Abstract Introduction: Aquatic birds (AB) are usually associated with wetlands, which provide refuge, food, and/or nesting sites for resident and migratory species. Despite their ecological importance, there is little knowledge on AB in some tropical environments, such as those found on the Colima coast. Objective: To investigate the spatial and temporal composition of the AB community in Juluapan Lagoon, Colima, Central Mexican Pacific. Methods: Monthly counts were conducted between June 2017 and May 2018 during low-tide conditions to record habitat use by AB. Species richness and bird counts were obtained to compare sampling areas; mean richness and number of individuals were compared between seasons. Results: We detected 53 species and 5 750 individuals. The highest species richness and relative abundance values were obtained in winter at the lagoon area farthest from the connection with the marine system, where anthropogenic activity is lower. Diversity was greater in zones 2 and 3 in spring, summer, and fall. Muddy flats were the most used environment, and the most frequent activity was resting. Nesting activity was only recorded in the middle of the lagoon at the mangrove during spring. “Shorebirds” and “waders” were the most dominant groups in the bird community of the Juluapan lagoon. Conclusions: This coastal wetland is a site of great biological importance for aquatic birds; thus, conservation measures should be implemented, and there should be a continuous study of the effects of anthropogenic pressure.

Resumen Introducción: Las aves acuáticas (AA) son usualmente relacionadas a los humedales debido a que éstos funcionan como sitios de refugio, alimentación y anidación de diferentes especies residentes y migratorias. Sin embargo, el conocimiento sobre las aves acuáticas en algunos humedales es nulo. Objetivo: Investigar la composición espacio-temporal de la comunidad de AA en la laguna Juluapan, Colima, en el Pacífico Central Mexicano. Métodos: Entre junio de 2017 y mayo de 2018 se llevaron a cabo conteos mensuales en condiciones de marea baja para registrar el uso de hábitat de las AA. Se obtuvieron valores de riqueza de especies y número de individuos para realizar comparaciones entre zonas de muestreo, así como el promedio del número de especies y número de individuos para comparaciones entre temporadas. Resultados: Se registraron un total de 53 especies y 5 750 individuos. Los valores de riqueza de especies y densidad de individuos fueron más altos durante invierno, en la zona más alejada al ambiente marino, donde la actividad antropogénica es menor. La diversidad tuvo valores más altos en la zona 2 y 3, durante primavera, verano y otoño. El ambiente más explotado por las aves fueron las planicies lodosas; y el descanso fue la actividad más frecuente. Asimismo, la actividad de anidación sólo se registró en el manglar de la zona media durante primavera. Las “aves playeras” y “aves zancudas” fueron los grupos más predominantes en la comunidad de aves de la laguna Juluapan. Conclusiones: Este humedal costero es un sitio de gran importancia biológica para aves acuáticas, por lo que resulta necesario la implementación de medidas de conservación, así como el estudio de los efectos por la presión antropogénica.

Resumen Durante las primeras excavaciones realizadas en el Parador QB (Parque Nacional Islote Lobos, costa Rionegrina) se recuperaron huesos de aves en los conjuntos zooarqueológicos. Al igual que en otras localidades arqueológicas del litoral Nordpatagónico, la representación de este taxón es escasa, aunque los huesos presentan buen estado de preservación. Con el objetivo de explorar el papel de las aves en la subsistencia de las sociedades cazadoras-recolectoras que ocuparon este litoral durante el Holoceno tardío, desarrollamos un estudio tafonómico para establecer si la depositación de sus huesos se debe a la acción antrópica o a causas naturales. La evaluación tafonómica de los restos avifaunísticos es fundamental dado que actualmente existen áreas de nidificación de diversas aves marino-costeras próximas a los sitios arqueológicos, por lo que sería factible la “contaminación ósea” -o mezcla de huesos naturales y materiales arqueológicos. Se concluye que los huesos de aves de los tres loci tienen trayectorias tafonómicas similares, mientras que la mezcla de restos óseos de diferente origen se registró principalmente en el caso de los pingüinos de Magallanes. Por último, señalar que, aunque las aves no son tan abundantes, tuvieron un lugar importante en el repertorio de presas de los cazadores-recolectores de la región.

