Skip to main content Accessibility help

Size versus health as a cue for host choice: a test of the tasty chick hypothesis

  • F. VALERA (a1), H. HOI (a2), A. DAROLOVÁ (a3) and J. KRISTOFIK (a3)


Knowledge about how parasites choose their hosts is scarce and incomplete. Recent work has primarily focused on host health (i.e. immunocompetence) whereas ecological factors have been largely neglected. Here we investigate whether the immunocompetence, the nutritional condition or body size of nestling European bee-eaters Merops apiaster are used as parameters for habitat choice of the haematophagous fly Carnus hemapterus. We found that (i) flies consistently and non-randomly preferred larger nestlings, even after controlling for differences in habitat availability (host surface), (ii) in the presence of similar-sized hosts, parasites' choice for an individual was less likely than if hosts differed in size, (iii) the more the hosts differed in size, the more the parasites aggregated on the larger nestling and (iv) parasites changed their preference according to size criteria regardless of the identity of the larger host. Neither immunocompetence nor host body condition could account for parasites' preference. Our results do not support the prediction of the Tasty Chick Hypothesis, namely that the poor immunocompetence ability of junior chicks makes them more attractive to parasites. We conclude that basic ecological factors (e.g. body size) can be essential for parasites when choosing a host.


Corresponding author

Estación Experimental de Zonas Áridas (CSIC), General Segura 1, E-04001 Almería, Spain. Tel: +34 950 281045. Fax: +34 950 277100. E-mail:


