Carpal tunnel syndrome, peripheral arthropathy, erosive spondyloarthropathy and lytic bone lesion... more Carpal tunnel syndrome, peripheral arthropathy, erosive spondyloarthropathy and lytic bone lesions have all been associated with dialysis amyloidosis. Recent studies indicate that beta 2-microglobulin is the major constituent protein in this new form of amyloidosis. Dialysis amyloidosis was reported to have a local rather than a systemic involvement, although its full extent is yet to be determined. We investigated 3 patients on maintenance hemodialysis with bilateral carpal tunnel syndrome and amyloid arthropathy and found amyloid depositions in several organs. These findings suggest that, in contrast to what had been thought previously, dialysis amyloidosis could have systemic as well as visceral distribution. The amyloid deposits found were resistant against potassium permanganate treatment and reacted with anti-human beta 2-microglobulin antibody.
Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with... more Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with a diet very similar to that fed to their own chicks. In both naturally and experimentally parasitized nests, great spotted cuckoo chicks were fed at a higher rate than magpie chicks in the same nest. This preferential allocation of food by magpie parents to great spotted cuckoo chicks is consistent with the supernormal stimulus hypothesis, because this result implies that cuckoo chicks provide stronger stimuli for parental care than host chicks. Great spotted cuckoo chicks receive most of the food brought to the nest by the foster parents, because they exploit a series of stimuli which jointly (or sometimes individually) operate as a supernormal stimulus. This hypothesis predicts that if any stimulus is masked, the efficiency of the cuckoo in eliciting parental care will decrease. Here, we analyze experimentally the effects of two of these stimuli, preferential feeding of large nestlings and of nestlings with conspicuous palatal papillae. Firstly, when we experimentally introduced one medium-sized (7–9 days) cuckoo chick into an unparasitized magpie nest where the largest magpie chick was 12–15 days old, the cuckoo did not receive significantly more food than the average or the largest magpie chick. Secondly, when unparasitized nests were experimentally parasitized with a cuckoo chick that had its gape painted to mimic that of magpie chicks, the parasitic cuckoo received less food than the average magpie chick.
Nest size has been suggested to be a sexually selected trait indicating parental ability of both ... more Nest size has been suggested to be a sexually selected trait indicating parental ability of both males and females. To test whether a female's reproductive decisions (eg, clutch size and starting incubation) change in relation to experimental manipulation of nest size, as would be ...
Despite the interest that avian brood parasites provoke due to their reproductive strategy, and t... more Despite the interest that avian brood parasites provoke due to their reproductive strategy, and the wealth of published studies, their mating system is one of the least known aspects of their natural history. This study describes the first attempt to use genetics to characterize mating patterns in a brood parasite, the great spotted cuckoo (Clamator glandarius). We developed a set of microsatellite markers for this species that allowed us to determine the parentage of 78% of the chicks sampled, with a high probability of certainty (false parental inclusion probability, P FI = 2 × 10 -4 ). Parentage analyses allowed us to determine mating patterns in the population, to show for the first time that there were several females laying in the same study site and sharing host nests, and that females used nests of two different host species in the same season. A total of 70% of the inferred mating relationships can be considered monogamous, and the rest were cases of genetic polygamy, although of unknown social structure. To ease parentage analyses, adult birds were successfully sexed using a combination of sexspecific PCR primers and SSCP techniques before parentage assignment.
Breasts of human females are large compared to those of closely related primate species, and they... more Breasts of human females are large compared to those of closely related primate species, and they can thus be hypothesized recently or currently to have been subject to directional sexual selection. Here we show that (1) large breasts have higher levels of fluctuating asymmetry than small breasts, (2) breast fluctuating asymmetry is higher in women without children than in women with at least one child, (3) breast fluctuating symmetry is a reliable predictor of age-independent fecundity, and (4) breast fluctuating symmetry appears to be associated with sexual selection. These conclusions were similar in studies from two cultures differing in fecundity and brenstfeeding traditions (Spain; New Mexico, U.S.A.). Choosy males that prefer females with symmetrical breasts may experience a direct fitness benefit in terms of increased fecundity and an indirect benefit in terms of attractive or fecund daughters.