Abstract During the first excavations carried out at the Parador QB (Islote Lobos National Park, Rio Negro coast), bird bones were recovered in the zooarchaeological assemblages. As in other archaeological localities on the North Patagonian coast, the representation of this taxon is scarce, although the bones present a good state of preservation. With the aim of exploring the role of birds in the subsistence of the hunter-gatherer societies that occupied this coastline during the Late Holocene, a taphonomic study was developed to establish whether the deposition of bird bones was due to anthropogenic action or to natural causes. The taphonomic evaluation of the avifauna remains is essential given that currently there are nesting areas of various marine-coastal birds close to the archaeological sites, so that "bone contamination," or the mixing of natural bones and archaeological materials, can result. It is concluded that bird bones from the three loci have similar taphonomic trajectories, while modern bones mixed with the archaeological materials were mainly of Magellanic penguins. Finally, it should be noted that, although bird bones are not abundant, birds had an important place in the prey repertoire of the hunter-gatherers of the region.

Abstract Floating structures, both natural and artificial, attract fish by providing shelter, feeding areas, and nesting sites. Occupancy can be either more permanent, leading to a gradual gathering of the assembly, or transient, occurring randomly. The ability of an attractor to hold a fish assemblage may depend on the availability of habitat resources in the environment. New artificial attractors are more valuable when natural ones are scarce. Additionally, fish characteristics play a role; young and small fishes may need new habitat for shelter more than adult fish. As aquatic herbaceous areas are abundant during high water, coinciding with the period of fish reproduction, they are particularly relevant for juveniles. We constructed fish attractors composed of natural materials to investigate the structure of fish assemblages during the flood of an Amazonian floodplain lake. Our aim was to test the hypothesis that assembly processes during the flood period would be random, with a predominance of juveniles in the attractors. We collected fish at intervals of 5, 15, and 30 days, resulting in 39 observations, and classified them as either adult or juvenile. Species composition was compared among treatments using Principal Coordinates Analysis (PCoA). The assembly process was tested through species co-occurrence patterns employing null models and the C-score index. The proportion of juveniles and adults was compared using a Chi-square test. Species composition remained consistent throughout the experiment. The assembly was random, with a prevalence of juveniles, possibly serving only as temporary shelter and feeding areas. Our study contributes to understanding the role of habitat availability for floodplain fishes during high waters. The results suggest that floating attractors and new habitats may be more valuable for the juveniles than adult fish and can be used as a management strategy for population recovery, especially when floating herbaceous habitats are scarce. structures sites permanent transient randomly environment scarce Additionally water reproduction lake random 5 15 3 days observations juvenile PCoA. PCoA . (PCoA) cooccurrence co occurrence Cscore C score index Chisquare Chi square experiment waters recovery 1 (PCoA

Resumo As estruturas flutuantes, naturais ou artificiais, atraem os peixes, fornecendo abrigo, áreas de alimentação e locais de nidificação. A ocupação pode ser mais permanente, resultando em um recolhimento gradativo da assembleia, ou transitória, ocorrendo aleatoriamente. A capacidade de um atrator de manter uma assembleia de peixes pode depender da disponibilidade de recursos de habitat no ambiente. Novos atratores artificiais são mais valiosos quando os naturais são escassos. Além disso, as características dos peixes desempenham um papel, já que peixes jovens e pequenos podem necessitar de novos habitats como abrigo mais do que peixes adultos. Como as áreas com herbáceas aquáticas são abundantes durante as cheias, coincidindo com o período de reprodução dos peixes, elas são especialmente relevantes para peixes juvenis. Construímos atratores de peixes compostos de material natural para investigar a estrutura das assembleias de peixes durante a cheia de um lago de várzea amazônico, a fim de testar a hipótese de que durante o período de cheia, os processos de montagem seriam aleatórios e com predominância de juvenis nos atratores. Os peixes foram coletados em intervalos de 5, 15 e 30 dias, resultando em 39 observações, e classificados como adultos ou juvenis. A composição de espécies foi comparada entre os tratamentos usando uma Análise de Coordenadas Principais (PCoA). O processo de montagem foi testado por meio de padrões de coocorrência de espécies usando modelos nulos e o índice C-score. A proporção de jovens e adultos foi comparada usando um teste Qui-quadrado. A composição de espécies permaneceu a mesma ao longo do experimento. A montagem da assembleia foi aleatória com prevalência de juvenis nos atratores, que possivelmente serviam apenas como abrigo temporário e áreas de alimentação. Nosso estudo contribui para entender o papel da disponibilidade de novos habitats para peixes de várzea durante a cheia. Os resultados sugerem que atratores flutuantes e novos habitats podem ser mais valiosos para os peixes jovens do que para adultos e podem ser usados como estratégia de manejo para a recuperação populacional, especialmente quando habitats de herbáceas flutuantes são escassos. nidificação permanente transitória aleatoriamente ambiente escassos disso cheias amazônico 5 1 3 dias observações PCoA. PCoA . (PCoA) Cscore. Cscore C score. score C-score Quiquadrado. Quiquadrado Qui quadrado. quadrado Qui-quadrado experimento populacional (PCoA

