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1.
Reprod Domest Anim ; 58(10): 1352-1358, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37559418

RESUMO

A retrospective study was used to analyse canine vaginal hyperplasia ambulatory cases in Small animal clinic of the University Veterinary Hospital of the Faculty of Veterinary Medicine, Trakia University in Stara Zagora, Bulgaria between 2012 and 2022. The study was done to investigate the morbidity of vaginal hyperplasia in the bitch and its relationship with the breed, body weight, age, stage of the oestrous cycle, parity of dogs and grade of the condition. Grade II and grade III vaginal hyperplasia were observed in 3.11% of all female dog genital pathological cases. Twenty-eight canine breeds were affected and the largest number were Central Asian Shepherds (30.47%). Most frequently the dogs were between 2 and 3 years old (29.68%), above 40 kg body weight (58.59%) and during follicular phase (proestrus and oestrus) of the oestrous cycle (82.02%). All the affected bitches were non-spayed (100%) and nulliparous were 70.31% of them. Grade III vaginal hyperplasia was more frequently observed (53.13%) than grade II of the condition. High correlation was found between age of the bitches and grade of the vaginal hyperplasia (R2 = .551; SEE = 0.053), body weight and grade of the condition (R2 = .820; SEE = 0.054), and age of the animals and their body weight (R2 = .820; SEE = 1.27).

2.
Anim Reprod ; 20(2): e20230004, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37416867

RESUMO

This study was aimed to assess the efficiency of coconut water extender with addition of soy lecithin and sucrose as nonpermeable cryoprotectants for canine semen vitrification, using a simple method that yields a high survival rate of spermatozoa for clinical use. Twelve ejaculates from 12 adult normozoospermic dogs were collected separately by digital manipulation and only the second semen fraction was used in this study. After evaluation of volume, concentration, viability, total and progressive motility, velocity parameters and morphology, semen was diluted with a coconut water extender (50% (v/v(volume per volume)) coconut water, 25% (v/v) distilled water and 25% (v/v) 5% anhydrous monosodium citrate solution) with addition of soy lecithin and fructose at 1% and 0.25M sucrose until final concentration of 100x106 spermatozoa/ml. After equilibration at 5ºC for 60 minutes, semen was vitrified by "direct dropping method" into liquid nitrogen in spheres with a volume of 30 µl. After a week of storage the spheres were devitrified as three of them were dropped into 0.5 mL of CaniPlus AI medium (Minitüb, Germany), which was previously warmed in a water bath at 42ºC for 2 minutes and evaluated about the above mentioned parameters. It was found that vitrification resulted in a lower percentage of viable sperms, normal morphology, total and progressive motilities (p<0.05), but most of velocity parameters (VCL, VSL, VAP, LIN, ALH and BCF) did not differ (p>0.05) compared to fresh semen samples. In conclusion, our results demonstrate that vitrification with coconut water extender with addition of 1% soy lecithin and 0.25M sucrose as cryoprotectants, has an excellent potential for routine canine sperm cryopreservation.

3.
Heart Lung Circ ; 29(6): 936-939, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31331672

RESUMO

BACKGROUND: Prior studies suggest increased rates of noise on the Tendril (St Jude Medical/Abbott, St. Paul, MN, USA) pacemaker lead. We aim to assess the incidence of lead noise in the Tendril and 5076 (Medtronic PLC, Minneapolis, MN, USA) pacemaker leads in our cohort and in the process assess the utility of remote monitoring for identifying lead malfunction. METHODS: Deidentified, multi-centre, prospectively collected observational cohort data was obtained to assess the incidence of noise on the Tendril and 5076 pacemaker leads. RESULTS: 148 Tendril and 737 CapSureFix Novus 5076 (Medtronic, MN, USA) pacemaker leads were remotely monitored. Incidence of noise on the Tendril was 8% and 0.27% on the CapSureFix Novus. CONCLUSION: Rates of noise in the Tendril lead are higher than a market competitor. Remote monitoring is useful in detecting this concerning anomaly.


