the cytoarchitecture or androgen receptor expression) were not found in vocal nonlearning swifts and suboscines, the taxonomic sister groups of hummingbirds and songbirds, respectively. These areas were also missing in owls, ring doves, gulls, and gallinaceous species, nonpasserines that do not learn vocalizations. Budgerigars (vocal learners) are known to have forebrain vocal areas, but these areas do not express sex steroid receptors. These data suggest that hummingbirds and songbirds belong to two groups of birds that have common forebrain circuits. Parts of this circuit are organized as nuclear-like structures (LMAN, HVC, RA) in species that learn to sing.

Records of Allen's Hummingbird in Louisiana and Possible Rufous × Allen's Hummingbird Hybrids

Records of Allen's Hummingbird in Louisiana and Possible Rufous × Allen's Hummingbird Hybrids

First Specimen of Allen's Hummingbird, Selasphorus sasins (Trochilidae), from Texas

First Specimen of Allen's Hummingbird, Selasphorus sasins (Trochilidae), from Texas

The Migrations of Allen's and Other Hummingbirds

tually migrates southward in numbers in late spring; further, its route soon veers away, geographically and ecologically, from the northward return route used chiefly in winter. Allen's Hummingbird (Selasphorus sasin) is remarkable in that it breeds only in California, barely overlapping that State's borders, and normally (at least until recent years) only in a narrow coastal strip. Of the few endemic California species, it is the only wholly migratory one! This distinction belongs to the northern, nominate race. The southern S. s. sedentarius Grinnell has the opposite distinction of being the only virtually sedentary hummingbird or nectar-feeder of any kind in the continental United States (see below). These amazing, somewhat elliptical migrations at the wrong seasons remain unappreciated because of: (1) the few records, mostly unpublished, between early September and mid-February; (2) reluctance to admit migrations in Californian endemics or ignorance in official check-lists (cf. for example, Swarth 1914:38, 90, on both Allen's and Anna's Hummingbirds, Calypte anna, in Arizona); (3) their seasonal displacement; and (4) failure to distinguish age/sex classes, or even the species (vs. the extremely similar Rufous Hummingbird, Selasphorus rufus), whose migrations are asynchronous. Authorities disagree widely on migrations and winter ranges (see A.O.U. 1931, 1957, Berlioz 1932, Friedmann et al. 1950). Loye H. Miller first pointed out (in Willett 1933:97) that even adult males of Allen's Hummingbird are not always safely distinguishable in color. This important fact is still generally overlooked; Peterson and Chalif (1973), Robbins et al. (1966), and Stiles (1972:31) all described the back of adult male S. rufus as rufous, or sometimes with scattered green feathers, thus not contrasting to the rufous tail and coverts as in S. sasin. But

