TY - JOUR AU - LaFleur, D. L. AU - Lozano, G. A. AU - Sclafani, M. PY - 1997 TI - Female mate choice copying in guppies, Poecilia reticulata SP - 579-586 JF - Animal Behaviour VL - 54 N1 - Female mate choice copying in guppies, Poecilia reticulata N1 - 9 N1 - Female mate choice copying in guppies, Poecilia reticulata KW - Guppy mate choice MCC ID - 80 ER - TY - JOUR AU - Lemon, R. E. AU - Perreault, S. AU - Lozano, G. A. PY - 1996 TI - Breeding dispersions and site fidelity of American redstarts (Setophaga ruticilla) SP - 2238-2247 JF - Canadian Journal of Zoology VL - 74 N1 - Breeding dispersions and site fidelity of American redstarts (Setophaga ruticilla) N1 - 8 N1 - Breeding dispersions and site fidelity of American redstarts (Setophaga ruticilla) N2 - I really have no clue what this is about!! ID - 81 ER - TY - JOUR AU - Lozano, G. PY - 2009 TI - Evolutionary explanations in medicine: how do they differ and how to benefit from them JF - Medical Hypotheses N1 - Evolutionary explanations in medicine: how do they differ and how to benefit from them N1 - 22 N1 - Evolutionary explanations in medicine: how do they differ and how to benefit from them KW - medicine evolution N2 - Evolutionary explanations, many of which have appeared on the pages of this journal, are becoming more pervasive and influential in medicine, so it is becoming more important to understand how these types of explanations differ from the proximate approach that is more common in medicine, and how the evolutionary approach can contribute to medicine. Understanding of any biological phenomenon can occur at 4 levels: (1) ontogeny (2) causation, (3) function and (4) evolution. These approaches are not mutually exclusive, and whereas the first two are more common in medical practice, a complete explanation requires all 4 levels of analysis. Two major differences among these approaches are the apparent degree of urgency associated with them, and the extent to which they apply to individuals rather than populations. Criticisms of adaptive explanations often arise from a failure to understand the complementary nature of these 4 types of explanations. Other unwarranted criticisms result from a failure to appreciate that adaptive explanations often apply to populations, not individuals. A third criticism is motivated by the mistaken belief that adaptive explanations somehow justify morally reprehensible behaviours. Finally, evolutionary explanations sometimes face the criticism of “personal incredulity”. Adaptive explanations must be consistent with basic evolutionary concepts and must adhere with the physical reality of the phenomenon. Their value, however, comes not in devising a seemingly rational explanation, but in their predictions. Testable predictions must be explicitly stated and clearly articulated. These predictions must differ from those of arising from other hypotheses and must not only be interesting to evolutionary biologists, but also useful to medical practitioners. Integration of the proximate and the ultimate approach is possible and potentially beneficial to both evolutionists and physicians, but it requires some basic understanding of our differences and a desire to co-operate. ID - 67 ER - TY - JOUR AU - Lozano, G. A. PY - 1991 TI - Optimal foraging theory: a possible role for parasites SP - 391-395 JF - Oikos VL - 60 N1 - Optimal foraging theory: a possible role for parasites N1 - 1 N1 - Optimal foraging theory: a possible role for parasites KW - parasitism OFT ID - 88 ER - TY - JOUR AU - Lozano, G. A. PY - 1994 TI - Carotenoids, parasites, and sexual selection SP - 309-311 JF - Oikos VL - 70 N1 - Carotenoids, parasites, and sexual selection N1 - 3 N1 - Carotenoids, parasites, and sexual selection KW - PMSS carotenoid immunity-be N2 - beta-carotene has antioxidant and immunostimulant effects that so far have not been considered in the study of sexual selection ID - 86 ER - TY - JOUR AU - Lozano, G. A. PY - 1994 TI - Size, condition, and territory ownership in male tree swallows (Tachycineta bicolor) SP - 330-333 JF - Canadian Journal of Zoology VL - 72 N1 - Size, condition, and territory ownership in male tree swallows (Tachycineta bicolor) N1 - 2 N1 - Size, condition, and territory ownership in male tree swallows (Tachycineta bicolor) KW - RHP territoriality tree swallow size condition N2 - Onwers were larger and heavier than floaters. Weight differences due to protein content. These differences may be the result of intrasexual conflicts or arrival times. ID - 87 ER - TY - CHAP AU - Lozano, G. A. PY - 1998 BT - Stress and Behavior CT - Parasitic stress and self-medication in wild animals CY - Sand Diego, CA PB - Academic Press T3 - Advances in the Study of Behavior SP - 291-317 N1 - Parasitic stress and self-medication in wild animals N1 - 11 N1 - Parasitic stress and self-medication in wild animals Adv. Stud. Behav. KW - anting Aspilia aversion chemical defense chimpanzee diet choice disease ethnobotany fur rubbing geophagia learning medicine nutrition OFT