Proceedings of the Royal Society B: Biological Sciences This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Of molecules, memories and migration: M1 acetylcholine receptors facilitate spatial memory formation and recall during migratory navigation
Many animals use complex cognitive processes, including the formation and recall of memories, for successful navigation. However, the developmental and neurological processes underlying these cognitive aspects of navigation are poorly understood. To address the importance of the formation and recollection of memories during navigation, we pharmacologically manipulated turtles (Chrysemys picta) that navigate long distances using precise, complex paths learned during a juvenile critical period. We treated freely navigating turtles both within and outside of their critical learning period with a specific M1 acetylcholine rece...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Roth, T. C., Krochmal, A. R. Tags: behaviour, cognition Source Type: research

Exploring mechanisms and origins of reduced dispersal in island Komodo dragons
Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo dragon (Varanus komodoensis, the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Jessop, T. S., Ariefiandy, A., Purwandana, D., Ciofi, C., Imansyah, J., Benu, Y. J., Fordham, D. A., Forsyth, D. M., Mulder, R. A., Phillips, B. L. Tags: ecology Source Type: research

The hidden cost of sexually selected traits: the metabolic expense of maintaining a sexually selected weapon
Sexually selected weapons are among the most exaggerated traits in nature. Sexual selection theory frequently assumes a high cost of this exaggeration; yet, those costs are rarely measured. We know very little about the energetic resources required to maintain these traits at rest and the difference in energetic costs for the largest individuals relative to the smallest individuals. Knowledge in this area is crucial; resting metabolic rate can account for 30–40% of daily energy expenditure in wild animals. Here, we capitalized on the phenomenon of autotomy to take a unique look at weapon maintenance costs. Using Lept...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Somjee, U., Woods, H. A., Duell, M., Miller, C. W. Tags: behaviour, ecology, evolution Source Type: research

Calcium transfer across the outer mantle epithelium in the Pacific oyster, Crassostrea gigas
The objective of the present study was to characterize the Ca2+ transfer performed by the OME of the Pacific oyster, Crassostrea gigas, as well as to develop an Ussing chamber technique for the functional assessment of transport activities in epithelia of marine bivalves. Kinetic studies revealed that the Ca2+ transfer across the OME consists of one saturable and one linear component, of which the saturable component fits best to Michaelis–Menten kinetics and is characterized by a Km of 6.2 mM and a Vmax of 3.3 nM min–1. The transcellular transfer of Ca2+ accounts for approximately 60% of the total Ca2+ transfe...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Sillanpää, J. K., Sundh, H., Sundell, K. S. Tags: physiology, cellular biology Development and physiology Source Type: research

Real or fake? Natural and artificial social stimuli elicit divergent behavioural and neural responses in mangrove rivulus, Kryptolebias marmoratus
We examined behaviour and neural activity patterns in socially relevant brain nuclei of hermaphroditic mangrove rivulus fish (Kryptolebias marmoratus) provided with different types of social stimuli: stationary model opponent, regular mirror, non-reversing mirror and live opponent. We found that: (i) individuals faced with a regular mirror were less willing to interact with, delivered fewer attacks towards and switched their orientation relative to the opponent more frequently than fish exposed to a non-reversing mirror image or live opponent; (ii) fighting with a regular mirror image caused higher expression of immediate-...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Li, C.-Y., Hofmann, H. A., Harris, M. L., Earley, R. L. Tags: neuroscience, behaviour, cognition Neuroscience and cognition Source Type: research

Early bursts of disparity and the reorganization of character integration
‘Early bursts' of morphological disparity (i.e. diversity of anatomical types) are common in the fossil record. We typically model such bursts as elevated early rates of independent character change. Developmental theory predicts that modules of linked characters can change together, which would mimic the effects of elevated independent rates on disparity. However, correlated change introducing suboptimal states should encourage breakup (parcellation) of character suites allowing new (or primitive) states to evolve until new suites arise (relinkage). Thus, correlated change–breakup–relinkage presents mech...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Wagner, P. J. Tags: palaeontology, developmental biology, evolution Palaeobiology Source Type: research

Experimental disturbances reveal group-level costs of social instability
In group-living species, social stability is an important trait associated with the evolution of complex behaviours such as cooperation. While the drivers of stability in small groups are relatively well studied, little is known about the potential impacts of unstable states on animal societies. Temporary changes in group composition, such as a social group splitting and recombining (i.e. a disturbance event), can result in individuals having to re-establish their social relationships, thus taking time away from other tasks such as foraging or vigilance. Here, we experimentally split socially stable groups of captive zebra...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Maldonado-Chaparro, A. A., Alarcon-Nieto, G., Klarevas-Irby, J. A., Farine, D. R. Tags: behaviour Source Type: research