ABSTRACT Studying nesting sites is especially important for understanding the habitat requirements and be-havior of species and planning efficient conservation strategies. We performed a bibliographic search of the lo-cations of all known nests of the Black-and-White Hawk-eagle (Spizaetus melanoleucus) in the Americas. We report the first active nest with successful reproduction for this species in Argentina. The first nest for the species was discovered in Panamá in 1972, while the first complete description was made 36 years later in Brazil. We found a total of 17 known nests to date. The nesting platform found in Argentina was discovered in the Salto Encantado Provincial Park in the province of Misiones in October 2019. On October 13, 2022, we found a 20-25-day-old chick and an adult female inside the nest, which was constructed in a 25-m-tall tree (Aralia warmingiana) in a valley with a steep slope, setting it apart from the canopy. During the following monitoring, in November 2022, the 60-day-old chick was observed flying with its parents among the nearby trees. The discovery of this nesting site emphasizes the importance of taking direct conservation measures. The study of environmental variables at the site and the reproductive behavior of these individuals will generate important information for improving the detection of sites of interest and proposing efficient conservation strategies for this threatened species.

RESUMEN El estudio de sitios reproductivos es de especial importancia para entender los requerimientos de hábitat y el comportamiento de especies, y para planear estrategias de conservación eficientes. Realizamos una revisión bibliográfica de la localización de los nidos conocidos del Águila Viuda (Spizaetus melanoleucus) para el continente Americano. Luego reportamos el primer nido activo con reproducción exitosa de esta especie para la Argentina. El primer nido descubierto fue en Panamá en 1972, pero la primera descripción completa fue 36 años después en Brasil. Encontramos que hasta el momento se conocían 17 nidos. La plataforma de nidifi-cación encontrada en Argentina se descubrió en octubre de 2019 el Parque Provincial Salto Encantado, en la provincia de Misiones. El 13 de octubre de 2022 se confirmó la presencia de un pichón de 20-25 días de edad y una hembra adulta en el interior del nido, ubicado en un Sabuguero (Aralia warmingiana) de 25 m de altura en la ladera de un valle de pendiente pronunciada, que lo destaca del dosel. En el siguiente monitoreo, en noviembre de 2022 se observó al pichón con 60 días de edad realizando vuelos en la cercanía del nido junto a sus padres. El descubrimiento de este sitio de nidificación es de importancia para tomar medidas directas para la conservación de la especie. El estudio de las variables ambientales del sitio y el comportamiento reproductivo de estos individuos generará información importante para mejorar la detección de sitios de interés y plantear estrategias de conservación eficientes para esta especie amenazada.

