COLOR ABERRATIONS IN SEVEN BIRD SPECIES IN COSTA RICA

Collective behaviors, including flocking and group vocalizing, are readily observable across a diversity of free-living avian populations, yet we know little about how neural and ecological factors interactively regulate these behaviors. Because of their involvement in mediating a variety of social behaviors, including avian flocking, nonapeptides are likely mediators of collective behaviors. To advance the neuroecological study of collective behaviors in birds, we sought to map the neuroanatomical distributions of nonapeptide receptors in three promising avian models that are found across a diversity of environments and widely ranging ecological conditions: European starlings, house sparrows, and rock doves. We performed receptor autoradiography using the commercially available nonapeptide receptor radioligands, 125I-ornithine vasotocin analog and 125I-linear vasopressin antagonist, on brain tissue sections from wild-caught individuals from each species. Because there is known pharmacological cross-reactivity between nonapeptide receptor subtypes, we also performed a novel, competitive-binding experiment to examine the composition of receptor populations. We detected binding in numerous regions throughout the brains of each species, with several similarities and differences worth noting. Specifically, we report that all three species exhibit binding in the lateral septum, a key brain area known to regulate avian flocking. In addition, sparrows and starlings show dense binding in the dorsal arcopallium, an area that has received scant attention in the study of social grouping. Furthermore, our competitive binding results suggest that receptor populations in sparrows and starlings differ in the lateral septum versus the dorsal arcopallium. By providing the first comprehensive maps of nonapeptide receptors in European starlings, house sparrows, and rock doves, our work supports the future use of these species as avian models for neuroecological studies of collective behaviors in wild birds.

Wild birds are one of the main natural reservoirs for avian influenza viruses, and their migratory behavior significantly influences the transmission of avian influenza. To better describe the migratory behavior of wild birds, a system of reaction-advection-diffusion equations is developed to characterize the interactions among wild birds, poultry, and humans. By the next-generation operator, the basic reproduction number of the model is formulated. Then the threshold dynamic of the model is explored by some techniques including the theory of uniform persistence, internally chain transitive sets, and so on. Subsequently, the sensitivity analysis of parameters associated with the basic reproduction number is implemented. According to the temporal and spatial overlapping relationship between wild blue-winged ducks and poultry in North America, the effect of this relationship on the characteristic of spatial-temporal distribution of the viruses is well studied. Additionally, the risk of virus transmission from wild birds to poultry and humans is evaluated. The main results highlight that the basic reproduction number is more significantly affected by the parameters related to wild birds. Interestingly, the model output regarding the spatial distribution of poultry infections is consistent with the actual findings. Moreover, the risk of virus spillover from wild birds into poultry and humans varies with wild bird behavior and has a more substantial impact on poultry. Throughout this study, the critical risk points in the transmission process are identified, providing a theoretical basis for the prevention and control of avian influenza.

Sometime between the years 1486 and 1502 A.D., the great-tailed grackle Quiscalus mexicanus, an exotic tropical bird from Veracruz, was introduced into the Valley of Mexico by Aztec Emperor Auitzotl. From there, this species spread to other areas of the Central Highlands, and is today one of the most common birds in that part of Mexico. The example of the great-tailed grackle, along with our knowledge of the extensive traffic of exotic birds that occurred during pre-Columbian times, leads us to suspect that the ancient Indians may have altered the ranges of other Latin American birds. The strange disjunctions and extraordinary distributions that we see today, and which have baffled ecologists for so long, are possibly the result of disturbance to the natural fauna long ago by Indians. THE STRANGE DISTRIBUTIONS of many Latin American birds have long been a mystery to biologists. Incredible disjunctions of thousands of kilometers, inexplicable small ranges, and the presence of tropical species in cold montane habitats are all anomalies which have both baffled and fired the imagination of theoretical ecologists. In recent years, a number of excellent books and papers have been written on the fauna of Latin America (MacArthur 1972, Howell 1969, Haffer 1974, Eisenmann 1955, Darlington 1938, etc.). These publications have stressed such factors as diffuse competition, tropical storms, and past climatic corridors and refugia to explain the present-day distribution of neotropical animals. Yet, while all these factors have doubtlessly influenced the Latin American fauna in many ways, one important factor has been overlooked. That is the possible role that the native Indians may have played in altering bird distributions before the European conquest.