Assuntos
Monitorização Fisiológica/métodos , Marca-Passo Artificial/efeitos adversos , Idoso , Arritmias Cardíacas/terapia , Falha de Equipamento , Feminino , Humanos , Incidência , Masculino , Estudos Prospectivos
4.
J Proteome Res ; 16(2): 773-779, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-28092160

RESUMO

Stroke remains a major public health problem worldwide; it causes severe disability and is associated with high mortality rates. However, early diagnosis of stroke is difficult, and no reliable biomarkers are currently established. In this study, mass-spectrometry-based metabolomics was utilized to characterize the metabolic features of the serum of patients with acute ischemic stroke (AIS) to identify novel sensitive biomarkers for diagnosis and progression. First, global metabolic profiling was performed on a training set of 80 human serum samples (40 cases and 40 controls). The metabolic profiling identified significant alterations in a series of 26 metabolites with related metabolic pathways involving amino acid, fatty acid, phospholipid, and choline metabolism. Subsequently, multiple algorithms were run on a test set consisting of 49 serum samples (26 cases and 23 controls) to develop different classifiers for verifying and evaluating potential biomarkers. Finally, a panel of five differential metabolites, including serine, isoleucine, betaine, PC(5:0/5:0), and LysoPE(18:2), exhibited potential to differentiate AIS samples from healthy control samples, with area under the receiver operating characteristic curve values of 0.988 and 0.971 in the training and test sets, respectively. These findings provided insights for the development of new diagnostic tests and therapeutic approaches for AIS.


Assuntos
Biomarcadores/sangue , Metaboloma/genética , Metabolômica , Acidente Vascular Cerebral/sangue , Idoso , Betaína/sangue , Progressão da Doença , Diagnóstico Precoce , Feminino , Humanos , Isoleucina/sangue , Masculino , Pessoa de Meia-Idade , Curva ROC , Serina/sangue , Acidente Vascular Cerebral/patologia
5.
Philos Trans A Math Phys Eng Sci ; 374(2059)2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26667916

RESUMO

The reconstruction of the geological (tectonic) structure and environments of subglacial Lake Vostok is based on geophysical surveys and the study of mineral particles found in cores of accreted ice and frozen lake water (sampled after the lake was unsealed). Seismic reflection and refraction investigations conducted in the southern part of Lake Vostok show very thin (200-300 m) sedimentary cover overlying a crystalline basement. Most of this thin veneer is thought to have been deposited during temperate-glacial conditions in Oligocene to Middle Miocene time (ca 34-14 Ma). The composition of the lake-bottom sediments can be deduced from mineral inclusions found in cores of accreted ice. Inclusions are represented by soft aggregates consisting mainly of clay-mica minerals and micrometre-sized quartz grains. Some of these inclusions contain subangular to semi-rounded rock clasts (siltstones and sandstones) ranging from 0.3 to 8 mm in size. In total, 31 zircon grains have been identified in two rock clasts and dated using SHRIMP-II. The ages of the studied zircons range from 0.6 to 2.0 Ga with two distinct clusters between 0.8 and 1.15 Ga and between 1.6 and 1.8 Ga. Rock clasts obviously came from the western lake shore, which is thus composed of terrigenous strata with an age of not older than 600 Ma. The sedimentary nature of the western lake shore is also confirmed by seismic refraction data showing seismic velocities there of 5.4-5.5 km s(-1) at the bedrock surface. After Lake Vostok was unsealed, its water (frozen and sampled next season) was also studied with scanning electron microscopy and X-ray microprobe analysis. This study showed the existence of calcium carbonate and silica microparticles (10-20 µm across) in frozen water.

6.
Theriogenology ; 81(7): 941-6, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24581586

RESUMO

A significantly reduced gonadotropin and testosterone secretion is a well-described result of long-term administration of GnRH agonists in the male dog and cat. To date, no data are available about the duration of efficacy and the reversibility of treatment-induced effects after long-term treatment with a 4.7 mg deslorelin implant. Seven healthy male European Shorthair cats (3.2 ± 0.5 kg, 1-6 years) were treated with a 4.7 mg deslorelin implant. Blood samples (testosterone, T), testicular volume, penile spines, and mating behavior were recorded once weekly. Considering T > 0.5 ng/mL as the biological endpoint, mean duration of efficacy was 78.8 ± 12.9 weeks (range: 61.7-100.7 weeks) with T concentrations increasing rapidly after the last T less than 0.1 ng/mL (basal) (P < 0.0001), and pretreatment T concentrations being reached after 3 weeks. Testicular volume rapidly increased after the first increase of T (P < 0.001) with pretreatment testicular volume being reached after 6.9 ± 3.4 weeks (5-11 weeks). "Normal" libido reoccurred 88.7 ± 12.4 weeks after treatment, and "normal" mating behavior was observed even later. Fertile matings occurred 7 to 42 weeks after the last T less than 0.1 ng/mL with a mean of 4.0 ± 0.0 kittens, and 13.6 to 47.6 weeks afterwards testicular histology revealed normal spermatogenesis. The present data confirm that the use of slow-release GnRH-agonist implants containing deslorelin in tomcats represents an effective and safe reversible alternative for long-term contraception; however, as number of animals is low, further fertility trials are recommended.


