Breeding density of Dippers Cinclus cinclus' Grey Wagtails Motacilla cinerea and Common Sandpipers Actitis hypoleucos in relation to the acidity of streams in south-west Scotland

The distribution of breeding pairs of Dippers Cinclus cinclus , Grey Wagtails Motacilla cinerea and Common Sandpipers Actitis hypoleucos was assessed along 18 streams in south-west Scotland during summer 1987, and the lengths of territories, occupied by 5 5 breeding pairs of Dippers, were measured. In each stream the water chemistry, physical structure (e.g. gradient, altitude, nature of bankside vegetation) and density of aquatic invertebrates was determined. The density of breeding pairs of dippers was significantly lower along streams of low pH (high acidity) and steep gradients, and territories were significantly longer at these sites compared with those of higher pH. Many of the invertebrate families that are important prey for Dippers were scarce at sites of low pH, particularly caddisfly larvae (Trichoptera) and mayfly nymphs (Ephemeroptera). The low numbers and large territories of breeding pairs of Dippers on acidic streams may be due to reduced density and diversity of macroinvertebrate prey. Stream pH was not an important correlate of the distribution or density of Grey Wagtails or Common Sandpipers. It is suggested that the lack of any similar effect of pH on these other two species compared with Dippers is attributable to differences in their feeding ecology.     

Unusual finding of Trichobilharzia sp. in Motacilla alba in the Czech Republic

Adult male worms of Trichobilharzia sp. recovered from a pied wagtail (Motacilla alba) in the Czech Republic were found to belong to a new species of the genus. The finding of Trichobilharzia sp. in a passeriform bird in Europe represents an important discovery, as only anseriform birds have thus far been reported as final hosts of the European Trichobilharzia species.     

Experimentally elevated testosterone levels enhance courtship behaviour and territoriality but depress acquired immune response in Red Bishops Euplectes orix

The immunocompetence handicap hypothesis (ICHH) posits that the hormone testosterone mediates a trade‐off between investment in reproduction and immunological condition. In this study, we tested the ICHH in the Red Bishop Euplectes orix, a polygynous weaverbird. Males of this strongly sexually dimorphic species show an elaborate courtship display to attract females and compete aggressively with other males for nesting sites in breeding colonies. We experimentally elevated testosterone levels in breeding male Red Bishops kept in an aviary with a subcutaneous implantation of testosterone‐releasing pellets. We then compared behaviour, development of territory size and immunological condition (as assessed through a white blood cell count) of the experimental group with a control group treated with placebos. In addition, we measured the primary and secondary response to phytohaemagglutinin (PHA) to investigate the effect of testosterone on both innate and acquired immunity. Males with elevated levels of testosterone enlarged their territories and conducted more courtship behaviour, while showing a decrease in health, expressed by an increased heterophil/lymphocyte ratio compared with the control group. Males of the control group showed an increase of the secondary response to PHA, as expected under the assumption that repeated exposure to an antigen enhanced the immune response due to acquired immunity. However, males with experimentally increased testosterone levels did not show such an enhanced immune response in the secondary PHA test (although sample size and power of the statistical tests were low), indicating that testosterone treatment might directly or indirectly suppress some component of the acquired immune response.     

Breeding season influxes and the behaviour of adult male samango monkeys (Cercopithecus mitis albogularis)

Troops comprising a high density population of samango monkeys (Cercopithecus mitis) in Natal province, South Africa, experienced an influx of adult males during the breeding season. Observation of one troop revealed that these males competed with one another and with two resident males for access to receptive females. Although both sexes initiated copulation, attempts to do so were more often successful if female-initiated. Males did not interact with non-receptive females and there were no recorded attempts at infanticide. Male-male interactions were agonistic in the presence of receptive females and neutral at other times. No ritualized displays of dominance and subordinance were seen. The significance of these observations for male reproductive strategies is discussed.     

艾比湖大白鹭的繁殖及雏鸟生长发育模式

2009年3—10月对新疆艾比湖大白鹭(Egretta alba alba)的巢、卵及雏鸟的生长发育模式进行了研究。结果表明,大白鹭的巢基厚度大于巢深(t=6.06,P0.01),巢外径远大于巢内径(t=21.53,P0.01),其目的是增加巢的稳定性和减少幼鸟跌出巢外的概率;窝卵数3～5枚(3.86±0.69),卵重44.00～60.00g(53.94±3.96),卵体积47.18～62.00cm3(55.19±4.09);双亲孵卵(26～28d),共同育雏(55～60d)。测量了4巢13雏26日龄以内的生长发育数据,并利用Gompertz方程对雏鸟的主要生长指标进行拟合,拟合结果将雏鸟生长发育划分为3个阶段:1)器官形成,生长速度准备加快的时期;2)物质积累,生长速度加快并逐渐过渡到中速时期;3)由物质积累逐渐过渡到物质消耗大于积累,生长速度较慢,雏鸟准备出飞。     

