Calendar 2023

2023 marks the 100th anniversary of JEB

As part of our celebration of 100 years of discovery, the 2023 JEB calendar features some of the images that have appeared on the front cover of the journal during this time. Further information about the images, together with a link to the associated research papers, can be found below.

We would like to thank all the authors who have provided cover images over the years, allowing us to showcase the huge variety of animals and physiological systems featured in the journal.

If you are attending the Society for Integrative and Comparative Biology (SICB) annual meeting in Austin, Texas, in the first week of January, be sure to visit The Company of Biologists' stand and pick up a copy of the calendar for your desk.

The raccoon's adaptability and heightened success in cities is often attributed to their cleverness. Yet, little is known about the cognition of raccoons, especially in wild populations. Stanton et al. employed advanced techniques to study the behavior and cognitive abilities of raccoons in the field using automated operant-conditioning devices. They found that although most raccoons excelled at tests of learning, they varied in their behavior and performance, probably as a result of multiple factors including age and personality. Photo credit: Melissa Groo.

Environmental, individual and social traits of free-ranging raccoons influence performance in cognitive testing
Lauren A. Stanton, Eli S. Bridge, Joost Huizinga, Sarah Benson-Amram

Some insects rhythmically compress large segments of their tracheal systems. The image on the right is a composited, high-resolution x-ray radiograph of the carabid beetle Pterostichus stygicus, a species that displays this behavior. Socha and colleagues used synchrotron x-ray phase contrast imaging to visualize internal tracheal dynamics in living P. stygicus beetles. Concurrent respiratory recordings show that one function of rhythmic tracheal compression is to convectively expel air from the body. Photo by Jake Socha; x-ray image by Jake Socha and Wah-Keat Lee.

Correlated patterns of tracheal compression and convective gas exchange in a carabid beetle
John J. Socha, Wah-Keat Lee, Jon F. Harrison, James S. Waters, Kamel Fezzaa, Mark W. Westneat

Image of a common carp Cyprinus carpio swimming through a 3D representation of the protein myoglobin. Using large-scale genomic screening technologies it has recently been identified that myoglobin is expressed in a range of important tissues other than muscle, for which it is already well known. Photo credit: Image generated by kmcreative.co.uk; copyright A. Cossins.

Special Issue: Post-genomic and systems approaches to comparative physiology and integrative biology - Guest editors' introduction
Andrew Cossins, George Somero

April

Hatchling green sea turtles scramble down the beach and then swim franticly for up to 24 h to escape the predator rich near-shore waters surrounding their nesting beach. Booth fitted lycra harnesses to hatchling green turtles and swam them in a chamber to measure their swimming effort and oxygen consumption simultaneously for the first 18 h after entering the water. Swimming effort and oxygen consumption were greatest during the first 2 h, decreased steadily from 2 to 12 h and plateaued to a sustainable level from 12 to 18 h. Photo credit: Nick Holmes.

Swimming for your life: locomotor effort and oxygen consumption during the green turtle (Chelonia mydas) hatchling frenzy
David T. Booth

May

Sea otter in Simpson Bay, Alaska. The photo shows the blunt carnassial teeth in which hard food items are placed during biting events. Timm-Davis et al. demonstrate that durophagy in sea otters is a specialized raptorial biting feeding mode. Their extreme blunt skull and mandibles, along with increased mechanical advantages of the masseter and increased bite force, form a repertoire of functional traits for durophagy. The kinematic data indicate innovations for the production of large bite forces at extreme wide gapes and gape angles. This image was taken under USFW permit number MA078744-4. Photo credit: Alice Cove Research.

Durophagous biting in sea otters (Enhydra lutris) differs kinematically from raptorial biting of other marine mammals
Lori L. Timm-Davis, Randall W. Davis, Christopher D. Marshall

June

Characterised by colourful claws and close-set eyestalks, a female fiddler crab (Uca vomeris) is feeding outside her burrow. These crabs live on intertidal mudflats, where they are vulnerable to predation. Despite carrying their eyes on high 'observation towers' that provide a 360 deg panoramic view, poor resolution and limited depth perception make it difficult to distinguish friends from foes at a safe distance. Fiddler crabs learn, though, to ignore approaching objects they have experienced to be harmless. This process, called habituation, is shown by Raderschall and colleagues to be accomplished by associative learning, which is in contrast to the traditional notion of habituation. Photo credit: J. M. Hemmi.