Resumen Introducción: Las abejas sin aguijón están muy extendidas en las regiones tropicales y subtropicales. En Indonesia, la distribución de las abejas sin aguijón se agrupa en tres regiones: Indo-Malayan, Wallacea e Indo-Australian. Se han registrado diez especies de abejas sin aguijón en Papua, siete de las cuales son endémicas. La Reserva Natural de las Montañas Cycloop (CMNR) es una de las áreas para la conservación de flora y la fauna en Papua, Indonesia. Desafortunadamente, el estudio de la diversidad de abejas sin aguijón en Papua ha sido limitado. Objetivo: Medir la diversidad, los sitios de anidación y describir la arquitectura y características de entrada al nido de las abejas sin aguijón. Métodos: Se observaron los nidos de abejas sin aguijón en reservas naturales y áreas residenciales, mediante el método de muestreo de caminos e información de la población local, respectivamente. Se estudiaron 22 colonias. Resultados: Se encontraron dos especies de abejas sin aguijón, Tetragonula sapiens (Cockerell, 1911) y Heterotrigona (Platytrigona) planifrons (Smith, 1865). Este estudio mostró nuevos registros de distribución de T. sapiens y H. planifrons en el CMNR. El sitio de anidación de T. sapiens se encontró comúnmente en los cimientos de las casas, mientras que el de H. planifrons estaba en las cavidades de las palmas de coco. La forma de la entrada al nido de T. sapiens varió: elíptica, ovalada, redondeada, irregular, alargada horizontal o verticalmente. Mientras tanto, la entrada al de H. planifrons se alarga verticalmente. Las celdas de cría de T. sapiens variaron, entre verticales, horizontales o semi-racimos, mientras que en H. planifrons eran verticales. Conclusiones: Se encontraron dos especies de abejas sin aguijón, T. sapiens y H. planifrons, que mostraron nuevos registros de distribución y T. sapiens fue una especie dominante en Papúa. La entrada al nido de las especies varió en forma, color y textura.

Abstract Introduction: Stingless bees are widespread in tropical and subtropical regions. In Indonesia, the distribution of stingless bees are grouped in three regions, namely Indo-Malayan, Wallacea, and Indo-Australian. Ten species of stingless bees have been recorded in Papua, seven of which are endemic. The Cycloop Mountains Nature Reserve (CMNR) is one of the conservation area in Papua, Indonesia, for flora and fauna. Unfortunately, the study of the diversity of stingless bees in Papua has been limited. Objective: To measure the diversity, nesting sites, nest entrance characteristics and nest architecture of stingless bees. Methods: Observation of the stingless bee nests in the nature reserves and in the residential areas used a road sampling method and information from local people, respectively. A total of 22 colonies were studied. Results: Two species of stingless bee were found, namely Tetragonula sapiens (Cockerell, 1911) and Heterotrigona (Platytrigona) planifrons (Smith, 1865). The current study showed new distribution records for T. sapiens and H. planifrons in the CMNR. The nesting site of T. sapiens was commonly found in house foundation, while that of H. planifrons was in coconut palm cavities. The nest entrance of T. sapiens varied, i.e., elliptical, oval, rounded, irregular, horizontally or vertically elongated. Meanwhile, the nest entrance of H. planifrons was vertically elongated. The brood cells of T. sapiens varied, i.e., vertical, horizontal, or semi-clusters, while in H. planifrons was layered vertically. Conclusions: Two species of stingless bees found, T. sapiens and H. planifrons, showed a new distribution records and T. sapiens was a dominant species in Papua. The nest entrance of the species varied in shape, color, and texture.

RESUMEN La tendencia al aumento de las actividades al aire libre relacionadas con el turismo de naturaleza genera preocupación entre investigadores y conservacionistas debido al impacto potencial sobre la vida silvestre. Entre los lugares que experimentan una mayor presión son los sitios de concentración de aves, como las colonias de nidificación. Topes de Collantes (centro-sur de Cuba) es un área protegida donde se encuentran las mayores colonias de nidificación de Vencejo de Collar de Cuba. Se evaluó si la actividad turística interfiere con los elementos clave de la biología reproductiva de la especie (la cronología reproductiva, los factores limitantes para establecer una colonia de anidación y los picos de actividad durante el día en las colonias de nidificación) en tres sitios de nidificación del área. Los impactos de las actividades recreativas y la interacción entre visitantes y aves se determinaron por observación directa a través de caminatas dentro de los sitios de estudio, sus alrededores y senderos. No se detecta impactos directos de los visitantes en las tres colonias de nidificación evaluadas, donde se observa una efectiva segregación espacio-temporal. Sin embargo, la presencia de especies exóticas y el daño a los sitios (las paredes de las cuevas) por graffiti requiere estrategias de manejo, que incluyan orientación y educación ambiental.

