Dr Nicholas Horrocks

Biography & Research

Dr Nicholas Horrocks

Nick Horrocks in the field during the dry season in Zambia.

I am broadly interested in how organisms cope with the challenges they face in life, whether that be from abiotic pressures such as temperature, biotic factors such as disease and pathogen pressure, or ecological factors such as intra- or interspecific competition.

I’ve been fortunate to be able to study some of these challenges by conducting fieldwork in Zambia, where I have focused on the breeding biology of greater and lesser honeyguides and their hosts – working especially with Luke McClean – and how ground-nesting birds (plovers, coursers and nightjars) cope with the extremes of temperature that they experience while incubating their eggs.

I joined the African Cuckoos team in 2013 on a two-year Marie Curie Intra-European Fellowship, having just completed my PhD at the University of Groningen, in the Netherlands. There, I studied the immune function and disease exposure of lark species in contrasting environments. I continued with a focus on ecoimmunology for my fellowship and took advantage of Claire Spottiswoode’s extensive knowledge of honeyguides in Zambia to study trade-offs between immunity and growth in these species. As virulent brood parasites, honeyguide chicks grow up potentially surrounded by the rotting carcasses of their dead nest mates. This presumably has consequences for immune investment, despite coming at a time when they must invest in growth. My research investigated how these birds manage to both stay healthy and grow at the same time.

As co-supervisor of Luke McClean’s PhD I have also been involved in some lovely studies with Luke and Claire that have investigated coevolution between honeyguides and their hosts. This has included investigating whether little bee-eaters use the dimensions of their nest tunnels as a defence against parasitism by greater honeyguides, and whether there are costs associated with the virulent egg puncturing behaviour of greater honeyguides. While chasing honeyguides during the dry season I became intrigued by the ground-nesting birds that were also breeding at that time, and was inspired by the work of Jolyon Troscianko and Jared Wilson-Aggarwal who were in the field examining camouflage efficacy and survival in plovers, coursers and nightjars. These species lay their eggs in exposed locations and rely on camouflage (either of their eggs – plovers and coursers, or themselves – nightjars) to remain undetected by predators. However, these exposed locations mean the eggs and incubating birds can be subjected to extremes of temperature, particularly during the middle of the day. Funded by a three-year Leverhulme Early Career Fellowship I have been investigating how these birds cope with the high temperatures they experience, how egg camouflage may interact with temperature, and whether birds must trade off predator avoidance behaviours with keeping their eggs protected from the sun.

While not in Zambia I have managed to combine both these research interests (interspecific interactions and temperature) by studying burying beetles (Nicrophorus) and their phoretic mites, in collaboration with Dr Syuan-Jyun Sun and Prof. Rebecca Kilner. Mites raise the body temperature of beetles, increasing their competitiveness in competitions over breeding resources. However, only small beetles, which would otherwise lose all competitive interactions, gain from the presence of mites, while larger beetles, which would win competitions anyway, lose reproductive success when breeding alongside mites. 

I have further probed the value of collaboration with Dr Jessica van der Wal and Prof. Rose Thorogood by examining how collaborative behaviour predicts career longevity and progression among behavioural ecologists.

Currently I am a Research Project Manager at the Cambridge Institute for Therapeutic Immunology & Infectious Disease. This mainly involves trying to overcome the administrative challenges of the University of Cambridge while attempting to drive forward projects to provide research facilities or collaborations to enhance research at this new institute. Projects related to COVID-19 have been a particular focus in the last months.


See also:

Google Scholar Profile


New paper on imperfect egg mimicry

Our paper “Combined measures of mimetic fidelity explain imperfect mimicry in a brood parasite-host system” has just been published in the journal Biology Letters. This study was led by Tanmay Dixit, and carried out together with Gary Choi, Salem al-Mosleh, Jess Lund, Jolyon Troscianko, Collins Moya, L Mahadevan, and Claire Spottiswoode, as part of a collaboration between our group and Prof. Mahadevan and his lab at Harvard University. Together we combined mathematical tools and field experiments in Zambia to quantify a key difference – “squiggle” markings – between the eggs of hosts (tawny-flanked prinias) and parasites (cuckoo finches). We showed that suboptimal behaviour on the part of prinias allows cuckoo finches to get by with an imperfect copy of prinia eggs.

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New paper on host aggression and hawk mimicry

Our paper “Aggressive hosts are undeterred by a cuckoo’s hawk mimicry, but probably make good foster parents” has just been published in the journal Proceedings of the Royal Society B. In the paper, we investigate the costs and benefits to the African cuckoo of specializing on a highly aggressive host species, the fork-tailed drongo.

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African Cuckoos Team at the Pan-African Ornithological Congress

The African Cuckoos Team had a fantastic time at the Pan-African Ornithological Congress (PAOC15), this year held in Vic Falls, Zimbabwe. Dr Chima Nwaogu gave a plenary talk on “Differing Priorities in the Timing of Annual Life History Events”, while Professor Claire Spottiswoode and Silky Hamama presented during a roundtable session on communities in conservation and research. Silky also presented a poster, with Claire, Jess Lund, Mairenn Attwood and Cameron Blair each giving research talks as well. 

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