Hide All


BEZZEL, E. & PRINZINGER, R. ( 1990). Ornithologie. Ulmer Verlag, Stuttgart.
BLANCO, G., TELLA, J. L. & POTTI, J. ( 1997). Feather mites on group-living Red-billed Choughs: a non-parasitic interaction? Journal of Avian Biology 28, 197206.
CANNINGS, R. J. ( 1986). Infestations of Carnus hemapterus Nitzsch (Diptera: Carnidae) in northern saw-whet owl nests. Murrelet 67, 8384.
CHRISTE, P., MØLLER, A. P. & DE LOPE, F. ( 1998). Immunocompetence and nestling survival in the house martin: the tasty chick hypothesis. Oikos 83, 175179.
CRAMP, S. ( 1985). Handbook of the Birds of Europe, the Middle East and North Africa, Vol. IV. Oxford University Press, Oxford.
DAROLOVÁ, E., HOI, H. & SCHLEICHER, B. ( 1997). The effect of ectoparasite nest load on the breeding biology of the Penduline tit Remiz pendulinus. Ibis 139, 115120.
DAWSON, R. D. & BORTOLOTTI, G. R. ( 1997). Ecology of parasitism of nestling American Kestrels by Carnus hemapterus (Diptera, Carnidae). Canadian Journal of Zoology 75, 20212026.
DESCAMPS, S., BLONDEL, J., LAMBRECHTS, M. M., HURTREZ-BOUSSES, S. & THOMAS, F. ( 2002). Asynchronous hatching in a blue tit population: a test of some predictions related to ectoparasites. Canadian Journal of Zoology 80, 14801484.
FRECKLETON, R. P. ( 2002). On the misuse of residuals in ecology: regression of residuals vs. multiple regression. Journal of Animal Ecology 71, 542545.
GARCIA-BERTHOU, E. ( 2001). On the misuse of residuals in ecology: testing regression residuals vs. the analysis of convariance. Journal of Animal Ecology 70, 708711.
GRIMALDI, D. ( 1997). The bird flies, Genus Carnus: species revision, generic relationships and a fossil Meoneura in amber (Diptera: Carnidae). American Museum Novitates no 3190, American Museum of Natural History, New York, USA.
GRUTTER, A. S. & POULIN, R. ( 1998). Intraspecific and interspecific relationships between host size and the abundance of parasitic larval gnathiid isopods on coral reef fishes. Marine Ecology Progress Series 164, 263271.
HEUSNER, A. A. ( 1985). Body size and energy metabolism. Annual Review of Nutrition 5, 267293.
KIRKPATRICK, C. E. & COLVIN, B. A. ( 1989). Ectoparasitic fly Carnus hemapterus (Diptera: Carnidae) in a nesting population of Common Barn-Owls (Strigiformes: Tytonidae). Journal of Medical Entomology 26, 109112.
KRASNOV, B. R., KHOKHLOVA, I. S. & SHENBROT, G. I. ( 2003). Density-dependent host selection in ectoparasites: An application of isodar theory to fleas parasitizing rodents. Oecologia 134, 365372.
KREBS, J. R. & AVERY, M. I. ( 1984). Chick growth and prey quality in the European bee-eater (Merops apiaster). Oecologia 64, 363368.
KRISTOFÍK, J., MASÁN, P. & SUSTEK, Z. ( 1996). Ectoparasites of bee-eater (Merops apiaster) and arthropods in its nests. Biologia 51, 557570.
LACINA, D. ( 1999). Ectoparasite Carnus hemapterus influences the mass growth rate of nestlings of European Kestrel (Falco tinnunculus). Third Eurasian Conference of Raptor Research Foundation, Buteo Suppl. p. 29.
LEE, P. L. M. & CLAYTON, D. H. ( 1995). Population biology of swift (Apus apus) ectoparasites in relation to host reproductive success. Ecological Entomology 20, 4350.
LEHANE, M. J. ( 1991). Biology of Blood-Sucking Insects. Harper Collins Academic, London.
LESSELLS, C. M. & AVERY, M. I. ( 1989). Hatching asynchrony in European bee-eaters Merops apiaster. Journal of Animal Ecology 58, 815835.
LIKER, A., MARKUS, M., VAZÁR, A., ZEMANKOVICS, E. & RÓZSA, L. ( 2001). Distribution of Carnus hemapterus in a starling colony. Canadian Journal of Zoology 79, 574580.
LOYE, J. E. & ZUK, M. ( 1991). Bird–Parasite Interactions. Oxford University Press, Oxford.
MARSHALL, A. G. ( 1981). The Ecology of Ectoparasitic Insects. Academic Press, London.
McCORKLE, Jr., F., OLAH, I. & GLICK, B. ( 1980). The morphology of the phytohemagglutinin-induced cell response in the chicken wattel. Poultry Science 59, 616623.
McCULLAGH, P. & NELDER, J. A. ( 1989). Generalised Linear Modelling, 2nd Edn. Chapman & Hall, London.
McMAHON, T. A. & BONNER, J. T. ( 1983). On Size and Life. Scientific American Library, New York.