ABSTRACT The trend to increase outdoor activities related to nature-based tourism raises concern among researchers and conservationists due to the potential impact on wildlife. Among the places experiencing increasing pressure are the sites of bird’s concentration, such as nesting colonies. Topes de Collantes (south-center Cuba) is a protected area where the largest nesting colonies of White-collared Swift are found in Cuba. In the work is evaluated if the tourist activity interferes with the key elements of the reproductive biology of the species (the breeding chronology, the limiting factors to establish a nesting colony and the peaks of activity during the day at nesting colonies) in three study sites at Topes de Collantes. The impacts of recreational activities and the interaction between visitors and birds were determined by direct observation through walks within the studied sites, their surroundings and trails. We did not detect direct impacts of visitors in either of the three nesting colonies evaluated, where we observed an effective space-time segregation. However, the presence of alien species and damage to cave walls by graffiti requires management strategies, including guidance and environmental education.

ABSTRACT Microplastics are an increasing threat to marine fauna and oceanic habitats, potentially affecting sea turtle nesting beaches. Hawksbill sea turtles (Eretmochelys imbricata) are a Critically Endangered species with decreasing population trends. There are several hawksbill rookeries in the southern Caribbean Sea, particularly on Los Garzos Beach, the main nesting site of continental Venezuela. A preliminary physical analysis of microplastics sampled from 10 sites on Los Garzos Beach reported high numbers (94 ± 2.5 items) of 14 different materials and colors. Microplastic counts at 10 sites averaged 1504 ± 405.61 items m−2, higher than other sea turtle nesting sites worldwide. There were no statistical differences in the concentration of microplastics at the sampled sites of Los Garzos Beach. However, the concentration of microplastics on this beach is higher at the midpoint of the falling tide (3520 ± 405.61 items m−2) and the top of the sea turtle nesting area (3840 ± 405.61 items m−2). We speculate that this debris could harm the nesting environment of hawksbill sea turtles in the region. While this study presents preliminary values for microplastics in an important hawksbill turtle nesting beach in Venezuela, it also serves as a baseline for long-term studies that can help determine the impact and sources of plastic pollution in sea turtle rookeries.

Resumen El garrobo (Ctenosaura similis) se encuentra principalmente en ambientes xéricos en la vertiente del Pacífico de Mesoamérica. La especie ha sido considerada omnívora, con un cambio ontogenético en su dieta; los juveniles son insectívoros y los adultos son principalmente herbívoros. El garrobo consume diferentes tipos de materia vegetal y animal, sin embargo, hay pocos informes de eventos concretos de depredación. Aquí reportamos la depredación de la paloma ala blanca (Zenaida asiatica) por el garrobo en Costa Rica. Una paloma adulta fue capturada en el nido por un garrobo, y el único volantón del nido fue depredado por otro garrobo hembra cuando cayó al suelo después del evento de depredación. La paloma ala blanca ha incrementado su distribución y abundancia y explota principalmente hábitats abiertos donde anida incluso en infraestructuras de humanos, donde queda expuesta a depredadores que habitan principalmente en este tipo de hábitat como el garrobo. Discutimos el contexto de este evento de depredación y agregamos a la paloma ala blanca a una lista basada en la recopilación de presas reportadas como consumidas por el garrobo tanto en su área de distribución natural como en sitios donde ha sido introducido.

Abstract The Black Iguana (Ctenosaura similis) mainly inhabits xeric environments at the Pacific slope of Mesoamerica. It has been considered omnivorous, showing ontogenetic changes; juveniles are insectivorous, while adults are primarily herbivorous. The Black Iguana consumes several types of plant and animal material; however, there are very few reports of the actual predation events. Here we report the predation by the Black Iguana in Costa Rica upon a White-winged Dove (Zenaida asiatica). A female Black Iguana took one adult from its nest, and the only nestling of the nest was predated by another female Black Iguana when it fell to the ground after the predation event. The White-winged Dove has increased its distribution and abundance, exploiting mainly open habitats, including nesting in human infrastructure, where it is exposed to predators inhabiting this habitat, such as the Black Iguana. We discuss the context of this predation event and add the White-winged Dove to a list based on the compilation of prey reported as consumed by the Black Iguana both in its natural distribution area and in sites where it has been introduced.

Abstract The Maguari Stork (Ciconia maguari) is one of the three species of the family Ciconiidae that occur in South America. Despite abundant in landscapes dominated by wetlands and grasslands, detailed studies on its biology are scarce. This study is aimed at investigating aspects of the breeding of Maguari Storks in Brazil. Photographic records were searched in the WikiAves database. A total of 65 records, obtained by citizens along 13 years in 32 municipalities, showed evidences of breeding activities in Brazil. Most (86%) of these records were gathered in the Pampa biome, in southern Brazil. Nests were large platforms and contained 1-3 young. Nests built on the ground were in grasslands or reed patches. Those built on shrubs were at boundaries between lakes and grasslands, and were often in colonial nesting sites with egrets and herons. Incubation occurred between July and November, and nestlings were found between August and December. Juveniles able to fly were recorded between late October and February. Most records of breeding activities were obtained at sites located < 300 m above sea level. As the Maguari Stork is a conspicuous and charismatic species, its conservation could substantially benefit from the awareness of landowners to promote eco-tourism in their properties, attracting birdwatchers. For this, it should be ensured the integrity of grasslands, marshes, and lakes with microhabitats often used for nesting (woody plants and reed patches). Ciconia maguari America scarce Brazil database 6 1 3 municipalities 86% 86 (86% biome 1- young patches herons November December February 30 level ecotourism eco tourism properties birdwatchers this marshes woody . patches) 8 (86 (8 (

Abstract In Colombia, few studies have focused on nest architecture, behavior or sociality of wild bees. This study provides basic information on the nests of Caenohalictus alexandrei and presents behavioral observations outside the nests, derived from direct field observation of 40 nests and 39 male sleeping cavities in two localities of the Savanna of Bogota, Colombia. We recognized four different behavioral activities carried out by adult females: foraging, guarding, opening and closing of the entrance of the nest, with foraging being the most frequent of them. The observed activities were carried out more frequently from 9:00 h to 13:00 h. Males were observed performing two behavioral activities in the sleeping cavities: staying at the cavity entrance and cavity departure. A third male activity, corporal grooming, was carried out outside the sleeping cavity. Our field observations indicate that more than one adult female was active simultaneously performing the different tasks within a single nest. The nests presented different levels of complexity in their architecture, depending on the age of the nest and number of adult females in them. Descriptions of the nesting sites and behavioral activities as well as illustrations of the nest architecture are provided. Colombia bees 4 3 Bogota guarding them 900 9 00 9:0 1300 13 13:0 departure activity grooming provided 90 0 9: 130 1 13:

Estuarine waterbodies typically support diverse and abundant waterbird communities. However, global environmental degradation as a result of anthropogenic activities is leading to species level changes in biodiversity, with top predators such as piscivorous waterbirds being particularly vulnerable to ecosystem changes. The study aimed to document long-term spatial and temporal patterns of abundance of piscivorous and scavenging waterbirds in the Wilderness Lakes Complex (WLC) in the Garden Route National Park, South Africa, and where possible identify potential causes for observed trends. The abundance of waterbirds on these wetlands was determined biannually from 1992 to 2019, with counts conducted from a boat following a standardised route. Historical waterbird abundance data from the 1980s were also used to describe long-term abundance changes. Eight of the species exhibited seasonal variability in abundance with most, excluding Common Tern Sterna hirundo, being more abundant in winter. Substantial changes occurred in the abundance of several species over the four-decade study period, notably increases in Cape Cormorant Phalacrocorax capensis and Great Crested Grebe Podiceps cristatus, and decreases in Common Tern and Black-necked Grebe Podiceps nigricollis. Long-term abundance trends indicate a combination of declining, increasing, and stable populations. Although some species have undergone contrasting abundance changes on different waterbodies in the WLC the dominant pattern was a similar direction of change on most or all waterbodies and in different seasons. Local reasons for changes probably include loss of sandbanks, changing prey availability, and the absence of recreational disturbance on some waterbodies. CONSERVATION IMPLICATIONS: Drivers of changes in the abundances of piscivores are likely to be multifaceted, functioning on multiple spatial and temporal scales, and affecting different species in different ways. Recommended local corrective actions include managing emergent macrophyte encroachment on sandbanks, reducing recreational disturbance, managing processes affecting indigenous fish stocks, and protecting nesting sites

Abstract Knowledge about the selection of nesting sites in birds of prey is essential to carry out any management of a population for its conservation. The golden eagle generally chooses rock walls to nest, and this selection is influenced by the natural and anthropic characteristics of the landscape. In Mexico, studying the golden eagle is important because it has a cultural value as a patriotic symbol and biological role regulating its prey populations. In addition, it is listed under the Official Mexican Norm 059-SEMARNAT-2010 in the category of threatened and there is little published scientific information on its ecology and biology in the country. Therefore, this study determined the habitat variables that influence the selection patterns of golden eagle nesting sites in Janos, Chihuahua; for which nesting sites and sites with similar characteristics without the presence of the golden eagle were located for its characterization. The obtained data was analyzed through generalized linear models, taking the presence and absence of nests as the response variable and the habitat characteristics of the sites as predictor variables. Fifteen nesting sites and sixteen sites without nests were located. Of 15 variables measured, there was only a statistically significant difference in the height of the rock walls (W = 44.5, p = 0.003001). The model with the best fit had an AICc value of 20.6, explaining 68% of the variability of the data and includes the variables of height of the rock walls and the roughness of the terrain, the latter being statistically significant (p = 0.0279). Terrain roughness was present in four of the top five candidate models reflecting the importance of topography for nest site selection that can provide isolation from disturbance for eagles.

Resumen El conocimiento sobre la selección de sitios de anidación en aves rapaces es uno de los factores críticos para realizar cualquier manejo de una población para su conservación. El águila real generalmente elige paredes de roca para anidar, y esta selección está influenciada por las características naturales y antrópicas del paisaje. En México el estudio del águila real es importante debido a que tiene un valor cultural por ser un símbolo patrio y biológico por regular las poblaciones de sus presas, además, se encuentra listada en la Norma Oficial Mexicana 059-SEMARNAT-2010 en la categoría de amenazada y existe escasa información científica publicada sobre su ecología y biología en nuestro país. Por ello, se elaboró un estudio que determinó las variables de hábitat que influyen en los patrones de selección de sitios de anidación del águila real en Janos, Chihuahua. Se buscaron sitios de anidación de águila real y sitios semejantes sin presencia de la especie para tomar los datos de dichas variables; con esta información se analizaron los datos a través de modelos lineales generalizados, tomando como variable de respuesta la presencia y ausencia de nidos y las características del hábitat de los sitios como variables predictoras. Se localizaron 15 sitios de anidación y 16 sitios sin nidos; de 15 variables medidas solo existió diferencia estadística significativa en la altura de las paredes de roca (W = 44.5, p = 0.003001). El modelo con mejor ajuste tuvo un valor de AICc de 20.6, explicando el 68% de la variabilidad de los datos e incluye las variables de altura de las paredes de roca y la rugosidad del terreno, siendo esta última estadísticamente significativa (p =0.0279). La rugosidad del terreno y la altura de la pared de la roca que se presentaron en el mejor modelo reflejando la importancia de la topografía para la selección de sitios de anidación que puede proporcionar aislamiento de perturbaciones para las águilas.

Resumen El gorrión doméstico (Passer domesticus), una especie invasora en México, tiene plasticidad en sus requerimientos ecológicos y fisiológicos que le permiten competir por recursos alimenticios y sitios de anidación en asentamientos humanos. P. domesticus usurpa nidos de diversas especies de aves, pero se ha documentado poco su comportamiento agresivo para utilizar los nidos. En ésta nota, presento un caso de usurpación de nidos de la golondrina risquera (Petrochelidon pyrrhonota) por el gorrión doméstico en la localidad de Ixcateopan de Cuauhtémoc, Guerrero, México. Durante la temporada de invernación, cinco gorriones domésticos usurparon ocho nidos de 10 golondrinas risqueras. Éste trabajo incluye un nuevo caso de usurpación en P. pyrrhonota y P. domesticus para México y el Neotrópico. Ésta información puede ayudar a entender los efectos de una especie exótica en aves nativas que utilizan un mismo hábitat.

Abstract The House Sparrow (Passer domesticus), an invasive species in Mexico, has ecological and physiological plasticity that enables the species to compete for food resources and nesting sites in human-modified environments. P. domesticus usurps nests of several bird species, but its aggressive behaviour in nest usurpation has been poorly documented. In this note, I documented a case of nest usurpation of the Cliff Swallow (Petrochelidon pyrrhonota) by House Sparrows in the town of Ixcateopan de Cuauhtémoc, Guerrero, Mexico. During the wintering season, five House Sparrows usurped eight nests of 10 Cliff Swallows. This note includes a new case of usurpation for P. pyrrhonota and P. domesticus in Mexico and the Neotropics. This information can help to understand the effects of an exotic species on native birds that use the same habitat.

