Exceptional preservation of a Late Cretaceous dinosaur nesting site from Mongolia reveals colonial nesting behavior in a non-avian theropod

Geology ◽  
2019 ◽  
Vol 47 (9) ◽  
pp. 843-847 ◽  
Author(s):  
Kohei Tanaka ◽  
Yoshitsugu Kobayashi ◽  
Darla K. Zelenitsky ◽  
François Therrien ◽  
Yuong-Nam Lee ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Bird Species ◽  
Nesting Behavior ◽  
Gobi Desert ◽  
Exceptional Preservation ◽  
Colonial Nesting ◽  
Nesting Site ◽  
High Concentrations ◽  
Lithologic Unit ◽  
Nesting Season

Abstract Colonial nesting behavior has been inferred in a variety of non-avian dinosaurs based on high concentrations of nests preserved in an area, but sedimentologic and taphonomic evidence demonstrating the contemporaneity of the nests is often lacking. A new nesting site discovered in the Upper Cretaceous Javkhlant Formation of the eastern Gobi Desert, Mongolia, preserves at least 15 egg clutches laid by a probable non-avian theropod, and provides strong evidence for colonial nesting in a non-avian dinosaur. The occurrence of the clutches at the top of a common paleosurface, the distribution of eggshell fragments within clutches, the presence of a consistent two-layer sediment infill within eggs, and a thin marker lithologic unit blanketing all the clutches indicate the clutches were laid and hatched in a single nesting season. Despite the absence of sedimentologic evidence indicative of nest structure, statistical analyses of egg characteristics and facies association reveal the clutches were likely incubated in covered or buried nests. Based on the number of hatched clutches, the hatching success rate of the colony was high (60%), similar to that of extant crocodylian populations and bird species that attend and/or protect their nests during the incubation period, which indicates nest attendance behavior in the Javkhlant theropods. Thus, colonial nesting with parental attendance, widespread in extant birds, likely evolved initially among non-brooding, non-avian dinosaurs to increase nesting success.

LITHOBIOTOPES OF THE NEMEGT GOBI BASIN

2021 ◽  
Author(s):  
Tomasz Jerzykiewicz ◽  
Philip J. Currie ◽  
Federico Fanti ◽  
Jerzy Lefeld
Keyword(s):  
Upper Cretaceous ◽  
Alluvial Plain ◽  
Gobi Desert ◽  
Large Species ◽  
Physical Processes ◽  
Desert Region ◽  
Ephemeral Channels ◽  
Temporal Succession ◽  
Asymmetric Distributions ◽  
Rich Fauna

Three distinct but overlapping dinosaur-dominated faunas characterize the Upper Cretaceous Djadokhta, Baruungoyot and Nemegt formations of the Nemegt Basin of Mongolia. Documented faunal differences cannot be explained easily by temporal succession, but can be understood in the light of physical processes controlling life, death, and burial of taxa. The stratigraphy of the Gobi Desert region records tectonically driven geometries, clearly documenting preservational processes different than those acting in most other dinosaur-dominated beds worldwide. Small, asymmetric tectonic grabens were filled with Upper Cretaceous, dinosaur bearing deposits showing asymmetric distributions of facies, here termed Lithobiotopes. The water-lain fluvial and alluvial plain facies of the Nemegt Lithobiotope supported and preserved a fauna dominated by gigantic dinosaurs, but had a preservational bias against smaller animals. The Nemegt passed laterally into interdune facies of the Baruungoyot Lithobiotope, which represented a hostile environment for large species, but preserved smaller animals. This in turn passed laterally into the aeolianite facies of the Djadokhta Lithobiotope, which is characterized by remains of small dinosaurs and a rich fauna of other animals. The Nemegt Gobi Basin can be visualized as an oasis with a central pond supplied with water from ephemeral channels and surrounded by a semi-arid alluvial plain and dune fields.

scholarly journals Geochemistry of strontium in fresh underground waters of the Sredneobskoy basin (Tomsk region, Russia)

2019 ◽  
Vol 98 ◽  
pp. 01024
Author(s):  
Irina Ivanova
Keyword(s):  
Chemical Composition ◽  
Upper Cretaceous ◽  
Biologically Active ◽  
Strontium Content ◽  
Rock Interaction ◽  
Underground Waters ◽  
Tomsk Region ◽  
Resident Time ◽  
High Concentrations ◽  
Water Rock Interaction

In the central part of Western Siberia a study of the chemical composition of fresh underground waters in the upper 600 m of the Sredneobskoy artesian basin was carried out. It was shown that underground waters generally contain high concentrations of strontium. The minimum concentrations of Sr are typical for Neogene-Quaternary sediments (600 µg/L), maximum values in the waters of the Upper Cretaceous sediments (more than 1300 µg/L). The study of strontium accumulation mechanisms in drinking underground waters is undoubtedly an important issue, as strontium is a biologically active element. Especially dangerous is the consumption of underground waters with a calcium-strontium ratio less than 100, that is the hydrogeochemical precondition for Urov endemic (Kashin-Beck disease). According to the calcium/strontium ratios data waters of the Neogene-Quaternary and Paleogene sediments selected in the south-western part of the Tomsk region are unsuitable for drinking water supply. Underground waters are shown to be in equilibrium with Al and Fe hydroxides; Ca, Mg, Fe carbonates; and clay minerals, including ferruginous. Increased strontium content in aquifers is determined not only by the chemical composition of the water-bearing rocks, but also increasing resident time of water rock interaction.