Endocrine and neuroendocrine regulation of fathering behavior in birds

Changes in vocal repertoire of the Hawaiian crow, Corvus hawaiiensis, from past wild to current captive populations

Biological effects of aqueous extract from Turkey vulture Cathartes aura (Cathartidae) meat

H5N1 subtype of highly pathogenic avian influenza virus (HPAIV) has been giving serious damage to the poultry industry since 2004 in Japan. Worst of all, from the end of November 2010 to March 2011, there were 24 outbreaks of HPAI among chicken farms and during the same period, HPAIV was isolated from the carcasses of 63 wild birds. The role of wild birds in spreading HPAIV has been suspected but controversial. This report reviews recent literatures regarding the epidemic cases of HPAIV in wild birds in Asia and Europe, the experimental infection studies using wild birds, and the satellite tracking studies of wild waterfowl in outbreak area. The epidemic cases showed common characteristic that the epidemics recur in the similar situation, i.e., among the same species, in the same area, at the same time of the year, for a limited period of about two months. These characteristics have been explained with the sensitivity difference among bird species and the behaviors of birds. From this study, it is concluded that the collaborative research from the views of both bird ecologists and virologists is an essential tool to elucidate the ecology of HPAIV.

Newcastle Disease Virus (NDV) genotype VII is a highly pathogenic Orthoavulavirus that has caused multiple outbreaks among poultry in Egypt since 2011. This study aimed to observe the prevalence and genetic diversity of NDV prevailing in domestic and wild birds in Egyptian governorates. A total of 37 oropharyngeal swabs from wild birds and 101 swabs from domestic bird flocks including chickens, ducks, turkeys, and pelicans, were collected from different geographic regions within 13 governorates during 2019–2020. Virus isolation and propagation via embryonated eggs revealed 91 swab samples produced allantoic fluid containing haemagglutination activity, suggestive of virus presence. The use of RT-PCR targeted to the F gene successfully detected NDV in 85 samples. The geographical prevalence of NDV was isolated in 12 governorates in domestic birds, migratory, and non-migratory wild birds. Following whole genome sequencing, we assembled six NDV genome sequences (70–99% of genome coverage), including five full F gene sequences. All NDV strains carried high virulence, with phylogenetic analysis revealing that the strains belonged to class II within genotype VII.1.1. The genetically similar yet geographically distinct virulent NDV isolates in poultry and a wild bird may allude to an external role contributing to the dissemination of NDV in poultry populations across Egypt. One such contribution may be the migratory behaviour of wild birds; however further investigation must be implemented to support the findings of this study. Additionally, continued genomic surveillance in both wild birds and poultry would be necessary for monitoring NDV dissemination and genetic diversification across Egypt, with the aim of controlling the disease and protecting poultry production.

A qualitative risk assessment was conducted to determine 1) the likelihood of introduction of Asian lineage H5N1 highly pathogenic avian influenza virus by migratory birds into the EU, 2) the likelihood of it becoming endemic in wild birds in the EU and 3) the likelihood of transmission of infection to domestic poultry. The conclusions reached included that the probability of the virus being released into the EU varied between low and high, depending on the species of migratory birds. A minority opinion was noted concluding that the risk was medium across species. In the light of this risk, it was recommended to educate poultry keepers in currently affected countries outside the EU in relation to minimum biosecurity standards. Surveillance should be enhanced in these countries in domestic poultry and wild birds, and vaccination programmes should be considered for controlling the infection. Trade with poultry and their products needs to be managed considering the risks of spreading virus between geographical areas. Research needs to be conducted to improve surveillance methods in poultry and widl birds. Wild bird migration data needs to be analysed to better understand the flyways used by the various species. The risk of the virus becoming endemic in European wild bird populations was considered to vary between low and high depending on species. A minority opinion was received concluding that this risk was medium across species. This risk could be reduced by intensifying surveillance in wild birds within the EU, and use the data to inform biosecurity measures in domestic birds. The behaviour of wild birds within the EU needs to be better studied so that the dynamics of transmission within and between species are better understood. The final step of the risk assessment indicates that there is a negligible risk of the virus infecting domestic poultry kept under a high biosecurity standard and not in high poultry density areas. The risk increases to very low if they are kept in high poultry density areas. For backyard and free-range poultry, and any poultry not kept under high biosecurity standards, it was concluded that the risk of introduction of Asian lineage H5N1 highly pathogenic avian influenza virus to the flock was low to medium. These risks emphasize the need to make better use of existing and new migratory bird behaviour data. Passive and active surveillance for AI in wild birds needs to be intensified. It should focus on the species identified in this risk assessment. Biosecurity measures for poultry holdings need to be reviewed, and research needs to be conducted to optimise their effectiveness. Poultry holdings should not be built in the vicinity of wetland areas. New vaccines and their use need to be researched.

