The annual cycle and breeding behaviour of the Mauritius Fody Foudia rubra

Safford, R.J. 1997. The annual cycle and breeding behaviour of the Mauritius Fody Foudia rubra. Ostrich 68 (24): 58–67.

The Mauritius Fody Foudia rubra, a highly endangered species of weaver (Ploceidae) endemic to Mauritius, was studied from 1989–1993. The plumage, various display postures (typical of the family), and seven adult and two juvenile vocalisations are described. The diet consisted of insects, nectar and fruit. Males were in breeding plumage, and breeding took place, between late August and early April, although severe weather in February 1992 terminated breeding activity early. The species appeared to be monogamous and was suspected to maintain a long-term pair bond. Pairs occupied exclusive territories of not less than 0.9 ha. Both sexes built the nest from the outset, but only the female lined it. Between breeding attempts, some pairs habitually started but then abandoned one or more nests. Clutch sizes of two to four were recorded, three being the norm. Incubation and brooding were carried out by the female; the male joined in feeding the young after daytime brooding ceased. Juvenile dependency appeared to last around two weeks after which the young were ousted from the territory. The potential productivity of up to three broods per pair per year was not achieved by any pair studied because of poor nesting success. A complete moult followed breeding. Territorial defence continued throughout the year, and no evidence for seasonal movements was seen. Two behavioural features seem unexpected: 1) male nest invitation and nest advertisement behaviour appeared to be absent; 2) females participated from the outset of nest-building (including prospecting). These could be explained by the existence of a long-term pair bond, which needs to be confirmed but would not be surprising in a species that remains on territory all year. Hypotheses that could be tested to find a mechanism responsible for the unusual features of the fody are suggested. In comparison with other fodies studied, the breeding behaviour most resembled that of the Seychelles Fody F. sechellarum (also a monogamous, non-graminivorous omnivore that breeds in solitary pairs in evergreen forest). The annual cycle was similar to that of other native passerines and most other fody taxa.     

Factors affecting the length of the breeding cycle and the frequency of nest attendance by Grey Herons Ardea cinerea

An investigation of the length of the breeding cycle and of the frequency of nest visits by Grey Herons at 3 heronries with different degrees of breeding success showed that the duration of reproduction, particularly the chickrearing period, decreased and the frequency of daily nest visits increased with increasing average breeding success of a colony. Successful pairs also seemed to spend less time displaying and incubating eggs. Herons arrived at their nests most frequently during twilight, especially in the morning. The mean time absent from the nest was greatest during incubation and smallest when feeding small chicks. The total reproductive period tended to be longer for those pairs whose periods of absence from the nest were longer.     

Distribution, abundance and breeding cycle of the Australian sea lion Neophoca cinerea (Mammalia: Pinnipedia)

Surveys of the Australian sea lion Neophoca cinerea were conducted throughout its range in Western and South Australia between December 1987 and February 1992. Almost every island was visited between Houtman Abrolhos and The Pages ( n = 255), many of them more than once.
Sea lions breed on at least 50 islands, 27 in Western Australia and 23 in South Australia. Of the 50 breeding sites, 31 have not been reported previously. A further 19 islands may also support breeding colonies. A total of 1,941 pups was counted and pup production was estimated at 2,432. Only five colonies produced more than 100 pups each and they accounted for almost half of the pup production. Most of these colonies are near Kangaroo Island, South Australia. A breeding cycle of 17–18 months has been reported for N. cinerea at Kangaroo Island and on the west coast of Western Australia; this was also noted at another 11 islands where repeated visits coincided with breeding. No evidence was found for breeding seasons shorter or longer than 17–18 months. The breeding season was not synchronized between islands, as it is in other pinnipeds. A predictive model is developed to estimate the population size from pup production figures. It indicates that pup numbers should be multiplied by between 3.81 and 4.81 to estimate the total population size just before the pupping season begins. This leads to estimates of 9,300–11,700 for the total population, considerably greater than earlier estimates.
Causes of the unique reproductive cycle of N. cinerea are unknown, but we hypothesize that it results from living in a temperate climate in some of the most biologically depauperate waters of the world. It is also clear that day length and water temperature cannot act as exogenous cues for implantation of the blastocyst; the physiological events of gestation must, rather, be cued endogenously.     

The annual cycle ofVibrio Parahaemolyticus in chesapeake bay

An ecological study ofVibrio parahaemolyticus was carried out from December 1970 to December 1971 in the Rhode River of Chesapeake Bay. The annual cycle of the organism was elucidated and factors restricting its distribution in the estuary were described, including the association of the organism with zooplankton. Numerical taxonomy was employed for identification and classification ofV. parahaemolyticus and related organisms on the basis of substrate utilization tests. From characteristics recorded forV. parahaemolyticus, it is concluded to be an estuarine organism.     