Carbon limitation of lake productivity
Phytoplankton productivity in lakes controls the rate of synthesis of organic matter that drives energy flow through the food webs and regulates the transparency and oxygen conditions in the water. Limitation of phytoplankton productivity and biomass by nutrients and light availability is an established paradigm for lake ecosystems, whereas invasion of atmospheric CO2 has been assumed to cover the high demands of dissolved inorganic carbon (DIC) during intense organic productivity. We challenge this paradigm, and show up to a 5-fold stimulation of phytoplankton productivity and biomass in outdoor mesocosms enriched with DI...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Kragh, T., Sand-Jensen, K. Tags: ecology, environmental science Source Type: research

Neonatal mice exposed to a high-fat diet in utero influence the behaviour of their nursing dam
In this study, we used a mouse model of high-fat (HF) diet feeding, which has been shown to influence maternal behaviours, combined with cross-fostering to discriminate between these effects. We tested whether the diet of the F0 dam or the exposure experienced by the F1 pups in utero is the most significant predictor of maternal behaviour. Neither factor significantly influenced pup retrieval behaviours. However, strikingly, F1 in utero exposure was a significant predictor of maternal behaviour in the 15 min immediately following pup retrieval while F0 diet had no discernable effect. Our findings suggest that in utero expo...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Baptissart, M., Lamb, H. E., To, K., Bradish, C., Tehrani, J., Reif, D., Cowley, M. Tags: behaviour, physiology, developmental biology Source Type: research

Prey abundance and urbanization influence the establishment of avian predators in a metropolitan landscape
Urbanization causes the simplification of natural habitats, resulting in animal communities dominated by exotic species with few top predators. In recent years, however, many predators such as hawks, and in the US coyotes and cougars, have become increasingly common in urban environments. Hawks in the Accipiter genus, especially, are recovering from widespread population declines and are increasingly common in urbanizing landscapes. Our goal was to identify factors that determine the occupancy, colonization and persistence of Accipiter hawks in a major metropolitan area. Through a novel combination of citizen science and a...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: McCabe, J. D., Yin, H., Cruz, J., Radeloff, V., Pidgeon, A., Bonter, D. N., Zuckerberg, B. Tags: ecology Source Type: research

A host immune hormone modifies parasite species interactions and epidemics: insights from a field manipulation
This study therefore experimentally links host immune hormones to within-host priority effects and parasite epidemics, advancing a more mechanistic understanding of how interactions among parasites alter their epidemics. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Halliday, F. W., Umbanhowar, J., Mitchell, C. E. Tags: ecology Source Type: research

Acute drivers influence recent inshore Great Barrier Reef dynamics
Understanding the dynamics of habitat-forming organisms is fundamental to managing natural ecosystems. Most studies of coral reef dynamics have focused on clear-water systems though corals inhabit many turbid regions. Here, we illustrate the key drivers of an inshore coral reef ecosystem using 10 years of biological, environmental, and disturbance data. Tropical cyclones, crown-of-thorns starfish, and coral bleaching are recognized as the major drivers of coral loss at mid- and offshore reefs along the Great Barrier Reef (GBR). In comparison, little is known about what drives temporal trends at inshore reefs closer to majo...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Lam, V. Y. Y., Chaloupka, M., Thompson, A., Doropoulos, C., Mumby, P. J. Tags: computational biology, ecology Source Type: research

Intraspecific brain size variation between coexisting sunfish ecotypes
Variation in spatial complexity and foraging requirements between habitats can impose different cognitive demands on animals that may influence brain size. However, the relationship between ecologically related cognitive performance and brain size is not well established. We test whether variation in relative brain size and brain region size is associated with habitat use within a population of pumpkinseed sunfish composed of different ecotypes that inhabit either the structurally complex shoreline littoral habitat or simpler open-water pelagic habitat. Sunfish using the littoral habitat have on average 8.3% larger brains ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Axelrod, C. J., Laberge, F., Robinson, B. W. Tags: neuroscience, ecology, evolution Neuroscience and cognition Source Type: research

Isogamy in large and complex volvocine algae is consistent with the gamete competition theory of the evolution of anisogamy
Although the gamete competition theory remains the dominant explanation for the evolution of anisogamy, well-known exceptions to its predictions have raised doubts about the completeness of the theory. One of these exceptions is isogamy in large or complex species of green algae. Here, we show that this exception may be explained in a manner consistent with a game-theoretic extension of the original theory: a constraint on the minimum size of a gamete may prevent the evolution of continuously stable anisogamy. We show that in the volvocine algae, both gametes of isogamous species retain an intact chloroplast, whereas the c...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: da Silva, J., Drysdale, V. L. Tags: evolution Source Type: research

An experimental test of the mutation-selection balance model for the maintenance of genetic variance in fitness components
We describe the underlying theory and use it to test the MSB model for three traits in Drosophila melanogaster. We find evidence for differences among traits, with MSB being sufficient to explain genetic variance in larval viability but not male mating success or female fecundity. Our results are consistent with balancing selection on sexual fitness components, and demonstrate the feasibility of rigorous statistical tests of the MSB model. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Sharp, N. P., Agrawal, A. F. Tags: genetics, evolution Source Type: research