Habituation under natural conditions: model predators are distinguished by approach direction
Chloé A. Raderschall, Robert D. Magrath, Jan M. Hemmi

July

The hydromedusa Colobonema sericeum lives at depths around 400 m in the temperate Pacific Ocean. The structural colours at either side of the swimming bell are associated with a thin epithelial layer of regularly arranged circular muscle fibres that can generate both fast and slow swimming. However, the giant axons that conduct impulses during fast swimming in some related species are absent in C. sericeum. This observation has allowed Meech et al. to pinpoint the phylogenetic branch point leading to giant axon-based swimming in the Trachymedusae. Photo credit: Steven Haddock, MBARI.

Two swimming modes in Trachymedusae; bell kinematics and the role of giant axons
Matthew E. Meech, Claudia E. Mills, Steven H. D. Haddock, Robert W. Meech

August

Force production differs in fluid and solid environments, so demands placed on animals’ bodies vary with the medium. Unlike many other swimming birds, mallard ducks can take off nearly vertically from both water and land. Taylor-Burt and Biewener report that mallards change their hindlimb kinematics and muscle function between environments, with environment-specific changes in the direction of knee motion, lateral gastrocnemius muscle strain and shortening velocity, and wing and tail contributions. The variable kinematics and muscle function in mallards demonstrate the challenge of moving in different environments. Photo credit: Roy and Marie Battell.

Aquatic and terrestrial takeoffs require different hindlimb kinematics and muscle function in mallard ducks
Kari R. Taylor-Burt, Andrew A. Biewener

September

An autonomous swimming robot, seen from underwater, and its reflections on the water surface and the floor of the experimental tank. The robot (Tadro) mimics the tadpole larva of a sea squirt by navigating towards a light source using a single eye and a propulsive tail with an artificial notochord. The stiffness of the notochord was evolved over ten generations in a small population of Tadros competing for a simulated food source. Use of autonomous biomimetic robots to test adaptation hypotheses provides biologists with a powerful new approach to model evolutionary scenarios. Photo by John Long.

Biomimetic evolutionary analysis: testing the adaptive value of vertebrate tail stiffness in autonomous swimming robots
J. H. Long, Jr, T. J. Koob, K. Irving, K. Combie, V. Engel, N. Livingston, A. Lammert, J. Schumacher

October

Oxygen levels inside the terrestrial eggs of red-eyed treefrogs (Agalychnis callidryas) vary with surface exposure but poorly exposed, hypoxic eggs develop synchronously with their better exposed clutchmates. J. R. Rogge and K. M. Warkentin show that the embryonic external gills contribute substantially to oxygen uptake, and that embryos behaviorally position their gills in the best-oxygenated part of the egg, near the air. Exploiting this spatial refuge from hypoxia within the egg allows extended embryonic development of hatching-competent embryos, improving their ability to escape from aquatic predators after hatching. Photograph by Karen M. Warkentin.

External gills and adaptive embryo behavior facilitate synchronous development and hatching plasticity under respiratory constraint
Jessica R. Rogge, Karen M. Warkentin

November

Female red-sided garter snakes produce a sex pheromone blend that elicits robust, vigorous courtship behavior from males, and this pheromone is the key signal mediating male mate choice in the massive spring mating aggregations in Manitoba, Canada. The study by Parker et al. in this issue demonstrates that male garter snakes can be made attractive by implanting them with estradiol and that these effects are activational. Much like plumage in basal bird species, the red-sided garter snake's sex pheromone, a powerful skin-based sexual signal, is directly regulated by estradiol. Photo by Chris R. Friesen.

How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes
M. Rockwell Parker, Robert T. Mason

December

A southern elephant seal (Mirounga leonina) buoyed up from resting on Bird Island, South Atlantic, before embarking on his long postbreeding migration. Seasonal on-land fasting and at-sea foraging cycles lead to remarkable fluctuations in the body composition of this species. Changes in body composition are reflected by changes in buoyancy, and in this issue Gordine et al. present a new method for detecting such buoyancy changes. Their method identifies dive phases during which seals drift for extended periods and measures changes in the rate at which an individual either sinks or rises whilst drifting.

Fishing for drifts: detecting buoyancy changes of a top marine predator using a step-wise filtering method
Samantha Alex Gordine, Michael Fedak, Lars Boehme