Mixed mating strategies in cooperatively breeding apostlebirds Struthidea cinerea

In cooperatively breeding apostlebirds Struthidea cinerea philopatry by both sexes is coupled with low levels of dispersal, resulting in large groups (up to 17 birds) that may include multiple males and females of varying age and relatedness. We investigated mating patterns within 18 groups of apostlebirds using a set of six polymorphic microsatellite loci. Apostlebirds appear to adopt flexible and context-dependent mating strategies, with both monogamy and polygamy detected in separate groups. Most groups (11/18, 17/26 group-seasons) were putatively monogamous, with a single pair matching all typed offspring. Despite the potential for inbreeding, members of breeding pairs were less closely related than other potential within-group mating combinations. Polygamy was inferred in four groups (four group-seasons) from the presence of more than four alleles at one locus among offspring within a brood. Pairwise relatedness was lower among adults in polygamous groups than those in groups that included a monogamous breeding pair. There was no conclusive evidence of extra-group paternity or egg dumping.     

Moult and the breeding cycle in Darwin's finches

Summary The moult and annual cycle of Darwin's finches were studied at Academy Bay, Indefatigable Island, from February 1963 to June 1964. In 1963 the only heavy rainfall of the year fell on 23–24 February, and was immediately followed by nesting. The next breeding season began in December, following moderate rainfall in late November.It was found that in February 1963, before breeding began, a high proportion of the adult finches were undergoing a wing-moult. When breeding began, this moult was arrested, and it was resumed when breeding ended, in April. By August moult had finished. A smaller proportion of the adults began a wing-moult before the next breeding season began, and this moult was again arrested when breeding took place.The moult regime described is very different from that given in the literature for Darwin's finches, which are said to undergo a single post-breeding moult. Some possible reasons are suggested for the discrepancy.The moult of juveniles was followed in detail in 1963, when the young birds were all hatched in March or April. Body-moult took place in May and June, followed in July by moult of the innermost secondaries and the irregular replacement of other flightfeathers. Later, in the last three months of the year, another wing-moult began, after which the young females were indistinguishable from adults and some, at least, of the males were in partly black plumage.

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Zusammenfassung Von Februar 1963 bis Juni 1964 wurden im Gebiet der Academy Bay der Indefatigable-Insel Mauser und Jahreszyklus von Darwinfinken studiert. Unmittelbar nach den einzigen ausgiebigen Regenfällen des Jahres 1963 am 23.–24. Februar begannen die Vögel zu nisten. Die nächste Brutperiode begann im Dezember, nachdem Ende November mäßige Regenfälle voraufgegangen waren.Ein großer Teil der adulten Darwinfinken befand sich im Februar 1963, bevor die Brutaktivität begann, in der Schwingenmauser. Mit dem Einsatz der Brutaktivität wurde diese Mauser unterbrochen und nach dem Ende der Fortpflanzungsperiode, im April, wieder fortgeführt. Etwa im August war die Mauser zu Ende. Ein kleinerer Teil der Altvögel begann die Schwingen zu mausern, bevor die nächste Brutperiode begonnen hatte, und auch in diesem Falle wurde die Mauser mit dem Einsetzen der Brutaktivität unterbrochen.Dieses Mauserverhalten unterscheidet sich sehr von den Literaturangaben über die Mauser der Darwinfinken, nach denen diese jährlich nur eine, und zwar eine postnuptiale Mauser durchmachen. Einige mögliche Erklärungen für die unterschiedlichen Angaben werden vorgebracht.Im Jahre 1963, als alle Jungvögel im März oder April schlüpften, wurde die Mauser der Jungvögel genauer untersucht. Das Kleingefieder wurde im Mai und Juni gemausert; im Juli wurden dann die innersten Armschwingen und in unregelmäßiger Folge auch andere Schwingen gemausert. In den letzten drei Monaten des Jahres begann dann eine neue Schwingenmauser, nach der die jungen von den alten nicht mehr zu unterscheiden waren, während wenigstens einige der nun teilweise schwarzes Gefieder besaßen.

     

The annual lipid cycle and feeding behavior of Alaskan redpolls

Summary Total lipids were extracted from 161 redpolls (Acanthis spp.) collected each month of the year from October 1962 to September 1963, in interior Alaska. A lipid index (Weight of ether extract x100/live body weight) was calculated for each sample. Lipids were also extracted from sections of pectoral muscle, livers and hearts representing each month.Body weight and lipid index were significantly positively correlated being highest in January and lowest in September. Total lipid content was significantly inversely correlated with air temperature; the high autumn and spring pre-migratory lipid peaks of migratory species were only weakly expressed in the redpolls. Liver lipid showed a significant annual variation being highest in December and lowest in August, while lipid from heart and pectoral muscle did not vary seasonally.Five birds were held in captivity during spring and summer at a constant temperature of 22°C. Food consumption was 5.1 g/day or 22.4 kcal. The caloric value of the most extensively utilized natural food, birch seed (Betula papyrifera), was determined (5.4–5.5 kcal/g dry wt). When esophageal diverticulae are full (2.0 g wet wt) of birch seeds, the resulting energy yield may sustain an individual for only a fraction of a 24 h winter day in contrast to other arctic herbivores (e.g. ptarmigan, Lagopus sp.) in which a full crop may suffice for the full 24 h period.     

