Limits to sustained energy intake (SusEI) during lactation are important because they provide an upper boundary below which females must trade-off competing physiological activities. To date, SusEI is thought to be limited either by the capacity of the mammary glands to produce milk (the peripheral limitation hypothesis), or by a female's ability to dissipate body heat (the heat dissipation hypothesis). In the present study, we examined the effects of litter size and ambient temperature on a set of physiological, behavioral, and morphological indicators of SusEI and reproductive performance in lactating Swiss mice. Our results indicate that energy input, output, and mammary gland mass increased with litter size, whereas pup body mass and survival rate decreased. The body temperature increased significantly, while food intake (18g/d at 21°C vs 10g/d at 30°C), thermal conductance (lower by 20-27% at 30°C than 21°C), litter mass and MEO decreased significantly in the females raising large litter size at 30°C compared to those at 21°C. Furthermore, an interaction between ambient temperature and litter size affected females' energy budget, imposing strong constraints on SusEI. Together, out data suggest that the limitation may be caused by both mammary glands and heat dissipation, i.e. the limits to mammary gland is dominant at the room temperature, but heat limitation is more significant at warm temperatures. Further, the level of heat dissipation limits may be temperature dependent, shifting down with increasing temperature.
2023 JEB Outstanding Paper Prize shortlist and winner
The JEB Editors are delighted to announce the shortlisted authors for the 2023 JEB Outstanding Paper Prize. Read the winning paper - Tiny spies: mosquito antennae are sensitive sensors for eavesdropping on frog calls - by Hoover Pantoja-Sanchez and Brian Leavell from Ximena Bernal's lab at Purdue University, USA.
JEB Science Communication Workshop for ECRs
If you’re an early-career researcher interested in science communication and are attending the SEB Annual Conference in Prague this summer, come a day early and join the JEB Editors at a sci comm workshop to learn the key writing skills needed to promote your research to a broad audience beyond your peers (1 July at 14.30-17.30). Places are limited to 24 attendees, and applicants should apply through the SEB registration page by 30 April 2024.
Bridging the gap between controlled conditions and natural habitats in understanding behaviour
Novel technologies enable behavioural experiments with non-model species, in naturalistic habitats and with underexplored behaviours. In their Commentary, Scholz and colleagues discuss how to obtain a deeper understanding of the natural ecology and lifestyle of study animals.
Beluga metabolic measures could help save species
To help save animals from extinction, it’s important to understand what each species needs to survive. This led Jason John et al. to measure the metabolic rates of captive belugas to develop a ‘fish calculator’ showing that the whales need to eat ~23 salmon per day.
ECR Workshop on Positive Peer Review
Are you an ECR looking for tips on how to write concise, astute and useful manuscript reviews? If so, join the JEB Editors at a 2-hour JEB-sponsored Workshop on Positive Peer Review at the Canadian Society of Zoologists annual meeting in Moncton on 9 May 2024 at 13.00-15.00. There are 25 spaces for ECRs and selection is first come, first serve. To sign up, check the ECR Workshop box when you register for the CSZ meeting.
Social media
