Biscayne National Park colonial nesting birds monitoring protocol—Version 1.1

Breeding colonies of wading birds (orders Ciconiiformes, Pelecaniformes) and seabirds (orders Suliformes, Pelecaniformes) serve as important indicators of aquatic ecosystem health, as they respond to changes in food abundance and quality, contaminants, invasive species, and disturbance. The Comprehensive Everglades Restoration Plan, Restoration Coordination & Verification program (CERP-RECOVER) has identified wading-bird colonies as an important ecosystem restoration indicator. The National Park Service South Florida/Caribbean Inventory & Monitoring Network (SFCN) ranked colonial nesting birds eighth out of 44 vital signs of park natural resource conditions for ecological significance and feasibility. However, while large-scale monitoring efforts are occurring in the rest of the Greater Everglades Ecosystem, only minimal historic data collection and no extensive ongoing monitoring of wading bird and seabird nesting have occurred in Biscayne National Park. Consequently, due to their high importance as biological indicators and because they are a gap occurring in regional monitoring efforts, the network has initiated a monitoring program of colonial nesting birds in Biscayne National Park. This protocol provides the rationale, approach, and detailed Standard Operating Procedures for annual colonial bird monitoring within and close to Biscayne National Park and conforms to the Oakley et al. (2003) guidelines for National Park Service long-term monitoring protocols. The specific objectives of this monitoring program are to determine status and long-term trends in: Numbers and locations of active colonies of colonial nesting birds with a special focus on Double-crested Cormorants, Great Egrets, Great White Herons, Great Blue Herons, White Ibises, and Roseate Spoonbills. Annual peak active nest counts of colonial nesting birds in Biscayne National Park with a special focus on the species mentioned above. An annual nesting index (i.e., sum of monthly nest counts) with a special focus on the species mentioned above. Timing of peak nest counts for the focal species.

Earliest evidence of herd-living and age segregation amongst dinosaurs

Sauropodomorph dinosaurs dominated the herbivorous niches during the first 40 million years of dinosaur history (Late Triassic–Early Jurassic), yet palaeobiological factors that influenced their evolutionary success are not fully understood. For instance, knowledge on their behaviour is limited, although herding in sauropodomorphs has been well documented in derived sauropods from the Late Jurassic and Cretaceous. Here we report an exceptional fossil occurrence from Patagonia that includes over 100 eggs and skeletal specimens of 80 individuals of the early sauropodomorph Mussaurus patagonicus, ranging from embryos to fully-grown adults, with an Early Jurassic age as determined by high-precision U–Pb zircon geochronology. Most specimens were found in a restricted area and stratigraphic interval, with some articulated skeletons grouped in clusters of individuals of approximately the same age. Our new discoveries indicate the presence of social cohesion throughout life and age-segregation within a herd structure, in addition to colonial nesting behaviour. These findings provide the earliest evidence of complex social behaviour in Dinosauria, predating previous records by at least 40 My. The presence of sociality in different sauropodomorph lineages suggests a possible Triassic origin of this behaviour, which may have influenced their early success as large terrestrial herbivores.

Heronry distribution and site preference dynamics of tree-nesting colonial waterbirds in Tamil Nadu

Anthropogenic disturbance and climate change have significantly affected the distribution of wetlands globally and particularly in Asian countries. Various types of wetlands are harboured across all the biogeographic zones in India. These wetlands provide vital ecological services and are rich in biodiversity. However, anthropogenic pressures continue to be a threat to these wetlands by affecting the flora and fauna that depend on them. Tree-nesting colonial waterbirds are vulnerable to these pressures as their colonies are typically located in wetlands and associated areas. Disturbances to these areas have resulted in the loss or shifting of many heronries. The present study was conducted in the Indian state of Tamil Nadu during the period of 2017–2019 to document the existing and previously unknown heronries of the landscape. A total of 101 heronries were documented in 22 districts. The Little Cormorant was the most dominant species, occurring in 79% of the sites, with relative abundances of 24% and 26% during 2017–2018 and 2018–2019, respectively. A total of 23 tree species were utilized by the birds for nesting and Vachellia nilotica trees were used for nesting in about 25% of the heronries. 19% of the heronries were situated inside protected areas and 81% were located outside protected areas. Out of the 58 active nesting sites reported in 2005, 43 have been lost or are no longer active. Species distribution modelling with presence only data indicated that the sites with a high probability of occurrence were confined to the major waterbodies and rivers. Spatial correlation showed that the heronries were dispersed randomly across the landscape. The population dynamics within heronries and colonial nesting waterbirds’ response to various environmental factors must be monitored continuously to conserve these heronries.

