Recent conservation plans for long-distance Neotropical migrant birds have emphasized the importance of understanding the ecology and threats facing a species throughout its life cycle, including migration and overwintering periods. To better understand the ecology of Broad-winged Hawks (Buteo platypterus) during the nonbreeding period, we followed the movements of 14 hawks from 2 breeding populations during July 2014–April 2019 to their overwintering sites. Three juvenile and 8 adult female Broad-winged Hawks were satellite-tracked from Pennsylvania, USA, and 3 adults (2 females and 1 male) were tracked from Alberta, Canada. We documented pre-migratory movements (post-breeding) of 4 of the 14 individuals. Adults initiated fall migration on x̄ = 25 August ± 16.38 d and 2 of the 3 juveniles began fall migration on x̄ = 20 August ± 2 d. Adults had 1–12 (x̄ = 5.0 ± 3.5) stopovers in autumn that lasted for 1–24 d and juveniles had 2–5 (x̄ = 3.0 ± 1.7) stopovers that lasted 2–51 d. Adults from Pennsylvania spent the overwintering period in Nicaragua, Brazil, Peru, and Colombia (n = 8) whereas those from Alberta wintered in Suriname, Venezuela, and Bolivia (n = 3). The distance traveled on autumn migration was greater for Alberta birds (x̄ = 10,021 ± 866 km, n = 3) than for Pennsylvania birds (x̄ = 7,925 ± 1,631 km, n = 8). Migration distance and overwintering region varied by geographic origin with age but with some overlap between the 2 distinct geographic breeding populations. Broad-winged Hawks appear to follow a hybrid time–energy minimization strategy during fall and spring migrations with (1) energy minimization in North America, and (2) time minimization in Mexico and Central America. Stopover frequency, duration, and migration rate support this hypothesis.

Little is known about migration patterns of Broad-winged Hawks (Buteo platypterus) in the western United States apart from small numbers that have been recorded at migration monitoring sites. To better understand their movements in coastal California, we radio-tracked 5 juveniles (1 in 1994, and 4 from 2012 to 2015) during fall migration from the Marin Headlands (near San Francisco) to the US–Mexico border. One hawk died near the Headlands within 2–3 d of release and the other 4 crossed into Baja California in 4–6 flight days with no stopovers beyond the Headlands. Daily straight-line flight distances ranged from about 110 to 265 km (mean = 189 ± 47 km SD). Migration began 2.5–3 h after sunrise and ended a similar amount of time before sunset. Flight paths along mountain ranges, and radio signal patterns, indicated slope-soaring was a primary strategy. The detailed flight paths we identified will be helpful to better evaluate proposed renewable energy facilities, given their current rapid development and potential for killing birds. More study is needed to determine complete migration routes and breeding and wintering grounds of Broad-winged Hawks on the Pacific coast.

The Mariana islands have a species-poor but functionally diverse and largely endemic bird assemblage that varies due to biogeographic legacy and anthropogenic impacts. The largest island in the chain, Guam, is the setting for one of the most extreme examples of recent avian population declines, indicating the capacity for avifaunal collapse and loss of function in neighboring islands. We performed a systematic survey of resident land birds in remnant karst forest on the Mariana Islands' 3 largest islands following Guam to assess the status of the avifauna in this habitat, characterize inter-island heterogeneity in bird communities, and consider the resulting differences in the functional roles of birds across the archipelago's native forests. We identified significantly greater functional diversity on Rota than either Saipan or Tinian, but lower bird population densities, species richness, and Shannon diversity. We recommend continued monitoring of avian population trends across the archipelago and assessments of ecosystem functions like pollination, seed dispersal, and food web dynamics.