parasitism primates self-medication sequestration social learning stress Vernonia N2 - The final, most up-to-date word on self-medication in wild animals. One of the best critical reviews I have ever seen. ID - 78 ER - TY - JOUR AU - Lozano, G. A. PY - 2000 TI - Letter to the Editor SP - 825 JF - Nature VL - 403 N1 - Letter to the Editor N1 - 14 N1 - May Letter to the Editor ID - 75 ER - TY - JOUR AU - Lozano, G. A. PY - 2001 TI - Carotenoids, immunity, and sexual selection: comparing apples and oranges? SP - 200-203 JF - American Naturalist VL - 158 IS - 2 N1 - Carotenoids, immunity, and sexual selection: comparing apples and oranges? N1 - 15 N1 - Carotenoids, immunity, and sexual selection: comparing apples and oranges? KW - Age Immunoecology Immunosenescence Life history Philomachus pugnax Ruff N2 - Hill refuted!! ID - 74 ER - TY - JOUR AU - Lozano, G. A. PY - 2008 TI - Obesity and sexually selected anorexia nervosa SP - 933-940 JF - Medical Hypotheses VL - 71 N1 - Obesity and sexually selected anorexia nervosa N1 - 19 N1 - Obesity and sexually selected anorexia nervosa KW - obesity anorexia Human disease N2 - Summary Anorexia nervosa is diagnosed by drastic weight loss, a fear of gaining weight, a distorted body image, and, in women, three consecutive episodes of amenorrhea. It is often associated with a compulsive need for exercise, a bright outlook on life, and a high level of competitiveness. It afflicts primarily young women in higher socioeconomic strata who are highly competitive and otherwise overachievers. There are three adaptive explanations for anorexia nervosa: the reproductive suppression, the fleeing famine and the pseudo-fema e hypotheses. Here I present a novel hypothesis, the age-related obesity hypothesis. It posits that the otherwise normal tendency by women to seek a youthful appearance can become maladaptive and lead to anorexia nervosa in environments in which thinness becomes the primary indicator of youth, such as in modern industrialized societies. This hypothesis explains the aforementioned associated features of anorexia nervosa, and its increasing prevalence in western societies. The hypothesis generates several testable predictions: (1) Prevalence of anorexia nervosa across societies should be related to the degree to which thinness is an indicator of youth in a population. (2) Conversely, perceptions of the weight-age relationship should differ among populations depending on the prevalence of anorexia nervosa. (3) Anorectic individuals, or those with the propensity to develop the disease, should have a biased perception of the weight-age relationship. (4) Experimental manipulation of individuals’ perception of the weight-age relationship should affect weight concerns, particularly among anorectic or at-risk individuals. Should the hypothesis be supported it might be used to screen at-risk individuals. Furthermore, it would call for more integrative public health programs that take a comprehensive approach encompassing both obesity and anorexia. ID - 70 ER - TY - JOUR AU - Lozano, G. A. PY - 2009 TI - The other side of the coin: intersexual selection and the expression of emotions to signal youth or maturity SP - 398-399 JF - Behavioral and Brain Sciences VL - 32 IS - 5 N1 - The other side of the coin: intersexual selection and the expression of emotions to signal youth or maturity N1 - 21 KW - emotions ID - 68 ER - TY - JOUR AU - Lozano, G. A. PY - 2009 TI - Multiple cues in mate selection: the sexual interference hypothesis SP - 37-42 JF - BioScience Hypotheses VL - 2 N1 - Multiple cues in mate selection: the sexual interference hypothesis N1 - 20 N1 - Multiple cues in mate selection: the sexual interference hypothesis KW - Multiple ornaments sexual selection sexual interference ID - 69 ER - TY - JOUR AU - Lozano, G. A. AU - Handford, P. T. PY - 1995 TI - A test of an assumption of delayed plumage maturation hypotheses using female tree swallows SP - 153-164 JF - Wilson Bulletin VL - 107 N1 - A test of an assumption of delayed plumage maturation hypotheses using female tree swallows N1 - 4 N1 - A test of an assumption of delayed plumage maturation hypotheses using female tree swallows KW - DPM tree swallow N2 - DPM hypotheses are based on the assumption that older individuals are competitive superior. Blue and brown females did not differ in their parental abilities, but blue ones were larger and, after accounting for size differences, heavier and in better nutritional condition than brown females. Blue plumage is therefore an honest signal of condition. ID - 85 ER - TY - JOUR AU - Lozano, G. A. AU - Lank, D. B. PY - 2003 TI - Seasonal trade-offs in cell-mediated immunosenescence in ruffs (Philomachus pugnax) SP - 1203-1208 JF - Proceedings of the Royal Society of London, Series B VL - 270 N1 - Seasonal trade-offs in cell-mediated immunosenescence in ruffs (Philomachus pugnax) N1 - 17 N1 - Seasonal trade-offs in cell-mediated immunosenescence in ruffs (Philomachus pugnax) 10.1098/rspb.2002.2309 KW - ruff alternative strategies N2 - The immune system is an energetically expensive self-maintenance complex that, given the risks of parasitism, cannot be carelessly compromised. Life-history theory posits that trade-offs between fitness components, such as self-maintenance and reproduction, vary between genders and age classes depending on their expected residual lifetime reproductive success, and seasonally as energetic requirements change. Using ruff (Philomachus pugnax), a bird with two genetically distinct male morphs, we demonstrate here a decrease in male immunocompetence during the breeding season, greater variance in immune response among males than females, immunosenescence in both sexes and male morphs, and a seasonal shift in the age range required to detect senescence. Using a phytohaemagglutinin delayed hypersensitivity assay, we assessed cell-mediated immunity (CMI) of males of typical breeding age during the breeding and non-breeding seasons, and of a larger sample that included females and birds of a greater age range during the non-breeding period. CMI was higher for breeding-aged males in May than in November, but the increase was not related to age or male morph. In November, mean CMI did not differ between the sexes, but the variance was higher for males than for females, and there were no differences in mean or variance between the two male morphs. For both sexes and male morphs, CMI was lower for young birds than for birds of typical breeding ages, and it declined again for older birds. In males, senescence was detected in the non-breeding season only when very old birds were included. These results, generally consistent with expectations from life-history theory, indicate that the immune system can be involved in multifarious trade-offs within a yearly cycle and along an individual's lifetime, and that specific predictions about means and variances in immune response should be considered in future immunoecological research. ID - 72 ER - TY - JOUR AU - Lozano, G. A. AU - Lank, D. B. PY - 2004 TI - Immunocompetence and testosterone-induced condition traits in male ruffs (Philomachus pugnax) SP - 315-329 JF - Animal Biology VL - 54 IS - 4 N1 - Immunocompetence and testosterone-induced condition traits in male ruffs (Philomachus pugnax) N1 - 18 N1 - Immunocompetence and testosterone-induced condition traits in male ruffs (Philomachus pugnax) N2 - The immune system is costly to operate, so we expect allocation to this function to relate to other indices of overall phenotypic condition. In captive male ruffs (Philomachus pugnax), we examine covariation between three seasonal male characteristics induced by testosterone (neck ‘ruff’, facial wattles, and increases in mass/size) and cell-mediated and humoral immunity. The ruff has two genetically distinct morphs of males, ‘independents’ and ‘satellites’, which differ in mating behaviour, somewhat in body size, and possibly life history strategy. Ruff length and wattle number were significantly correlated with each other and with body size, but unrelated to mass/size. Humoral immunity was weakly correlated with size, but not with secondary male traits, or with cell-mediated immunity. We did not detect differences in humoral immunity between morphs. Cell-mediated immunity was weakly correlated with ruff length, but not with wattle number, size, or mass/size. Cell mediated immunity decreased significantly with age. Controlling for age, independents had higher cell-mediated immunity responses than satellites. The expected relationships between two measures of immune function and other measures of condition were not always present, which suggests we need more data and/or more specific predictions about how the different aspects of immune function relate to each other and to ecological variables. ID - 71 ER - TY - JOUR AU - Lozano, G. A. AU - Lemon, R. E. PY - 1995 TI - Food abundance and parental care in yellow warblers (Dendroica petechia) SP - 45-50 JF - Behavioral Ecology and Sociobiology VL - 37 N1 - Food abundance and parental care in yellow warblers (Dendroica petechia) N1 - 5 N1 - Food abundance and parental care in yellow warblers (Dendroica petechia) KW - PC-pass yellow warbler food abundance N2 - If monogamy in birds is maintained because of the need for biparental care, under conditions of high food abundance males should decrease their paternal effert to exploit any existing polygyny potential. Experimental manipulations of food abundance, however, affected only female care. ID - 84 ER - TY - JOUR AU - Lozano, G. A. AU - Lemon, R. E. PY - 1996 TI - Male plumage, paternal care and reproductive success in yellow warblers, Dendroica petechia SP - 265-272 JF - Animal Behaviour VL - 51 N1 - Male plumage, paternal care and reproductive success in yellow warblers, Dendroica petechia N1 - 6 N1 - Male plumage, paternal care and reproductive success in yellow warblers, Dendroica petechia KW - PC-pass yellow warbler plumage FMC-birds N2 - Female choice based on paternal care can only occur if there are features, visible at the time of mating, correlated with paternal care. In males plumage was not correlated with PC. Experimental reductions in paternal care were not compensated by females, and they reduced nestling growth. ID - 83 ER - TY - JOUR AU - Lozano, G. A. AU - Lemon, R. E. PY - 1998 TI - Adoption of yellow warbler nestlings by song sparrows SP - 131-133 JF - Wilson Bulletin VL - 110 N1 - Adoption of yellow warbler nestlings by song sparrows N1 - 12 N1 - Adoption of yellow warbler nestlings by song sparrows ID - 77 ER - TY - JOUR AU - Lozano, G. A. AU - Lemon, R. E. PY - 1998 TI - Parental care responses by yellow warblers (Dendroica petechia) to simultaneous manipulations of food abundance and brood size SP - 916-924 JF - Canadian Journal of Zoology VL - 76 N1 - Parental care responses by yellow warblers (Dendroica petechia) to simultaneous manipulations of food abundance and brood size N1 - 10 N1 - Parental care responses by yellow warblers (Dendroica petechia) to simultaneous manipulations of food abundance and brood size KW - yellow warbler N2 - Failed to find evidence contrary to the partial compensation model of biparental care, yet argue against it at the end, anyway. ID - 79 ER - TY - JOUR AU - Lozano, G. A. AU - Lemon, R. E. PY - 1999 TI - Effects of prior residency and age on breeding performance in yellow warblers SP - 381-388 JF - Wilson Bulletin VL - 111 IS - 3 N1 - Effects of prior residency and age on breeding performance in yellow warblers N1 - 13 N1 - Effects of prior residency and age on breeding performance in yellow warblers KW - carotenoid N2 - An instant classic!! 1.-The effects fo prior residency differed between the sexes; in females it affected the prospect of breeding, in males only the timing of breeding 2.-As a group or individually, returning males were larger than new arrivals, but among females individuals were larger in consecutive breeding season, but not so as a group. 3.-Results are consistent with the constraint hypothesis, but it is now clear whether these diffs are the result of age itself, or local experience. ID - 76 ER - TY - JOUR AU - Lozano, G. A. AU - Perreault, S. AU - Lemon, R. E. PY - 1996 TI - Age, arrival date and reproductive success of male American redstarts Setophaga ruticilla SP - 164-170 JF - Journal of Avian Biology VL - 27 N1 - Age, arrival date and reproductive success of male American redstarts Setophaga ruticilla N1 - 7 N1 - Age, arrival date and reproductive success of male American redstarts Setophaga ruticilla KW - territoriality redstart RS age arrival N2 - RS in redstarts is independently affected by age and arrival date. ID - 82 ER - TY - JOUR AU - Lozano, G. A. AU - Ydenberg, R. C. PY - 2002 TI - Transgenerational effects of maternal immune challenge in tree swallows (Tachycyneta bicolor) SP - 918-925 JF - Canadian Journal of Zoology VL - 80 N1 - Transgenerational effects of maternal immune challenge in tree swallows (Tachycyneta bicolor) N1 - 16 N1 - Transgenerational effects of maternal immune challenge in tree swallows (Tachycyneta bicolor) KW - Tree swallow immunity eggs maternal effects N2 - The fact that avian eggs contain antibody of maternal origin is well documented, but only recently has this phenomenon been considered in an ecological context. We used tree swallows (Tachycineta bicolor) to examine the possibility of transgenerational immunity and its effect on nestling growth and immune development. We measured cell-mediated immunity with a delayed-hypersensitivity assay and antibody-mediated immunity with a hemagglutination test with sheep red blood cells (SRBCs). We tested for differences in immunocompetence and growth between nestlings from females who had been exposed to a novel antigen prior to egg laying and nestlings from unexposed females. To determine whether the effect, if any, resulted from something transferred to the eggs prior to egg laying or from subsequent changes in parental behaviour, nestlings were exchanged so that at each nest half the nestlings were from females who had been injected with SRBCs and half were from females who had not been exposed to SRBCs. Finally, brood sizes were independently manipulated to either 4 or 6 nestlings. We failed to detect maternal antibodies in any nestlings, and whether a female was exposed to SRBCs or not had no effect on the growth or cell-mediated immunity of her brood. However, nestlings in smaller broods grew better than nestlings in larger broods, though we did not find the expected differences in cell-mediated immunity. Furthermore, within each nest, nestlings whose mothers had been exposed to SRBCs grew better than nestlings whose mothers had not been exposed. These results are contrary to the idea of a simple trade-off in the allocation of resources between parasite protection and reproduction; however, they support the idea that exposure of females to parasites prior to egg laying leads to better nestling growth, and are congruous with the possibility of mithridatic parental care ID - 73 ER -