Petrochelidon Pyrrhonota Research Articles

Migratory track from the United States breeding population of Cliff Swallows (Petrochelidon pyrrhonota) and effects of geolocators on annual survival

Migratory track from the United States breeding population of Cliff Swallows (Petrochelidon pyrrhonota) and effects of geolocators on annual survival

Pathogen Surveillance in Swallows (family Hirundinidae): Investigation into Role as Avian Influenza Vector in Eastern Canada Agricultural Landscapes.

First detected in Atlantic Canada in December 2021, highly pathogenic avian influenza virus (HPAIV) subtype H5N1 clade 2.3.4.4b, A/Goose/Guangdong/1/96 lineage, has caused massive mortality in wild birds and domestic poultry in North America. Swallows (Hirundinidae), abundant in North American agricultural ecosystems, have been proposed as possible (bridge) species for HPAIV transmission between wild and domestic birds. We aimed to seek evidence of the potential role of swallows in bridging AIV infection between wild bird reservoirs and poultry flocks in eastern Canada. During a wide-scale outbreak of HPAIV in wild birds and poultry farms across eastern Canada, 200 samples were collected from swallow breeding sites in the Canadian provinces of New Brunswick, Nova Scotia, Ontario, and Quebec, June-August 2022. Samples came from Barn Swallow (Hirundo rustica; n=142), Tree Swallow (Tachycineta bicolor; n=56), and Cliff Swallow (Petrochelidon pyrrhonota; n=2) nests. All samples tested negative for AIV, suggesting that HPAIV and low pathogenic AIV (LPAIV) strains were probably not circulating widely in swallows during the 2022 breeding season in eastern Canada; thus swallows may present a low risk of transmitting AIV. Within a management context, these findings suggest that removing nests of Barn Swallows, a species at risk in Canada, from the exterior of biosecure domestic poultry facilities may not significantly reduce risks of HPAI transmission to poultry.

Social foraging and the associated benefits of group-living in Cliff Swallows decrease over 40 years.

Animals that feed socially can sometimes better locate prey, often by transferring information about food that is patchy, dense, and temporally and spatially unpredictable. Information transfer is a potential benefit of living in breeding colonies where unsuccessful foragers can more readily locate successful ones and thereby improve feeding efficiency. Most studies on social foraging have been short-term, and how long-term environmental change affects both foraging strategies and the associated benefits of coloniality is generally unknown. In the colonial Cliff Swallow (Petrochelidon pyrrhonota), we examined how social foraging, information transfer, and feeding ecology changed over a 40-year period in western Nebraska. Relative to the 1980's, Cliff Swallows in 2016-2022 were more likely to forage solitarily or in smaller groups, spent less time foraging, were more successful as solitaries, fed in more variable locations, and engaged less in information transfer at the colony site. The total mass of insects brought back to nestlings per parental visit declined over the study. The diversity of insect families captured increased over time, and some insect taxa dropped out of the diet, although the three most common insect families remained the same among the decades. Nestling Cliff Swallow body mass at 10 days of age and the number of nestlings surviving per nest declined more sharply with colony size in 2015-2022 than in 1984-1991 at sites where the confounding effects of ectoparasites were removed. Adult body mass during provisioning of nestlings was lower in more recent years, but the change did not vary with colony size. The reason(s) for the reduction in social foraging and information transfer over time are unclear, but the consequence is that colonial nesting may no longer offer the same fitness advantages for Cliff Swallows as in the 1980's. The results illustrate flexibility of foraging behavior and dynamic shifts in the potential selective pressures for group-living.

Multi-isotope (δ2H, δ13C, δ15N) feather profiles and morphometrics inform patterns of migratory connectivity in three species of North American swallows

Aerial insectivorous birds have suffered steep population declines in North America over the last 60 years. A lack of information on migratory connectivity between breeding and non-breeding grounds for these species limits our ability to interpret factors affecting their population-specific trends. We determined likely Latin American non-breeding regions of Bank (Riparia riparia), Barn (Hirundo rustica) and Cliff (Petrochelidon pyrrhonota) swallow from populations across their breeding ranges. We used predicted feather hydrogen (δ2Hf) and carbon (δ13Cf) isoscapes for winter-grown feathers to indicate areas of highest probability of moult origin and incorporated these results into a cluster analysis to determine likely broad non-breeding regions. We also assessed variation in wing length among populations to determine the potential for this metric to differentiate population moult origins. We then investigated patterns of multi-isotopic (δ2Hf, δ13Cf, δ15Nf) and wing-length niche occupancy by quantifying niche size and overlap among populations under the assumption that broad niches were consistent with low within-species migratory connectivity and narrow and non-overlapping niches with higher connectivity. Multivariate assignment identified different non-breeding regions and potential clusters of moult origin generally corresponding to Central America and northern South America, eastern and south-central South America, and the western and southern part of that continent, with variation within and among populations and species. Separate niche space indicated different wintering habitat or areas used by species or populations whereas niche overlap indicated only potential spatial similarity. Wing length varied significantly among populations by species, being longer in the west and north for Bank and Cliff Swallow and longer in eastern Canadian Barn Swallow populations. Barn Swallow occupied consistently larger isotopic and wing length niche space than the other species. Comparisons among populations across species showed variable isotopic and wing-length niche overlap generally being greater within breeding regions and lower between western and eastern breeding populations supporting a general North American continental divide for all species with generally low migratory connectivity for all species. We present a novel approach to assessing connectivity using inexpensive and broad isotopic approaches that provides the basis for hypothesis testing using more spatially explicit expensive techniques.

Relationships between environmental stressors and Cliff Swallow (Petrochelidon pyrrhonota) feather coloration and colony size

Cliff Swallows (Petrochelidon pyrrhonota) are aerial insectivores that experience mortality from vehicle collisions because they often nest and hunt under bridges and road culverts. Individual traits that may convey social information, such as body condition, or feather reflectance, may be associated with better coping around cars and other environmental stressors. Cliff swallow colony size may also be affected by environmental stressors. Our objective is to determine if proximity to roads and water level near the colony were related to wing length, body condition, colony size, and feather coloration in Cliff Swallows. We will do this by taking feather samples and measuring reflectance, and taking other body condition measurements, in addition to measuring colonies’ proximity to roads and level of water near the colonies’ locations.

Annual adult survival rates for four sympatric breeding swallow species: effects of environmental factors and density-dependence

Swallow (Family: Hirundinidae) populations in the Canadian Maritimes have declined since the 1980s. Using mark–recapture data from 2012 to 2019, we determined apparent annual adult survival rates for Barn ( Hirundo rustica Linnaeus, 1758), Tree ( Tachycineta bicolor (Vieillot, 1808)), Bank ( Riparia riparia (Linnaeus, 1758)), and Cliff ( Petrochelidon pyrrhonota (Vieillot, 1817)) swallows. For two data-rich species (Barn and Tree swallows), we modelled the relationships between survival and weather (cold snaps, precipitation, temperature, and wind speed), climate (El Niño–Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO)), Enhanced Vegetation Index (EVI) as a measure of primary productivity during the winter, number of active nests as a measure of site quality, and the Breeding Bird Survey (BBS) annual population index as density-dependent processes. Survival rates for all four species were typically higher (Barn and Tree) or similar to (Cliff and Bank) of estimates from populations that have not undergone severe, long-term declines. Across weather and climate variables, conditions that are typically favourable for high insect availability (e.g., higher precipitation, warmer temperatures, and lower wind speeds) resulted in higher survival. For female Barn and Tree swallows, survival was higher when EVI was lower, and for Barn Swallows, survival was also higher when the BBS index was higher. Collectively our results demonstrate that conditions throughout the annual cycle affect survival, and the relationships with weather and climate variables support the importance of high insect availability.

Elevated Temperature Reduces Overwintering Survival of an Avian Ectoparasite, the Swallow Bug (Hemiptera: Cimicidae: Cimex vicarius).

The survival of insects that are dormant in winter may either increase or decrease as a consequence of elevated winter temperatures under climate change. Warming can be deleterious when metabolism of the overwintering life stages increases to the point that energy reserves are exhausted before postoverwintering reemergence. We examined experimentally how overwintering survival of swallow bugs (Hemiptera: Cimicidae: Cimex vicarius Horvath), an ectoparasite primarily of cliff swallows (Passeriformes: Hirundinidae: Petrochelidon pyrrhonota Vieillot), was affected by a 3°C rise in mean daily temperature for populations in Oklahoma, Nebraska, and North Dakota. Adult and nymphal swallow bugs exposed to elevated temperature had an average reduction of approximately 31% in overwintering survival (from July/August to April/May), relative to controls exposed to current region-specific ambient-like conditions. Adult males in both groups survived less well in Nebraska and North Dakota than adult males in Oklahoma, but there was no consistent latitudinal effect of the elevated heat treatment. Our results indicate that projected increases in mean temperature in the Great Plains by 2050 could result in fewer swallow bugs surviving the winter and thus a reduced population size upon the arrival of their primary host in the spring, potentially affecting cliff swallow reproductive success, site use, and breeding phenology. Global climate change may alter the dynamics of host-parasite systems by reducing overall parasite abundance.