Annual Mortality Limit for Four Gull Species in the Atlantic Flyway

We estimated the allowable annual take of great black-backed gulls Larus marinus, herring gulls L. argentatus, ring-billed gulls L. delawarensis, and laughing gulls Leucophaeus atricilla in the U.S. portion of the Atlantic Flyway to help meet human safety and resource management goals. Gulls can pose a serious threat to aviation, negatively impact other colonial-nesting migratory bird species, and conflict with other human activities. We estimated an annual take limit using a model that incorporated intrinsic population growth rate, minimum population size, and a recovery factor for each species. We estimated intrinsic population growth by combining allometric with life table approaches. We used the recovery factor to restrict the take level of the great black-backed gull beyond that of the other species because of poor data quality and concern about its population status. The herring gull was the only species with comprehensive demographic data. Population sizes used in estimating potential take limit varied greatly among the four species, but estimates of intrinsic population growth rate were similar (range 0.118 to 0.197). The annual potential take limits for the four gull species were 7,963 for herring gulls, 2,081 for great black-backed gulls, 15,039 for laughing gulls, and 14,826 for ring-billed gulls. Comparing average annual take from 2012–2019 to our modeled potential take limit, overharvest has not occurred for great black-backed and laughing gulls, occurred once every 8 y for ring-billed gulls, and occurred over half the time for herring gulls.

General characteristics of the intensity of elimination in the early ontogenesis of colonial bird species

This paper examines the rate of elimination in the early ontogeny of colonial bird species. The research objects were colonial nesting species - black-necked gull ( Larus ridibundus L.) and black-necked grebe ( Podiceps nigricollis C.L. Brehm), which form monospecific and poly-species colonial settlements. The rate of elimination was determined taking into account the stage of completion of the clutch, as well as the position of the nest in the structure of the colonial settlement: in the biological center or at the periphery of the colony. The nesting life of colonially nesting species was studied according to the generally accepted method, taking into account the choice of a place for building a nest by birds, the morphology of the nest, the intensity of oviposition and other characteristics. In the course of many years of research 3 types of nest placement within the colony have been identified. The maximum elimination rate has been proven for fixing the nest on the floodplain of common reed. The minimum rate of elimination was found for black-headed gull nests built on the fold of common reed ( Phragmites australis ) and narrow-leaved cattail ( Typha angustifolia ). Near-nesting vegetation is located around the nests of black-necked gull and black-necked grebe. The variant of placing vegetation around the nest prevails. Less common are options in which vegetation is located on one side. Observations have not revealed a relationship between the rate of elimination and the nature of the distribution of vegetation around the nest. The authors have compared the rate of elimination of black-headed gull nests located in the biological center and at the periphery of the colony. Elimination is possible both during the laying of the first egg and after the end of the clutch. Observations have shown that the rate of elimination is higher for nests from the periphery of the colony, which may be associated with differences in the size of the nests, the rate of their construction, as well as with the behavior of birds incubating eggs. The maximum rate of elimination of nests and eggs at the periphery of the colony is also manifested in the early ontogenesis of the black-necked grebe. The intensity of elimination and the forms of its manifestation affect the structure of the colonial settlement of birds and characterize the level of individual and group adaptation of birds to the conditions in which the nesting period takes place.

Sex-specific effects of cooperative breeding and colonial nesting on prosociality in corvids

The investigation of prosocial behavior is of particular interest from an evolutionary perspective. Comparisons of prosociality across non-human animal species have, however, so far largely focused on primates, and their interpretation is hampered by the diversity of paradigms and procedures used. Here, we present the first systematic comparison of prosocial behavior across multiple species in a taxonomic group outside the primate order, namely the bird family Corvidae. We measured prosociality in eight corvid species, which vary in the expression of cooperative breeding and colonial nesting. We show that cooperative breeding is positively associated with prosocial behavior across species. Also, colonial nesting is associated with a stronger propensity for prosocial behavior, but only in males. The combined results of our study strongly suggest that both cooperative breeding and colonial nesting, which may both rely on heightened social tolerance at the nest, are likely evolutionary pathways to prosocial behavior in corvids.