Age and Sex Determination in Rufous and Allen Hummingbirds

Female and immature Rufous (Selasphorus and migrations of the three taxa is given by rufus) and Allen (S. sn situation is further complicated by the fact sasin breeds along the western slope of the that the fairly clear-cut mensural differences coast ranges of California, from western Venbetween rufus and the mainland population tura County north to about the Oregon line. of sasin are largely bridged by the Channel These two taxa may come in contact in exIsland population of sasin, S. s. sedentarius. treme northern California. Although previously The objective of this paper is to present a thought to be confined to the Channel Isworkable method for identification and age lands, sedentarius is now known to breed on and sex determination of these three taxa, the Palos Vserdes Peninsula just south of Los hereafter referred to as rufus, sasin, and sedAngeles ( Stiles and Wells, in prep. ) . This is entarius. The need for such a method is espeabout 100 mi. SE of the nearest breeding popcially pressing at present, since several humulation of sasin. mingbird banding studies have recently been During January and February migrating initiated in southern California. Moreover, susin pass through at least the mainland part sedentarius has recently been found breeding of the range of sedentarius. At this time the on the mainland (Stiles and Wells, in prep.), nonmigratory sedentarius may have been and identification of females and immatures breeding for several months in some years, and will be essential for documentation of possible immatures may be common. All migrating further spread of this population. sasin should be in essentially adult plumage, Literature review. Ridgway’ s (1911) dethus reducing somewhat the difficulty of idenscriptions of the adult plumages of rufus and tification. In March and April large numbers sasin are reasonably complete and accurate, of rufus pass northward through the breeding but the measurements are based upon very ranges of sedentarius (at least the mainland small samples that may not have been unipart) and sasin. Again all rufus should be in form with respect to molt, plumage wear, etc. essentially adult plumage; adult and immature However, sedentarius had not yet been desasin and sedentarius should be present in scribed when Ridgway wrote. The only distheir respective breeding ranges (cf. Aldrich cussion of mensural differences between sasin 1956 ) . and sedentarius is in Grinnell’ s ( 1929) original After breeding, adult and immature sasin description of the latter, which was based on and rufus move southward in the mountains a small and not entirely representative samand along the coastal slope. At favorable feedple. The most detailed discussion of molt and ing areas, such as Nicotiana stands in coastal plumage sequences in sasin and rufus is by lowlands and Penstemon patches in mountain Aldrich (1956) but certain of his conclusions meadows, large numbers of individuals may were apparently based on specimens with congregate (see Stiles 1972, and included reffaulty sex and age data and require correcerences). It appears that susin moves south tion. To date there is no adequate published earlier, passing through southern California reference for distinguishing immature pluin June and July. By August and September, mages osf these taxa. most or all of the birds in such feeding assemDistribution and identification. A reasonblages in the Los Angeles area are rufus ably detailed discussion of breeding ranges (Stiles 1972). However, I also collected a young male sedentarius (along with 10 im1 Present address: c/o Orgnnization for Tropical Studies, Apartado 16, Cuidad Universitaria, Costa Rica, C. A. mature rufus) from a feeding assemblage in

From Field and Study

Journal Article Speed of the Allen Hummingbird While Diving Get access Oliver P. Pearson Oliver P. Pearson Museum of Vertebrate Zoology, Berkeley, California Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 62, Issue 5, 1 September 1960, Page 403, https://doi.org/10.2307/1365168 Published: 01 September 1960

Hybrids of the Anna and Allen Hummingbirds

Hybrids of the Anna and Allen Hummingbirds

Pterlyography and Molt of the Allen Hummingbird

Pterlyography and Molt of the Allen Hummingbird

Trochilidae or Humming-birds brought in our Country

There are many Japanese who have heard the word "Humming-bird", but few have seen a live one and even the stuffed specimens were not seen by many people. Humming-birds were imported into Japan only twice before the Pacific War. The first person who bred the hummer was Mr. Rihee Okada, the aviculturist in Itami, Hyôgo Pref. while the second was Yamashina, the senior author. Thirteen humming-birds were brought into Japan in four groups across the Pacific by Mr. E.Kinsey, the bird-fancier in San Francisco. The species then imported were the Anna Humming-bird Calypte anna and the Allen Humming-bird Selasphorus sasin both of which inhabit the United States. One male of the former and a pair of the latter were the first to come to Japan on April 9, 1937 and the rest of them arrived one after the other in the following twelve months. Afterwards a pair of the Anna Humming-birds selected from among them were presented by the senior author to the Zoological Garden at Uéno, Tokyo. Here the first time in our country the live humming-birds were exhibited to the public to the great wonder of many Japanese, but unfortunately in a week they were found missing.On March 16, 1955 eight hummers from Brazil were brought in Japan and several of them were exhibited to the public in Uéno Zoo. It is said that those birds were the gift of a Japanese living there. Since those hummers were the first ones to arrive in this country after the war, they became a great topic among those who are fond of birds and animals. One of them represents Anthracothorax viridigula and the rest of them seem to be Eupetomena macroura.The senior author was so enthusiastic about keeping the hummers alive that one of the Anna Humming-birds lived for three years and nine months and one of the Allen Humming-birds for exactly four years both of which are the highest records of humming-bird breeding in Japan.One hummer sent to Mr. Okada from the U. S. A. died in a week, but the specific name of which is unknown.