Assuntos
Gatos/fisiologia , Anticoncepcionais Masculinos/farmacologia , Implantes de Medicamento/administração & dosagem , Hormônio Liberador de Gonadotropina/agonistas , Testículo/efeitos dos fármacos , Pamoato de Triptorrelina/análogos & derivados , Animais , Anticoncepcionais Masculinos/administração & dosagem , Fertilidade , Masculino , Pênis/anatomia & histologia , Pênis/efeitos dos fármacos , Comportamento Sexual Animal , Testículo/fisiologia , Pamoato de Triptorrelina/administração & dosagem , Pamoato de Triptorrelina/farmacologia
7.
PLoS One ; 8(12): e82886, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24391725

RESUMO

BACKGROUND: Climate change potentially has important effects on distribution, abundance, transmission and virulence of parasites in wild populations of animals. METHODOLOGY/PRINCIPAL FINDING: Here we analyzed paired information on 89 parasite populations for 24 species of bird hosts some years ago and again in 2010 with an average interval of 10 years. The parasite taxa included protozoa, feather parasites, diptera, ticks, mites and fleas. We investigated whether change in abundance and prevalence of parasites was related to change in body condition, reproduction and population size of hosts. We conducted analyses based on the entire dataset, but also on a restricted dataset with intervals between study years being 5-15 years. Parasite abundance increased over time when restricting the analyses to datasets with an interval of 5-15 years, with no significant effect of changes in temperature at the time of breeding among study sites. Changes in host body condition and clutch size were related to change in temperature between first and second study year. In addition, changes in clutch size, brood size and body condition of hosts were correlated with change in abundance of parasites. Finally, changes in population size of hosts were not significantly related to changes in abundance of parasites or their prevalence. CONCLUSIONS/SIGNIFICANCE: Climate change is associated with a general increase in parasite abundance. Variation in laying date depended on locality and was associated with latitude while body condition of hosts was associated with a change in temperature. Because clutch size, brood size and body condition were associated with change in parasitism, these results suggest that parasites, perhaps mediated through the indirect effects of temperature, may affect fecundity and condition of their hosts. The conclusions were particularly in accordance with predictions when the restricted dataset with intervals of 5-15 years was used, suggesting that short intervals may bias findings.


Assuntos
Aves/parasitologia , Mudança Climática , Interações Hospedeiro-Patógeno , Animais , Aves/fisiologia , Europa (Continente) , Feminino , Aquecimento Global , Masculino , Dinâmica Populacional , Reprodução , Fatores de Tempo
8.
Zoolog Sci ; 29(7): 419-22, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22775248

RESUMO

Evolution of avian life histories is typically strongly influenced by both altitude and latitude. To date, most studies have investigated the effects of extreme differences in altitude and latitude on variation in reproductive traits. Studies based on small altitude and latitude spans are needed to better understand the resolution of selective pressures. We compared several aspects of russet sparrow (Passer cinnamomeus) breeding biology between a low-altitude (200 m) and a high-altitude (1,500 m) population in China, representing a relatively small altitudinal gradient (1,300 m). High-altitude birds initiated breeding significantly later compared to their low-altitude counterparts. Interestingly, breeding season was significantly longer in the high-altitude site (57 vs. 84 d). Lowland sparrows laid larger clutches (4.92 vs. 4.09 eggs) and showed greater fledging success (4.20 vs. 3.46 fledgings) than did upland birds. Variation in life history traits thus appears to occur even along a small scale altitudinal gradient. We suggest that the longer breeding season and smaller clutch size in the highland population may be an adaptation or acclimation to compensate for the reduced annual productivity resulting from unfavourable or sub-optimal habitats for these sparrows.