Orcadian rhythm of Oecophylla longinoda in relation to territoriality and predatory behaviour

Abstract Circadian rhythms of activity in four societies of Oecophylla longinoda (Latreille) have been studied. Activity is continuous, but diurnal activity is greater than the nocturnal activity. This species is characterized by a strong sense of territoriality and the workers occupy: central territories, trees and immediate surroundings occupied by the society; secondary territories, used for hunting purposes, in natural conditions located on the ground; and intermittent territories in the forest zone (diurnal), scarcely used for hunting, but mainly in relation to the tending of homopterans.
The circadian rhythm of activity can be reversed by artificially lighting certain territories at night (reinforcement by attraction of numerous prey). This reversal can only be obtained progressively. By permanent surveillance of the territories and efficient recruitment, the societies rapidly adapt to fluctuations in the quantity of prey. There is a close correlation between agressive territoriality and predation.     

Butterflyfish social behaviour,with special reference to the incidence of territoriality: a review

Synopsis Butterflyfishes (Chaetodontidae) are among the best studied of coral reef fishes. Feeding ecology and some aspects of behaviour have been firmly established. However, spacing behaviour remains controversial. Two major studies made in the 1970s concluded that the majority of species were not territorial. We suggest that these and other studies which have concluded that territories are not held have generally suffered from short observation periods, and have not mapped the ranges occupied by individuals. Further, low frequencies of agonistic behaviour have been interpreted as evidence of non-territoriality. By contrast, studies which have proven territoriality have had long observation periods and have mapped ranges. These have shown that territories are usually maintained with very little overt aggression. Spacing behaviour and feeding behaviour are clearly linked, with territoriality common among benthic-feeding species, especially obligate corallivores. Species with broad dietary flexibility tend to have flexible social systems, while plankton feeders are usually gregarious. The widespread occurrence of monogamy in butterflyfishes appears linked to territoriality, the majority of territorial species identified to date occurring predominantly as pairs. Data currently available suggest that this is because pair defence of the territory is more efficient than by individuals. However, several alternative hypotheses for the evolution of monogamy based on spawning constraints and predation risk cannot yet be ruled out.     

Breeding behaviour, home range and habitat selection in Rock Firefinches Lagonosticta sanguinodorsalis in the wet and dry season in central Nigeria

Knowledge of a species’ movement behaviour and habitat choice is a prerequisite for assessing its ecological requirements to plan successful conservation strategies. Little is known about these factors in the Rock Firefinch, a recently described species which is probably endemic to the Jos Plateau in central Nigeria. We investigated home range size, habitat use and breeding behaviour of the Rock Firefinch in Amurum forest reserve in central Nigeria during the wet (August–October) and the dry season (November–December) using radiotracking. Birds showed high site fidelity. They mainly moved alone or in pairs but did not have exclusive home ranges. Home range size tended to be larger during the dry season due to long movements to water sources. Birds generally preferred inselberg habitat and avoided farmland. During the dry season they additionally utilized gallery forests where water was readily available, and as a result of having to cross scrub savannah to get to water, scrub savannah was also more heavily used during the dry season. Birds bred between the late rainy (September–October) and the early dry season (November). Nest‐sites were associated with rocky boulders. Both sexes contributed to incubation. Daily egg survival rate calculated using the Mayfield method was 0.89 (0.83–0.95 95% confidence interval); no nests failed during the chick stage, but sample size was only four nests. Of all 14 nests found, 50% were depredated and only 29% of breeding attempts succeeded in producing Rock Firefinch chicks. A second breeding attempt was recorded when the first one failed. Chick production just about compensated adult mortality (measured in a separate study at the site) such that the population is probably stable at present. However, given the large uncertainty in our underlying assumptions, more data are needed to confirm this. We suggest that the presence of inselberg habitat in close proximity to water sources is the essential and limiting resource for this species.     

