bluuebunny/crossref_metadata_2025 huggingface dataset:
Survivorship, dispersal and sex ratios of Zebra Finches Taeniopygia guttata in southeast Australia
Authors: ZANN RICHARD , RUNCIMAN DAVID
Published: April 2008

Membership of three permanent breeding colonies of Zebra Finches Taeniopygia guttata studied in farmland changed continually due to arrival and departure of birds from distant colonies. Sixty‐six percent of adults stayed for less than 1 month, and many that stayed longer disappeared for extended periods. Over 78% of adults captured were hatched in other colonies and only 23% made a breeding attempt in their natal colony. There was no sex‐biased natal dispersal or philopatry, but there were sex differences in the timing of dispersal. Sex ratios at the end of parental care were variable and may depend on food resources. Adult ratios were slightly male‐biased. Annual losses of adults ranged from 72 to 82% across colonies, but mortalities and dispersal were heavily confounded by high adult mobility. The oldest bird was more than 5 years old. A total of 67% of young were lost between fledging and nutritional independence at 35 days of age, and only 20% of fledglings survived to day 80, the age of first breeding. Artificial supplies of seed at baited walk‐in traps prolonged the stay of dispersing adults from other colonies, enhanced the survivorship of young hatched in the colony and possibly affected the secondary sex ratio. In this southeast part of their Australia‐wide distribution, Zebra Finch populations appear to be highly mobile over a very large home range with extensive free interchange of members among a number of permanent breeding colonies. High mobility may be adaptive for exploiting patches of seed and water in a highly erratic environment.
‘Overlooked’ units of comparative and conservation biology: a case study of a small African bustard, the Black Korhaan Eupodotis afra
Authors: CROWE T. M. , ESSOP M. F. , ALLAN D. G. , BROOKE R. K. , KOMEN J.
Published: April 2008

Two small southern African bustards, the Black‐winged Korhaan Eupodotis afra afra and the White‐winged Korhaan E. a. afraoides, have long been treated as conspecific. However, differences in their habitats, plumage, morphometrics, displays and vocalizations of males, mitochondrial DNA restriction fragment length polymorphisms and, possibly, social systems strongly suggest that they are distinct species.
The role of Greater Yellow‐headed Vultures Cathartes melambrotus as scavengers in neotropical forest
Authors: GOMEZ LUIS G. , HOUSTON DAVID C. , COTTON PETER , TYE ALAN
Published: April 2008

The scavenging activities of Greater Yellow‐headed Vultures Cathartes melambrotus were studied in the Amacayacu National Park, Colombia. This species is the most abundant vulture in the area and is usually the first species to locate a carcass, both in open clearings and inside the forest. The birds use olfaction to locate food. Vultures located 63% of provided carcasses, while mammalian scavengers found only 5%. Greater Yellow‐headed Vultures were displaced when feeding by both Turkey Vultures Cathartes aura and King Vultures Sarcorhamphus papa.
Colonial breeding and nest predation in the Jackdaw Corvus monedula using old Black Woodpecker Dryocopus martius holes
Authors: JOHNSSON KRISTINA
Published: April 2008

Jackdaws Corvus monedula breeding in old holes of the Black Woodpecker Dryocopus martius were studied during 6 years in central Sweden. Of 131 breeding attempts, only 56% were successful. Nest predation caused 74% of the breeding failures. The most common predator was probably the Pine Marten Mattes mattes, as fresh hair was found in 42% of the nests whose contents had been predated. Predation risk of nest contents was not related to the height above ground, but it was significantly reduced with increasing colony size. Since Jackdaws are known to communally defend their nests, a likely explanation is that the Jackdaw benefits from group defence against predators. During the study, the number of breeding Jackdaw pairs in Black Woodpecker holes declined, probably linked with a recent increase in the numbers of Pine Martens in the area.
Breeding success of a Lesser Spotted Woodpecker Dendrocopos minor population
Authors: WIKTANDER ULF , NILSSON SVEN G. , OLSSON OLA , STAGEN ANDERS
Published: April 2008

We made intensive observations of 50 pairs of Lesser Spotted Woodpecker Dendrocopos minor in southern Sweden from 1989 to 1992. Between 7% and 22% of the pairs each year defended a territory but laid no eggs. Overall, 76% of the pairs laying eggs raised fledglings, but this proportion was only 33% in 1991 when the weather was cold and wet. The mean clutch size (5.9) and brood size (4.5) in successful nests did not vary significantly between years. Incubation time was 1 day longer in 1991 (11–12 days) than in 1990 and 1992 (10–11 days). Number of young fledged per nesting attempt (3.5) and per pair (2.7) in the population also varied significantly between years. The initiation of egg laying varied between years but coincided each year remarkably well with the date when oak came into leaf. Breeding success is discussed, and comparisons are made with other hole‐nesting species.
Latitudinal variation in the body‐size of Sparrowhawks Accipiter nisus within Britain
Authors: WYLLIE I. , NEWTON I.
Published: April 2008

On the basis of Sparrowhawks Accipiter nisus found dead in various parts of Britain during 1979–1991. wing‐length was found to provide the most reliable index of overall body‐size because it gave the best and most consistent correlations with five other measures of body‐size.

A marked latitudinal trend in the body‐size of Sparrowhawks was found within Britain, with birds of each sex and age group increasing in size from south to north, in line with Bergmann's Rule. For each successive degree of latitude (approximately 110 km), wing‐length increased by an average of 0.86 mm in adult males and O.75 mm in adult females. No obvious west‐east trend in body‐size was found within Britain.
Different habitat use among three sympatric species of couas Coua cristata, C. coquereli and C. ruficeps in western Madagascar
Authors: URANO EIICHIRO , YAMAGISHI SATOSHI , ANDRIANARIMISA ARISTIDE , ANDRIATSARAFARA SOLOFO
Published: April 2008

This study compares the habitat use by three species of couas, the Crested Coua Coua cristata, Coquerel's Coua C. coquereli and the Red‐capped Coua C. rujiceps, in a dry forest at Ampijoroa, western Madagascar. The Crested Coua used higher layers (> 5 m) exclusively. Both Coquerel's and the Red‐capped Coua stayed mainly on the ground, but the former used middle layers (1–5 m) for inactive behaviour (including resting, preening and basking) and whistling more frequently than did the Red‐capped Coua. Both Coquerel's and the Red‐capped Coua foraged almost exclusively on the ground but differed slightly in feeding technique. The Red‐capped Coua took food on trails, relatively open areas in the forest, more frequently and more efficiently than Coquerel's Coua.
Provisional classifications v standard avian sequences: heuristics and communication in ornithology
Authors: MAYR ERNST , BOCK WALTER J.
Published: April 2008

The past decades have been exciting ones for ornithologists interested in avian macrosystematics with many new ideas being proposed for consideration and further study. But this excitement should not blind ornithologists to the important distinction between the provisional classifications proposed by specialists in macrosystematics, no matter how convincing they may appear at first glance, and the standard sequence needed to maintain optimal communication among all students of avian biologists. An excellent standard sequence for Recent birds exists in Peters' Check‐list. We urge that all ornithologists, authors and editors use this sequence until the time arrives, as it undoubtedly will, when enough is known about avian relationships to permit agreement on a new and better standard sequence.
Factors affecting flock size in the Alpine Chough Pyrrhocorax graculus
Authors: DELESTRADE ANNE
Published: April 2008

The Alpine Chough Pyrrhocorax graculus is a social corvid which now uses food provided by tourist activities in mountain regions (e.g. at ski stations, refuse dumps, picnic areas). Foraging flock size, flock distribution and flock structure of Alpine Choughs were studied in the northern French Alps between 1988 and 1992. Flock size varied during the year, being larger in winter than in summer. Alpine Choughs were not evenly distributed in space, and their numbers depended principally on site‐specific factors, such as seasonal human presence. A significant positive correlation existed between Alpine Chough foraging flock size and the local human population. Immature birds gathered in winter in the largest flocks and principally frequented sites with the greatest food availability (e.g. refuse dump). In summer, immatures dispersed, joined small breeding groups and were more homogeneously distributed.
Altitude choice by night migrants in a desert area predicted by meteorological factors
Authors: BRUDERER B. , UNDERHILL L. G. , LIECHTI F.
Published: April 2008

