The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectopara... more The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectoparasitism. Although nestlings are typically considered the intended targets, recent work indicates that Philornis infest adult birds more frequently than previously appreciated, yet few studies have concurrently surveyed nestlings and adults for Philornis in the same population. Over six field seasons (2012–17), I documented the presence of current or recent subcutaneous Philornis infestations on adult and nestling Hispaniolan Woodpeckers Melanerpes striatus from the same population in the central Dominican Republic. I tested the following three non‐mutually exclusive hypotheses regarding the occurrence of Philornis on adult birds: (1) nestlings are more vulnerable to Philornis parasitism than adults, (2) nesting is associated with Philornis parasitism in adults, and (3) Philornis parasitism is associated with incubation and brooding investment. Although nestling and adult woodpeckers exhibited similar prevalence of parasitism, parasitized nestlings hosted on average 3.5 times more Philornis wounds (larvae plus empty wounds) than parasitized adults. Nesting per se was not significantly associated with parasitism among adults, as breeding and non‐breeding adults showed similar prevalence and intensity. However, nests with Philornis‐infested young were significantly more likely to have one or both parents also infested, in contrast to nests with infestation‐free young. Furthermore, adult males, which perform overnight incubation and brooding, were significantly more likely to be parasitized than adult females. This last result supports the hypothesis that incubation and brooding investment increase the risk of Philornis parasitism for adults, but this conclusion is complicated by the lack of an association between parasitism and nesting status. Together, these results raise questions about the degree of host life‐stage specialization and whether adult parasitism is incidental or part of an alternative parasitic strategy for Philornis.
Proceedings of the National Academy of Sciences of the United States of America, May 1, 2023
Referential signaling, a complex form of communication in which specific signals are associated w... more Referential signaling, a complex form of communication in which specific signals are associated with external referents, was once thought to be limited to primates. Recent research has documented referential signaling in several other cooperative taxa, predominantly in kin-based societies. Here, we show that greater anis, communally nesting birds that breed in nonkin groups, give one type of alarm call in response to aerial threats (flying raptors) and another to more general threats (nonaerial predators). Observational data show that anis give these calls in response to different classes of threats, and playback experiments in the field confirmed that the alarm calls alone are sufficient to elicit appropriate behavioral responses even in the absence of an actual threat. Genetic data on a subset of groups confirmed that breeding groups are composed of nonkin, suggesting that referential alarm calls are often given in situations when no genetic relatives are present. These results suggest that complex referential communication can occur in social groups composed of nonrelatives, despite the absence of kin-selected fitness benefits.
The ecological importance of avian myiasis caused by fly (Diptera) larvae, especially in the ge... more The ecological importance of avian myiasis caused by fly (Diptera) larvae, especially in the genus Philornis, remains poorly understood. One major gap in our knowledge is which bird species experience such parasitism. We present here the first report of Philornis parasitism on an adult Antillean Palm Swift (Tachornis phoenicobia) from the Dominican Republic, representing the first documented record of Philornis parasitism of a swift species (Apodidae). The host bird was found dead shortly after being observed alive with clear evidence of myiasis, and we suggest the bird’s death was due to the detected fly larvae. We also propose that this parasite-associated adult mortality implicates Philornis as another potential factor contributing to observed aerial insectivore declines, and highlights the pressing need for more comprehensive studies investigating the occurrence of parasitism in other Caribbean avian species. Keywords aerial insectivores, Antillean Palm Swift, Philornis, Sier...