Territorial protandry, or early season male-biased settlement at breeding sites, is a widespread phenomenon in a range of animal breeding systems. While protandry is common across several avian lineages and has been linked with increased reproductive success of earlier breeding males in terrestrial species, the selective advantage of breeding protandry has only rarely been studied in seabirds. We assessed the seasonal changes in the sex ratio at the breeding site and sex-specific correlates of arrival date with reproductive success during 2 breeding seasons of a colonial seabird, the Australasian Gannet (Morus serrator), at Cape Kidnappers, New Zealand. We found no biases in overall sex ratios of adults and fledglings but detected a male sex bias during nest site establishment, and a significantly higher probability of reproductive success for earlier-settling males. In contrast, the reproductive success of females did not correlate with the timing of arrival. Our findings provide an assessment of the sex differences in reproductive correlates of the timing of breeding settlement in gannets and are consistent with selective advantages as suggested by indirect selection hypotheses. This study contributes to our understanding of the fitness benefits of protandry, and its linkages with sex differences in breeding philopatry and mate fidelity, in a long-lived seabird species with obligate and extended biparental care.

Male Red-winged Blackbirds (Agelaius phoeniceus) have red epaulets that are used as badges for intrasexual competition for territory acquisition and defense. Red epaulets reflect very little across ultraviolet (UV) wavelengths (300–400 nm) yet most birds, including Red-winged Blackbirds, are visually sensitive to UV light. Here, we conducted a field experiment to test if adding UV reflectance (UV+) to epaulets changed the effectiveness of signals to receivers relative to control epaulets. We constructed blackbird models with an epaulet made from red felt that reflected both long-wavelength (i.e., red) and UV wavelengths (UV+). To half of the models we applied sunscreen over the epaulets to block UV reflectance (UV–) and therefore mimic reflectance spectra of natural epaulets. UV+ and UV– models, along with small playback recorders playing oak-a-lee calls, were presented in established territories of male Red-winged Blackbirds. UV+ models received significantly more song flight displays (2017) and song spread displays (2019) from territorial males. Two territorial males physically attacked UV+ models but none attacked UV– models. To our knowledge, this is the first field experiment to add UV color to a plumage signal, resulting in a behavioral response from wild birds, raising questions for future research to explore a potential pre-existing visual bias for UV coloration in Red-winged Blackbirds and potential phylogenetic constraints on expression of UV reflectance of epaulets.

I use point-count survey data collected from 171 locations across 11 vegetation conditions in western Mexico to illustrate common patterns of winter habitat use by 97 Nearctic–Neotropical migratory landbird species. A number of bird species are relatively restricted in their habitat use, with some (e.g., Northern Waterthrush [Parkesia noveboracensis], American Redstart [Setophaga ruticilla]) occurring only in relatively undisturbed habitats, and others (e.g., Say's Phoebe [Sayornis saya], Horned Lark [Eremophila alpestris]) occurring only in relatively disturbed lands associated with agriculture. A large number of bird species (e.g., Cassin's Vireo [Vireo cassinii], MacGillivray's Warbler [Geothlypis tolmiei]) use every one of the vegetation types considered, from low-elevation tropical deciduous forests to high-elevation conifer forests. Bird species showing patterns of restricted habitat use deserve conservation attention, but even the more broadly distributed species might become significantly less abundant in human-altered portions of habitats. Identifying the latter will require the inclusion of a wider spectrum of altered vegetation types/conditions than what I included here, or than what is typically considered in wildlife–habitat relationship programs.

Understanding which factors influence nest site selection can lead to more effective species conservation. The Loggerhead Shrike (Lanius ludovicianus) has experienced severe declines since the 1940s and could potentially benefit from fine-scale management for nesting habitat, especially where fragmentation impedes conservation at the landscape scale. We examined how habitat characteristics at the nest tree and territory core scales influenced nest site selection by Loggerhead Shrikes in the coastal plain of South Carolina. We found 41 Loggerhead Shrike nests and measured habitat characteristics at the nest site and at available sites to model selection factors at the tree and territory core scales. Loggerhead Shrikes selected for low heterogeneity of vegetation density, high heterogeneity of vegetation height, and lower shrub and tree densities at the territory core scale. Loggerhead Shrikes also preferred nest trees with larger diameters at breast height. Overall, Loggerhead Shrikes appeared to select for nest site characteristics that enhanced foraging ease and success, and limited predation risk. We suggest that landowners in the southeastern coastal plain increase grassy habitat on their property and retain large trees in suitable nesting locations to increase optimal nesting habitat for Loggerhead Shrikes.

We documented prebasic flight feather molt of passerines captured in fall 2013 and 2015 at McGill Bird Observatory (MBO) in Montreal, Quebec. We recorded active molt of flight feathers (remiges) in 11 species that do not breed on site. Flight feather molt was frequent among Swainson's Thrush (Catharus ustulatus; 64% of adults), Tennessee Warbler (Oreothlypis peregrina; 57%), Nashville Warbler (Leiothlypis ruficapilla; 67%), and Yellow-rumped Warbler (Setophaga coronata; 44%), and was observed less frequently in other species. The minimum stopover length of molting individuals was on average 8 times longer than that of non-molting individuals of the same species. Among Swainson's Thrushes and Yellow-rumped Warblers, far more females were undergoing molt than males, whereas for Tennessee Warblers molt was slightly more frequent among males. Frequency of molt was similar between years for most species but not Yellow-rumped Warbler, with 59% of adults captured in 2013 molting compared to none in 2015. We also observed molting site fidelity with multiyear returns of Tennessee and Nashville warblers. The use of separate breeding and molting sites is not well understood among eastern North American species, and with recent studies highlighting the importance of molt locations in western North America, we demonstrate the value in additional study of the use of discrete molt locations in the East.

Temperature of avian nest sites is a critical component of reproduction because thermal environments influence both fitness and survival of incubating adults and developing embryos. Given that the orientation of nest sites can alleviate or intensify thermal extremes through exposure to solar radiation and wind effects, it is important to quantify the mechanistic role orientation has on thermal conditions. Moreover, identifying how nesting decisions (i.e., orientation) influence nest site temperature may also provide insight into the adaptive responses of species commonly exposed to thermal extremes. Therefore, to better understand the relationship between nest orientation and nest site temperature, we examined nest sites of 2 ground-nesting sympatric species, Northern Bobwhite (Colinus virginianus) and Scaled Quail (Callipepla squamata), in the Southern Great Plains, a region prone to high thermal variability. Specifically, we measured temperature of nest sites by nest orientation using black bulb temperature (T_bb) data loggers. We found that, despite uniform distribution of nest orientations, orientation was a major driver of nest site temperature during peak heating periods (1200–1830 h) with temperatures of south- and west-facing nests on average 6 °C warmer for Northern Bobwhite and 2 °C warmer for Scaled Quail when compared to the temperature of north- and east-oriented nests. However, no significant differences were observed in nest vegetation characteristics between nest orientations, and orientation failed to predict nest success for either species. This is contrary to similar studies and suggests that nest site selection is an interaction between multiple drivers (i.e., thermal environment, predation risks) with the importance of factors varying between years and locations.

In spite of comprising more than 50% of the world's 10,000+ living species of birds, the songbirds (Passeriformes) generally have a poor fossil record. An exception is the Icteridae, with substantial Quaternary fossils at certain sites in North America, South America, and the West Indies. Here we describe 2 new extinct species of icterids from the late Pleistocene Talara Tar Seeps of northwestern Peru. The first is Icterus turmalis, based on 22 fossils (2 skeletal elements); I. turmalis was part of the radiation of “troupial”-type orioles (Icterus icterus s.l.). The second new species, Molothrus resinosus, was a large cowbird based on 15 fossils (4 skeletal elements). Icterus turmalis and Molothrus resinosus are both known thus far only from Talara. They become the second and third extinct species of icterid known from Talara, the other being Euphagus magnirostrisMiller 1929, first described from Rancho La Brea, and recorded recently from Talara as well as the Mene de Inciarte Tar Seep in Venezuela. Just as some extant species of icterids often occur today alongside large grazing mammals, the extinct species may have been closely associated with the Pleistocene large mammal community, which collapsed from 15 to 12 thousand years ago.