Birds of a Feather Flock Together: Extent of Long-Term Consistency of Colony-Size Choice in Cliff Swallows

Explaining why animal groups vary in size is a fundamental problem in behavioral ecology. One hypothesis is that life-history differences among individuals lead to sorting of phenotypes into groups of different sizes where each individual does best. This hypothesis predicts that individuals should be relatively consistent in their use of particular group sizes across time. Little is known about whether animals’ choice of group size is repeatable across their lives, especially in long-lived species. We studied consistency in choice of breeding-colony size in colonially nesting cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, United States, over a 32-year period, following 6,296 birds for at least four breeding seasons. Formal repeatability of size choice for the population was about 0.41. About 45% of individuals were relatively consistent in choice of colony size, while about 40% varied widely in the colony size they occupied. Birds using the smaller and larger colonies appeared more consistent in size use than birds occupying more intermediate sized colonies. Consistency in colony size was also influenced by whether a bird used the same physical colony site each year and whether the site had been fumigated to remove ectoparasites. The difference between the final and initial colony sizes for an individual, a measure of the net change in its colony size over its life, did not significantly depart from 0 for the dataset as a whole. However, different year-cohorts did show significant net change in colony size, both positive and negative, that may have reflected fluctuating selection on colony size among years based on climatic conditions. The results support phenotypic sorting as an explanation for group size variation, although cliff swallows also likely use past experience at a given site and the extent of ectoparasitism to select breeding colonies.

Change in beak overhangs of cliff swallows over 40 years: Partly a response to parasites?

Some birds exhibit a maxillary overhang, in which the tip of the upper beak projects beyond the lower mandible and may curve downward. The overhang is thought to help control ectoparasites on the feathers. Little is known about the extent to which the maxillary overhang varies spatially or temporally within populations of the same species. The colonial cliff swallow (Petrochelidon pyrrhonota) has relatively recently shifted to almost exclusive use of artificial structures such as bridges and highway culverts for nesting and consequently has been exposed to higher levels of parasitism than on its ancestral cliff nesting sites. We examined whether increased ectoparasitism may have favored recent changes in the extent of the maxillary overhang. Using a specimen collection of cliff swallows from western Nebraska, USA, spanning 40 years and field data on live birds, we found that the extent of the maxillary overhang increased across years in a nonlinear way, peaking in the late 2000’s, and varied inversely with cliff swallow colony size for unknown reasons. The number of fleas on nestling cliff swallows declined in general over this period. Those birds with perceptible overhangs had fewer swallow bugs on the outside of their nest, but they did not have higher nesting success than birds with no overhangs. The intraspecific variation in the maxillary overhang in cliff swallows was partly consistent with it having a functional role in combatting ectoparasites. The temporal increase in the extent of the overhang may be a response by cliff swallows to their relatively recent increased exposure to parasitism. Our results demonstrate that this avian morphological trait can change rapidly over time.

Effects of turbine height and cut-in speed on bat and swallow fatalities at wind energy facilities

Understanding the relationship between the height of wind turbines and wildlife fatalities is important for informing and mitigating wildlife collisions as ever taller and denser arrays of wind turbines are erected across the landscape. We examined relationships between turbine height and fatalities of bats and swallows at 811 turbines in Ontario, Canada, ranging from 119 to 186 m tall. We accounted for cut-in speeds, operational mitigation, and taller turbines projecting carcasses farther from the turbine base than shorter turbines. Fatalities of hoary bats ( Lasiurus cinereus Palisot de Beauvois, 1796), silver-haired bats ( Lasionycteris noctivagans Le Conte, 1831), and big brown bats ( Eptesicus fuscus Palisot de Beauvois, 1796) increased with increased maximum blade height of turbines. In contrast, fatalities of little brown bat ( Myotis lucifugus Le Conte, 1831) and eastern red bat ( Lasiurus borealis Müller, 1776) decreased with increased turbine height. Fatalities of purple martins ( Progne subis Linnaeus, 1758) and tree swallows ( Tachycineta bicolor Vieillot, 1808) were higher at taller turbines than shorter turbines. However, fatalities of cliff swallow ( Petrochelidon pyrrhonota Vieillot, 1817) and barn swallow ( Hirundo rustica Linnaeus, 1758) were not associated with turbine height. Our results suggest that varying flight height among species may be one factor affecting collision risk.

Endogenous biomarkers reveal diet partitioning among three sympatric species of swallows

Abstract Since the early 1990s, aerial insectivorous birds have shown serious population declines in North America, but it is not clear if factors common to all species within this guild account for these declines. Among sympatric swallows, population trends differ, and this may be due to differences in ecology operating throughout the annual cycle. Although these species all feed on aerial insects, prey taxa can differ tremendously in their “aeroecology” and use by swallows. We examined the potential for dietary differences among three species of swallows, Barn Swallow (Hirundo rustica), Cliff Swallow (Petrochelidon pyrrhonota), and Tree Swallow (Tachycineta bicolor), breeding sympatrically in southern Ontario, Canada. Potential interspecific differences in nestling diet were examined using two endogenous biomarkers, DNA barcoding of nestling feces and stable isotope analysis (δ 2H, δ 13C, δ 15N) of nestling feathers. We found evidence for differences in dietary sources of provisioned young where Barn Swallows provisioned more terrestrial-based prey, Cliff Swallows provisioned an intermediate diet, and Tree Swallows the most aquatic-emergent insect diet. We suggest this information may help to identify potential factors contributing to differential declines of aerial insectivores operating on the breeding grounds, including diet quality.

DIPLOTRIAENA OBTUSA (NEMATODA: DIPLOTRIAENIDAE) FROM BARN SWALLOWS (HIRUNDO RUSTICA) AND CLIFF SWALLOWS (PETROCHELIDON PYRRHONOTA) COLLECTED DURING MORTALITY EVENTS IN THE UPPER MIDWEST, USA.

Several mortality events involving barn swallows (Hirundo rustica) and cliff swallows (Petrochelidon pyrrhonota) were reported in the Upper Midwestern states in 2017 and 2018. Barn swallow mortality followed unseasonal cold snaps, with the primary cause of death being emaciation with concurrent air sac nematodiasis. Lesions in cliff swallows were consistent with blunt force trauma from suspected car impacts. Examination of air sac nematodes from both bird species revealed morphological characters consistent with Diplotriaena obtusa. Sequence analysis of the partial 18S rRNA gene indicated the samples clustered with other species in the genus Diplotriaena. These nematodes provide a link between morphological specimens and DNA sequence data for D. obtusa.

Conservation Measures to Increase Breeding Success of Cliff Swallows (Petrochelidon pyrrhonota) in Massachusetts

Petrochelidon pyrrhonota (Cliff Swallow) is experiencing significant population declines in parts of its breeding range, particularly in northeastern North America. At 12 active Cliff Swallow colonies in western Massachusetts in 2019–2020, we examined the extent to which installation of artificial nests, providing of mud sources, and control of Passer domesticus (House Sparrow) affected colony size and reproductive success of Cliff Swallows. While there was a trend for colony size to increase at sites with artificial nests, there was not a significant size increase at these sites from 2019–2020. Cliff Swallow nesting success was significantly lower at colony sites where House Sparrows were present, compared to those at which they were absent. The number of nesting Cliff Swallows at 2 sites where mud sources were enhanced increased from 2019 to 2020. Efforts to control House Sparrows by shooting at 1 site were unsuccessful. Our study suggests that without effective control of House Sparrows, Cliff Swallows are likely to keep declining in Massachusetts, regardless of other management techniques used.

Rapid adjustments of migration and life history in hemisphere-switching cliff swallows

