Issues
-
Cover image
Cover Image
Cover: Hummingbirds can lower their body temperature and metabolism at night to save energy, using a strategy called torpor. Shankar et al. (jeb243208) found much finer control of hummingbird body temperature than birds are usually shown to have: they lower their temperature by varying amounts, and use a shallow form of torpor to balance the trade-offs of using deep torpor versus remaining in normal body temperature sleep. This composite thermal image shows a male black-chinned hummingbird in normal sleep early in the night (left), transitioning to deep torpor, and then in deep torpor (right). Photo credit: Anusha Shankar, Isabelle Cisneros and Don Powers.
- PDF Icon PDF LinkTable of contents
- PDF Icon PDF LinkIssue info
INSIDE JEB
NEWS
COMMENTARY
On the feeding biomechanics of nectarivorous birds
Summary: Nectar-feeding birds employ unique mechanisms to collect minute liquid rewards from floral structures. This Commentary details the three stages of nectar feeding and suggests research pathways to expand our current knowledge.
SHORT COMMUNICATION
Long distance homing in the cane toad (Rhinella marina) in its native range
Summary: Translocation-homing experiments reveal that non-territorial, non-migratory Rhinella marina can navigate to home areas following displacements exceeding regular, natural movements, suggesting a previously unconsidered prevalence of navigational abilities amongst amphibians.
RESEARCH ARTICLES
A novel intramandibular joint facilitates feeding versatility in the sixbar distichodus
Summary: The sixbar distichodus is a freshwater, plant-eating fish with an extra joint in its lower jaw that allows it to feed in new ways compared with fishes lacking the joint.
Discontinuous gas exchange in Madagascar hissing cockroaches is not a consequence of hysteresis around a fixed PCO2 threshold
Summary: Discontinuous gas exchange cycles in cockroaches do not arise from internal PCO2 oscillations around a fixed ventilatory threshold. DGCs continue when haemolymph PCO2 exceeds values recorded during continuous gas exchange.
Severe hypoxia exposure inhibits larval brain development but does not affect the capacity to mount a cortisol stress response in zebrafish
Summary: Severe acute hypoxia exposure in larval zebrafish significantly decreases forebrain neural proliferation but does not affect the long-term capacity to mount a cortisol stress response.
A heterothermic spectrum in hummingbirds
Editor's Choice: Three hummingbird species are capable of a temperature spectrum from normothermy to torpor, implying that some birds, at least, can precisely control their metabolic state.
Rapid blood acid–base regulation by European sea bass (Dicentrarchus labrax) in response to sudden exposure to high environmental CO2
Summary: European sea bass exposed to 1 kPa (10,000 µatm) CO2 regulate blood and red cell pH within 2 h and 40 min, respectively, protecting O2 transport capacity, via enhanced gill acid excretion.
Elastic energy storage across speeds during steady-state hopping of desert kangaroo rats (Dipodomys deserti)
Summary: The ankle extensor tendons of desert kangaroo rats store and return elastic energy in relation to hopping speed, recovering more energy at faster speeds.
Maternal food restriction during pregnancy affects offspring development and swimming performance in a placental live-bearing fish
Highlighted Article: Maternal food restriction during pregnancy results in smaller offspring, slower postnatal body fat gain and an inhibition of postnatal improvement of swimming skills during feeding, possibly leading to lower competitive abilities after birth.
Genetic variation in haemoglobin is associated with evolved changes in breathing in high-altitude deer mice
Highlighted Article: High-altitude variants in haemoglobin genes are associated with evolved changes in breathing that likely enhance O2 uptake in hypoxia in deer mice.
Behavioural responses of threespine stickleback with lateral line asymmetries to experimental mechanosensory stimuli
Summary: Stickleback with more mechanoreceptors have a stronger bias towards hovering with their right side adjacent to a surface when illuminated but a weaker bias in the dark.
CORRECTION
Using the reactive scope model to redefine social stress in fishes

In their Review, Katie Gilmour and colleagues redefine the ambiguous concept of social stress by using the reactive scope model as a framework to explain the divergent physiological phenotypes of dominant and subordinate fishes.
JEB grants to support junior faculty

Learn about the grants that we launched in 2023 to support junior faculty from two of our awardees: Erin Leonard, Early-Career Researcher (ECR) Visiting Fellowship recipient, and Pauline Fleischmann, Research Partnership Kickstart Travel Grant recipient. The next deadline to apply is 6 June 2025.
Thirteen-lined ground squirrels survive extraordinarily low blood oxygen

Brynne Duffy and colleagues reveal that thirteen-lined ground squirrels are true hypoxia champions surviving extreme low blood oxygen, down to just 34% oxygen, when they emerge briefly from hibernation.
The Company of Biologists Workshops

For the last 15 years, our publisher, The Company of Biologists, has provided an apt environment to inspire biology and support biologists through our Workshops series. Read about the evolution of the Workshop series and revisit JEB's experience with hosting the first Global South Workshop.
Fast & Fair peer review

Our sister journal Biology Open has recently launched the next phase of their Fast & Fair peer review initiative: offering high-quality peer review within 7 working days. To learn more about BiO’s progress and future plans, read the Editorial by Daniel Gorelick, or visit the Fast & Fair peer review page.