Avian social and genetic mating systems are influenced by parental care roles as well as by repro... more Avian social and genetic mating systems are influenced by parental care roles as well as by reproductive opportunities. Alternative reproductive tactics, including conspecific brood parasitism and extra-pair mating, are predicted to be most common when females have access to potential host nests and when adults have access to potential mating partners, respectively. We tested these predictions in the facultatively colonial Hispaniolan woodpecker (Melanerpes striatus), a socially monogamous species with biparental care. Up to 12 pairs may nest concurrently in the same tree or, less frequently, two adjacent trees, potentially facilitating both conspecific brood parasitism and extra-pair mating. Contrary to our predictions, genotyping with single-nucleotide polymorphisms (SNPs) revealed no evidence of extra-pair paternity in either solitary or colonial nests: all 307 nestlings in 101 broods were matched to their social parents. Two instances of apparent conspecific brood parasitism were detected via changes in clutch size, but these could not be confirmed genetically since none of the apparently parasitic eggs survived to hatching. Therefore, if conspecific brood parasitism did occur, it was not a successful route to reproduction: parents fledged only their genetic offspring. These results suggest that reproductive opportunities alone are insufficient to favor alternative reproductive tactics, and that genetic monogamy can persist despite locally high densities of breeding pairs. Other life-history traits, including high levels of nest attendance and male parental care, may constrain parasitism and extra-pair mating in this long-lived tropical species. Significance statement High breeding density, a feature of colonial nesting, should increase opportunities for infidelity and conspecific brood parasitism because of the close proximity of potential extra-pair mates and parasitic females. Yet, we found that Hispaniolan woodpeckers, which nest both solitarily and colonially (two or more pairs in the same tree) in the same population, were genetically monogamous and lacked successful brood parasitism. Colonial nesting is exceptionally rare in the woodpecker family, which is also characterized by high investment in male parental care, including nocturnal incubation. The essential role of paternal care for successful reproduction in the Hispaniolan woodpecker might have selected against extra-pair mating and conspecific brood parasitism despite the apparent ample opportunities provided by nesting so close to others.
Explaining intra- and interspecific variation in sociality requires understanding the underlying ... more Explaining intra- and interspecific variation in sociality requires understanding the underlying ecological factors that promote or preclude grouping and the fitness consequences of group living. Colonial nesting, the dense concentration of individuals during breeding, offers an excellent opportunity for testing hypotheses to explain sociality and its variation. I studied the Hispaniolan Woodpecker (Melanerpes striatus), a facultative colonial breeder, in the Dominican Republic with the following goals, corresponding to the three chapters of this dissertation: (1) identify the ecological resources that explain colony size variation; (2) test for the effects of colony size on reproductive success with the goal of distinguishing the hypotheses of grouping for socially derived benefits from aggregations that form due to the spatiotemporal clustering of resources; and (3) determine whether coloniality impacts the genetic mating system by increasing the incidence of conspecific brood parasitism and extra-pair paternity. In Chapter 1, I show that Hispaniolan Woodpecker colony size is explained in part by the number of cavities on a tree and a nesting tree’s status: dead Roystonea palms hosted larger colonies than live palms. Dead palms were relatively rare on the landscape but were potentially higher quality because they were easier to excavate and immune to nest loss via cavity flooding. In Chapter 2, I show that, per nesting attempt, clutch size, hatching success, partial brood loss, and the number of fledglings produced were unrelated to colony size. However, nesting success, fledging one or more young vs. complete failure, was positively associated with colony size. Additionally, annual nesting success and annual fledging success were not associated with colony size. In Chapter 3, I show that Hispaniolan Woodpeckers were socially and genetically monogamous. Conspecific brood parasitism, though not detected genetically, was suspected in three nests based on aberrant changes in clutch size. Together, these chapters suggest that resource availability (dead trees and old cavities) likely promotes coloniality while there are minimal costs and very modest (if any) benefits of sociality for the Hispaniolan Woodpecker
Proceedings of the National Academy of Sciences, 2023
Referential signaling, a complex form of communication in which specific signals are associated w... more Referential signaling, a complex form of communication in which specific signals are associated with external referents, was once thought to be limited to primates. Recent research has documented referential signaling in several other cooperative taxa, predominantly in kin-based societies. Here, we show that greater anis, communally nesting birds that breed in nonkin groups, give one type of alarm call in response to aerial threats (flying raptors) and another to more general threats (nonaerial predators). Observational data show that anis give these calls in response to different classes of threats, and playback experiments in the field confirmed that the alarm calls alone are sufficient to elicit appropriate behavioral responses even in the absence of an actual threat. Genetic data on a subset of groups confirmed that breeding groups are composed of nonkin, suggesting that referential alarm calls are often given in situations when no genetic relatives are present. These results suggest that complex referential communication can occur in social groups composed of nonrelatives, despite the absence of kin-selected fitness benefits.
