ZSL
Zoological Society of London
As we face more frequent and extreme climate events across Europe, understanding how wildlife experience these and respond is becoming increasingly important. For seabirds, the challenge is particularly complex. Unlike many species, breeding seabirds depend on both marine and terrestrial habitats, exposing them to a wide array of environmental pressures.
For his MSc in Wild Animal Biology at ZSL, Jayden Parker is investigating this challenge through his research project, Heat, Habitat, and High Exposure: Operative Temperatures within Lundy’s Seabird Colonies. Supervised by Dr Henry Hakkinen at the Institute of Zoology, whose work focuses on mitigating the impacts of climate change on biodiversity, Jayden’s research explores how heat is experienced by nesting seabirds and whether current climate assessments are accurately reflecting the conditions they face.
Why heat matters for seabirds
During the breeding season, seabird chicks are largely immobile, and adults are tied to their nests, often unable to escape extreme conditions. Subsequently, they are at risk from the impacts of both marine and terrestrial heatwaves. Physiological stress from terrestrial heatwaves is of particular concern, as many European seabird species are adapted to cold, high latitude environments and have limited capacity to dissipate excess heat.
While the impact of terrestrial heatwaves has been observed and discussed in the context of seabird conservation, there remain substantial knowledge gaps regarding the effects of heat exposure on seabird colonies at local scales. Most existing climate models and conservation risk assessments rely on coarse ambient air temperature data, which may not be representative of actual temperatures experienced by birds at nesting sites.
Bringing the research to Lundy Island
To address these knowledge gaps, Jayden carried out a pilot field study on Lundy Island, a rugged granite island situated 19km off the North Devon coast in the Bristol Channel in southwest UK. Lundy is well-known for its storied history and iconic wildlife. The island supports large seabird populations, including important breeding populations of common guillemots, razorbills and the famed Atlantic puffins, the latter having been positively affected by successful invasive rat eradication efforts in recent decades.
Measuring the true heat experience of seabirds
Jayden implemented a pilot field study on Lundy using mobile iButton temperature loggers and custom-built physical bird models across representative nesting microhabitats. The 3D-printed guillemot models were carefully constructed to recreate the heat absorption characteristics of real seabirds, each one fitted with a hardy internal thermometer and affixed to a cliff near a nesting colony.
The models were deployed across a range of microhabitats with differing levels of shade, wind exposure and albedo (surface reflectivity). On these exposed granite ledges, conditions can differ substantially from what air temperature alone would suggest. This more representative measure of heat is known as the ‘operative temperature’ experienced by these nesting birds.
Challenging existing climate assumptions
The project is based on the hypothesis that operative temperatures will diverge substantially from those suggested by coarse climate data, and microhabitat conditions will strongly drive higher or lower thermal exposure than would be predicted from ambient air temperature alone. Maximum heat exposure was also hypothesised to be substantially higher than that predicted by low-resolution data, suggesting heat stress may be much higher in vulnerable sites than previously thought.
Collection and interrogation of this data will help refine climate impact models, improve conservation assessment, and identify the most vulnerable nesting sites within colonies, enabling us to better protect them.
A successful field season
Beyond gathering valuable data, the field season offered opportunities to contribute to a wider range of conservation activities on the island.
“Overall, I would consider the fieldwork successful,” said Jayden. “The Lundy staff were extremely helpful, and I was even able to assist with a variety of monitoring efforts. I am now extremely interested to work through my analysis.”
With heatwaves increasing in frequency and intensity across Europe, these findings may have implications for seabird welfare and breeding success. They could also help to identify the qualities of microhabitats that make them most vulnerable to heat, while further validating the use of 3D-printed thermal models to improve both conservation planning and climate resilience strategies.
Many thanks to the Lundy Bird Observatory for supporting this research and providing an unforgettable fieldwork experience.