Brood parasitism can decrease the reproductive success of host species and contribute to population declines, especially in small populations with naturally low fecundity. The ability of host species to recognize foreign eggs varies, as do the behavioral responses of hosts to brood parasitism. We experimentally tested the ability of a putative host, the White-breasted Thrasher (Ramphocinclus brachyurus), to recognize and reject the eggs of a recently established generalist brood parasite. The White-breasted Thrasher is an endangered songbird restricted to 2 small Caribbean islands that are not known to ever have supported obligate brood parasites. We experimentally parasitized active nests within the stronghold of the species' distribution in Saint Lucia and found that White-breasted Thrashers rejected 83% of mimetic Shiny Cowbird (Molothrus bonariensis) eggs (i.e., wooden eggs painted to look like Shiny Cowbird eggs) within 5 d of being parasitized. Rejection of mimetic eggs was not associated with nest initiation date, distance to habitat edge or agricultural area, nest-attempt number, or presence of helpers or dependent young. We conclude that White-breasted Thrashers can detect foreign eggs and possess behavioral adaptations to counter brood parasitism, and propose that these anti-parasitism traits are likely retained from ancestors that evolved in the presence of brood parasites. Our results suggest that brood parasitism by Shiny Cowbirds is unlikely to become a major threat to the White-breasted Thrasher in Saint Lucia. However, ongoing anthropogenic land alteration is likely to increase contact between the 2 species, warranting continued monitoring of their nascent relationship.

Indirect predator cues have been shown to enhance perceived nest predation risk in both open-cup and cavity-nesting birds. We hypothesized that scent from the raccoon (Procyon lotor) inside nest boxes, supplemented with raccoon hair as a visual cue on the outside of the box, would enhance perceived risk to the European Starling (Sturnus vulgaris), resulting in reduced use of treated nest boxes and negative effects on reproduction. The starling is recognized, outside its native range, as a competitor with indigenous cavity nesters and a pest species, and efforts to deter its nesting have generally been unsuccessful. Our objectives were to examine nest initiation, clutch development, and hatching success by starlings relative to 4 nest box treatments. Starlings selected from nest boxes treated with a novel visual cue at the entry hole, predator scent inside the nest box and supplemented with a predator visual cue at the entry hole, the predator visual cue, or a novel odor inside the box and supplemented with the novel visual cue at the entry hole (n = 120 boxes; n = 30 per treatment). Starlings established nest bowls in 65% of nest boxes (novel visual cue = 21 boxes, predator scent/predator visual cue = 19 boxes, predator visual cue = 17 boxes, novel odor/novel visual cue = 21 boxes); clutches (≥1 egg) were laid in 80 boxes, but 2 boxes contained a single egg with no nest. We observed no effects of treatment on likelihood of starlings laying a clutch, date of first egg, clutch size, or hatchling number. We conclude that raccoon scent inside nest boxes, supplemented by raccoon hair as a visual cue, failed to enhance perceived risk to starlings such that nesting was deterred. We suggest that direct or indirect experience with nest predation attempts (which enhance perceived risk) and the starling's plasticity in antipredator responses are key hurdles in development of an efficacious nesting deterrent. Therefore, we encourage the evaluation of direct predation risk via use of predator effigies on or in nest boxes, as well as in foraging areas proximate to nest boxes.

Life history theory in ornithology has been mostly based on temperate birds in part because a relative paucity of biological data has been described for tropical species. Expanding our knowledge about life histories of tropical birds can help us to better understand global trends in life history strategies. To aid in this endeavor, we studied Mountain Wren-Babblers (Gypsophila crassus) breeding in Malaysian Borneo from 2009 to 2017. Relatively small (mean = 28.8 g), dark brown birds, they were cooperative breeders and foraged and cared for the nest in groups of typically 4 or 5 birds. We located 145 nests, which were globular and partially domed (91.8 mm mean opening height accounted for half of 180.7 mm total mean nest height), constructed from fern fronds on the outside and dead leaves on the inside, and most often placed on banks. Brooding attentiveness decreased with nestling age and was rare after day 7 once they began growing their primary feathers. Provisioning rate slightly increased with nestling age. Nestling growth rate constants were typical of many tropical birds, asymptoting a few days prior to fledging. Predation accounted for nearly all nest failures (87 of 88), with a daily nest predation rate for the total nesting period of 0.056 and nest success decreasing with elevation. Daily predation rate was highest during lay (0.117) and lowest during incubation (0.046). We compared these results with related species to identify potential explanations for the trends we described. The most notable result from these comparisons was that Mountain Wren-Babblers have a long incubation period (23.5 d) and adults only incubate for a small part of the day. This anomalous behavior emphasizes the importance of understanding the great variation in tropical life history strategies to ultimately improve life history theory.

We studied the nesting ecology of White-faced Ibis (Plegadis chihi) at 3 sites within the Bear River Migratory Bird Refuge, Great Salt Lake, Utah, USA. Ibises built nests in small mounds (mean height = 14.4 ± 4.3 cm) above shallow water (mean depth = 12.0 ± 6.6 cm) located within patchy vegetation (mean percent vegetative cover = 17.2 ± 17.8% vegetative cover) with mean vegetation height of 31.7 ± 9.8 cm. White-faced Ibis typically laid a clutch of 3 or 4 eggs (mean clutch size = 3.08 ± 0.76) and initiated nests over a 50 d period between 24 April 2012 and 12 June 2012. Mean nest success was 38% (95% CI: 31–45%) and hatching success of eggs from successful nests was 76 ± 26%. Although most of the breeding parameters estimated for White-faced Ibis nesting in Utah were comparable to other populations in Oregon and Idaho (USA), nest success may now be lower than has been historically documented.

Some mature-forest bird species use early-successional habitat to a great extent during the breeding season, but the specific drivers behind this habitat association remain poorly understood. In this study we identified important species-specific ecological factors contributing to early-successional site-use by mature-forest bird species during the breeding season. From 2015 to 2017, we used constant-effort mist-netting to survey breeding birds in six 7 to 9 year-old regenerating forest clearcuts in southern Indiana, and characterized early-successional habitat associations of the 6 most-frequently captured mature-forest bird species (Worm-eating Warbler [Helmitheros vermivorum], Ovenbird [Seiurus aurocapilla], Scarlet Tanager [Piranga olivacea], Wood Thrush [Hylocichla mustelina], Black-and-white Warbler [Mniotilta varia], and Red-eyed Vireo [Vireo olivaceus]). We collected detailed environmental covariate data to account for variation in food availability and habitat structure variables corresponding to each 10 d sampling period at the clearcut-site scale. We fit separate generalized linear mixed models, using a negative binomial error structure, for each of the 6 focal bird species captured within clearcuts. Both habitat structure and food availability variables were important predictors of site use for mature-forest birds in early-successional habitat. Vegetation density was included in best-fit models for 5 of the 6 mature-forest species. Fruit availability was included in best-fit models explaining Scarlet Tanager and Wood Thrush captures, and invertebrate dry mass was included in best-fit models for Worm-eating Warbler, Ovenbird, and Black-and-white Warbler. The varying importance of both habitat structure and food availability variables for multiple mature-forest bird species suggests that the factors influencing the use of early-successional habitat by mature-forest birds during the breeding season may differ among species.

Most migratory birds, particularly passerines or songbirds, migrate at night. However, diurnal migration has many benefits, including the ability to use a fly-and-forage migration strategy that allows an individual to refuel while migrating. Despite these benefits, very little research has been undertaken on diurnal migrants, including aerial foragers, who can refuel on the wing. In this study, we use the Motus Wildlife Tracking System to examine the timing of Bank Swallow (Riparia riparia), Barn Swallow (Hirundo rustica), Cliff Swallow (Petrochelidon pyrrhonota), and Tree Swallow (Tachycineta bicolor) movements during fall migration. Using these data, we confirm the “common knowledge” that these species of aerial foragers are diurnal migrants. During fall migration, 88.2% detections across all species were during the day, and the remaining detections were during civil twilight (range of sun elevation angles: –5.4° to 0°). Most of the detections during the day were consistent with migratory movement, and most detections during civil twilight were consistent with movements to and from communal roosts. Collectively, these results indicate that during fall migration, these 4 swallow species migrate during the day and, like other aerial foragers, may use a fly-and-forage migration strategy.

The Indian subcontinent is the primary wintering ground and stopover site for migratory shorebirds to refuel along the Central Asian and South Asian Flyways. Despite the conservation importance of this region for migratory shorebirds, we lack information on the distribution and abundance of over-summering shorebirds—migrants that remain on their wintering grounds during the breeding season—to evaluate the impacts of anthropogenic change on this poorly understood life history strategy. We conducted weekly surveys of over-summering shorebirds at mudflats, mangroves, and sand beaches at the Kadalundi-Vallikkunnu Community Reserve on the southwest coast of India, 2005–2018. We examined long-term patterns of over-summering shorebird abundance, species composition, and habitat use and estimated proportional changes in over-summering abundance of each shorebird species documented at this globally important site. Over the 14 yr study, we documented 7 over-summering species, including Lesser Sand Plover (Charadrius mongolus), Whimbrel (Numenius phaeopus), Greater Sand Plover (Charadrius leschenaultia), Kentish Plover (Charadrius alexandrinus), Common Sandpiper (Actitis hypoleucos), Ruddy Turnstone (Arenaria interpres), and Pacific Golden-Plover (Pluvialis fulva). Mean abundance and species richness were higher at mudflats than at mangroves and sand beaches, with fewer individuals and species observed over-summering after 2010. Mudflats also had the highest species diversity and evenness compared to mangroves and sand beaches. Management plans that aim to restore vulnerable mudflats and mangroves and to reduce anthropogenic threats such as sand mining and waste dumping are needed to prevent the loss of important over-summering, foraging habitat for migratory shorebirds in southern India and along the Central Asian and South Asian Flyways.

One of the causes of nest failure in woodpeckers is competition for nest sites among cavity-nesting bird species, expressed through aggressive interactions. Here I report a case of mortal aggression by an adult White-fronted Woodpecker (Melanerpes cactorum) toward nestlings of the White-barred Piculet (Picumnus cirratus), presumably caused by interference competition, in the dry Chaco woodlands of northwestern Argentina. The woodpecker killed 2 piculet nestlings but did not consume or remove them to feed its own nestlings. The attack could have been motivated by territorial defense, and to reduce competition for nest sites, since the piculet nest was within the territory of the woodpecker, and near its active nest and one of its most consumed sap trees. The observations described here provide new ethological information about the levels of aggression of the White-fronted Woodpecker, and suggests that interspecific competition likely could constitute one of the causes of nest failure among Neotropical woodpeckers.

The breeding range of the Common Eider (Somateria mollissima dresseri) has been expanded south of its traditional range through the use of transplanted birds. Originally introduced to one coastal island in southeastern Massachusetts in the 1970s, eiders spread out to other islands and now ≥870 eiders nest on more than 20 islands along the Massachusetts coastline from Cape Ann to Boston Harbor to Buzzards Bay and may be further spreading south.

The Snail Kite (Rostrhamus sociabilis plumbeus) is a wetland-dependent raptor that feeds primarily on aquatic apple snails (Pomacea sp.). In the United States, Snail Kites are endangered and breed exclusively in south and central Florida. Here we report that in 2018 and 2019, Snail Kites bred approximately 175 km north-northwest of the current northernmost breeding range. We combine historical and present information to interpret this new breeding event. Breeding occurred at Payne's Prairie Preserve State Park, an isolated wetland in Alachua County, Florida, USA, that was impacted in 2017 by high water levels due to Hurricane Irma and invasion of exotic apple snails (P. maculata). Counts of Snail Kites within the area rose steadily throughout 2018 and 2019 from 1 to a high of 84 individuals. We discovered 3 nests with eggs or chicks in 2018, and 75 nests in 2019, with nest success rates of 100% and 40%, respectively. To our knowledge, sightings within the county from 1968 to 2017 occurred on only 7 occasions, and nesting was observed only once, in 1919. From 2005 to 2019, the extent of Snail Kite breeding in counties across Florida was greater than previous years. However, long-term range expansion may depend on maintenance of wetland conditions as well as a number of factors including snail availability, drought, hydrology, predation, and temperature.