The height distribution of nocturnal migrants in southern Israel was determined by con‐ically scanning the sky with the pencil‐beam of an X‐band radar at different elevation angles. Altitudinal profiles of meteorological parameters were derived from radio sondes launched at midnight and from pilot balloons launched every 4 h. A model to predict the height distribution of birds by means of meteorological variables was developed by assuming that the observed proportions of birds within a height zone, compared with the neighbouring height zones, reflect the degree of the birds' preference for that height zone. Only one among the variables included in the multiple regression analysis proved to have a significant influence on the height distribution of migrants: the difference of tailwind speed between height zones. Simulations with 1000 birds choosing altitudes by means of the night's altitudinal profile of tailwind speed closely traced the observed distributions. The fact that all the other meteorological factors which were previously suggested to have an influence on the flight range in trans‐desert migration were not selected as relevant factors is discussed. The following basic information on nocturnal bird migration in the Negev is provided as a background for the statistical analysis: Directions of migration are within very narrow limits. During the first hour after take‐off, 60% of autumn migrants and 75% of spring migrants are climbing, with vertical speeds of 0.1–2 m per s and 0.1–4 m per s, respectively. During the rest of the night, climbing and descending birds are in nearly equal proportions. Thus, there is a high potential of sampling atmospheric conditions at different altitudes. Height distributions in spring and autumn show the influence of the trade wind situation, autumn migrants making use of the northerly winds at low levels in spite of high temperatures, while spring migrants tend to reach the southwesterly winds at higher levels.
Rapid laying by Brown‐headed CowbirdsMolothrus aterand other parasitic birds
Authors: SEALY SPENCER G. , NEUDORF DIANE L. , HILL DOROTHY P.
Published: April 2008

We compared the length of time parasitic and nonparasitic female birds spent on nests while laying eggs (laying bouts) to evaluate the hypothesis that rapid laving by parasitic Brown‐headed CowbirdsMolothrus aterand other parasitic birds is a specialization for brood parasitism. Brown‐headed Cowbirds typically spent less than 1 min on host nests while laying (41.0 ± 4.58 [mean ± s.e.] s,n =21). In contrast, mean laving bouts of six nonparasitic icterine species ranged from 21.5 min to 53.4 min, and laying bouts of 13 other passerine species ranged from 20.7 min to 103.7 min. By spending only a few seconds on the nest while laying, brood parasites probably increase their chances of parasitizing nests unnoticed by hosts or, if noticed, are harassed by hosts for less time. Rapid laying may be adaptive if aggression by hosts can thwart attempted parasitism by chasing away the parasite, preventing the parasite from entering the nest or injuring the parasite. Rapid laying may increase the likelihood that the parasitic egg will be accepted. We tested some of these hypotheses by recording the responses of three frequently parasitized species to a stuffed female cowbird placed on their nests for 1 min. All species attacked the model vigorously; however, the mean time for discovery of the model ranged from 3 min to 17 min, ample time for female cowbirds to parasitize the nests. We concluded that rapid laying by parasitic birds is an adaptation for parasitism and, in Brown‐headed Cowbirds, reduces the chances that the parasite will be attacked by hosts.
Breeding success of ducks in relation to different habitat factors
Authors: NUMMI PETRI , POYSA HANNU
Published: April 2008

Breeding success of four duck species, Teal Anas crecca, Mallard Anas platyrhynchos, Wigeon Anas penelope and Goldeneye Bucephala clangula, was studied in a boreal watershed in southern Finland during 1988–1991 in relation to habitat type (based on vegetation development) and food abundance. Of the three common breeders, breeding success (broods/ pair) was highest in Teal (1.7) and lower in Mallard (1.4) and Goldeneye (1.2). Over the years, Goldeneye brood densities were less variable than were pair densities, so breeding success varied more among years that did that of Mallard or Teal. In Teal, the yearly numbers of pairs and broods fluctuated together, whereas in Mallard neither varied appreciably. Breeding success by Goldeneye was higher where nektonic invertebrates were more abundant, whereas breeding success of the dabbling ducks had very few significant correlations with environmental factors.
Relationship between west African rainfall and the survival of central European Sand Martins Riparia riparia
Authors: SZEP TIBOR
Published: April 2008

The aim of this study was to investigate the effects of Sahelian rainfall on the central European Sand Martin Riparia riparia population for the period 1986–1992. The studied population breeds along the River Tisza in Hungary and is one of the largest in central Europe. The changes in the population size did not show a significant relationship to Sahelian rainfall, but a large decrease in 1991 coincided with the drought in three Sahelian areas. The survival rates of adults had a significant relationship to the rainfall of the southern Sahel but not to the other two studied areas (northern Sahel, central Sudan). The model selection included this relationship and raised the possibility of predicting the adult survival rate in autumn for the following wintering season, using African rainfall data. The analysis showed a significant difference in the survival rates between the sexes, with that of the female being lower. Differences in the changes of the population size and adult survival rate showed the importance of the recruitment of adults, and this may depend mainly on the survival of juveniles.
Basal metabolic rates of North Atlantic seabirds
Authors: BRYANT D. M. , FURNESS R. W.
Published: April 2008