RESUMEN Las abejas sin aguijón (ASA) son organismos relevantes en los ecosistemas por su desempeño como polinizadores. En México, la mayor diversidad de ASA se encuentra en el sureste. En este estudio se determinaron las especies de ASA y densidad de nidos en dos sitios con diferente perturbación dentro de la Reserva de la Biósfera de los Petenes (RBLP) Campeche (México). Asimismo, se identificaron los sustratos y las especies arbóreas de nidificación. En total se realizaron diez muestreos en transectos entre los meses de enero a mayo de 2018. Se registraron 56 nidos pertenecientes a ocho especies diferentes de ASA (Cephalotrigona zexmeniae, Frieseomelitta nigra, Lestrimellita niitkib, Nannotrigona perilampoides, Partamona bilineata, Plebeia frontalis, Scaptotrigona pectoralis y Trígona fulviventris). Las especies con mayor número de nidos correspondieron a F. nigra (41,07 %) y S. pectoralis (28,57 %). No se encontraron diferencias significativas en la densidad de nidos entre los sitios Hecelchakán (2,15 nidos/ha) y Calkiní (0,19 nidos/ha). El sustrato preferido para anidación son las cavidades en árboles vivos (78,57 %). En total 15 especies arbóreas fueron identificadas como sustrato de nidificación y la especie más abundante correspondió a Crescentia cujete (n = 18, 40,9 %). El grado de perturbación tuvo poco efecto en el número y densidad de nidos de ASA, sin embargo, en general, la RBLP presentó una composición de especies y densidad de nidos reducida. Por lo tanto, este estudio permitió establecer las bases para futuros estudios sobre estrategias de manejo y conservación de estas especies para evitar su desaparición en la RBLP.

ABSTRACT Stingless bees (ASA) are relevant organisms in ecosystems because of their performance as pollinators. In Mexico, the higher diversity of ASA is found in the southeast. In this study, the ASA species and nest density of nests were identified at two sites with different disturbances (Hecelchakán and Calkiní) within the Petenes Biosphere Reserve (RBLP), Campeche (Mexico). Also, the substrates and the nesting tree species were identified. In total, ten sampling transects were performed between January and May 2018. In total 56 nests belonging to eight different species of ASA (Cephalotrigonazexmeniae, Frieseomelitta nigra, Lestrimellita niitkib, Nanotrigonaperilampoides, Partamona bilineata, Plebeia frontalis, Scaptotrigona pectoralis and Trigona fulviventris) were found. The species with the highest number of nests corresponded to F. nigra (41.07 %) and S. pectoralis (28.57 %). No significant differences were found in nest density between the Hecelchakán (2.15 nests/ha) and Calkiní (0.19 nests/ha) site. The preferred substrate for nesting is cavities in living trees (78.57 %). In total 15 tree species were identified as nesting substrate and the most abundant species corresponded to Crescentia cujete (n = 8, 40.90 %). The degree of disturbance had little effect on the number and density of ASA nest, however, in general, the RBLP presented low species composition and nest density. Therefore, this study allowed to establish the bases for future studies on management and conservation strategies of these species to avoid their loss in the RBLP.

Abstract This study characterized the physical, chemical, macro- and micromorphological soil properties from three successive marine terrace levels from Harmony Point (Nelson Island, Maritime Antarctica) in order to understand the pedological signatures of Quaternary coastal landscape evolution of Maritime Antarctica. Soils were sampled on the Late Holocene beach (current beach) and Mid Holocene marine terraces higher up, at 3, 8, and 12 m a.s.l. At the lower levels, the predominant soils were Gelorthents, whereas Haplogelepts dominate the higher terraces. Soil properties are mostly influenced by parent material and faunal activity, in which cryoclastic (thermal weathering) and phosphatization are the main soil-forming processes. Soils from the upper levels are more developed, deeper with reddish colors, granular structures and incipient formation B horizon. These horizonation features highlight that soils vary according with age of glacier-isostatic terrace uplift, representing a Quaternary soil chronosequence. All marine terrace levels are Ornithogenic soils, at varying degrees. However, the presence of old bird nesting sites for long periods led to formation of phosphatic horizons, stable Fe-phosphate minerals and abundant vegetation in the highest terraces of this part of Maritime Antarctica.