Behavioral plasticity can drive feeding innovations, a frequent trait of urban exploiter species. The House Sparrow (Passer domesticus) is a widespread and abundant urban dweller whose success has often been related to its dietary breadth. Although both formal and informal sources (e.g., internet videos, news, and blogs) have shown meat scavenging behaviors of this sparrow, it has been overlooked in the literature. While it is recognized that this sparrow has a diverse diet in urban settings, quantitative sources report only 3 types of foods (i.e., seeds, plant origin, and invertebrates). Our field observation of a female House Sparrow feeding on a chicken “drumstick” (presumably fibula/tibia) leftover at a greenspace of Manhattan (i.e., High Line), USA, adds to the available formal and informal information regarding the opportunistic scavenging of dressed and cooked meat by these sparrows when available. Thus, our observation adds to the feeding plasticity knowledge of this urban-related invasive bird and suggests the importance of the role of pedestrians in molding House Sparrow diet.

Despite a long history of biological exploration, there remains much to learn about the avifauna of the Solomon Islands. Here, we report new records of the Blue-faced Parrotfinch (Erythrura trichroa) on Malaita and Makira islands, thus expanding the known distribution of the species in the geographic Solomon Islands to include Bougainville, Kolombangara, Guadalcanal, Malaita, and Makira islands. Morphometric comparison of specimens from these populations showed no consistent differences in plumage or measurements, although sample sizes were small for all populations (n = 1–2 comparable specimens from 3 populations). Likewise, mitochondrial DNA sequence data showed little genetic differentiation among these populations. Our results suggest that the Blue-faced Parrotfinch exhibits some of the lowest interpopulation divergence of any montane bird species in the Solomon Islands and provides useful comparison to biogeographic patterns in other bird populations that share a similar distribution across multiple Pleistocene islands. Our discovery of 2 new populations of Blue-faced Parrotfinches highlights the need for continued biodiversity work in the region for both conservation and research.

Interspecific nest usurpation, a relatively common nesting strategy, is the act of one bird species taking over the nesting site of another species. Although used by secondary cavity-nesters, nest usurpation has never been reported for the Tufted Titmouse (Baeolophus bicolor). In this paper, we document a mixed brood successfully reared by Tufted Titmice after usurpation of an Eastern Bluebird (Sialia sialis) nest in northeastern Arkansas during the 2019 breeding season. We monitored the focal nest box every 3–4 d from the first sign of nest building on 23 March 2019 until chick fledging by 12 May 2019. The Tufted Titmice took over the nest at the time the Eastern Bluebird had laid its fourth egg in the nest. By the end of the nesting period, the Tufted Titmice fledged 2 of their own chicks and 3 Eastern Bluebird chicks. Such successful rearing of non-conspecific nestlings is rare and we discuss factors that may have allowed it.

Avian brood parasites can be classified as either obligate or facultative. Obligate brood parasites, such as Brown-headed Cowbirds (Molothrus ater), must lay their eggs in the nests of other species because they exhibit no parental care. Although facultative brood parasitism, when species that would normally lay eggs in their own nests dump eggs in the nest of another individual, may occur frequently among conspecifics, facultative interspecific brood parasitism is relatively rare. Here I report on observations made during the breeding season of 2018 of an example of facultative brood parasitism by an American Robin (Turdus migratorius) in the nest of a Gray Catbird (Dumetella carolinensis). Two robin eggs were laid in the nest of the catbird and were successfully raised by the catbird to fledging age. Although the young of obligate brood parasitic cowbirds are rarely raised successfully by catbirds, this is the first documented example, of which I am aware, of a Gray Catbird successfully raising the young of a facultative brood parasite.

Only 2 of Alexander Wilson's (1766–1813) study skins are known to exist in modern collections with data confirming their provenance. Both are type specimens, preserved at the Academy of Natural Sciences of Drexel University (ANSP), and are among the most precious artifacts of American science. In 2018, I discovered a third Wilson type in the ANSP collection with a note from John Cassin (1813–1869) confirming its provenance. This paper describes the discovery and rediscovery of the type specimen of Wilson's “variety of the Black Hawk” (Falco niger), overlooked by ornithologists and historians for more than 150 yr. Nomenclature is unaffected because F. niger Wilson is a synonym of Buteo lagopus (Pontoppidan 1763), the Rough-legged Hawk.