Hõrak, P., Männiste, M. (2015) Viability selection affects black but not yellow plumage colour in greenfinches. – Oecologia (in press).
 
Hõrak, P., Valge, M. (2015). Why did children grow so well at hard times? The ultimate importance of pathogen control during puberty.Evolution, Medicine, and Public Health, 167-178. (doi:10.1093/emph/eov017). PDF for download
 
Visse, M., Sild, E., Kesler, M.,  Saks, L., Hõrak, P. (2015) Do Atlantic salmon parr trade growth against immunity? – Marine and Freshwater Behaviour and Physiology (in press). /doi/full/10.1080/10236244.2015.1035536.
 
Rattiste, K.; Klandorf, H.; Urvik, J. ; Sepp, T.; Asghar, M.; Hasselquist, D.; Cooey, C.; Hõrak, P. (2015) Skin pentosidine and telomere length do not covary with age in a long-lived seabird. – Biogerontology (in press). DOI: 10.1007/s10522-015-9564-1
 
Moore, F.R.; Cīrule, D.; Kivleniece, I.; Vrublevska, J.; Rantala, M.J.; Sild, E.; Sepp, T.; Hõrak, P.; Krama, T.; Krams, I. (2015) Investment in a sexual signal results in reduced survival under extreme conditions in the male great tit (Parus major). Behavioral Ecology and Sociobiology 69: 151-158. DOI: 10.1007/s00265-014-1828-2
 
Meitern, R., Andreson, R. & Hõrak, P. (2014) Profile of whole blood gene expression following immune stimulation in a wild passerine. BMC Genomics 15, 533. PDF for download
 
Sild, E., Meitern, R., Männiste, M., Karu, U. & Hõrak, P. (2014) High feather corticosterone indicates better coccidian infection resistance in greenfinches. General and Comparative Endocrinology 204: 203-210. http://dx.doi.org/10.1016/j.ygcen.2014.05.026

 

Kilk, K., Meitern, R., Härmson, O., Soomets, U. & Hõrak, P. (2014) Assessment of oxidative stress in serum by the d-ROMs test. Free Radical Research 48: 883-889. DOI: 10.3109/10715762.2014.919390

 

Sepp, T., Männiste, M., Kaasik, A., Hõrak, P. (2014) Multidimensionality of fear in captive greenfinches (Carduelis chloris). Behavioral Ecology and Sociobiology 68: 1173-1181 DOI: 10.1007/s00265-014-1728-5

 

Männiste, M., Hõrak, P. (2014) Emerging infectious disease selects for darker plumage coloration in greenfinches. Frontiers in Ecology and Evolution - Behavioral and Evolutionary Ecology 2: doi: 10.3389/fevo.2014.00004

 

Hõrak, P., Männiste, M., Meitern, R., Sild, E., Saks, L., Sepp, T. (2013) Dexamethasone inhibits corticosterone deposition in feathers of greenfinches. General and Comparative Endocrinology 191: 210-214 http://dx.doi.org/10.1016/j.ygcen.2013.07.002

 

Meitern, R., Sild, E., Lind, M.-A., Männiste, M., Sepp, T., Karu, U., Hõrak, P. (2013). Effects of endotoxin and psychological stress on redox physiology, immunity and feather corticosterone in greenfinches.PloS ONE 8 (6):e67545  PDF for download

 

Männiste M, Sepp T, Hõrak P (2013) Locomotor activity of captive greenfinches involves two different behavioural traits. Ethology 119: 581-591 DOI: 10.1111/eth.12099

 

Meitern R, Sild E, Kilk K, Porosk R, Hõrak P (2013) On the methodological limitations of detecting oxidative stress: effects of paraquat on measures of oxidative status in greenfinches. Journal of Experimental Biology 216: 2713-2721 PDF for download

 

Krams I, Vrublevska J, Cīrule D, Kivleniece I, Krama T, Rantala MJ, Kaasik A, Hõrak P, Sepp T (2013) Stress, behaviour and immunity in wild-caught wintering great tits (Parus major). Ethology:119: 397–406.

 

Sepp, T., Karu, U., Blount, J., Sild, E., Männiste, M., Hõrak, P. (2012) Coccidian infection causes oxidative damage in greenfinches. PLoS ONE 7 (5):e36495. PDF for download

 

Sepp, T., Sild, E., Blount, J., Männiste, M., Karu, U. & Hõrak, P. (2012) Individual consistency and covariation of measures of oxidative status in greenfinches.Physiological and Biochemical Zoology 85:299-307

 

Krams, I., Vrublevska, J., Cirule, D., Kivleniece, I., Krama, T., Rantala, M.J., Sild, E., Hõrak, P. (2012) Heterophil/lymphocyte ratios predict the magnitude of humoral immune response to a novel antigen in great tits (Parus major).  Comparative Biochemistry and Physiology A 161:422-428.  DOI: 10.1016/j.cbpa.2011.12.018

 

Sild, E, Sepp, T, Männiste, M & Hõrak, P (2011) Carotenoid intake does not affect immune-stimulated oxidative burst in greenfinches. Journal Of Experimental Biology 214:3467-3473

 

Männiste, M. & Hõrak, P. (2011) Effects of immune activation and glucocorticoid administration on feather growth in greenfinches  Journal of Experimental Zoology Part A: Ecological Genetics and Physiology 315A: 527-535 DOI: 10.1002/jez.701

 

Sild, E., Sepp, T. & Hõrak, P. (2011) Behavioural trait covaries with immune responsiveness in a wild passerine. Brain Behavior and Immunity 25, 1349-1354  doi:10.1016/j.bbi.2011.03.020

 

Lõhmus, M., Sild, E., Hõrak, P. & Björklund, M. (2011) Effects of chronic leptin administration on nitric oxide production and immune responsiveness of greenfinches. Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology, 158, 560-565. http://www.sciencedirect.com/scidirimg/clear.gifdoi:10.1016/j.cbpa.2011.01.002

 

Sepp, T., Karu, U., Sild, E., Männiste, M. & Hõrak, P. (2011) Effects of carotenoids, immune activation and immune suppression on the intensity of chronic coccidiosis in greenfinches. Experimental Parasitology, 127, 651-657. doi:10.1016/j.exppara.2010.12.004

 

Sild, E. & Hõrak, P. (2010) Assessment of oxidative burst in avian whole blood samples: validation and application of a chemiluminescence method based on Pholasin. Behavioral Ecology and Sociobiology 64, 2065-2076

 

Kilgas, P., Tilgar, V., Külavee, R., Saks, L., Hõrak, P. & Mänd, R. (2010) Antioxidant protection, immune function and growth of nestling great tits Parus major in relation to within-brood hierarchy. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 157, 288-293.

 

McGraw, K.J., Cohen, A.A., Costantini, D. & Hõrak, P. (2010) The ecological significance of antioxidants and oxidative stress: a marriage between mechanistic and functional perspectives. Functional Ecology 24, 947-949.

 

Hõrak, P. & Cohen A. (2010) How to measure oxidative stress in an ecological context: methodological and statistical issues. – Functional Ecology 24, 960-970.

 

Hõrak, P., Sild, E., Soomets, U., Sepp, T. &  Kilk, K. (2010) Oxidative stress and information content of black and yellow plumage coloration: an experiment with greenfinches. – Journal of Experimental Biology 213: 2225-2233 © The Company of Biologists  PDF for download

 

Sepp, T., Sild, E. & Hõrak, P.(2010) Hematological condition indices in greenfinches: effects of captivity and diurnal variation. Physiological and Biochemical Zoology 83: 276-282

 

Sarv, T. & Hõrak, P. (2009) Phytohaemagglutinin injection has a long-lasting effect on immune cells. Journal of Avian Biology 40: 569-571 PDF for download

 

Sild, E. & Hõrak, P. (2009) Nitric oxide production: an easily measurable condition index for vertebrates. Behavioral Ecology and Sociobiology 63: 959-966.

 

Karu, U., Saks, L. & Hõrak, P. (2008) Carotenoid-based plumage coloration is not affected by vitamin E supplementation in male greenfinches. Ecological Research 23: 931-935 © 2008 The Ecological Society of Japan  PDF for download

 

Hõrak, P., Saks, L., Zilmer, M., Karu, U. & Zilmer, K. (2007) Do dietary antioxidants alleviate the cost of immune activation? An experiment with greenfinches. American Naturalist 170, 625-635 © 2007 by The University of Chicago  PDF for download

 

Karu, U., Saks, L. & Hõrak, P. (2007) Carotenoid coloration in greenfinches is individually consistent irrespective of foraging ability. Physiological & Biochemical Zoology 80, 663-670. © 2007 by The University of Chicago PDF for download. Please read also ERRATUM (PDF for download) for this paperwe are really sorry for this mess!

 

Hõrak, P., Zilmer, M., Saks, L., Ots, I., Karu, U. & Zilmer, K. (2006) Antioxidant protection, carotenoids, and the costs of immune challenge in greenfinches. Journal of Experimental Biology 209, 4329-4338 © The Company of Biologists  PDF for download

 

Tummeleht, L., Mägi, M., Kilgas, P., Mänd, R. & Hõrak, P. (2006) Antioxidant protection and plasma carotenoids of incubating great tits (Parus major L.) in relation to health state and breeding conditions Comparative Biochemistry and Physiology, Part C 144, 166-172

 

Saks, L., Karu, U., Ots, I. & Hõrak, P. (2006) Do standard measures of immunocompetence reflect parasite resistance? The case of greenfinch coccidiosis Functional Ecology 20, 75-82.

 

Hõrak, P., Tummeleht, L. & Talvik, H. (2006) Predictors and markers of resistance to neurotropic nematode infection in rodent host Parasitology Research 98, 396-402 © Springer PDF for download

 

Hõrak, P., Tummeleht, L. & Talvik, H. (2006) Predator threat, copulation effort, and immunity in male rats (Rattus norvegicus) Journal of Zoology 268, 9-16 © The Zoological Society of London and Blackwell Publishing PDF for download

 

Hõrak P., Saks L., Karu U. & Ots I. (2006) Host resistance and parasite virulence in greenfinch coccidiosis Journal of Evolutionary Biology 19, 277-288 © 2005 European Society for Evolutionary Biology PDF for download

 

Hõrak P., Saks L., Karu U., Ots I., Surai P. F., & McGraw, K. J. (2004) How coccidian parasites affect health and appearance of greenfinches. Journal of Animal Ecology 73, 935-937

Hõrak, P., Surai, P. F., Ots, I. & Møller, A. P. (2004) Fat soluble antioxidants in brood-rearing great tits: relations to health and appearance. Journal of Avian Biology 35, 63-70. PDF for download

Freitak, D., Ots, I., Vanatoa, A. & Hõrak, P. (2003) Immune response is energetically costly in white cabbage butterfly pupae. Proceedings of the Royal Society of London Series B Supplementum (Biology Letters) 270, S220-222.

Hõrak, P. & Saks, L. (2003) Animal allure and health linked by plant pigments. BioEssays 25, 746-747.

Saks, L., McGraw, K. J. M. &  Hõrak, P. (2003) How feather colour reflects its carotenoid content. Functional Ecology 17, 555-561.

Hõrak, P. (2003) When to pay the cost of reproduction? A brood size manipulation experiment in great tits (Parus major). Behavioral Ecology and Sociobiology 54, 105-112.

Hõrak, P., Saks, L., Ots, I., Kullisaar, T., Kollist, H. & Zilmer, M. (2003) Physiological effects of immune challenge in captive greenfinches (Carduelis chloris). Canadian Journal of Zoology 81, 371-379.

Saks, L., Ots, I., Hõrak, P. (2003) Carotenoid-based plumage coloration of male greenfinches reflects health and immunocompetence. Oecologia 134, 301-307.

Hõrak, P., Surai, P. F. & Møller, A. P. (2002) Fat-soluble antioxidants in the eggs of great tits Parus major in relation to breeding habitat and laying sequence. Avian Science 2, 123-130  PDF for download

Hõrak, P., Saks, L., Ots, I. & Kollist, H. (2002) Repeatability of condition indices in captive greenfinches (Carduelis chloris). Canadian Journal of Zoology 80, 636-643.

Ots, I., Kerimov, A. B, Ivankina, E. V., Ilyina, T. A., Hõrak, P. (2001) Immune challenge affects basal metabolic
 activity in wintering great tits. Proceedings of the Royal Society of London Series B 268, 1475-1482.

Hõrak, P., Ots, I., Vellau, H., Spottiswoode, C. & Møller, A. P. (2001) Carotenoid-based plumage coloration reflects hemoparasite infection and local survival in breeding great tits. Oecologia 123, 166-173.

Hõrak, P.,Vellau, H., Ots, I., & Møller, A. P. (2000) Growth conditions affect carotenoid-based plumage coloration of great tit nestlings Naturwissenschaften 87, 460-464.

Hõrak, P., Ots, I., Tegelmann, L. & Møller, A.P. (2000) Health impact of phytohaemagglutinin-induced immune challenge on great tit nestlings. Canadian Journal of Zoology 78, 905-910.

Hõrak, P., Tegelmann, L., Ots, I., & Møller, A.P. (1999) Immune function and survival of great tit nestlings in relation to growth conditions. Oecologia 121, 316-322.

Hõrak, P., Jenni-Eiermann, S., & Ots, I. (1999) Do great tits (Parus major) starve to reproduce? Oecologia 119, 293-299.

Tammaru, T. & Hõrak, P. (1999) Should one invest more in large broods? Not necessarily. Oikos 85, 574-81.

Hõrak, P., Ots, I., & Murumägi, A. (1998) Hematological health state indices of reproducing Great Tits: a response to brood size manipulation. Functional Ecology 12 , 750-756.

Hõrak, P. & Lebreton, J.-D. (1998) Survival of adult Great Tits in relation to sex and habitat: a comparison of urban and rural populations. Ibis140, 205-209.

Hõrak, P., Jenni-Eiermann, S., Ots, I., & Tegelmann, L. (1998) Health and reproduction: sex-specific clinical profile of Great Tits (Parus major) in relation to breeding. Canadian Journal of Zoology 76, 2235-2244.

Hõrak, P. & Ots, I. (1998) Health state and local survival in the Great Tit. Biol. Cons. Fauna 102, 307-311.

Ots, I. & Hõrak, P. (1998) Health impact of blood parasites in breeding great tits. Oecologia 116, 441-448.

Ots, I., Murumägi, A., & Hõrak, P. (1998) Hematological health state indices of reproducing Great Tits: methodology and sources of natural variation. Functional Ecology 12, 700-707.

Hõrak, P., Mänd, R., & Ots, I. (1997) Identifying targets of selection: a multivariate analysis of reproductive traits in the Great Tit. Oikos 78, 592-600.

Hõrak, P. & Tammaru, T. (1996) Between-year variation in breeding conditions biases heritability estimates for body size in birds. Ardea 84, 127-135.

Ots, I. & Hõrak, P. (1996) Great Tits Parus major trade health for reproduction. Proceedings of the Royal Society of London Series B 263, 1443-1447.

Hõrak, P., Mänd, R., Ots, I., & Leivits, A. (1995) Egg size variation in the Great Tit: individual, habitat and geographic differences. Ornis Fennica 73, 97-114.

Hõrak, P. (1995) Brood reduction facilitates female but not offspring survival in the great tit. Oecologia 102, 515-519.

Hõrak, P. (1994) Effect of nestling history on adult size and reproduction in the Great Tit. Ornis Fennica 71, 47-54.  PDF for download

Hõrak, P. (1993) Low fledging success of urban Great Tits. Ornis Fennica 70, 168-172.