Bird-window collisions in Costa Rica: taxonomic characterization, migratory status, geographic distribution and conservation

Worldwide, billions of birds die annually due to window collisions. Nevertheless, few accounts document bird-window collisions in the Neotropics. In this study, we document species that collided with windows in Monteverde, Costa Rica, and describe their ecological and conservation status. We gathered information from different sources, including data from museum records and accounts by Monteverde residents who participated as “citizen scientists” between May 2014 and December 2017. We conducted carcass searches between March 2015 and February 2016. We classified window-strike species by migratory, forest dependence, trophic guild, weight, abundance, conservation, and endemism status. We registered 103 species striking windows in Monteverde, which includes 98 of 267 species known to occur in three life zones in Monteverde and five not registered in the area. Window strike casualties’ frequencies differed by species, trophic guild and migratory status. Most window victims were residents, small, insectivorous, considered common or fairly common, with declining population trends. The families with the most species represented were Parulidae (14 spp.), Trochilidae (13 spp.), Turdidae (10 spp.), and Tyrannidae (9 spp.). Most species were passerines (Order Passeriformes) (71 spp.). No hawks or vultures were found colliding with buildings. The three species most commonly killed by windows were frugivores: Swainson’s Thrush (Catharus ustulatus), Northern Emerald-Toucanet (Aulacorhynchus prasinus), and Black-faced Solitaire (Myadestes melanops). Among window-kills were five species whose status on the IUCN Red List are Near Threatened and one Vulnerable, including the Resplendent Quetzal (Pharomachrus mocinno) and the Three-wattled Bellbird (Procnias tricarunculatus). Six species are listed as in danger of extinction and four are listed as species with reduced populations by the National System of Conservation Areas for Costa Rica (SINAC). 12 endemic species are strike casualties. The premontane wet forest is the life zone where more species were found (n=64 spp.), followed by the premontane moist forest (n = 49 spp.) and the lower montane wet forest (n = 31 spp.). These findings demonstrate the urgent need for conservation measures to mitigate bird mortality due to window collisions. Promoting use of methods to protect birds from windows should be an important goal for this IBA and the rest of Costa Rica. We also recommend collecting data in order to increase understanding about bird window collisions.

Bird-window collisions are an important cause of bird mortality worldwide. Reducing collisions requires understanding of the costs and benefits perceived by stakeholders. I consulted two focus groups, conducted 18-semi-strcutured interviews and applied surveys to 58 residents of Monteverde, Costa Rica, to understand their perception of the problem. Many reported collisions in their houses but there is a lack of information about the magnitude of the situation. Black silhouettes are the most frequent method of prevention, even though they are mostly ineffective. The main factors for selecting methods include unblocked views, aesthetics, effectiveness, ease of installation and removal, and ease of maintenance. The preferred effective method was cords (Acopian Bird Savers), and painted dots was the least liked. I recommend education about effective methods for Monteverde and similar communities.

Wetlands maintain high biodiversity and provide important habitat for many bird species, but now have strong pressure from anthropogenic activities. Birds in wetlands are important indicators of environmental changes and our goal was to characterize the bird community in the wetlands Palustrine Corral de Piedra as a mechanism for conservation of tropical dry forest of Costa Rica. We used point counts to describe bird richness and abundance in open (lakes and flooded grasslands) and wooded areas. We described habitat use and microhabitats, trophic guilds, biogeographic distribution and status in Costa Rica. We recorded 83 species of resident birds belonging to 36 families, of which 65 are resident species and 18 have some migratory status in Costa Rica. Secondary consumer species of small vertebrates corresponded to 45,8% and primary consumers were 25,3%. The birds mainly used trees for perching but use emergent shrubs, floating vegetation and water. We found a large number of Egrets, Flycatchers and Hawks playing important roles as pollinators, seed dispersers and predator is adding significant value to the ecological dynamics of forests and lakes in the area. Corral de Piedra has special importance as a site for the establishment of migratory birds and large number of resident species of conservation concern. We consider that joint efforts between residents and researchers are an important tool for bird conservation in the region.