Many aspects of bird migration are necessarily innate.1 However, the extent of deterministic genetic control, environmental influence, and individual decision making in the control of migration remains unclear.2-8 Globally, few cases of rapid and dramatic life-history changes resulting in novel migration strategies are known. An example is latitudinal trans-hemispheric breeding colonization, whereby a subpopulation suddenly begins breeding on its non-breeding range.9-13 These life-history reversals demand concomitant changes in the timing of migration, feather molt, and breeding if the population is to remain viable.13 Cliff swallows, Petrochelidon pyrrhonota, are long-distance migrants that breed in North America and spend the non-breeding season mostly in South America.14 However, in 2015, a small population switched hemispheres by breeding successfully in Argentina,9 over 8,000km from the nearest potential source, after presumably failed attempts.15,16 This provided a unique chance to characterize the early mechanisms of change in migratory behavior and phenology and to assess the possibility of double breeding. We tracked cliff swallows with geolocators following their second and fourth breeding seasons in Argentina, documenting inverted seasonality, three new migratory patterns and non-breeding areas (North America, Mesoamerica, and South America), and a shift of molt phenology by approximately 6months, all possibly arising within a single generation. These birds did not practice migratory double breeding, although some spent the boreal summer in the traditional breeding range. Our data show that fundamental phenological changes occurred very rapidly during colonization and that phenotypic plasticity can underlie profound changes in the life histories of migratory birds.

The cost of ectoparasitism in Cliff Swallows declines over 35 years

AbstractHost–parasite dynamics often vary over time, brought about by changes in the parasite’s virulence or the host’s ability to resist or tolerate the parasite. Although virulence evolution in microparasites is well studied, we know little about temporal change in the pathogenicity of macroparasites such as blood‐feeding insects. Using data collected over 35 yr, we report a reduction in pathogenicity of the hematophagous swallow bug (Cimex vicarius) on its Cliff Swallow (Petrochelidon pyrrhonota) host. Relative to experimentally fumigated, parasite‐free nests, the negative effects of bugs on nestling swallow body mass and survival were less in the later years of the study than in the earlier years, and the negative relationship between nestling body mass and bug abundance became weaker over time. The survival of adult birds exposed to swallow bugs increased throughout the study, while survival of birds from parasite‐free nests decreased over time. Swallow bug abundance per nest, bug body size, and bug age ratios did not change during the study. Between‐colony transmission of bugs showed less immigration into larger colonies than in earlier studies, but there was no net change in transmission. Cliff Swallows did not reduce their exposure to bugs over time by being more likely to avoid infested nest or colony sites. Parents increased the number of food deliveries to their offspring over time in the presence of parasites, but the total amount of food delivered was unchanged. The reduced cost of swallow bug ectoparasitism does not seem related to changes in parasite narrow‐sense virulence, the host’s avoidance of parasites, the presence of alternative hosts for bugs, or climate‐driven phenological mismatches. The results probably reflect the Cliff Swallow’s evolving of greater tolerance to swallow bugs, brought about by the bird’s shift from natural cliff nesting sites to artificial structures that may harbor more bugs than natural cliffs. This study shows that hosts can respond relatively rapidly to high levels of parasitism, and provides support for models that suggest the evolution of tolerance should be expected in some host–parasite systems.

Human presence outweighs non-anthropogenic factors as a driver of avian nest parasite loads

Human presence and landscape change can alter many aspects of ecological communities and can interact with natural factors to change host–parasite dynamics. In the study reported here, we tested whether an anthropogenic factor, urbanization, affected the abundance and size of hematophagous ectoparasites (swallow bugs: Oeciacus vicarius) found in the nests of cliff swallows (Petrochelidon pyrrhonota). We also examined how swallow bug infestations might be affected by multiple non-anthropogenic biotic and abiotic factors, including season, nest mass, nest colony size, the history of colony occupation, and the presence of other parasitic and non-parasitic arthropods in cliff swallow nests. Our sample included 73 nests collected from 18 cliff swallow colonies in Northern Colorado, USA. Results indicated that swallow bug loads were most strongly predicted by human land use and density, with urban colonies having much heavier infestations than rural colonies. Swallow bugs were more numerous in colonies that were known to have been recently occupied by cliff swallows, and in nests that contained high numbers of other parasitic arthropods, including fleas and ticks. Swallow bug population size did not vary with season, nest mass, or nest colony size, and none of our measured factors predicted swallow bug body length. Results suggest that cities may exacerbate harmful effects of avian ectoparasites by promoting large population sizes, and that these effects may be compounded by the presence of multiple parasitic species in heavily infested nests.

Diurnal and crepuscular activity during fall migration for four species of aerial foragers

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.

Mercury exposure to swallows breeding in Canada inferred from feathers grown on breeding and non-breeding grounds.

Aerial insectivorous birds such as swallows have been the steepest declining groups of birds in North America over the last 50 years but whether such declines are linked to contaminants has not been examined. We sampled feathers from five species of swallow at multiple locations to assess total mercury [THg] exposure for adults during the non-breeding season, and for juveniles on the breeding grounds. We assessed Hg exposure to juvenile birds in crop- and grass-dominated landscapes to determine if land-use practices influenced feather [THg]. We assayed feathers for stable isotopes (δ2H, δ13C, δ15N) as proxies for relative habitat use and diet to determine their potential influence on feather [THg]. Feather [THg] was highest in adult bank swallows (Riparia riparia) and purple martins (Progne subis) from Saskatchewan and adult cliff swallows (Petrochelidon pyrrhonota) from western regions, indicating differential exposure to Hg on the non-breeding grounds. Juvenile bank, barn (Hirundo rustica) and tree (Tachycineta bicolor) swallows had lower feather [THg] in crop-dominated landscapes than grass-dominated landscapes in Saskatchewan, potentially resulting from lower use of wetland-derived insects due to wetland drainage and intensive agriculture. Feather [THg] was related to juvenile feather stable isotopes for several species, suggesting complex interactions with diet and environmental factors. Many individuals had feather [THg] values >2 µg/g, a threshold at which deleterious effects may occur. Our findings indicate differential Hg exposure among species of swallow, regions and land-uses and highlight the need for additional research to determine dietary and finer-scale land-use impacts on individual species and populations.

FOURTH REPORT OF THE COMMITTEE FOR ECUADORIAN RECORDS IN ORNITHOLOGY (CERO) AND A REVISION OF UNDOCUMENTED AND ERRONEOUS RECORDS IN LITERATURE

We present new distributional records of birds in Ecuador submitted to the Committee for Ecuadorian Records in Ornithology (CERO) from September 2015 through July 2017. This report includes four species new to Ecuador (Plegadis ridgwayi, Cathartes burrovianus, Malacoptila mystacalis, Vireo gilvus), two species new to Galapagos (Calidris pugnax, Larosterna inca), five species with first documented country records (Fregata minor, Syrigma sibilatrix, Calidris pugnax, Larus belcheri, Sternula antillarum), remarkable range extensions for eight species (Anas bahamensis, Fregata sp., Jabiru mycteria, Phimosus infuscatus, Caracara cheriway, Larus dominicanus, Chloroceryle aenea, Sturnella militaris), new records of eight rare species (Anhima cornuta, Mustelirallus albicollis, Larus argentatus, Larosterna inca, Myrmoborus lugubris, Machetornis rixosa, Progne elegans, Conirostrum bicolor) and new records of Nothoprocta curvirostris and Tyrannus tyrannus. We present the first Ecuadorian records of three subspecies (Tolmomyias sulphurescens insignis, Myiarchus swainsoni phaenotus, Oxyura jamaicensis andina, although the taxonomic validity of the latter is debated). Further we discuss the subspecific identity of Petrochelidon pyrrhonota in Ecuador. Finally, we invalidate previous records of 43 species for mainland Ecuador and 6 species for Galapagos, as published in different sources, and reject a remotesensing record of Cypseloides niger. CERO revises and updates the country bird list, which currently stands at 1690 species (1632 confirmed and documented; 58 undocumented).

Variation in neophobia among cliff swallows at different colonies.

Animal groups often represent nonrandom subsets of individuals, and increasing evidence indicates that individuals may sort among groups based on their personalities. The size of a group can predict its personality composition in some species due to differential suitability of a personality for groups of certain sizes, and the group itself may function more effectively if particular personality types are present. We quantified cliff swallow (Petrochelidon pyrrhonota) behavioral measures using linear and generalized linear mixed models to identify whether they: (1) varied among individuals within colonies and among colonies, (2) were related to reproductive success, and (3) predicted levels of parental care. Significant among-individual and among-colony site variation in a cliff swallow’s latency to enter its nest when presented with a novel stimulus was revealed. We also found significant among-individual variation in the number of attacks directed toward a novel stimulus at the nest and in the response to broadcast of a cliff swallow alarm call recording, but among site variation in these measures was not significant. We did not find evidence for behavioral syndromes linking the personalities measured. Differences among individuals in latency to enter the nest and the number of attacks were not significantly related to reproductive success or to the extent to which birds fed their nestlings. However, extent of nestling feeding was significantly predicted by the number of mist net captures. The limited evidence in general of systematic variation in the behavior we measured among cliff swallow colonies may reflect the different and sometimes opposing selection pressures on behavior in different social environments. Future work should perhaps examine variation in other behavioral traits, such as foraging, in cliff swallow colonies of different sizes.