Brood parasitism is one of the systems where coevolutionary processes have received the most rese... more Brood parasitism is one of the systems where coevolutionary processes have received the most research. Here, we review experiments that suggest a coevolutionary process between the great spotted cuckoo (Clamator glandarius) and its magpie (Pica pica) host. We focus on different stages of establishment of the relationship, from cuckoos selecting individual hosts and hosts defending their nests from adult cuckoos, to the ability of magpies to detect cuckoo eggs in their nests. Novel coevolutionary insights emerge from our synthesis of the literature, including how the evolution of "Mafia" behaviour in cuckoos does not necessarily inhibit the evolution of host recognition and rejection of cuckoo offspring, and how different populations of black-billed magpies in Europe have evolved specific host traits (e.g. nest and clutch size) as a result of interactions with the great spotted cuckoo. Finally, the results of the synthesis reveal the importance of using a meta-population approach when studying coevolution. This is especially relevant in those cases where gene flow among populations with different degrees of brood parasitism explains patterns of coexistence between defensive and non-defensive host phenotypes. We propose the use of a meta-population approach to distinguish between the "evolutionary equilibrium" hypothesis and the "evolutionary lag" hypothesis.
ABSTRACT Nestlings of many brood parasites are reared together with those of their hosts, but sti... more ABSTRACT Nestlings of many brood parasites are reared together with those of their hosts, but still manage to monopolize,a disproportionate share of the food delivered by adult hosts. Weh ypothesized that: (1) the low levels of host-speciWc pathogens of such brood parasite nestlings provide them with an advantage,in competition,for limited food; (2) a higher,provisioning rate and the re- sulting better
Most studies that have tested the egg-recognition and egg-rejection ability of European cuckoo Cu... more Most studies that have tested the egg-recognition and egg-rejection ability of European cuckoo Cuculus canorus hosts have used artificial model eggs that are much harder than real Cuckoo eggs. Here we evaluate whether the use of such models overestimates the costs of egg rejection by hosts. We tested 17 potential cuckoo host species in south-eastern Spain with both artificial hard cuckoo-egg models and real eggs taken from a population of house sparrows Passer domesticus breeding in captivity. The puncture resistance of sparrow eggs, measured in the laboratory, was more similar to that of real cuckoo eggs than was the resistance of artificial models, although sparrow eggs were less resistant than real cuckoo eggs. Potential host species with a grasp index greater than 200 mm2 did not suffer high rejection costs when rejecting hard models, probably because they are grasp ejectors. However, all species with a smaller grasp index suffered high costs when rejecting hard artificial models. For these species the frequency and magnitude of costs were significantly higher when rejecting artificial hard models than when rejecting real eggs. For some species the breakage of real eggs was quite difficult (they needed 97 to more than 4000 pecks in video-recorded ejections), and sometimes the birds suffered rejection costs. These results show that realistic estimates of the frequency and magnitude of rejection costs for hosts with small bills cannot be obtained by using artificial models, and also that for a variety of medium-sized puncture ejector species the costs when rejecting real eggs may be low.
A long-term study of the interactions between a brood parasite, the great spotted cuckoo Clamator... more A long-term study of the interactions between a brood parasite, the great spotted cuckoo Clamator glandarius, and its primary host the magpie Pica pica, demonstrated local changes in the distribution of both magpies and cuckoos and a rapid increase of rejection of both mimetic and non-mimetic model eggs by the host. In rich areas, magpies improved three of their defensive mechanisms: nest density and breeding synchrony increased dramatically and rejection rate of cuckoo eggs increased more slowly. A stepwise multiple regression analysis showed that parasitism rate decreased as host density increased and cuckoo density decreased. A logistic regression analysis indicated that the probability of changes in magpie nest density in the study plots was significantly affected by the density of magpie nests during the previous year (positively) and the rejection rate of mimetic model eggs (negatively). These results are consistent with a hypothesis (the intermittent arms race hypothesis) of spatially structured cyclic changes in parasitism. During periods of parasitism, host defences continuously improve, and as a consequence, the fitness gains for parasites decrease. When host defences against parasites reach a high level, dispersing parasites have a selective advantage if they are able to emigrate to areas of low resistance. Once parasites have left an area hosts will lose their defensive adaptations due to their cost in the absence of parasitism. The scene is then set for re-colonization by great spotted cuckoos.
Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with... more Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with a diet very similar to that fed to their own chicks. In both naturally and experimentally parasitized nests, great spotted cuckoo chicks were fed at a higher rate than magpie chicks in the same nest. This preferential allocation of food by magpie parents to great spotted cuckoo chicks is consistent with the supernormal stimulus hypothesis, because this result implies that cuckoo chicks provide stronger stimuli for parental care than host chicks. Great spotted cuckoo chicks receive most of the food brought to the nest by the foster parents, because they exploit a series of stimuli which jointly (or sometimes individually) operate as a supernormal stimulus. This hypothesis predicts that if any stimulus is masked, the efficiency of the cuckoo in eliciting parental care will decrease. Here, we analyze experimentally the effects of two of these stimuli, preferential feeding of large nestlings and of nestlings with conspicuous palatal papillae. Firstly, when we experimentally introduced one medium-sized (7-9 days) cuckoo chick into an unparasitized magpie nest where the largest magpie chick was 12-15 days old, the cuckoo did not receive significantly more food than the average or the largest magpie chick. Secondly, when unparasitized nests were experimentally parasitized with a cuckoo chick that had its gape painted to mimic that of magpie chicks, the parasitic cuckoo received less food than the average magpie chick.
Male black wheatears Oenanthe leucura demonstrate an exaggerated sexual display by carrying many ... more Male black wheatears Oenanthe leucura demonstrate an exaggerated sexual display by carrying many heavy stones (on average 3.1 kg per season for this 35-g passerine) to cavities inside caves before the start of each clutch. The energetic cost of this display is mainly determined by the size of stones, which gives rise to the largest power output of a muscle ever recorded for any species (400 W/kg), rather than the total number of stones carried, which only amounts to 1% of daily energy expenditure for a black wheatear male. We tested whether stone carrying reflected male health status by removing two primaries from a group of males, but not from controls. Experimental manipulation did not significantly affect stone carrying. Similarly, male health status measured as hematocrit, leukocyte concentration, and T-cell response to an injection with phytohemagglutinin (a lectin) was not affected by experimental manipulation. Male black wheatears that carried very heavy stones, each on average more than a quarter of their own body mass, had a stronger T-cell response to injection with a lectin than males that carried light stones. Furthermore, males that carried heavy stones had a reduced hematocrit level, which may have arisen from the effects of the extremely heavy work load. Rate of stone carrying and mass of stones was not significantly related to the abundance of two species of ectoparasites. Male black wheatears with high T-cell responses were significantly more likely to survive than males with low responses, but other measures of male performance did not differ significantly between survivors and nonsurvivors. The male stone-carrying display thus reflects male health status as demonstrated by a component of immunocompetence.
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1999
Page 1. Begging behaviour and its energetic cost in great spotted cuckoo and magpie host chicks M... more Page 1. Begging behaviour and its energetic cost in great spotted cuckoo and magpie host chicks Manuel Soler, Juan J. Soler, Juan G. Martínez, and Juan Moreno Abstract: Begging is one of the main factors governing food ...
Avian nest building has traditionally been viewed as resulting in natural selection advantages, b... more Avian nest building has traditionally been viewed as resulting in natural selection advantages, but it is also been associated with courtship and pair formation. We hypothesize that nest-building activity could be used as a sexually selected display, allowing each sex to obtain reliable information on the condition of the other. In this paper, we test the`good parent' process in a scenario where nest size is a sexually selected trait. Thus, individuals with more extreme displays (larger nests) might obtain bene®ts in terms of either parental investment or dierential parental investment by the partner. We predicted that: (1) species in which both sexes contribute to nest building have larger nests than those in which the nest is built only by one sex, because both sexes are using the nest-building process as a signal of their quality; (2) species in which both sexes work together in the nest-building process invest more in reproduction, because each can assess the other more reliably than in species where only one sex participates in nest building; and (3) in light of the two preceding predictions, nest size should be positively related to investment in parental care. A comparative analysis of 76 passerine species con®rmed that nest size, relative to the species' body size, is larger when both sexes build the nest and that species with a larger nest relative to their body size invest more in reproduction.
... THE RUFOUS BUSH ROBIN CERCOTRICHAS GALACTOTES JOSE JAVIERPALOMINO, MANUEL MARTIN-VIVALDI, MAN... more ... THE RUFOUS BUSH ROBIN CERCOTRICHAS GALACTOTES JOSE JAVIERPALOMINO, MANUEL MARTIN-VIVALDI, MANUEL SOLER & JUAN JOSE SOLERPalomino JJ, M. Martin-Vivaldi, M. Soler & U. Soler 1998. Functional ...
Males of the black wheatear (Oenanthe leucura) carry on average almost 2 kg of stones to cavities... more Males of the black wheatear (Oenanthe leucura) carry on average almost 2 kg of stones to cavities inside caves before the laying of each clutch, a display involved in postulating sexual selection as determined from female adjustment of timing and rate of reproduction to experimentally manipulated numbers of stones carried. A large wing area in relation to body mass would allow males to carry many and heavy stones. The number and mass of stones carried were inversely related to wing loading, suggesting that a large wing area has evolved as an adaptation to stone carrying. We tested mis functional hypothesis in a field experiment with three treatments: (1) two primaries removed from each wing (manipulation), (2) the tips of two primaries removed from each wing (sham-manipulation), and (3) the male just captured and handled (control). The number and mass of stones carried were inversely related to original wing area, as predicted by die hypothesis, and males widi initially large wing areas were better able to cope widi the experimental treatment than odiers. These results are consistent widi stone carrying being a reliable signal of maximum working ability of males during short bursts of stone carrying, and intraspecific differences in wing morphology dierefore allow males to display at different levels. Key words: black wheatear, morphological adaptations, Oenanthe, Oenanthe leucura, reliable signaling, sexual display, stone carrying. [Behav Ecol 6:368-375 (1995)]
Hosts of brood parasites have evolved the ability to discriminate non-mimetic and even mimetic eg... more Hosts of brood parasites have evolved the ability to discriminate non-mimetic and even mimetic eggs, but not non-mimetic chicks. Here we demonstrate that the great spotted cuckoo Clamator glandarius does not provide its magpie Pica pica host with a super-normal stimulus that helps to avoid recognition, because single cuckoo chicks introduced into otherwise unparasitized magpie nests are not fed at a higher frequency than single magpie chicks introduced to parasitized magpie nests. Another series of experiments demonstrated that magpies have the ability to discriminate cuckoo chicks, mainly when these are introduced at the end of the nestling period, and especially when the cuckoo chick together with a magpie chick is presented to adult magpies outside the nest. This supports the idea that cuckoos exploit the obligatory reaction of magpies to feed all young that have been hatched in their nests and whose “signatures” they have learnt. Furthermore, the experimental cuckoo chicks in parasitized magpie nests were more likely to be accepted than they were in non-parasitized nests. This supports the hypothesis that magpies may learn to recognise their own nestlings as those present in the nest and may indicate that a comparison between cuckoo and magpie nestlings is the basis of discrimination.
Adult great spotted cuckoos, Clamator glandarius, damage the eggs of their magpie, Pica pica, hos... more Adult great spotted cuckoos, Clamator glandarius, damage the eggs of their magpie, Pica pica, host without removing or eating them. The number of damaged magpie eggs was recorded in 360 parasitized nests of which 62.2% contained between one and eight damaged magpie eggs. Eggdestroying behaviour may be adaptive if it reduces nestling competition and/or enhances the hatching success of the cuckoo. To clarify the role of egg destruction for the reproductive success of great spotted cuckoos, unparasitized magpie nests were experimentally parasitized (without egg damage) by introducing cuckoo eggs or chicks. Egg damage was common in parasitized nests but the eggs were not damaged by the hosts. Egg damage increased the breeding success of the cuckoos, by both reducing the number of competing host chicks in the nest and increasing the likelihood that late-laid cuckoo eggs would hatch.
The relationship between brood parasites and their hosts is usually assumed to result in coevolut... more The relationship between brood parasites and their hosts is usually assumed to result in coevolution, and documentation of changes in extant populations should thus be possible. Here we describe how the ejection rate of eggs of an obligate brood parasite, the great spotted cuckoo Clamator glandarius, by its host, the magpie Pica pica, has recently increased in an area in southern Spain. The ejection rate of great spotted cuckoo eggs in naturally parasitized nests of the magpie increased at a rate of 0.5% year' during the period 1982–1992. This result was verified in a number of field experiments using nonmimetic and mimetic model eggs. The rate of increase in ejection rate was 4.7% year-1 for mimetic eggs and 2.3% year-1 for nonmimetic eggs. There were clear differences in parasitism by the great spotted cuckoo between study plots and years, which makes comparisons of rates of parasitism between areas difficult without considering temporal variation. The recent increase in the ejection response of magpies to great spotted cuckoo eggs was not due to magpies using the abundance of cuckoos as a cue to the intensity of parasitism.
Two Jackdaw Corvus monedula colonies were given supplementary food before and during breeding in ... more Two Jackdaw Corvus monedula colonies were given supplementary food before and during breeding in 1983. Breeding density and cavity use were compared with those of the same colonies in previous years, when no food was provided. Predation rate and reproductive parameters were compared with those in the same colonies in previous years and with those of two control colonies, without experimental food. Jackdaws preferred safe cavities with small minimum nest-entrance dimensions and avoided those with a high risk of nest predation. In experimental (fed) colonies, however, there was a tendency to use all cavities, which resulted in an increased breeding density. No nests were preyed upon by Ravens Corvus corax in the experimental colonies because supplemental food favoured group defence by increasing colony size and by increasing the time the Jackdaws spent in the colony. Additional food advanced laying date, increased clutch size independently of laying date and increased fledging success. Supplementary food significantly increased fledging success in less than half of all experimental studies on birds. We suggest that the key to this problem is the species' breeding strategy, and we show that supplementary food significantly increased fledging success in brood-reduction strategist species but not in species which directly adjusted their clutch size.
Carpal tunnel syndrome, peripheral arthropathy, erosive spondyloarthropathy and lytic bone lesion... more Carpal tunnel syndrome, peripheral arthropathy, erosive spondyloarthropathy and lytic bone lesions have all been associated with dialysis amyloidosis. Recent studies indicate that beta 2-microglobulin is the major constituent protein in this new form of amyloidosis. Dialysis amyloidosis was reported to have a local rather than a systemic involvement, although its full extent is yet to be determined. We investigated 3 patients on maintenance hemodialysis with bilateral carpal tunnel syndrome and amyloid arthropathy and found amyloid depositions in several organs. These findings suggest that, in contrast to what had been thought previously, dialysis amyloidosis could have systemic as well as visceral distribution. The amyloid deposits found were resistant against potassium permanganate treatment and reacted with anti-human beta 2-microglobulin antibody.
Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with... more Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with a diet very similar to that fed to their own chicks. In both naturally and experimentally parasitized nests, great spotted cuckoo chicks were fed at a higher rate than magpie chicks in the same nest. This preferential allocation of food by magpie parents to great spotted cuckoo chicks is consistent with the supernormal stimulus hypothesis, because this result implies that cuckoo chicks provide stronger stimuli for parental care than host chicks. Great spotted cuckoo chicks receive most of the food brought to the nest by the foster parents, because they exploit a series of stimuli which jointly (or sometimes individually) operate as a supernormal stimulus. This hypothesis predicts that if any stimulus is masked, the efficiency of the cuckoo in eliciting parental care will decrease. Here, we analyze experimentally the effects of two of these stimuli, preferential feeding of large nestlings and of nestlings with conspicuous palatal papillae. Firstly, when we experimentally introduced one medium-sized (7–9 days) cuckoo chick into an unparasitized magpie nest where the largest magpie chick was 12–15 days old, the cuckoo did not receive significantly more food than the average or the largest magpie chick. Secondly, when unparasitized nests were experimentally parasitized with a cuckoo chick that had its gape painted to mimic that of magpie chicks, the parasitic cuckoo received less food than the average magpie chick.
Nest size has been suggested to be a sexually selected trait indicating parental ability of both ... more Nest size has been suggested to be a sexually selected trait indicating parental ability of both males and females. To test whether a female's reproductive decisions (eg, clutch size and starting incubation) change in relation to experimental manipulation of nest size, as would be ...
Despite the interest that avian brood parasites provoke due to their reproductive strategy, and t... more Despite the interest that avian brood parasites provoke due to their reproductive strategy, and the wealth of published studies, their mating system is one of the least known aspects of their natural history. This study describes the first attempt to use genetics to characterize mating patterns in a brood parasite, the great spotted cuckoo (Clamator glandarius). We developed a set of microsatellite markers for this species that allowed us to determine the parentage of 78% of the chicks sampled, with a high probability of certainty (false parental inclusion probability, P FI = 2 × 10 -4 ). Parentage analyses allowed us to determine mating patterns in the population, to show for the first time that there were several females laying in the same study site and sharing host nests, and that females used nests of two different host species in the same season. A total of 70% of the inferred mating relationships can be considered monogamous, and the rest were cases of genetic polygamy, although of unknown social structure. To ease parentage analyses, adult birds were successfully sexed using a combination of sexspecific PCR primers and SSCP techniques before parentage assignment.
Breasts of human females are large compared to those of closely related primate species, and they... more Breasts of human females are large compared to those of closely related primate species, and they can thus be hypothesized recently or currently to have been subject to directional sexual selection. Here we show that (1) large breasts have higher levels of fluctuating asymmetry than small breasts, (2) breast fluctuating asymmetry is higher in women without children than in women with at least one child, (3) breast fluctuating symmetry is a reliable predictor of age-independent fecundity, and (4) breast fluctuating symmetry appears to be associated with sexual selection. These conclusions were similar in studies from two cultures differing in fecundity and brenstfeeding traditions (Spain; New Mexico, U.S.A.). Choosy males that prefer females with symmetrical breasts may experience a direct fitness benefit in terms of increased fecundity and an indirect benefit in terms of attractive or fecund daughters.
Brood parasitism is one of the systems where coevolutionary processes have received the most rese... more Brood parasitism is one of the systems where coevolutionary processes have received the most research. Here, we review experiments that suggest a coevolutionary process between the great spotted cuckoo (Clamator glandarius) and its magpie (Pica pica) host. We focus on different stages of establishment of the relationship, from cuckoos selecting individual hosts and hosts defending their nests from adult cuckoos, to the ability of magpies to detect cuckoo eggs in their nests. Novel coevolutionary insights emerge from our synthesis of the literature, including how the evolution of "Mafia" behaviour in cuckoos does not necessarily inhibit the evolution of host recognition and rejection of cuckoo offspring, and how different populations of black-billed magpies in Europe have evolved specific host traits (e.g. nest and clutch size) as a result of interactions with the great spotted cuckoo. Finally, the results of the synthesis reveal the importance of using a meta-population approach when studying coevolution. This is especially relevant in those cases where gene flow among populations with different degrees of brood parasitism explains patterns of coexistence between defensive and non-defensive host phenotypes. We propose the use of a meta-population approach to distinguish between the "evolutionary equilibrium" hypothesis and the "evolutionary lag" hypothesis.
ABSTRACT Nestlings of many brood parasites are reared together with those of their hosts, but sti... more ABSTRACT Nestlings of many brood parasites are reared together with those of their hosts, but still manage to monopolize,a disproportionate share of the food delivered by adult hosts. Weh ypothesized that: (1) the low levels of host-speciWc pathogens of such brood parasite nestlings provide them with an advantage,in competition,for limited food; (2) a higher,provisioning rate and the re- sulting better
Most studies that have tested the egg-recognition and egg-rejection ability of European cuckoo Cu... more Most studies that have tested the egg-recognition and egg-rejection ability of European cuckoo Cuculus canorus hosts have used artificial model eggs that are much harder than real Cuckoo eggs. Here we evaluate whether the use of such models overestimates the costs of egg rejection by hosts. We tested 17 potential cuckoo host species in south-eastern Spain with both artificial hard cuckoo-egg models and real eggs taken from a population of house sparrows Passer domesticus breeding in captivity. The puncture resistance of sparrow eggs, measured in the laboratory, was more similar to that of real cuckoo eggs than was the resistance of artificial models, although sparrow eggs were less resistant than real cuckoo eggs. Potential host species with a grasp index greater than 200 mm2 did not suffer high rejection costs when rejecting hard models, probably because they are grasp ejectors. However, all species with a smaller grasp index suffered high costs when rejecting hard artificial models. For these species the frequency and magnitude of costs were significantly higher when rejecting artificial hard models than when rejecting real eggs. For some species the breakage of real eggs was quite difficult (they needed 97 to more than 4000 pecks in video-recorded ejections), and sometimes the birds suffered rejection costs. These results show that realistic estimates of the frequency and magnitude of rejection costs for hosts with small bills cannot be obtained by using artificial models, and also that for a variety of medium-sized puncture ejector species the costs when rejecting real eggs may be low.
A long-term study of the interactions between a brood parasite, the great spotted cuckoo Clamator... more A long-term study of the interactions between a brood parasite, the great spotted cuckoo Clamator glandarius, and its primary host the magpie Pica pica, demonstrated local changes in the distribution of both magpies and cuckoos and a rapid increase of rejection of both mimetic and non-mimetic model eggs by the host. In rich areas, magpies improved three of their defensive mechanisms: nest density and breeding synchrony increased dramatically and rejection rate of cuckoo eggs increased more slowly. A stepwise multiple regression analysis showed that parasitism rate decreased as host density increased and cuckoo density decreased. A logistic regression analysis indicated that the probability of changes in magpie nest density in the study plots was significantly affected by the density of magpie nests during the previous year (positively) and the rejection rate of mimetic model eggs (negatively). These results are consistent with a hypothesis (the intermittent arms race hypothesis) of spatially structured cyclic changes in parasitism. During periods of parasitism, host defences continuously improve, and as a consequence, the fitness gains for parasites decrease. When host defences against parasites reach a high level, dispersing parasites have a selective advantage if they are able to emigrate to areas of low resistance. Once parasites have left an area hosts will lose their defensive adaptations due to their cost in the absence of parasitism. The scene is then set for re-colonization by great spotted cuckoos.
Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with... more Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with a diet very similar to that fed to their own chicks. In both naturally and experimentally parasitized nests, great spotted cuckoo chicks were fed at a higher rate than magpie chicks in the same nest. This preferential allocation of food by magpie parents to great spotted cuckoo chicks is consistent with the supernormal stimulus hypothesis, because this result implies that cuckoo chicks provide stronger stimuli for parental care than host chicks. Great spotted cuckoo chicks receive most of the food brought to the nest by the foster parents, because they exploit a series of stimuli which jointly (or sometimes individually) operate as a supernormal stimulus. This hypothesis predicts that if any stimulus is masked, the efficiency of the cuckoo in eliciting parental care will decrease. Here, we analyze experimentally the effects of two of these stimuli, preferential feeding of large nestlings and of nestlings with conspicuous palatal papillae. Firstly, when we experimentally introduced one medium-sized (7-9 days) cuckoo chick into an unparasitized magpie nest where the largest magpie chick was 12-15 days old, the cuckoo did not receive significantly more food than the average or the largest magpie chick. Secondly, when unparasitized nests were experimentally parasitized with a cuckoo chick that had its gape painted to mimic that of magpie chicks, the parasitic cuckoo received less food than the average magpie chick.
Male black wheatears Oenanthe leucura demonstrate an exaggerated sexual display by carrying many ... more Male black wheatears Oenanthe leucura demonstrate an exaggerated sexual display by carrying many heavy stones (on average 3.1 kg per season for this 35-g passerine) to cavities inside caves before the start of each clutch. The energetic cost of this display is mainly determined by the size of stones, which gives rise to the largest power output of a muscle ever recorded for any species (400 W/kg), rather than the total number of stones carried, which only amounts to 1% of daily energy expenditure for a black wheatear male. We tested whether stone carrying reflected male health status by removing two primaries from a group of males, but not from controls. Experimental manipulation did not significantly affect stone carrying. Similarly, male health status measured as hematocrit, leukocyte concentration, and T-cell response to an injection with phytohemagglutinin (a lectin) was not affected by experimental manipulation. Male black wheatears that carried very heavy stones, each on average more than a quarter of their own body mass, had a stronger T-cell response to injection with a lectin than males that carried light stones. Furthermore, males that carried heavy stones had a reduced hematocrit level, which may have arisen from the effects of the extremely heavy work load. Rate of stone carrying and mass of stones was not significantly related to the abundance of two species of ectoparasites. Male black wheatears with high T-cell responses were significantly more likely to survive than males with low responses, but other measures of male performance did not differ significantly between survivors and nonsurvivors. The male stone-carrying display thus reflects male health status as demonstrated by a component of immunocompetence.
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1999
Page 1. Begging behaviour and its energetic cost in great spotted cuckoo and magpie host chicks M... more Page 1. Begging behaviour and its energetic cost in great spotted cuckoo and magpie host chicks Manuel Soler, Juan J. Soler, Juan G. Martínez, and Juan Moreno Abstract: Begging is one of the main factors governing food ...
Avian nest building has traditionally been viewed as resulting in natural selection advantages, b... more Avian nest building has traditionally been viewed as resulting in natural selection advantages, but it is also been associated with courtship and pair formation. We hypothesize that nest-building activity could be used as a sexually selected display, allowing each sex to obtain reliable information on the condition of the other. In this paper, we test the`good parent' process in a scenario where nest size is a sexually selected trait. Thus, individuals with more extreme displays (larger nests) might obtain bene®ts in terms of either parental investment or dierential parental investment by the partner. We predicted that: (1) species in which both sexes contribute to nest building have larger nests than those in which the nest is built only by one sex, because both sexes are using the nest-building process as a signal of their quality; (2) species in which both sexes work together in the nest-building process invest more in reproduction, because each can assess the other more reliably than in species where only one sex participates in nest building; and (3) in light of the two preceding predictions, nest size should be positively related to investment in parental care. A comparative analysis of 76 passerine species con®rmed that nest size, relative to the species' body size, is larger when both sexes build the nest and that species with a larger nest relative to their body size invest more in reproduction.
... THE RUFOUS BUSH ROBIN CERCOTRICHAS GALACTOTES JOSE JAVIERPALOMINO, MANUEL MARTIN-VIVALDI, MAN... more ... THE RUFOUS BUSH ROBIN CERCOTRICHAS GALACTOTES JOSE JAVIERPALOMINO, MANUEL MARTIN-VIVALDI, MANUEL SOLER & JUAN JOSE SOLERPalomino JJ, M. Martin-Vivaldi, M. Soler & U. Soler 1998. Functional ...
Males of the black wheatear (Oenanthe leucura) carry on average almost 2 kg of stones to cavities... more Males of the black wheatear (Oenanthe leucura) carry on average almost 2 kg of stones to cavities inside caves before the laying of each clutch, a display involved in postulating sexual selection as determined from female adjustment of timing and rate of reproduction to experimentally manipulated numbers of stones carried. A large wing area in relation to body mass would allow males to carry many and heavy stones. The number and mass of stones carried were inversely related to wing loading, suggesting that a large wing area has evolved as an adaptation to stone carrying. We tested mis functional hypothesis in a field experiment with three treatments: (1) two primaries removed from each wing (manipulation), (2) the tips of two primaries removed from each wing (sham-manipulation), and (3) the male just captured and handled (control). The number and mass of stones carried were inversely related to original wing area, as predicted by die hypothesis, and males widi initially large wing areas were better able to cope widi the experimental treatment than odiers. These results are consistent widi stone carrying being a reliable signal of maximum working ability of males during short bursts of stone carrying, and intraspecific differences in wing morphology dierefore allow males to display at different levels. Key words: black wheatear, morphological adaptations, Oenanthe, Oenanthe leucura, reliable signaling, sexual display, stone carrying. [Behav Ecol 6:368-375 (1995)]
Hosts of brood parasites have evolved the ability to discriminate non-mimetic and even mimetic eg... more Hosts of brood parasites have evolved the ability to discriminate non-mimetic and even mimetic eggs, but not non-mimetic chicks. Here we demonstrate that the great spotted cuckoo Clamator glandarius does not provide its magpie Pica pica host with a super-normal stimulus that helps to avoid recognition, because single cuckoo chicks introduced into otherwise unparasitized magpie nests are not fed at a higher frequency than single magpie chicks introduced to parasitized magpie nests. Another series of experiments demonstrated that magpies have the ability to discriminate cuckoo chicks, mainly when these are introduced at the end of the nestling period, and especially when the cuckoo chick together with a magpie chick is presented to adult magpies outside the nest. This supports the idea that cuckoos exploit the obligatory reaction of magpies to feed all young that have been hatched in their nests and whose “signatures” they have learnt. Furthermore, the experimental cuckoo chicks in parasitized magpie nests were more likely to be accepted than they were in non-parasitized nests. This supports the hypothesis that magpies may learn to recognise their own nestlings as those present in the nest and may indicate that a comparison between cuckoo and magpie nestlings is the basis of discrimination.
Adult great spotted cuckoos, Clamator glandarius, damage the eggs of their magpie, Pica pica, hos... more Adult great spotted cuckoos, Clamator glandarius, damage the eggs of their magpie, Pica pica, host without removing or eating them. The number of damaged magpie eggs was recorded in 360 parasitized nests of which 62.2% contained between one and eight damaged magpie eggs. Eggdestroying behaviour may be adaptive if it reduces nestling competition and/or enhances the hatching success of the cuckoo. To clarify the role of egg destruction for the reproductive success of great spotted cuckoos, unparasitized magpie nests were experimentally parasitized (without egg damage) by introducing cuckoo eggs or chicks. Egg damage was common in parasitized nests but the eggs were not damaged by the hosts. Egg damage increased the breeding success of the cuckoos, by both reducing the number of competing host chicks in the nest and increasing the likelihood that late-laid cuckoo eggs would hatch.
The relationship between brood parasites and their hosts is usually assumed to result in coevolut... more The relationship between brood parasites and their hosts is usually assumed to result in coevolution, and documentation of changes in extant populations should thus be possible. Here we describe how the ejection rate of eggs of an obligate brood parasite, the great spotted cuckoo Clamator glandarius, by its host, the magpie Pica pica, has recently increased in an area in southern Spain. The ejection rate of great spotted cuckoo eggs in naturally parasitized nests of the magpie increased at a rate of 0.5% year' during the period 1982–1992. This result was verified in a number of field experiments using nonmimetic and mimetic model eggs. The rate of increase in ejection rate was 4.7% year-1 for mimetic eggs and 2.3% year-1 for nonmimetic eggs. There were clear differences in parasitism by the great spotted cuckoo between study plots and years, which makes comparisons of rates of parasitism between areas difficult without considering temporal variation. The recent increase in the ejection response of magpies to great spotted cuckoo eggs was not due to magpies using the abundance of cuckoos as a cue to the intensity of parasitism.
Two Jackdaw Corvus monedula colonies were given supplementary food before and during breeding in ... more Two Jackdaw Corvus monedula colonies were given supplementary food before and during breeding in 1983. Breeding density and cavity use were compared with those of the same colonies in previous years, when no food was provided. Predation rate and reproductive parameters were compared with those in the same colonies in previous years and with those of two control colonies, without experimental food. Jackdaws preferred safe cavities with small minimum nest-entrance dimensions and avoided those with a high risk of nest predation. In experimental (fed) colonies, however, there was a tendency to use all cavities, which resulted in an increased breeding density. No nests were preyed upon by Ravens Corvus corax in the experimental colonies because supplemental food favoured group defence by increasing colony size and by increasing the time the Jackdaws spent in the colony. Additional food advanced laying date, increased clutch size independently of laying date and increased fledging success. Supplementary food significantly increased fledging success in less than half of all experimental studies on birds. We suggest that the key to this problem is the species' breeding strategy, and we show that supplementary food significantly increased fledging success in brood-reduction strategist species but not in species which directly adjusted their clutch size.
Uploads
Papers by MANUEL SOLER