The annual glucido-lipid cycle in a varanid of Senegal]

Lipid and carbohydrate storage depots on one hand, blood lipids and glucose on the other hand, were measured every month in Varanus exanthematicus exanthematicus, the annual cycle of which is correlated to the characteristic succession of one dry and one wet season in the Sahel area. The large cyclic variations of these figures are discussed as a function of the animal behaviour and what is known about its endocrine cycle.     

The role of the Ghana coast in the annual cycle of migratory terns

Ntiamoa-Baidu, Y. & Nuoh, A. A. 2000. The role of the Ghana coast in the annual cycle of migratory terns. Ostrich 71 (1 & 2): 183.

Data are presented on counts of migratory terns on the Ghana coast over a ten-year period, 1986–1996. Fourteen species of terns were recorded during the period. Influx of terns begins in late August, peaking in September/October, with the highest likelihood of tern occurrence on the Ghana coast recorded in August-November and April-May. Terns fed mostly offshore and used the coastal lagoons as roosting sites, although a few species e.g. Black Tern Chlidonias niger and Little Tern Sterna albifrons, foraged also on the lagoons. Two sites, Songor Lagoon and Densu Delta, regularly held over 50 % of the total count recorded for all sites. A comparison of the day-time counts with dusk roost counts indicate that the day time counts under-represent the total numbers of terns using the Ghana coast. Trends in the populations of the four most abundant tern species: Black Tern, Common Tern Sterna hirundo, Sandwich Tern S. sandvicensis and Royal Tern S. maxima, are analysed; and the implications for conservation of the species are discussed.     

The annual reproductive cycle of the freshwater mussel Dreissena polymorpha Pallas in lakes

Summary The annual development of the gonads of Dreissena polymorpha was studied at three sampling sites in two lakes over 3 and 1 1/2 years, respectively. A resting stage occurred after the last spawning in summer/autumn. Oogenesis (accompanied by multiplying segmentation of the oogonia and early growth processes of its oocytes) restarted in specimens at least 1 year old at low temperatures (below 10° C) during winter and early spring. At one location (Fühlinger See) the onset of the spawning season was correlated with an increase of water temperatures above 12° C. At 2 m depth, two main spawning periods in May and August were normally recognized, the first at temperatures of 12–16° C, the second at 16–21° C. It was clearly demonstrated for the first time in Dreissena polymorpha that the oocytes became mature in successive cohorts within one gonad. A female mussel may spawn several times during the reproductive season. At 9 m depth, the onset of spawning also started at about 12° C; this occurred in late summer, with two spawning periods within 1 month at a temperature range of 12–16° C. At another location (Heider Bergsee) the size of the gonads and the oocytes was reduced during April of both years studied, when food supply was low simultaneously with rapidly rising water temperatures in this shallow lake. There was no spawning period during spring. The major spawning period was delayed until July (temperatures 19–22°C). This shows (1) the synchronizing influence of low winter temperatures on the annual reproductive cycle and (2) a temperature threshold of at least 12° C for the start of the spawning processes. The results are discussed with regard to the geographical limits of further spread of Dreissena polymorpha.     

A comparison of breeding and moult cycles and life histories in two tropical starling species: the Blue-eared Glossy Starling Lamprotornis chalybaeus and Rüppell's Long-tailed Glossy Starling L. purpuropterus

The Blue-eared Glossy Starling Lamprotornis chalybaeus and Rüppell's Long-tailed Glossy Starling Lamprotornis purpuropterus were investigated in the field and in aviaries at Lake Nakuru National Park, Kenya for seasonality in reproductive activity and moult. The former species was found to be a seasonal breeder which nests after the onset of the heavy rains in April. Although some birds had large gonads prior to the rains in the dry season no nesting occurred. The rains were contemporary with increases in gonadal size and the plasma titres of LH, testosterone (T) in males and estradiol (E2) in females. These hormones are associated with the initiation of breeding activity. As breeding ceased in July and the moult began, the plasma titres again decreased. There was a bimodal breeding pattern which paralleled a change in biotope preference for nesting. Early nests, in the heavy rains, were on the open savanna and later nests were in the acacia forest. Late nesting birds also had delayed peaks in gonadal size, plasma titres of LH, T and E2 and a delayed moult onset. Data on individual captive birds demonstrate that these annual cycles have a distinctly individual character superimposed on the seasonal trends. In Rüppell's Long-tailed Glossy Starlings no seasonality in breeding was found although the flight feather moult commenced and was completed in all individuals at about the same time. The moult extended over about ten months, so a great deal of breeding-moult overlap was present. The absence of seasonality in field birds was reflected in the aviary birds, which had no pronounced cycles in the reproductive parameters measured (gonadal size, LH, T and E2 plasma titres). Breeding in field birds was regulated on a pair basis and correlated with increases in duetting. The striking differences in the seasonal organization between this species and Blue-eared Glossy Starlings were presumably due to the different biotope preferences and social behaviour of the two species.