四川南充地区白鶺鴒的繁殖习性

2004年2~5月在四川省南充市嘉陵江中上游的河漫滩内对白鶺鴒(Motacilla alba)的繁殖习性进行了研究。结果表明:白鶺鴒2月开始繁殖;雌雄参与筑巢,营巢期7~10 d;主要雌鸟孵卵,孵卵期13~14 d,上午8:00~9:00时孵卵出现一次高峰;窝卵数(5.00±0.52)(n=16)枚,孵化率42.5%;雌雄参与育雏,育雏期15~16 d,下午18:00~19:00时育雏出现一次高峰,日育雏次数(112.9±48.6)(n=17),育雏时间间隔(5.60±5.34)min(n=1 584);雏鸟形态生长曲线呈“S”型。     

Photoperiodic conditions during molting of the Indian pied wagtail (Motacilla alba dukhunensis) and location of its winter habitats

The results of studying molting before the start of the mating season in Indian pied wagtail yearlings taken from the nests in the Lower Ob’ region and in the mid-Urals and kept in captivity for a year are studied. Reliable differences in the completeness of molting in northern birds as compared with it in mid-Ural birds are revealed, as are requirements for the wintering photoperiod. We assume the existence of a latitudinal differentiation during this period: 20°–30° N for mid-Ural birds and 10°–20° N for northern wagtails.     

Physiological correlates to courtship, mating, ovarian development and maternal behaviour in the ring-legged earwig

Abstract. The involvement of the endocrine system in courtship, mating, maternal behaviour and the gonadotrophic cycle was studied in the earwig, Euborellia annulipes, after application of JH III and, alternatively, precocene II. Topical application of 35 or 122 μg of JH III to newly eclosed females advanced the onset of courtship behaviour from 6.6 ± 1.3 days in acetone-treated controls to 1.4 ± 2.8 and 0.5 ± 2.5 days, respectively. Application of 6 μg of JH III had no effect on the onset of courtship behaviour. Applications of Juvenile Hormone had no significant effect on the age at first mating nor on the duration of mating, though the trend is towards advanced onset. The age at first oviposition was advanced by hormone treatment; clutch size and the proportion of offspring hatching was reduced by hormone treatment. The interclutch interval, size and proportion hatching of the second clutch were not affected by hormone treatment. Topical application of 50 μg of JH III to females on the day of oviposition shortened the total duration of maternal care from 15.4 ± 0.5 to 5.3 ± 1.7 days; whereas in acetone-treated and precocene II-treated groups maternal care lasted 16.1 ± 1.9 and 13.8 ± 1.6 days, respectively. The duration of maternal care was positively correlated with number of offspring hatching and fledging. In a corollary experiment, topical application of JH III significantly enhanced the onset of the second gonadotrophic cycle as assessed by basal follicle length; application of 20 μg of precocene II, either singly or in repeated doses, did not delay growth of basal follicles. Finally, repeated application of as much as 80 μg of precocene II had no effect on basal follicle length, nor on ovary wet weights. These results are consistent with the hypothesis that intermediate to high titres of JH are associated with oocyte growth, mating, and the cessation of maternal care; low titres of JH appear to be associated with the period of maternal behaviour and slow ovarian follicle development.     

Effect of genes, social experience, and their interaction on the courtship behaviour of transgenic Drosophila males

Behaviour depends (a) on genes that specify the neural and non-neural elements involved in the perception of and responses to sensory stimuli and (b) on experience that can modulate the fine development of these elements. We exposed transgenic and control Drosophila melanogaster males, and their hybrids, to male siblings during adult development and measured the contribution of genes and of experience to their courtship behaviour. The transgene CheB42a specifically targets male gustatory sensillae and alters the perception of male inhibitory pheromones which leads to frequent male-male interactions. The age at which social experience occurred and the genotype of tester males induced a variable effect on the intensity of male homo- and heterosexual courtship. The strong interaction between the effects of genes and of social experience reveals the plasticity of the apparently stereotyped elements involved in male courtship behaviour. Finally, a high intensity of homosexual courtship was found only in males that simultaneously carried a mutation in their white gene and the CheB42a transgene.     

Exploratory and fear behaviour in the Macropodus opercularis subspecies, M. o. opercularis and M. o. concolor

The exploratory and fear behaviours of the black paradise fish M. o. concolor, a subspecies of Macropodus opercularis, were studied and compared with those of an outbred and two inbred populations of M. o. opercularis. Adult females of both subspecies were used in the behaviour tests (open-field, novel-object approach, restricted space), and their behaviour in novel and startling situations was described by recording the sequence of ethologically defined units. It was found that M. o. concolor more often responded passively to novelty and fear-evoking stimuli. In 11 out of 14 test measures they were less active (p less than 0.01 and 0.001) than the outbred M. o. opercularis, but were very similar to our extremely timid strain P. Subtle differences of behaviour units were found between the subspecies, e.g. the absence of interrupted movements and unoriented panic behaviour in M. o. concolor. It is supposed that alternative passive and active strategies represent genetic polymorphism of defensive behaviour.