Assuntos
Altitude , Ecossistema , Reprodução/fisiologia , Pardais/fisiologia , Animais , China , Tamanho da Ninhada , Fatores de Tempo
9.
PLoS One ; 7(5): e36884, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22615833

RESUMO

Sex allocation theory and empirical evidence both suggest that natural selection should favour maternal control of offspring sex ratio in relation to their ability to invest in the offspring. Generalist parasites constitute a particularly interesting group to test this theory as different females commonly utilize different host species showing large variation in provisioning ability. The common cuckoo (Cuculus canorus) is a generalist brood parasite that lays its eggs in the nest of many different passerine birds, but each female tends to specialize on one particular host species giving rise to highly specialized host races. The different host species show large variation in their ability to invest in the parasitic offspring, presenting an opportunity for female cuckoos to bias offspring sex ratio in relation to host species quality. Here, we investigate host-race specific sex allocation controlling for maternal identity in the common cuckoo. We found no evidence of any significant relationship between host race and sex ratio in one sympatric population harbouring three different host races, or in a total of five geographically separated populations. There was also no significant association between host quality, as determined by species-specific female host body mass, and cuckoo sex ratio. Finally, we found no significant relationship between individual cuckoo maternal quality, as determined by her egg volume, and sex ratio within each host race. We conclude that the generalist brood-parasitic common cuckoo show no significant sex-ratio bias in relation to host race and discuss this finding in light of gene flow and host adaptations.


Assuntos
Aves/fisiologia , Fluxo Gênico , Comportamento de Nidação/fisiologia , Animais , Aves/genética , Feminino , Identidade de Gênero , Masculino , Óvulo/fisiologia , Razão de Masculinidade
10.
PLoS One ; 7(2): e31704, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22384060

RESUMO

BACKGROUND: Avian brood parasites and their hosts are involved in complex offence-defense coevolutionary arms races. The most common pair of reciprocal adaptations in these systems is egg discrimination by hosts and egg mimicry by parasites. As mimicry improves, more advanced host adaptations evolve such as decreased intra- and increased interclutch variation in egg appearance to facilitate detection of parasitic eggs. As interclutch variation increases, parasites able to choose hosts matching best their own egg phenotype should be selected, but this requires that parasites know their own egg phenotype and select host nests correspondingly. METHODOLOGY/PRINCIPAL FINDINGS: We compared egg mimicry of common cuckoo Cuculus canorus eggs in naturally parasitized marsh warbler Acrocephalus palustris nests and their nearest unparasitized conspecific neighbors having similar laying dates and nest-site characteristics. Modeling of avian vision and image analyses revealed no evidence that cuckoos parasitize nests where their eggs better match the host eggs. Cuckoo eggs were as good mimics, in terms of background and spot color, background luminance, spotting pattern and egg size, of host eggs in the nests actually exploited as those in the neighboring unparasitized nests. CONCLUSIONS/SIGNIFICANCE: We reviewed the evidence for brood parasites selecting better-matching host egg phenotypes from several relevant studies and argue that such selection probably cannot exist in host-parasite systems where host interclutch variation is continuous and overall low or moderate. To date there is also no evidence that parasites prefer certain egg phenotypes in systems where it should be most advantageous, i.e., when both hosts and parasites lay polymorphic eggs. Hence, the existence of an ability to select host nests to maximize mimicry by brood parasites appears unlikely, but this possibility should be further explored in cuckoo-host systems where the host has evolved discrete egg phenotypes.


Assuntos
Aves/fisiologia , Óvulo/fisiologia , Passeriformes/fisiologia , Animais , Comportamento Animal , Aves/parasitologia , Bulgária , Cor , Feminino , Interações Hospedeiro-Parasita , Oviposição , Passeriformes/parasitologia , Fenótipo , Reprodutibilidade dos Testes , Software
11.
Proc Biol Sci ; 279(1735): 1967-76, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22237911

RESUMO

Although parasites and their hosts often coexist in a set of environmentally differentiated populations connected by gene flow, few empirical studies have considered a role of environmental variation in shaping correlations between traits of hosts and parasites. Here, we studied for the first time the association between the frequency of adaptive parasitic common cuckoo Cuculus canorus phenotypes in terms of egg matching and level of defences exhibited by its reed warbler Acrocephalus scirpaceus hosts across seven geographically distant populations in Europe. We also explored the influence of spring climatic conditions experienced by cuckoos and hosts on cuckoo-host egg matching. We found that between-population differences in host defences against cuckoos (i.e. rejection rate) covaried with between-population differences in degree of matching. Between-population differences in host egg phenotype were associated with between-population differences in parasitism rate and spring climatic conditions, but not with host level of defences. Between-population differences in cuckoo egg phenotype covaried with between-population differences in host defences and spring climatic conditions. However, differences in host defences still explained differences in mimicry once differences in climatic conditions were controlled, suggesting that selection exerted by host defences must be strong relative to selection imposed by climatic factors on egg phenotypes.


Assuntos
Aves/fisiologia , Clima , Óvulo , Animais , Evolução Biológica , Cor , Genótipo , Geografia , Interações Hospedeiro-Parasita , Repetições de Microssatélites , Comportamento de Nidação , Fenótipo , Dinâmica Populacional , Aves Canoras/anatomia & histologia , Aves Canoras/genética , Aves Canoras/parasitologia
12.
Theriogenology ; 75(5): 803-10, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21196037

RESUMO

The aim of the present study was to test for the efficacy of a slow release GnRH-agonist implant (4.7 mg deslorelin, Suprelorin) in the male cat. Ten toms were implanted sc in the neck. Changes in testosterone (T) secretion, testicular size, body weight and behaviour (mounting, mating, urine marking) were monitored. T concentrations were significantly decreased (P < 0.0001) to basal levels (< 0.1 ng/mL) in 5 of 10 cats after 4 weeks and in all but one tom after 11 weeks (T < 0.1 ng/mL). In this respective tom only partial downregulation with T-values from 0.2 to 0.1 ng/mL was achieved until week 27. In weeks 28 and 32, T concentrations were below 0.1 ng/mL. Compared to pretreatment values, testicular volume was significantly decreased by about 60% in week 12 and about 73% after 36 weeks (P < 0.001). Penile spines disappeared 9.4 ± 1.0 weeks after treatment. Food intake was significantly increased during treatment period (P < 0.001). In all tomcats libido, mating behaviour and urine marking were significantly reduced (P < 0.0001) after an initial stimulation. In one tom, mating an oestrous queen on day 20 after implant administration resulted in pregnancy. Mating of another tom that had T-values between 0.1 and < 0.1 ng/mL since day 24 in week 8 revealed the presence of spermatozoa; however, this mating did not result in pregnancy. Subcutaneous implant administration was well tolerated by all tomcats without sedation or anaesthesia and no treatment related negative effects were observed. These results demonstrate the clinical efficacy of the 4.7 mg deslorelin implants (Suprelorin) in the tom inducing all castration related effects.


Assuntos
Gatos , Anticoncepção/veterinária , Hormônio Liberador de Gonadotropina/agonistas , Orquiectomia/veterinária , Reprodução/efeitos dos fármacos , Pamoato de Triptorrelina/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Anticoncepção/métodos , Implantes de Medicamento , Ingestão de Alimentos/efeitos dos fármacos , Masculino , Orquiectomia/métodos , Comportamento Sexual Animal/efeitos dos fármacos , Testículo/anatomia & histologia , Testículo/efeitos dos fármacos , Testosterona/sangue , Pamoato de Triptorrelina/administração & dosagem , Pamoato de Triptorrelina/efeitos adversos
13.
Proc Biol Sci ; 278(1712): 1639-45, 2011 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-21068043

RESUMO

Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo, Cuculus canorus. In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.


Assuntos
Aves/genética , Variação Genética , Animais , Aves/anatomia & histologia , Aves/fisiologia , DNA Mitocondrial/química , Feminino , Fluxo Gênico , Marcadores Genéticos , Genótipo , Masculino , Repetições de Microssatélites , Comportamento de Nidação , Cromossomos Sexuais/química , Fatores Sexuais , Comportamento Sexual Animal
14.
PLoS One ; 5(5): e10816, 2010 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-20520815

RESUMO

BACKGROUND: Trait polymorphism can evolve as a consequence of frequency-dependent selection. Coevolutionary interactions between hosts and parasites may lead to selection on both to evolve extreme phenotypes deviating from the norm, through disruptive selection. METHODOLOGY/PRINCIPAL FINDING: Here, we show through detailed field studies and experimental procedures that the ashy-throated parrotbill (Paradoxornis alphonsianus) and its avian brood parasite, the common cuckoo (Cuculus canorus), have both evolved egg polymorphism manifested in discrete immaculate white, pale blue, and blue egg phenotypes within a single population. In this host-parasite system the most common egg colours were white and blue, with no significant difference in parasitism rates between hosts laying eggs of either colour. Furthermore, selection on parasites for countering the evolution of host egg types appears to be strong, since ashy-throated parrotbills have evolved rejection abilities for even partially mimetic eggs. CONCLUSIONS/SIGNIFICANCE: The parrotbill-cuckoo system constitutes a clear outcome of disruptive selection on both host and parasite egg phenotypes driven by coevolution, due to the cost of parasitism in the host and by host defences in the parasite. The present study is to our knowledge the first to report the influence of disruptive selection on evolution of discrete phenotypes in both parasite and host traits in an avian brood parasitism system.


Assuntos
Evolução Biológica , Aves/parasitologia , Interações Hospedeiro-Parasita , Comportamento de Nidação/fisiologia , Óvulo/fisiologia , Parasitos/fisiologia , Pigmentação/fisiologia , Animais , Tamanho da Ninhada , Sensibilidades de Contraste , Comportamento Predatório/fisiologia , Fatores de Tempo
15.
J Evol Biol ; 23(6): 1170-82, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20345810

RESUMO

The brood parasitic common cuckoo Cuculus canorus consists of gentes, which typically parasitize only a single host species whose eggs they often mimic. Where multiple cuckoo gentes co-exist in sympatry, we may expect variable but generally poorer mimicry because of host switches or inter-gens gene flow via males if these also contribute to egg phenotypes. Here, we investigated egg trait differentiation and mimicry in three cuckoo gentes parasitizing great reed warblers Acrocephalus arundinaceus, marsh warblers Acrocephalus palustris and corn buntings Miliaria calandra breeding in close sympatry in partially overlapping habitat types. The three cuckoo gentes showed a remarkable degree of mimicry to their three host species in some but not all egg features, including egg size, a hitherto largely ignored feature of egg mimicry. Egg phenotype matching for both background and spot colours as well as for egg size has been maintained in close sympatry despite the possibility for gene flow.


Assuntos
Aves/fisiologia , Ovos , Animais , Fenótipo , Especificidade da Espécie
16.
Biol Lett ; 5(2): 169-71, 2009 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-19126530

RESUMO

Given the high costs of avian obligate brood parasitism, host individuals are selected to reject parasitic eggs they recognize as foreign. We show that rejection may not necessarily follow egg discrimination when selective removal of the parasitic egg is difficult. We studied egg rejection behaviour in a small host of the common cuckoo Cuculus canorus, the eastern olivaceous warbler Hippolais pallida, by experimental parasitism with model and real non-mimetic cuckoo eggs and video recordings of host behaviour. Hosts pecked 87 per cent (20 out of 23) of the model eggs but eventually accepted 43.5 per cent (10 out of 23) of them. A similar pattern was found for real cuckoo eggs, which were all pecked, but as many as 47 per cent (7 out of 15) of them were accepted. To our knowledge, this is the first demonstration of a cuckoo host discriminating against real parasitic eggs but often accepting them. Our results also show that in host species experiencing difficulties in performing puncture ejection, non-mimetic cuckoo eggs may avoid rejection by means of their unusually high structural strength.


Assuntos
Ovos , Comportamento de Nidação , Aves Canoras/parasitologia , Animais , Tamanho Corporal
17.
Naturwissenschaften ; 94(4): 307-12, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17160581

RESUMO

Coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. A particularly suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts. The common cuckoo (Cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. However, warblers of the genus Hippolais have rarely been reported as being victims of cuckoos, and furthermore, few data exist on the occurrence of antiparasite defenses in these hosts. In this study, we examined possible host-parasite coevolution between cuckoos and eastern olivaceous warblers (Hippolais pallida elaeica, hereafter olivaceous warblers) in three closely situated areas in northwestern Bulgaria. The olivaceous warbler has never been reported to be a regular cuckoo host. However, the present study, carried out in 2001-2003 shows that the olivaceous warbler is regularly and heavily parasitized by the cuckoo in this area. Parasitism rate was high (26.6%, 34/128) and consistent among years, with some variation between areas. The cuckoo egg mimicry was moderately good, and olivaceous warbler rejection rate of such eggs was 50%. Cuckoo eggs laid in olivaceous warbler nests had a whitish to whitish-green ground color, and the majority appeared to be distinctly different from cuckoo eggs found in other host species in the area. The olivaceous warbler proved to be a rather good host for cuckoos as 20.6% (7/34) of cuckoo eggs laid produced fledglings, a breeding success comparable to other suitable hosts in Europe. This is the first in-depth study of brood parasitism in a warbler of the genus Hippolais, and cuckoos parasitizing olivaceous warblers probably represent a previously unknown gens.


Assuntos
Aves/fisiologia , Passeriformes/parasitologia , Animais , Evolução Biológica , Ovos , Feminino , Comportamento de Nidação , Olea
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