Window strikes are among the most worrisome causes of bird mortality. Being responsible for billions of avian deaths, bird-window collisions have been widely studied in the US and Canada, with few studies from Europe, Asia, and Latin America. Thus, there is still a dearth of knowledge regarding this alarming phenomenon in regions where biodiversity and urbanization peek, such as Latin America. In this study, we assessed bird-window collisions in Xalapa, a small-to-medium-sized Neotropical city located in Southeast Mexico. We gathered data under two schemes: (1) a standardized survey procedure and (2) non-systematic records. Regarding the former, we evaluated the role of building and surrounding vegetation traits, as well as the location of focal buildings in driving bird-window collisions. Considering both schemes, we recorded bird-window collisions for 43 species. The most frequent striking groups were hummingbirds and thrushes, which had already been identified as vulnerable given some of their natural and life history traits. Regarding the standardized survey, we found no statistical differences in the number of collisions among seasons; yet, we did record a predominance of strikes from resident bird species over migrants among all studied seasons. Our results show a significant positive relationship between the amount of surrounding vegetation area of the studied buildings and bird-window collision frequency, while building non-glass material area showed a significant negative relationship. Based on our findings and the limitations of our study, we encourage future research to combine systematic and standard surveys throughout the year with citizen science, together with carcass removal assessments and bird density surveys in the immediate vicinity of focal buildings.

Bird collisions with buildings are an increasing concern and yet understanding the factors contributing to collisions at the species level remains largely unknown. This gap in our knowledge of species-specific strike patterns hinders the development of accurate estimates for the impact of death-by-collision on bird populations and impedes on our ability to minimize its effects. Our study offers the first examination of the impact of environmental variables on bird- window collisions at the species level. The Fatal Light Awareness Program Canada collected bird-window collision data in three distinct regions of Toronto, Canada during the migratory season of the years 2009 and 2010. Our results indicated that building percent window cover, exposed habitat cover, and cover of built structures significantly affect bird-window collisions. Multivariate analyses showed that the bird species that collided with buildings surrounded by a high level of urban greenery are species that typically occur in forested habitats and are foliage gleaners. In contrast, species that collided with buildings surrounded by a higher level of urbanization are species that typically occur in open woodland and are ground foragers. These results suggest that the composition of bird species colliding with buildings across various regions of the Greater Toronto Area is influenced by the local bird species community composition, by the configuration of the surrounding landscape, and by the levels of greenery around the buildings.

Bird–window collisions (BWCs) represent a source of mortality for both resident and migratory birds that researchers aim to quantify. Factors that limit carcass detection, including removal of carcasses by scavengers and inherent error in observer detection, can complicate these efforts. We combined 2 studies to examine what proportion of carcasses were scavenged and removed and how successful observers were at detecting bird decoys of multiple types. In fall 2019 and spring 2020, we deployed 40 bird carcasses at Radford University campus buildings and monitored visitation events with game cameras for up to 4 nights/5 days. Scavengers visited 31 of the carcasses and scavenged (disturbed but not removed) 14/31. Scavengers included Felis catus (Domestic Cat, n = 6 events), Mephitis mephitis (Striped Skunk, n = 3), and Procyon lotor (Raccoon, n = 3). All mammalian scavenging events were nocturnal. Cats visited carcasses without disturbing them (n = 22 events), whereas Raccoons (3/3 events) and Striped Skunks (3/4) scavenged carcasses on discovery. Mammals scavenged or removed 3 carcasses in the first night after deployment (e.g., in the first 14 h), suggesting that scavenging can cause daily surveyors to miss ∼7.5% of carcasses. Across spring and fall 2020, we deployed 60 decoys of 4 unique types (varying in color or shape), partially obscuring them under shrubs and along landscaped herbaceous vegetation. We found that observers detected 48% of the decoys on their first attempts (min–max: 8.7–100%). Decoy type did not affect observer detection. By our estimates, 2 observers per day could have collectively missed 27% of carcasses. Although BWC projects typically complete surveys once or twice daily, we suggest twice-daily surveys when monitoring BWC during migratory seasons and once-daily surveys at other times to minimize carcass loss due to scavenging.

For many years, it has been hypothesized that Neotropical migrants breeding in the United States and Canada accumulate organochlorine pesticides (OCPs) while on their wintering grounds in Latin America. We investigated the seasonal accumulation of persistent organic pollutant (POPs) in migrant and resident passerines in Texas, Yucatán, and Costa Rica collected during the fall, winter, and spring from 2011 to 2013. A total of 153 birds were collected, and all contained detectable levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and OCPs with dichlorodiphenyldichloroethylene (DDE) being the most predominant pesticide. OCPs and PCBs were the predominant contaminants, accounting for≥80% of the total POPs burden, whereas PBDEs accounted for≤16%. Only spring migrants from Texas had significantly greater DDE concentrations (64.6ng/gdry weight [dw]) than migrants collected in Costa Rica (23.2ng/gdw). Resident birds in Texas had significantly greater levels of DDE (121ng/g dw) and ΣPBDEs (34.8ng/gdw) compared with residents in Yucatán and Costa Rica. For ΣPCBs, resident birds from Costa Rica had significantly lower concentrations (9.60ng/gdw) compared with their migrant counterparts (43.7ng/gdw) and residents from Texas (48.3ng/gdw) and the Yucatán (32.1ng/gdw). Migrant and resident passerines had similar congener profiles for PCBs and PBDEs suggesting similar exposure and retention of these contaminants. No significant accumulation of DDE was observed in migrants while on their wintering grounds. Relatively high concentrations of PBDEs in resident birds from Costa Rica warrant future studies of PBDE contamination in Latin America.

Understanding the diversity and structure of bird communities is indispensable to delineate the importance of regional or local landscapes for avian conservation. The aim of the present study was to appraise community composition and threat status of avifauna of Bakhira Bird Sanctuary. The various species of birds were identified by using key references. During the study period 84 species of birds were identified. Maximum 15 species of birds were found to be belonging to order Anseriformes followed by minimum 2 species in Bucerotiformes and Gruiformes. We have enlisted 22 species of wetland birds in family Anatidae. However, only 1 species has been recognized in 11 different families. The documentation of the residential status of avifauna showed that 47 resident species (R), 28 migrant species (M) and 9 as resident migrant species (RM). According to the IUCN based categorization, maximum 86.90% species were recorded as least concerned (LC), followed by 1.19% endangered (EN), 4.76% near threatened (NT) and 7.14% vulnerable (VU). Guild based classification uncovered that maximum (44) birds were carnivorous and minimum (1) piscivorous. The result of our study concluded that Bakhira Bird Sanctuary is facing huge anthropogenic threats which include trapping and hunting of birds, habitat destruction by soil erosion, sedimentation and extension of crop fields, water pollution and eutrophication.

Bird-window collisions (BWCs) constitute a significant source of mortality for both resident and migratory birds. Because windows reflect surrounding landscape components, such as vegetation or sky, birds do not always perceive glass as a barrier. Here we demonstrate a novel technique to classify and quantify reflections in windows on the Radford University campus in southwest Virginia, U.S.A. We deployed a consumer-grade Unmanned Aerial Vehicle, i.e., drone, to photograph 14 contiguous or near-contiguous window columns across five campus buildings in August 2020. For each study aspect, the drone (equipped with an RGB camera) captured images at ca. 5 m altitudinal increments from the ground floor to the roof of each building (three to six images/vertical column). We then manually classified each image in ImageJ to calculate approximate proportions of reflected: (1) vegetation, (2) sky, (3) and artificial structures or impervious surfaces, plus (4) nonreflective glass. We used a generalized linear model to determine how proportional reflections of vegetation, sky, buildings, and nonreflective glass varied across vertical increments. We found the proportion of sky significantly decreased with increasing photo heights, whereas proportion of nonreflective glass significantly increased with increasing heights. This supports previous findings that because birds are drawn to sky reflections, they may collide at relatively lower positions on buildings. Inconsistency in landscape design and building positioning on the campus precluded trends in vegetative or building reflections by height. Our pilot study demonstrates the applicability of a consumer-grade drone for investigating visual characteristics of reflections that influence BWCs from variable observation angles. We suggest the expanded use of drone images as a straightforward technique to measure changes in reflection characteristics from varying degrees of observation. They are a novel method in developing a BWC risk assessment as well as potential mitigation strategies in a suburban or campus environment with buildings of intermediate heights.

We used fecal samples collected from birds captured in mist nets to determine the occurrence of fruit in the diets of neotropical migrant birds (species that breed in North America and winter in Central and South America) at six study sites in Costa Rica. A total of 1016 migrants representing 30 species were captured. Fecal samples were collected from 85 percent of all birds captured. Fruits (seeds, pulp) occurred in 58 percent of all fecal samples; the proportion of fecal samples containing fruit ranged from 0 percent (9 species) to over 90 percent (9 species). Individual fecal samples contained seeds from as many as 4 species of plants. At least 98 plant species from at least 29 plant families were represented in fecal samples. Species of Melastomataceae accounted for 37 percent and those of Rubiaceae for 16 percent of all species recorded. Number of fruit species in diets of individual migrant species ranged from 0 (9 species) to 63 (Swainson's Thrush, Catharus ustulatus). Our data demonstrate that some migrants may rival permanent residents in the diversity of fruits they consume. A shift to increased frugivory in the late dry season, as birds were preparing to migrate north, was noted.

SUMMARY Tropical America (TA) holds 8% of the world's population, 11% of the world's continental area, 23% and 22%, respectively, of the world's forest and water resources, and 13% of the world's pasture and agro-pastoral land, this representing 77% of TA's agricultural land. Recent interest in carbon sequestration and preliminary research suggest that well-managed pasture systems in TA could provide a good combination of economic production, poverty reduction, recovery of degraded areas and delivery of environmental services, particularly, carbon sequestration. This paper presents 3-year research results generated by the “Carbon Sequestration Project, The Netherlands Cooperation CO-01002” on soil carbon stocks (SCS) for a range of pasture and silvo-pastoral systems prevalent in agro-ecosystems of TA compared to native forest and degraded land. In the tropical Andean hillsides, Colombia (1350-1900 m.a.s.L, 1800 mm rainfall/yr, 14-18°C mean annual temperature, medium to high slopes, medium fertility soils), SCS from Brachiaria decumbenspastures were statistically lower than those from native forest, but higher than those from natural regeneration of a degraded pasture (fallow land), degraded pasture and mixed-forage bank. In contrast, in the humid tropical forest of the Atlantic Coast, Costa Rica (200 ma.s.L, 28-35°C, 3500 mm/year, poor acid soils), pasture or silvo-pastoral systems with native or planted pasture species such as Ischaemum ciliare, Brachiaria brizantha + Arachis pintoiand Acacia mangium + Arachis pintoishowed statistically higher SCS than native forest. Similar rankings were found in the humid tropical forest of Amazonia, Colombia (800 ma.s.L, 30-42°C, 4200 mm/yr, flat, very poor acid soils) where improved Brachiariapastures (monoculture and legume-associated) showed statistically higher SCS than native forest. In the sub-humid tropical forest of the Pacific Coast, Costa Rica (200 ma.s.L, 6-monfh dry season, 2200 mm/year, poor acid soils) no statistical differences in SCS were found between land-use systems. In tropical ecosystems, improved pasture and silvo-pastoral systems show comparable or even higher SCS than those from native forests, depending on climatic and environmental conditions (altitude, temperature, precipitation, topography and soil), and represent attractive alternatives as C-improved systems.

A good immune condition imposes an energetic cost and depends on many factors such as stressful situations and extenuating activities, especially for migratory birds. The energetic demands during migration may be compromised due to limited food availability, higher predation risks or novel diseases. We collected blood samples in the adults of three species of sparrows with different migratory status in central Mexico: the Clay-coloured Sparrow Spizella pallida (long distance migrant), the Chipping Sparrow S. passerina (local and long distance migrant individuals present at the study site), and the Black-chinned Sparrow S. atrogularis (permanent resident). These were used to compare the immune condition through analyses of their leukocyte profiles, the heterophil/lymphocyte (H/L) ratio and the presence of blood parasites. We found differences in the immune condition: the resident species showed a lower percentage of lymphocytes than the long distance migrant, and also had more heterophils and a higher H/L than the two migratory species. We found that body mass was not related to the leukocyte parameters. Trypanosoma was recorded in the three bird species. The Chipping Sparrow was the most parasitised, followed by the Black-chinned Sparrow. Intensity of infection in the Chipping Sparrow and the Black-chinned Sparrow was correlated with changes in the abundance of lymphocytes. Our results suggest that the resident species had a reduced immune condition compared to the two migratory species, while the presence of parasites and the intensity of parasitism did not differ between species. This is the first study that evaluates and compares the immunological condition and blood parasitism in three congeneric species of birds with different migratory status.

A description is provided for Meliola trichostroma . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Meliola trichostroma parasitizes a cultivated plant very frequent in tropical America, but without the production of evident symptoms of any disease in the host. HOSTS: Psidium araca, P. guajava, P. guineense, P. pomiferum . GEOGRAPHICAL DISTRIBUTION: Brazil, British Guiana, Colombia, Costa Rica, Cuba, Ecuador, Honduras, Jamaica, Nicaragua, Panama, Paraguay, Puerto Rico, Dominican Republic, Surinam, Trinidad & Tobago, Venezuela. TRANSMISSION: By air-borne ascospores.

To advance our limited knowledge of global mosquito biogeography, we analyzed country occurrence records from the Systematic Catalog of the Culicidae (http://www.mosquitocatalog. org/main.asp), and we present world maps of species richness and endemism. A latitudinal biodiversity gradient was observed, with species richness increasing toward the equator. A linear log-log species (y)-area (x) relationship (SAR) was found that we used to compare observed and expected species densities for each country. Brazil, Indonesia, Malaysia, and Thailand had the highest numbers of species, and Brazil also had the highest taxonomic output and number of type locations. Brazil, Australia, the Philippines, and Indonesia had the highest numbers of endemic species, but excluding small island countries, Panama, French Guiana, Malaysia, and Costa Rica had the highest densities of total species and endemic species. Globally, 50% of mosquito species are endemic. Island countries had higher total number of species and higher number of endemic species than mainland countries of similar size, but the slope of the SAR was similar for island and mainland countries. Islands also had higher numbers of publications and type locations, possibly due to greater sampling effort and/or species endemism on islands. The taxonomic output was lowest for some countries in Africa and the Middle East. A consideration of country estimates of past sampling effort and species richness and endemism is proposed to guide mosquito biodiversity surveys. For species groups, we show that the number of species of Anopheles subgenus Anopheles varies with those of subgenus Cellia in a consistent manner between countries depending on the region. This pattern is discussed in relation to hypotheses about the historical biogeography and ecology of this medically important genus. Spatial analysis of country species records offers new insight into global patterns of mosquito biodiversity and survey history.

The tropical montane cloud forests (TMCF) of the Talamanca Mountains of Costa Rica are a unique and understudied habitat that is home to a high number of endemic bird species. Cloudbridge Nature Reserve is a TMCF reforestation reserve lying on the Pacific slope of Cerro Chirripó in the cantón of Pérez Zeledón. Here, we synthesize data collected at Cloudbridge between March 2016 and May 2020 from multi-year point count, walking, call-playback, and camera trap surveys along with photographs collected from February 2007 to April 2021 to present a bird species inventory of the reserve. In total, 204 bird species from 40 families, including 40 endemic species, were identified, and monthly presence summarized for each species. We discuss the implications of our findings for understanding TMCF avian communities, as well as the importance of year-round surveys using a variety of techniques to better capture overall avian diversity.