New World vultures (Cathartidae) have essential roles in ecosystem functioning, but are susceptible to increasing anthropogenic impacts. Knowledge of several breeding, behavioral, and distributional parameters of Neotropical vultures is poorly organized and have not been properly reviewed. Here, we made a comprehensive review of original breeding records from museums, literature, and citizen science (WikiAves) for each of the six species of vultures occurring in the Neotropical region. These data were used to review breeding patterns and geographical distribution, and identify information gaps. The 567 records of breeding from the Neotropics assembled are very biased, mostly for Black Vulture Coragyps atratus (n = 319) and Turkey Vulture Cathartes aura (n = 166), and unevenly distributed among regions and subspecies. The four other species still have a great lack of knowledge about their breeding in the wild (Lesser Yellow-headed Vulture Cathartes burrovianus (n = 20), Greater Yellow-headed Vulture C. melambrotus (n = 2), King Vulture Sarcoramphus papa (n = 21), and Andean Condor Vultur gryphus (n = 30)). We show for the first time that Neotropical Cathartidae have convergent breeding seasons among sympatric taxa, delay start of breeding with increasing latitude, and have an allometric relationship between adult size and egg size. Nevertheless, larger samples of breeding data, especially from some regions and taxa, such as the two “Yellow-headed Vulture” species, are still needed. We also show that breeding traits could be helpful for preventive management and conservation strategies involving both expanding and decreasing populations of vultures in the Neotropics.

The scavenging activities of Greater Yellow‐headed Vultures Cathartes melambrotus were studied in the Amacayacu National Park, Colombia. This species is the most abundant vulture in the area and is usually the first species to locate a carcass, both in open clearings and inside the forest. The birds use olfaction to locate food. Vultures located 63% of provided carcasses, while mammalian scavengers found only 5%. Greater Yellow‐headed Vultures were displaced when feeding by both Turkey Vultures Cathartes aura and King Vultures Sarcorhamphus papa.

Three new species of chigger mites, Eutrombicula costaricensis sp. n., Eutrombicula passerinoruni sp. n., and Eutrombicula hectochaeta sp. n. are described from wild birds from Costa Rica. Two species, Eutrombicula pacae (Floch et Fauran, 1957) and Parasecia findata (Brennan, 1969), are recorded for the first time in Costa Rica and on new host species. Data on the distribution of Blankaartia sinnamaryi (Floch et Fauran, 1956) in Costa Rica are also reported.

Summary. The great-tailed grackle Quiscalus mexicanus was introduced by Aztec Emperor Auitzotl beyond its native range in 16th century Mexico. Haemig (2011) provides valuable details on the transport, introduction, establishment, and spread of this species. However, here I argue that while this is an interesting account of a historical bird translocation, this is not the reason why this species has undergone one of the greatest range expansions of any native North American species during the 20th century. Fossil records indicate that the species was already present in areas further north before this historical translocation. Moreover, it is a very plastic species and human commensal. Therefore, the northward expansion of this tropical species has been aided by anthropogenic habitat changes rather than a consequence of the active translocation by the Aztec Emperor Auitzotl.

Multiple studies have focused on the importance of single modalities (visual, auditory, olfactory) in eliciting anti-predator behavior, however multiple channels are often engaged simultaneously. While examining responses to multiple cues can potentially reveal more complex behavioral responses, little is known about how multimodal processing evolves. By contrasting response to familiar and novel predators, insights can be gained into the evolution of multimodal responses. We studied brown anoles’ (Anolis sagrei) response to acoustic and visual predatory cues of a common potential predator, the great-tailed grackle Quiscalus mexicanus and to the American kestrel Falco sparverius, a species found in other populations but not present in our study population. We observed anole behavior before and after a stimulus and quantified rates of looking, display, and locomotion. Anoles increased their rate of locomotion in response to grackle models, an effect modulated by grackle vocalizations. No such response or modulation was seen when anoles were presented with kestrel stimuli. This suggests that the degree of sophistication of anole response to predators is experience dependent and that relaxed selection can result in reduced anti-predator response following loss of predators.

Late pleistocene passerine birds from Sonora, Mexico