Frequency and distribution of behaviour of red-necked grebes breeding colonially and in classic territories

Behaviour ◽  
2004 ◽  
Vol 141 (3) ◽  
pp. 263-277 ◽  
Author(s):  
Paul Klatt ◽  
Gary Nuechterlein ◽  
Deborah Buitron
Keyword(s):  
Egg Laying ◽  
Female Aggression ◽  
Large Lake ◽  
Colonial Nesting ◽  
Close Proximity ◽  
Solitary Males ◽  
Podiceps Grisegena ◽  
Insight Into ◽  
Grebe Species ◽  
Nesting Season

AbstractOver the two-year period, 1997 to 1998, nearly half of a population of over 200 red-necked grebes (Podiceps grisegena) breeding within a large lake (2,537 ha) in central Minnesota, chose to opportunistically nest in concentrated groups on large floating mats of cattail (Typha spp.). In this study, we examined how members of this typically territorial grebe species coped with living in a more social environment. The behaviour of pairs that nested close to conspecifics differed from that of solitary pairs throughout the nesting season. Colonial pairs tended to be less likely than solitary birds to leave their nest vacant and unguarded from competitors or predators. During the pre-nesting stage, colonial females and males spent more of their time in aggression than did solitary-nesting birds. However, after a pair established their nest and egg-laying began, female aggression declined dramatically in both colonial and solitary pairs. During the egg-laying period, females spent significantly more time on the nest than did males, while males were more active than females in nest defense. Throughout the incubation period, colonial males remained closer to the nest and their females than did solitary males. In general, birds nesting in close proximity exhibited a compressed use of the space surrounding their investments in the platform, mate, eggs, and even young, all of which may have become more vulnerable to competitors and predators in areas of higher aggregation. Examining how opportunistically colonial species adapt to breeding in close aggregations may provide insight into the early evolution of colonial nesting birds.

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

2021 ◽  
Vol 10 (2) ◽  
pp. 54-60
Author(s):  
Yuri Gennadievich Lamekhov ◽  
Marina Anatolyevna Bulanova ◽  
Elena Anatolyevna Lamekhova
Keyword(s):  
Elimination Rate ◽  
Bird Species ◽  
Common Reed ◽  
Early Ontogeny ◽  
Early Ontogenesis ◽  
Colonial Nesting ◽  
Larus Ridibundus ◽  
Colonial Bird ◽  
Research Objects ◽  
Colonial Settlement

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.

Avian dispersal of Frankia

1993 ◽  
Vol 71 (8) ◽  
pp. 1128-1131 ◽  
Author(s):  
Mark W. Paschke ◽  
Jeffrey O. Dawson
Keyword(s):  
Key Words ◽  
Host Species ◽  
Bird Species ◽  
Alnus Glutinosa ◽  
Nest Building ◽  
Elaeagnus Umbellata ◽  
High Concentrations ◽  
Central Illinois ◽  
Serial Dilutions

Nests of six common bird species in central Illinois, U.S.A. were collected and examined for the presence of Frankia capable of infecting Alnus glutinosa and Elaeagnus umbellata. Serial dilutions of nest extracts were used in a bioassay to estimate the number of Frankia nodulation units for these two host species in each nest. Nests of two bird species contained soil as a nest component and had high concentrations of Frankia nodulation units. Nests of two bird species that did not use soil in nest building also had relatively high levels of Frankia. Results indicate that some bird species can transport Frankia, possibly by moving soil for nest building and also by other unknown mechanisms. Key words: actinorhizae, bioassay, bird nests, Frankia dispersal, Alnus glutinosa, Elaeagnus umbellata.

scholarly journals Multiple Dinosaur Egg-Shell Occurrence in an Upper Cretaceous Nesting Site from Patagonia

Ameghiniana ◽  
2010 ◽  
Vol 47 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Rodolfo A. Coria ◽  
Leonardo Salgado ◽  
Luis M. Chiappe
Keyword(s):  
Upper Cretaceous ◽  
Nesting Site ◽  
Egg Shell

scholarly journals Annual Mortality Limit for Four Gull Species in the Atlantic Flyway

2021 ◽  
Vol 12 (2) ◽  
pp. 453-463
Author(s):  
Mark E. Seamans ◽  
Chris Dwyer
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Demographic Data ◽  
Bird Species ◽  
Recovery Factor ◽  
Herring Gulls ◽  
Colonial Nesting ◽  
Atlantic Flyway ◽  
Laughing Gulls

Abstract 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.

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