En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Mel... more En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Melanoptila glabrirostris, algunas de ellas descritas por primera vez. El dzibabán es un mímido tropical endémico de la península de Yucatán muy poco estudiado. El estudio lo realizamos en la costa norte de la Reserva de la Biosfera de Sian Ka’an, México, entre febrero y agosto de 2008. Presentamos medidas de culmen, tarso y masa corporal. Proponemos un método de sexado válido durante la temporada no reproductiva, ya que los machos presentaron longitud de cuerda alar mayor que las hembras. La coloración del ojo puede ser un criterio suplementario para determinar la edad, puesto que los individuos de segundo año presentaron frecuentemente coloración ocular marrón, similar a los individuos de primer año. La temporada reproductiva inicia en abril y termina a mediados de agosto. El ciclo del nido es de 27 y 32 días y el tamaño de nidada es de dos a tres huevos. El macho construye la mayor part...
We report the first definitive Mexican breeding records of the range-restricted Yucatan Vireo (Vi... more We report the first definitive Mexican breeding records of the range-restricted Yucatan Vireo (Vireo magister). We discovered two V. magister nests in July and August 2009 in Sian Ka’an Biosphere Reserve (near Tulum) and one nest on Isla Cozumel in June 2009. We observed two possible additional V. magister nests with eggs in Sian Ka’an in 2009, one each in June and July. All nests were open cups woven onto branches and hung beneath forks. Clutch size was two eggs at definitive V. magister nests. Nests and eggs were similar to those of most Vireo spp., including sympatric nesting congeners. Breeding activities—including egg-laying, incubation, and nestling and post-fledging provisioning—at definite Yucatan Vireo nests occurred in June and July on Cozumel and July and August on the mainland. Incubation and nestling stages lasted ~ 15 days and ~ 14 days, respectively. Yucatan Vireo remains poorly known, warranting further study.
The Yucatan Vireo (Vireo magister) is a poorly known, range-restricted species with two recognize... more The Yucatan Vireo (Vireo magister) is a poorly known, range-restricted species with two recognized subspecies: magister and caymanensis. We report nesting observations of the Yucatan Vireo from continental Mexico and Isla Cozumel, representing the first definitive nesting records for V. m. magister. We discovered two nests in July and August 2009 in Sian Ka'an Biosphere Reserve (near Tulum) and one nest on Isla Cozumel in June 2009. All nests were open cups woven onto branches and hung beneath forks, and clutch size was t wo eggs. Nests and eggs were similar to those of most Vireo spp., including sympatric nesting congeners. Breeding activities-including egg-laying, incubation, and nestling and post-fledging provisioning-occurred during June and July in Cozumel and in July and August on the mainland. Incubation and nestling stages lasted c. 15 days and c. 14 days, respectively. We advocate for more work on V. m. magister because it might warrant full species recognition. Resumen • Anidamiento del Vireo magister en México continental y en la Isla Cozumel, con notas sobre la fenología reproductiva El vireo de Yucatán (Vireo magister) es una especie poco conocida y de distribución restringida con dos subespecies reconocidas: magister y caymanensis. Reportamos observaciones de anidación del vireo de Yucatán en México continental y en la Isla Cozumel, los primeros registros inequívocos del anidamiento del V. m. magister. Descubrimos dos nidos en julio y agosto de 2009 en la Reserva de Biósfera Sian Ka'an (Tulum) y un nido en Isla Cozumel en junio de 2009. Todos los nidos eran copas abiertas tejidas en ramas debajo de horquetas y el tamaño de la puesta fue de dos huevos. Los nidos y huevos fueron similares a los de la mayoría de otras especies de Vireo, incluidas las especies congenéricas simpátricas. Las actividades de reproducción (incluida la puesta de huevos, la incubación y el aprovisionamiento de polluelos posterior al emplumamiento) ocurrieron durante junio y julio en Cozumel, y en julio y agosto en continente. La duración de las etapas de incubación y cría fueron de c. 15 días y c. 14 días, respectivamente. Recomendamos estudios adicionales de V. m. magister porque tal vez deba reconocerse cabalmente como especie.
The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectopara... more The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectoparasitism. While nestlings are typically considered the intended targets, recent work indicates that Philornis infest adult birds more frequently than previously appreciated, yet few studies have concurrently surveyed nestlings and adults for Philornis in the same population. Over six field seasons (2012–2017), I documented the presence of current or recent subcutaneous Philornis infestations on adult and nestling Hispaniolan Woodpeckers (Melanerpes striatus) from the same population. I tested the following three non-mutually exclusive hypotheses regarding occurrence of Philornis on adult birds: (1) nestlings are more vulnerable to Philornis parasitism than adults, (2) nesting is associated with Philornis parasitism in adults, and (3) Philornis parasitism is associated with incubation and brooding investment. While nestling and adult woodpeckers exhibited similar prevalence of parasitism, p...
I observed a group of 4 albino Dasypus novemcinctus (Nine-banded Armadillo) foraging in close pro... more I observed a group of 4 albino Dasypus novemcinctus (Nine-banded Armadillo) foraging in close proximity to one another on Isla Cozumel, Mexico, in July 2009. To my knowledge, this observation represents the first directly documented account of albinism in the species and only the fourth incidence of albinism in the Xenarthra. Given this armadillo’s mode of reproduction (i.e., birthing identical quadruplets) and the relative rarity of xenarthran albinism, I hypothesize that this group comprised close kin (perhaps clonal siblings) and encourage further work on the Cozumel population of Nine-banded Armadillos and in the species more generally.
∙ Molt patterns, often useful for determining age of individuals and, hence, demographic structu... more ∙ Molt patterns, often useful for determining age of individuals and, hence, demographic structure of a population, are generally poorly known for resident Neotropical birds. Neotropical woodpeckers are no exception to this latitudinal bias. We focused on the Hispaniolan Woodpecker ( Melanerpes striatus ) to study molt in regards to age and phenology. The objectives of this study were: (1) to provide the first description of the Hispaniolan Woodpecker’s molt pattern, and (2) to describe the relationship of molt within the breeding phenology. For six consecutive breeding seasons (March–July) from 2012 to 2017, we monitored a color‐banded population of the Hispaniolan Woodpeckers in a mid‐elevation (~ 600 m a.s.l.) landscape of wet forest fragments and cattle pastures in the Dominican Republic. We analyzed standardized photos taken during banding sessions to characterize patterns of retained and replaced feathers, resulting in an accurate method for aging. We found similarities in pr...
The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectopara... more The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectoparasitism. Although nestlings are typically considered the intended targets, recent work indicates that Philornis infest adult birds more frequently than previously appreciated, yet few studies have concurrently surveyed nestlings and adults for Philornis in the same population. Over six field seasons (2012–17), I documented the presence of current or recent subcutaneous Philornis infestations on adult and nestling Hispaniolan Woodpeckers Melanerpes striatus from the same population in the central Dominican Republic. I tested the following three non‐mutually exclusive hypotheses regarding the occurrence of Philornis on adult birds: (1) nestlings are more vulnerable to Philornis parasitism than adults, (2) nesting is associated with Philornis parasitism in adults, and (3) Philornis parasitism is associated with incubation and brooding investment. Although nestling and adult woodpeckers exhibited similar prevalence of parasitism, parasitized nestlings hosted on average 3.5 times more Philornis wounds (larvae plus empty wounds) than parasitized adults. Nesting per se was not significantly associated with parasitism among adults, as breeding and non‐breeding adults showed similar prevalence and intensity. However, nests with Philornis‐infested young were significantly more likely to have one or both parents also infested, in contrast to nests with infestation‐free young. Furthermore, adult males, which perform overnight incubation and brooding, were significantly more likely to be parasitized than adult females. This last result supports the hypothesis that incubation and brooding investment increase the risk of Philornis parasitism for adults, but this conclusion is complicated by the lack of an association between parasitism and nesting status. Together, these results raise questions about the degree of host life‐stage specialization and whether adult parasitism is incidental or part of an alternative parasitic strategy for Philornis.
Proceedings of the National Academy of Sciences of the United States of America, May 1, 2023
Referential signaling, a complex form of communication in which specific signals are associated w... more Referential signaling, a complex form of communication in which specific signals are associated with external referents, was once thought to be limited to primates. Recent research has documented referential signaling in several other cooperative taxa, predominantly in kin-based societies. Here, we show that greater anis, communally nesting birds that breed in nonkin groups, give one type of alarm call in response to aerial threats (flying raptors) and another to more general threats (nonaerial predators). Observational data show that anis give these calls in response to different classes of threats, and playback experiments in the field confirmed that the alarm calls alone are sufficient to elicit appropriate behavioral responses even in the absence of an actual threat. Genetic data on a subset of groups confirmed that breeding groups are composed of nonkin, suggesting that referential alarm calls are often given in situations when no genetic relatives are present. These results suggest that complex referential communication can occur in social groups composed of nonrelatives, despite the absence of kin-selected fitness benefits.
The ecological importance of avian myiasis caused by fly (Diptera) larvae, especially in the ge... more The ecological importance of avian myiasis caused by fly (Diptera) larvae, especially in the genus Philornis, remains poorly understood. One major gap in our knowledge is which bird species experience such parasitism. We present here the first report of Philornis parasitism on an adult Antillean Palm Swift (Tachornis phoenicobia) from the Dominican Republic, representing the first documented record of Philornis parasitism of a swift species (Apodidae). The host bird was found dead shortly after being observed alive with clear evidence of myiasis, and we suggest the bird’s death was due to the detected fly larvae. We also propose that this parasite-associated adult mortality implicates Philornis as another potential factor contributing to observed aerial insectivore declines, and highlights the pressing need for more comprehensive studies investigating the occurrence of parasitism in other Caribbean avian species. Keywords aerial insectivores, Antillean Palm Swift, Philornis, Sier...
Avian social and genetic mating systems are influenced by parental care roles as well as by repro... more Avian social and genetic mating systems are influenced by parental care roles as well as by reproductive opportunities. Alternative reproductive tactics, including conspecific brood parasitism and extra-pair mating, are predicted to be most common when females have access to potential host nests and when adults have access to potential mating partners, respectively. We tested these predictions in the facultatively colonial Hispaniolan woodpecker (Melanerpes striatus), a socially monogamous species with biparental care. Up to 12 pairs may nest concurrently in the same tree or, less frequently, two adjacent trees, potentially facilitating both conspecific brood parasitism and extra-pair mating. Contrary to our predictions, genotyping with single-nucleotide polymorphisms (SNPs) revealed no evidence of extra-pair paternity in either solitary or colonial nests: all 307 nestlings in 101 broods were matched to their social parents. Two instances of apparent conspecific brood parasitism were detected via changes in clutch size, but these could not be confirmed genetically since none of the apparently parasitic eggs survived to hatching. Therefore, if conspecific brood parasitism did occur, it was not a successful route to reproduction: parents fledged only their genetic offspring. These results suggest that reproductive opportunities alone are insufficient to favor alternative reproductive tactics, and that genetic monogamy can persist despite locally high densities of breeding pairs. Other life-history traits, including high levels of nest attendance and male parental care, may constrain parasitism and extra-pair mating in this long-lived tropical species. Significance statement High breeding density, a feature of colonial nesting, should increase opportunities for infidelity and conspecific brood parasitism because of the close proximity of potential extra-pair mates and parasitic females. Yet, we found that Hispaniolan woodpeckers, which nest both solitarily and colonially (two or more pairs in the same tree) in the same population, were genetically monogamous and lacked successful brood parasitism. Colonial nesting is exceptionally rare in the woodpecker family, which is also characterized by high investment in male parental care, including nocturnal incubation. The essential role of paternal care for successful reproduction in the Hispaniolan woodpecker might have selected against extra-pair mating and conspecific brood parasitism despite the apparent ample opportunities provided by nesting so close to others.
Explaining intra- and interspecific variation in sociality requires understanding the underlying ... more Explaining intra- and interspecific variation in sociality requires understanding the underlying ecological factors that promote or preclude grouping and the fitness consequences of group living. Colonial nesting, the dense concentration of individuals during breeding, offers an excellent opportunity for testing hypotheses to explain sociality and its variation. I studied the Hispaniolan Woodpecker (Melanerpes striatus), a facultative colonial breeder, in the Dominican Republic with the following goals, corresponding to the three chapters of this dissertation: (1) identify the ecological resources that explain colony size variation; (2) test for the effects of colony size on reproductive success with the goal of distinguishing the hypotheses of grouping for socially derived benefits from aggregations that form due to the spatiotemporal clustering of resources; and (3) determine whether coloniality impacts the genetic mating system by increasing the incidence of conspecific brood parasitism and extra-pair paternity. In Chapter 1, I show that Hispaniolan Woodpecker colony size is explained in part by the number of cavities on a tree and a nesting tree’s status: dead Roystonea palms hosted larger colonies than live palms. Dead palms were relatively rare on the landscape but were potentially higher quality because they were easier to excavate and immune to nest loss via cavity flooding. In Chapter 2, I show that, per nesting attempt, clutch size, hatching success, partial brood loss, and the number of fledglings produced were unrelated to colony size. However, nesting success, fledging one or more young vs. complete failure, was positively associated with colony size. Additionally, annual nesting success and annual fledging success were not associated with colony size. In Chapter 3, I show that Hispaniolan Woodpeckers were socially and genetically monogamous. Conspecific brood parasitism, though not detected genetically, was suspected in three nests based on aberrant changes in clutch size. Together, these chapters suggest that resource availability (dead trees and old cavities) likely promotes coloniality while there are minimal costs and very modest (if any) benefits of sociality for the Hispaniolan Woodpecker
Proceedings of the National Academy of Sciences, 2023
Referential signaling, a complex form of communication in which specific signals are associated w... more Referential signaling, a complex form of communication in which specific signals are associated with external referents, was once thought to be limited to primates. Recent research has documented referential signaling in several other cooperative taxa, predominantly in kin-based societies. Here, we show that greater anis, communally nesting birds that breed in nonkin groups, give one type of alarm call in response to aerial threats (flying raptors) and another to more general threats (nonaerial predators). Observational data show that anis give these calls in response to different classes of threats, and playback experiments in the field confirmed that the alarm calls alone are sufficient to elicit appropriate behavioral responses even in the absence of an actual threat. Genetic data on a subset of groups confirmed that breeding groups are composed of nonkin, suggesting that referential alarm calls are often given in situations when no genetic relatives are present. These results suggest that complex referential communication can occur in social groups composed of nonrelatives, despite the absence of kin-selected fitness benefits.
En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Mel... more En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Melanoptila glabrirostris, algunas de ellas descritas por primera vez. El dzibabán es un mímido tropical endémico de la península de Yucatán muy poco estudiado. El estudio lo realizamos en la costa norte de la Reserva de la Biosfera de Sian Ka’an, México, entre febrero y agosto de 2008. Presentamos medidas de culmen, tarso y masa corporal. Proponemos un método de sexado válido durante la temporada no reproductiva, ya que los machos presentaron longitud de cuerda alar mayor que las hembras. La coloración del ojo puede ser un criterio suplementario para determinar la edad, puesto que los individuos de segundo año presentaron frecuentemente coloración ocular marrón, similar a los individuos de primer año. La temporada reproductiva inicia en abril y termina a mediados de agosto. El ciclo del nido es de 27 y 32 días y el tamaño de nidada es de dos a tres huevos. El macho construye la mayor part...
We report the first definitive Mexican breeding records of the range-restricted Yucatan Vireo (Vi... more We report the first definitive Mexican breeding records of the range-restricted Yucatan Vireo (Vireo magister). We discovered two V. magister nests in July and August 2009 in Sian Ka’an Biosphere Reserve (near Tulum) and one nest on Isla Cozumel in June 2009. We observed two possible additional V. magister nests with eggs in Sian Ka’an in 2009, one each in June and July. All nests were open cups woven onto branches and hung beneath forks. Clutch size was two eggs at definitive V. magister nests. Nests and eggs were similar to those of most Vireo spp., including sympatric nesting congeners. Breeding activities—including egg-laying, incubation, and nestling and post-fledging provisioning—at definite Yucatan Vireo nests occurred in June and July on Cozumel and July and August on the mainland. Incubation and nestling stages lasted ~ 15 days and ~ 14 days, respectively. Yucatan Vireo remains poorly known, warranting further study.
The Yucatan Vireo (Vireo magister) is a poorly known, range-restricted species with two recognize... more The Yucatan Vireo (Vireo magister) is a poorly known, range-restricted species with two recognized subspecies: magister and caymanensis. We report nesting observations of the Yucatan Vireo from continental Mexico and Isla Cozumel, representing the first definitive nesting records for V. m. magister. We discovered two nests in July and August 2009 in Sian Ka'an Biosphere Reserve (near Tulum) and one nest on Isla Cozumel in June 2009. All nests were open cups woven onto branches and hung beneath forks, and clutch size was t wo eggs. Nests and eggs were similar to those of most Vireo spp., including sympatric nesting congeners. Breeding activities-including egg-laying, incubation, and nestling and post-fledging provisioning-occurred during June and July in Cozumel and in July and August on the mainland. Incubation and nestling stages lasted c. 15 days and c. 14 days, respectively. We advocate for more work on V. m. magister because it might warrant full species recognition. Resumen • Anidamiento del Vireo magister en México continental y en la Isla Cozumel, con notas sobre la fenología reproductiva El vireo de Yucatán (Vireo magister) es una especie poco conocida y de distribución restringida con dos subespecies reconocidas: magister y caymanensis. Reportamos observaciones de anidación del vireo de Yucatán en México continental y en la Isla Cozumel, los primeros registros inequívocos del anidamiento del V. m. magister. Descubrimos dos nidos en julio y agosto de 2009 en la Reserva de Biósfera Sian Ka'an (Tulum) y un nido en Isla Cozumel en junio de 2009. Todos los nidos eran copas abiertas tejidas en ramas debajo de horquetas y el tamaño de la puesta fue de dos huevos. Los nidos y huevos fueron similares a los de la mayoría de otras especies de Vireo, incluidas las especies congenéricas simpátricas. Las actividades de reproducción (incluida la puesta de huevos, la incubación y el aprovisionamiento de polluelos posterior al emplumamiento) ocurrieron durante junio y julio en Cozumel, y en julio y agosto en continente. La duración de las etapas de incubación y cría fueron de c. 15 días y c. 14 días, respectivamente. Recomendamos estudios adicionales de V. m. magister porque tal vez deba reconocerse cabalmente como especie.
The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectopara... more The nestlings of many Neotropical bird species suffer from Philornis (Diptera: Muscidae) ectoparasitism. While nestlings are typically considered the intended targets, recent work indicates that Philornis infest adult birds more frequently than previously appreciated, yet few studies have concurrently surveyed nestlings and adults for Philornis in the same population. Over six field seasons (2012–2017), I documented the presence of current or recent subcutaneous Philornis infestations on adult and nestling Hispaniolan Woodpeckers (Melanerpes striatus) from the same population. I tested the following three non-mutually exclusive hypotheses regarding occurrence of Philornis on adult birds: (1) nestlings are more vulnerable to Philornis parasitism than adults, (2) nesting is associated with Philornis parasitism in adults, and (3) Philornis parasitism is associated with incubation and brooding investment. While nestling and adult woodpeckers exhibited similar prevalence of parasitism, p...
I observed a group of 4 albino Dasypus novemcinctus (Nine-banded Armadillo) foraging in close pro... more I observed a group of 4 albino Dasypus novemcinctus (Nine-banded Armadillo) foraging in close proximity to one another on Isla Cozumel, Mexico, in July 2009. To my knowledge, this observation represents the first directly documented account of albinism in the species and only the fourth incidence of albinism in the Xenarthra. Given this armadillo’s mode of reproduction (i.e., birthing identical quadruplets) and the relative rarity of xenarthran albinism, I hypothesize that this group comprised close kin (perhaps clonal siblings) and encourage further work on the Cozumel population of Nine-banded Armadillos and in the species more generally.
∙ Molt patterns, often useful for determining age of individuals and, hence, demographic structu... more ∙ Molt patterns, often useful for determining age of individuals and, hence, demographic structure of a population, are generally poorly known for resident Neotropical birds. Neotropical woodpeckers are no exception to this latitudinal bias. We focused on the Hispaniolan Woodpecker ( Melanerpes striatus ) to study molt in regards to age and phenology. The objectives of this study were: (1) to provide the first description of the Hispaniolan Woodpecker’s molt pattern, and (2) to describe the relationship of molt within the breeding phenology. For six consecutive breeding seasons (March–July) from 2012 to 2017, we monitored a color‐banded population of the Hispaniolan Woodpeckers in a mid‐elevation (~ 600 m a.s.l.) landscape of wet forest fragments and cattle pastures in the Dominican Republic. We analyzed standardized photos taken during banding sessions to characterize patterns of retained and replaced feathers, resulting in an accurate method for aging. We found similarities in pr...
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