MØLLER, A. P. ( 1997). Parasitism and the evolution of host life history. In Host–Parasite Evolution, General Principles and Avian Models (ed. Clayton, D. H. & Moore, J. ), pp. 105127. Oxford University Press, Oxford.
MØLLER, A. P., ALLANDER, K. & DUFVA, R. (1990). Fitness effects of parasites on passerine birds: a review. In Population Biology of Passerine Birds. An Integrated Approach (ed. Blondel, J., Gosler, A. G., Lebreton, J. D. & McCleery, R. ), pp. 269280. Springer-Verlag, Berlin.
MØLLER, A. P., ERRITZOE, J. & SAINO, N. ( 2003). Seasonal changes in immune response and parasite impact on hosts. American Naturalist 161, 657671.
POULIN, R. ( 1996). Sexual inequalities in helminth infections: a cost of being a male? American Naturalist 147, 287295.
POULIN, R. & ROHDE, K. ( 1997). Comparing the richness of metazoan ectoparasite communities of marine fishes: controlling for host phylogeny. Oecologia 110, 278283.
RANTA, E., LAURILA, A. & ELMBERG, J. ( 1994). Reinventing the wheel: analysis of sexual dimorphism in body size. Oikos 70, 313321.
ROULIN, A. ( 1998). Cycle de reproduction et abondance du diptère parasite Carnus hemapterus dans les nichées de chouettes effraies Tyto alba. Alauda 66, 265272.
ROULIN, A. ( 1999). Fécondité de la mouche Carnus hemapterus, ectoparasite des jeunes chouettes effraies Tyto alba. Alauda 67, 205212.
ROULIN, A., BRINKHOF, M. W. G., BIZE, P., RICHNER, H., JUNGI, T. W., BAVOUX, C., BOILEAU, N. & BURNELEAU, G. ( 2003). Which chick is tasty to parasites? The importance of host immunology versus parasite life history. Journal of Animal Ecology 72, 7581.
ROULIN, A., RIOLS, C., DIJKSTRA, C. & DUCREST, A. L. ( 2001). Female plumage spottiness signals parasite resistance in the barn owl (Tyto alba). Behavioral Ecology 12, 103110.
RÓZSA, L. ( 1997 a). Patterns in the abundance of avian lice (Phthiraptera: Amblycera, Ischnocera). Journal of Avian Biology 28, 249254.
RÓZSA, L. ( 1997 b). Wing-feather mite (Acari: Proctophyllodidae) abundance correlates with body mass of passerine hosts: a comparative study. Canadian Journal of Zoology 75, 15351539.
SCHALK, G. & FORBES, M. R. ( 1997). Male biases in parasitism of mammals. Oikos 78, 6774.
SCHMID-HEMPEL, P. & EBERT, D. ( 2003). On the evolutionary ecology of specific immune defence. Trends in Ecology and Evolution 18, 2732.
SCHULZ, T. A. ( 1986). The conservation and rehabilitation of the common barn owl. In Wildlife Rehabilitation (ed. Beaver, P. & Mackey, D. J. ), pp. 146166. National Wildlife Rehabilitation Association (NWRA), Cocon Creek, Fla.
SCHULZ, T. A. ( 1990). New and unusual ectoparasites on raptors. In Wildife Rehabilitation (ed. Ludwig, D. R. ), pp. 205213. Burger Printing Co., Edina, Minn.
SIMON, A., THOMAS, D. W., BLONDEL, J., LAMBRECHTS, M. M. & PERRET, P. ( 2003). Within-brood distribution of ectoparasite attacks on nestling blue tits: a test of the tasty chick hypothesis using inulin as a tracer. Oikos 102, 551558.
SOLER, J. J., MØLLER, A. P., SOLER, M. & MARTÍNEZ, J. G. ( 1999). Interactions between a brood parasite and its host in relation to parasitism and immune defence. Evolutionary Ecology Research 1, 189210.
STATSOFT, INC. ( 2001). STATISTICA for Windows. Tulsa, OK: StatSoft, Inc.
SZEP, T. & MØLLER, A. P. ( 1999). Cost of parasitism and host immune defence in the sand martin Riparia riparia: a role for parent–offspring conflict? Oecologia 119, 915.
SZEP, T. & MØLLER, A. P. ( 2000). Exposure to ectoparasites increases within-brood variability in size and body mass in the sand martin. Oecologia 125, 201207.
WAKELIN, D. ( 1984). Immunity to Parasites. Cambridge University Press, Cambridge.
WALTER, G. & HUDDE, H. ( 1987). Die Gefiederfliege Carnus hemapterus (Milichiidae, Diptera), ein Ektoparasit der Nestlinge. Journal für Ornithologie 128, 251255.
WHITWORTH, T. L. ( 1976). Host and habitat preferences, life history, pathogenicity and population regulation in species of Protocallyphora Hough (Diptera: Calliphoridae). Ph.D. dissertation. Utah State University, Logan.
ZAR, J. ( 1984). Biostatistical Analysis. Prentice-Hall, New Jersey.


Size versus health as a cue for host choice: a test of the tasty chick hypothesis

  • F. VALERA (a1), H. HOI (a2), A. DAROLOVÁ (a3) and J. KRISTOFIK (a3)


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed