Ejaculate allocation by male sand martins, Riparia riparia.

Males of many species allocate sperm to ejaculates strategically in response to variation in the risk and intensity of sperm competition. The notable exception is passerine birds, in which evidence for strategic allocation is absent. Here we report the results of a study testing for strategic ejaculate allocation in a passerine bird, the sand martin (Riparia riparia). Natural ejaculates were collected from males copulating with a model female. Ejaculates transferred in the presence of a rival male contained significantly more sperm than ejaculates transferred in the absence of a rival male. There was no evidence that this difference was due to the confounding effects of the year of ejaculate collection, the identity of the model female, the colony, the stage of season or the period of the day in which ejaculates were collected. A more detailed examination of the ejaculate patterns of individual males, achieved by the DNA profiling of ejaculates, provided additional evidence for strategic allocation of sperm.     

Sperm length in sand martins Riparia riparia: a comment on Helfenstein et al

How long is a sand martin Riparia riparia spermatozoon? In a recent study, Helfenstein et al. (2008) presented data on the intraspecific variation in sperm length, swimming speed and longevity in this species and some interesting correlations between these variables. However, the reported sperm lengths are remarkably short for the species, which casts doubts about whether sperm total length has actually been measured and how the observed relationships should be interpreted.     

Between‐male variation in sperm size,velocity and longevity in sand martins Riparia riparia

Sperm mobility is known to be an important determinant of a male's sperm competitive ability. Although more debated, sperm length and its relation to sperm swimming ability has also been proposed to determine a male's fertilisation potential. Furthermore, both mobility and length may covary with a male's phenotype, either positively (the phenotype‐linked fertility hypothesis) or negatively if, for instance, low‐quality males have less access to females but invest more in sperm production. Using dummy females, we collected sperm samples from wild sand martins Riparia raparia males. We investigated the relationship between sperm length and sperm swimming speed as measured by sperm straight line velocity (VSL), and determined whether sperm traits are correlated with male body size and condition. We found that total sperm length is repeatable within‐ejaculate and shows substantial inter‐male variation. Sperm length was associated with sperm velocity: males with short sperm have sperm that swim initially faster but die sooner, whereas males with longer sperm have sperm that swim more slowly but for a longer time. Smaller males produced sperm with higher overall velocity. This correlation between male size and sperm behaviour may reflect alternative fertilisation strategies where small males having less mating opportunities invest more in sperm competitive ability. The existence of such alternative strategies would participate in maintaining variation in sperm length and velocity in this species.     

First records of Ixodes lividus from sand martin (Riparia riparia) nests in Lithuania

Ixodes lividus (Koch, 1844) ticks are specific parasites of the sand martin Riparia riparia (L.). The distribution range of I. lividus covers Europe (being absent from the Mediterranean area) and Asia. However, until now there have been no reports on the presence of this tick in Lithuania. A total of 47 nests were collected in three different colonies of sand martins in the central part of Lithuania and 46.8% of them were infested with ticks. In total, 2,770 ticks were found and identified as I. lividus based on morphological characteristics. Larvae were the predominant stage, representing 99.6% of all collected ticks. The taxonomic identification of I. lividus was confirmed by sequence analysis of the tick mitochondrial 16S rRNA gene. Phylogenetic analysis of 16S rRNA sequences indicates six genotypes of I. lividus transported by the sand martin in the Baltic region. The detection of genotypes like those reported from other European regions pointed to the importance of avian migratory connections, which are associated with the dispersal of I. lividus and the related tick‐borne pathogens in the Baltic region. This study represents the first record of I. lividus from sand martin nests in Lithuania.     

Food sources of Sand Martins Riparia riparia during their breeding season: insights from stable-isotope analysis

Capsule Stable-isotope analysis indicated that terrestrial dipteran insects were the main food at a site in northern Japan.     

Discovering the migration and non‐breeding areas of sand martins and house martins breeding in the Pannonian basin (central‐eastern Europe)

The central‐eastern European populations of sand martin and house martin have declined in the last decades. The drivers for this decline cannot be identified as long as the whereabouts of these long distance migrants remain unknown outside the breeding season. Ringing recoveries of sand martins from central‐eastern Europe are widely scattered in the Mediterranean basin and in Africa, suggesting various migration routes and a broad non‐breeding range. The European populations of house martins are assumed to be longitudinally separated across their non‐breeding range and thus narrow population‐specific non‐breeding areas are expected. By using geolocators, we identified for the first time, the migration routes and non‐breeding areas of sand martins (n = 4) and house martins (n = 5) breeding in central‐eastern Europe. In autumn, the Carpathian Bend and northern parts of the Balkan Peninsula serve as important pre‐migration areas for both species. All individuals crossed the Mediterranean Sea from Greece to Libya. Sand martins spent the non‐breeding season in northern Cameroon and the Lake Chad Basin, within less than a 700 km radius, while house martins were widely scattered in three distinct regions in central, eastern, and southern Africa. Thus, for both species, the expected strength of migratory connectivity could not be confirmed. House martins, but not sand martins, migrated about twice as fast in spring compared to autumn. The spring migration started with a net average speed of > 400 km d^–1 for sand martins, and > 800 km d^–1 for house martins. However, both species used several stopover sites for 0.5–4 d and were stationary for nearly half of their spring migration. Arrival at breeding grounds was mainly related to departure from the last sub‐Saharan non‐breeding site rather than distance, route, or stopovers. We assume a strong carry‐over effect on timing in spring.     

崖沙燕繁殖期雄鸟的鸣叫行为

2003年3月～2004年4月在南充市郊的嘉陵江边记录了崖沙燕(Riparia riparia)繁殖期雄鸟的呜叫。声谱分析结果表明,崖沙燕繁殖期有8种呜叫(恫吓叫声、屈服叫声、求救叫声、警报叫声以及4种鸣唱声)。通过对其行为的实时观察,确定了每种呜叫的生物学意义。4种叫声是整个繁殖期的主要呜叫,而4种鸣唱声则主要出现在开春以后的集群求偶与筑巢期间。虽其鸣唱声仅有两种类型的短音节,但通过组合可形成含有多达4个或6个音节的鸣唱声。鸣唱声的持续时间分别为3184、1030、1274、1232ms。鸣唱声中的间歇时间分别占持续时间的47％、39％、50％、48％。     

The Influence of Repeated Releases on the Homing Behaviour of Sand Martins (Riparia riparia)

Data on the effect of repeated releases on the homing behaviour of sand martins released four times from the same site (beyond 50 km from the nesting colony) are presented. The results, obtained by two series of releases, show a progressive improvement of both the initial orientation and the homing performances. When the birds released four times from the same site were displaced in a new site, located roughly at the same distance, but in the opposite direction to the former, they do not change directional preferences with respect to the last experimental release; the homing speeds were also not different to those recorded for birds without any release experience. While the learning of orienting cues can not be excluded, the data point out that the habituation to the handling stress and a form of directional training seem to play a major role in determining the observed behaviour. The familiarity with a site does not seem to improve the homing behaviour of sand martins when released from a different one.     

Energetics of free existence in swallows and martins (hirundinidae) during breeding: a comparative study using doubly labeled water

Energy metabolism of three sympatric swallows (Hirundinidae) was investigated during the breeding season using doubly labeled water (²H₂ ¹⁸O). Interspecific and intraspecific differences in energy metabolism were examined in relation to the habits, size and environment of the birds. To facilitate comparisons we expressed energy metabolism (M) as the ratio of average daily metabolic rate (ADMR, cm³CO_2g ^-1h^-1) to basal metabolic rate (BMR). We observed adults during incubation and when feeding nestlings. Then, both sexes of Sand Martins Riparia riparia and House Martins Delinchon urbica were either at the nest or on the wing. Incubation reduced activity levels during the day resulting in M (incubation) being 17–26% lower than during rearing. Differences in energy costs for rearing chicks depended mainly on flight behaviour, the smaller Sand Martin doing nearly twice as much flapping during flight as the House Martin, giving higher values for M. In Swallows Hirundo rustica the female incubates alone, alternating between short feeding trips and incubating in daytime. This pattern was linked with a relatively high value for M in the only individual behaving like our controls. Both sexes of Swallows feed the chicks, and they showed similar values of M. They also closely resembled House Martins, despite contrasts in the time spent flying and their behaviour during flight. Feeding conditions affected activity, and thereby M, in a species specific way. The House Martin did more gliding in poor weather, taking less mobile prey, reducing M. Swallows reduced foraging costs further by using body reserves, as in the House Martin. The smaller Sand Martin, in contrast, showed a high expenditure in poor weather. Over two breeding seasons ADMR reached values around 5 BMR for all three species.     

Importance of Hydrologic and Landscape Heterogeneity for Restoring Bank Swallow (Riparia riparia) Colonies along the Sacramento River, California

Human activities have degraded riparian systems in numerous ways, including homogenization of the floodplain landscape and minimization of extreme flows. We analyzed the effects of changes in these and other factors for extinction–colonization dynamics of a threatened Bank Swallow population along the upper Sacramento River, California, U.S.A. We monitored Bank Swallow distributions along a 160‐km stretch of the river from 1986–1992 and 1996–2003 and tested whether site extinctions and colonizations corresponded with changes in maximum river discharge, surrounding land cover, estimated colony size, temperature, and precipitation. Colonization probabilities increased with maximum discharge. Extinction probabilities decreased with proximity to the nearest grassland, decreased with colony size, and increased with maximum discharge. To explore the implications for restoration, we incorporated the statistically estimated effects of distance to grassland and maximum discharge into simple metapopulation models. Under current conditions, the Bank Swallow metapopulation appears to be in continued decline, although stable or increasing numbers cannot be ruled out with the existing data. Maximum likelihood parameters from these regression models suggest that the Sacramento River metapopulation could be restored to 45 colonies through moderate amounts of grassland restoration, large increases in discharge, or direct restoration of nesting habitat by removing approximately 10% of existing bank protection (riprap) from suitable areas. Our results highlight the importance of grassland restoration, mixed benefits of restoring high spring discharge, and the importance of within‐colony dynamics as areas for future research.     

Body condition and feather molt of a migratory shorebird during the non‐breeding season

Migratory shorebirds have some of the highest fat loads among birds, especially species which migrate long distances. The upland sandpiper Bartramia longicauda makes long‐distance migrations twice a year, but variation in body condition or timing of feather molt during the non‐breeding season has not been studied. Molt is an important part of the annual cycle of migratory birds because feather condition determines flight performance during migration, and long‐distance movements are energetically costly. However, variation in body condition during molt has been poorly studied. The objective of our field study was to examine the timing and patterns of feather molt of a long distance migratory shorebird during the non‐breeding season and test for relationships with body size, fat depots, mass, and sex. Field work was conducted at four ranches in the Northern Campos of Uruguay (Paysandú and Salto Departments). We captured and marked 62 sandpipers in a 2‐month period (Nov–Jan) during four non‐breeding seasons (2008–2012). Sex was determined by genetic analyses of blood samples taken at capture. Molt was measured in captured birds using rank scores based on published standards. Body mass and tarsus length measurements showed female‐biased sexual size dimorphism with males smaller than females. Size‐corrected body mass (body condition) showed a U‐shaped relationship with the day of the season, indicating that birds arrived at non‐breeding grounds in relatively good condition. Arriving in good body condition at non‐breeding grounds is probably important because of the energetic demands due to physiological adjustments after migration and the costs of feather molt.     

郑州郊区崖沙燕(Riparia riparia)的巢址选择

2014年3—8月,采用样方法对分布于河南省郑州市郊区的4处崖沙燕(Riparia riparia Linnaeus 1758)营巢地的13个生境因子进行了调查,测定了巢址样方和对照样方各160组数据,并利用Mann-Whitney U检验对这些数据的显著水平进行了检验;最后采用逐步判别分析(stepwise discriminate analysis)方法确定影响崖沙燕巢址选择的主要生态因子,并建立了标准化的典则判别函数。结果表明,1)崖沙燕洞巢的洞口横径(8.46±0.79)cm,纵径(8.30±0.79)cm,巢洞深(87.80±11.97)cm,巢室长径(11.25±1.33)cm,短径(10.43±1.33)cm,巢室高(9.99±1.33)cm;2)巢址样方与对照样方在植被均高、植被密度、坡位、坡度、崖高、崖长、崖龄及干扰度等8个方面差异达到显著水平,崖沙燕偏好选择的洞巢周围植被较高(97.24±8.42)cm,植被密度较大(64.34±7.15)株/m~2,坡度较大(83.78±0.35)°、上坡位(1.41±0.04)、崖较高处(7.54±0.13)m、崖壁较长(51.18±3.54)m、崖龄较短(2.41±0.05)月及人类干扰较低(1.94±0.06);3)逐步判别分析结果表明,影响崖沙燕营巢地选择的主要生境因子是坡位、崖龄和干扰度,标准化的典则判别函数为y=0.753×坡位+0.681×崖龄+0.288×干扰度。建议在城市化建设过程中针对崖沙燕的巢址选择特性建立合理的保护措施。     

Density‐dependent survival and recruitment in a long‐distance Palaearctic migrant,the Sand Martin Riparia riparia

Long‐term studies can provide powerful insights into the relative importance of different demographic and environmental factors determining avian population dynamics. Here we use 23 years of capture–mark–recapture data (1981–2003) to estimate recruitment and survival rates for a Sand Martin Riparia riparia population in Cheshire, NW England. Inter‐annual variation in recruitment and adult survival was positively related to rainfall in the sub‐Saharan wintering grounds, but unrelated to weather conditions on the breeding grounds. After allowing for the effects of African rainfall, both demographic rates were negatively density‐dependent: adult survival was related to the size of the western European Sand Martin population (probably reflecting competition for resources in the shared wintering grounds) while recruitment was related to the size of the local study population in Cheshire (potentially reflecting competition for nesting sites or food). Local population size was more sensitive to variation in adult survival than to variation in recruitment, and an increase in population size after 1995 was driven mainly by the impact of more favourable conditions in the African wintering grounds on survival rates of adults. Overwinter survival in this long‐distance Palaearctic migrant is determined partly by the amount of suitable wetland foraging habitat in the sub‐Saharan wintering grounds (which is limited by the extent of summer rainfall) and partly by the number of birds exploiting that habitat.     

Live weight and body condition changes of matebele does during their breeding cycle in a semi-arid environment

The live weights of Matebele does kept in seven communally grazed flocks in southern Zimbabwe were established by survey over a two-year period. The does showed a cyclical change in weight around the breeding cycle, the mean live weight at mating, immediately after kidding and 60 days after kidding were 30.0, 35.2 and 32.8 kg, respectively. The month of mating and kidding had a major effect on live weight. The post-kidding weight of does kidding in the late-dry to early-wet season was approximately 25% less than that of does kidding at the end of the wet season. Does mating during the wet season had the greatest gains over the course of the breeding cycle. The mean mating weight of primiparous does was 24.0 kg, approximately two-third that of adult does. Younger does tended to gain more weight over the course of the breeding cycle than older does. There were consistent differences in live weight among flocks. The results illustrate the profound effects of seasonal factors on live weight changes and the abilities of Matabele goats to adapt to their harsh environment.     

Body, nuclear, and ciliary changes during conjugation of Protospathidium serpens (Ciliophora, Haptoria)

We studied cell size and shape, nuclear changes, and the ciliary pattern during conjugation of Protospathidium serpens, using protargol impregnation and morphometry. Preliminary data were gathered from Epispathidium ascendens and Apertospathula armata. Conjugation of P. serpens is temporary, isogamic, and without preconjugation divisions. Pair formation is heteropolar, and the partners unite obliquely with the oral bulge. The body becomes smaller and broader during conjugation, but no basic changes occur in the ciliary pattern. Conjugation and nuclear reconstruction follow the usual mode of ciliates. However, some peculiarities occur: only two of the four synkaryon derivatives of the second synkaryon division enter the third division and generate four macronuclear anlagen, which fuse to a single, long macronucleus strand. During conjugation, E. ascendens unites obliquely as P. serpens, while A. armata can pair dorsal-to-dorsal surface, ventral-to-dorsal surface, or obliquely as P. serpens. The nuclear processes of these three species are also rather different, showing a considerable diversity in union modes and nuclear events of spathidiids; E. ascendens even has preconjugation division. Confirming previous data, the present study shows convincingly that most of the spathidiid nuclear variability is caused by reconstruction processes occurring in post-dividers, exconjugants and, possibly, exautogamonts. When these specimens are removed from the populations, spathidiid species are as stable (or variable) as other ciliate species.     

Body condition is associated with a shorter breeding season and reduced ovulation rate in subtropical goats

To determine the effect of body condition on the characteristics of the breeding season in female goats from subtropical Mexico, does in either greater- or lesser-body condition (n=20/group) were monitored for the expression of estrous behavior, ovulation and ovulation rate between June and April. The commencement of estrus and ovulation occurred earlier (P<0.05) in does in greater than lesser body condition. The cessation of estrus and ovulation was later (P<0.05) in female goats with greater than those with lesser body condition. Does in greater body condition had more (P<0.001) normal estrous cycles than those in lesser body condition. As consequence, does from the greater body condition group had fewer short (P<0.001) or long (P<0.05) estrous cycles than those of in the lesser body condition group. The ovulation rate was greater (P<0.01) in the greater (1.9+/-0.1) than lesser body condition does (1.6+/-0.1). In conclusion, female goats in lesser body condition have a shorter breeding season, more abnormal estrous cycles, and fewer ovulations than does in greater body condition.     

No evidence of genetic benefits from extra-pair fertilisations in female sand martins (Riparia riparia)

Genetic parentage studies of socially monogamous birds reveal a widespread prevalence of extra-pair paternity. Variation in extra-pair paternity among individuals may depend on how different individuals benefit from extra-pair fertilisations and on the opportunity to pursue extra-pair copulations. A long-term study of sand martins (Riparia riparia) in Hungary allowed us to examine patterns of extra-pair fertilisations in a large colony of over 3,000 breeding pairs with many known age individuals. We used multi-locus DNA fingerprinting to determine whether extra-pair fertilisations occur when females are paired to (1) presumably low quality mates, or (2) genetically similar or dissimilar mates, and whether extra-pair fertilisations result in offspring of higher quality. Extra-paternal young were found in 38% of 47 broods and comprised 19% of 190 offspring. Males that lost paternity did not differ significantly from others in age or body condition. Social mates of broods containing extra-pair offspring did not differ in genetic similarity from pairs without extra-pair offspring. Furthermore, there was no significant difference in body condition between extra-pair young and their maternal half-siblings. We were unable to assign paternity and therefore cannot exclude the possibility that extra-pair males differed from the within-pair males they cuckolded, in age, body condition or genetic similarity with the female. We found a positive relationship between paternity losses and breeding density, suggesting that low breeding density may constrain opportunities for seeking extra-pair copulations.     

Body condition and ruminal morphology responses of free-ranging impala (Aepyceros melampus) to changes in diet

Variation of the intraruminal papillation pattern with diet quality has been described in many ruminant species, but the use of papillation measures as a proxy for habitat quality and nutritional status of animals has not been evaluated. We compared various measures of body condition (body mass, body condition score, kidney fat index, bone marrow fat index, adrenal mass, kidney to adrenal mass ratio), diet quality (%browse, protein and fibre content) and rumen papillation in 106 impalas (Aepyceros melampus) from four different locations in Zimbabwe. The various condition proxies indicated that periods of low diet quality are characterised by a high proportion of browse in the diet of this species. Animals with a high proportion of browse had more voluminous rumens, suggesting a compensation for lower diet quality by increased intake. Macroscopic papillation indices did not yield meaningful significant correlations with diet quality or body condition proxies, and hence, their use for estimating habitat or body condition cannot be advocated. In contrast to previous histological reports, ballooning cells of the Stratum corneum of the ruminal mucosa were more prominent in animals on lower-quality diets. There were significant correlations of the kidney to adrenal mass ratio with other body conditions and with diet quality indices, suggesting that poor body condition and low diet quality represent stressful situations.     

Metabolic changes in male snakes, Thamnophis melanogaster, during a breeding period

1. Daily basking periods were lengthened substantially during a breeding period in a natural population of the snake, Thamnophis melanogaster. 2. In the laboratory, oxygen consumption of male T. melanogaster significantly increased during a breeding period, compared to pre- and post-breeding levels in the same males. 3. In both laboratory and field males, serum lipid increased initially and then decreased during the breeding period. 4. Serum protein of laboratory males decreased significantly following the breeding period. 5. Serum glucose did not change significantly in laboratory males, but increased significantly during the breeding period in field males. 6. Changes in oxygen consumption and nutrient distribution may reflect changing energy demands attendant with gonadal recrudescence in this snake.