Basal metabolic rates (BMR) were measured for 11 species of North Atlantic seabirds, ranging in size from the Kittiwake Rissa tridactyla to the Gannet Sula bassana. BMRs for all species were higher than those predicted from the allometric equations of Lasiewski and Dawson (1967), Aschoff and Pohl (1970) and Ellis (1984). The equations of Ellis (1984), incorporating a latitude correction, and of Bennett and Harvey (1987), involving deviations by seabird families from a general avian trend line, gave predictions for BMR which were closer to, but respectively lower and higher than, those observed in this study. BMR for seabirds in Scotland (55–60oN) is described by the equation: BMR (kj/d) = 2.30W0774. The principal sources of variability in BMR amongst seabirds and the selective forces shaping the differences between seabirds and most other birds with lower BMRs remain unclear but deserve further study.
Do White Pelicans Pelecanus onocrotalus benefit from foraging in flocks using synchronous feeding?
Authors: SAINO NICOLA , FASOLA MAURO , WAIYAKP EDWARD
Published: April 2008

White Pelicans Pelecanus onocrotalus foraging at Lake Nakuru, Kenya, spent most of their time in flocks of two to several tens of individuals, and most flocks adopted a synchronized fishing behaviour. However, the maximum capture rate when feeding was attained by solitary individuals, and it decreased non‐linearly as flock size increased. Individuals in non‐synchronized flocks had a higher capture rate than those in synchronized flocks of the same size. The total number of bill probes decreased with the size of synchronized flocks, but this reduction in foraging costs did not compensate for the decrease in capture rate, since the ratio of successful probes to total probes did not increase with flock size. We discuss some hypotheses that might explain the paradoxical result that most White Pelicans aggregate into flocks and synchronize their behaviour and yet they attain a lower capture rate than those foraging alone.
Relationship between breeding and wintering ranges in Palaearctic‐African migrants
Authors: NEWTON I.
Published: April 2008

During the northern winter, Palaearctic migrant species are not evenly distributed within sub‐Saharan Africa. Species numbers are greatest in a belt of savannah, lying south of the Sahara, and decline southwards. For any one latitude, species numbers are also greater in the east of Africa than in the west. Only about 3% of 187 species winter exclusively south of the equator, but other species migrate from north to south during the course of the northern winter.

For 62 Palaearctic species which winter entirely in Africa, the areas of breeding and wintering ranges are strongly correlated. With some exceptions, species with the largest breeding ranges also have the largest wintering ranges. However, in 69% of species, the breeding range is larger than the wintering range, whereas in 31% of species the wintering range is larger. On average, the wintering ranges of 57 landbird species cover about two‐thirds the area of their breeding ranges, and in many species only parts of the wintering range may be occupied at any one time. This implies that the per area carrying capacity of African wintering areas is greater than that of Eurasian breeding areas.

The general correlation between the sizes of breeding and wintering ranges may have its basis in ecology, with generalists able to occupy wider areas than specialists in both breeding and winter quarters. At the same time, the correlation may result partly from an effect of numbers on range size, in that species which have a wide range at one time of the year may then achieve large numbers which occupy a wide range at the other time of year.
A new species of Phylloscopus warbler from Sichuan Province, China
Authors: ALSTRÖM PER , OLSSON URBAN
Published: April 2008

A new species of leaf warbler (Sylviidae: Phylloscopus) is described from the mountain Emei Shan, Sichuan Province, China. Morphologically it is extremely similar to, yet significantly different from, the sympatric Blyth's Leaf Warbler Phylloscopus reguloides and White‐tailed Leaf Warbler Phylloscopus davisoni. Songs and calls are both very different from P. reguloides and P. davisoni, and playback tests confirmed the specific status of the new species.
Production and costs of nesting attempts in Snow Buntings Plectrophenax nivalis: why do they attempt second broods?
Authors: SMITH R. D. , MARQUISS M.
Published: April 2008

During 1988–1993, pairs of Snow Buntings Plectrophenax nivalis on our study sites in northeast Scotland reared an average of 1.2 broods. Clutch sizes of first and second broods were similar, but partial losses were greater in second broods, leading to a difference of at least 40% in overall nest productivity between successful first and second broods. Over and above this, total nest failure was four times higher in the second broods, and autumn sightings of ringed nestlings from second broods were only a third of those of first‐brood nestlings. As a result, second broods produced a mere 10% of future recruits to the breeding population. However, there was also little evidence of costs associated with producing, or attempting to produce, second broods. Young from first broods were not less likely to reach independence if a second brood was attempted, between‐year return rates of double‐brooded adults were similar to those of single‐brooded birds and double‐brooded adults did not appear to be less fecund in the following summer. Therefore low costs to the adults of attempting second broods may allow the continuation of a strategy which appears to have only a marginal influence on overall reproductive success in the area studied.
Prey abundance and male parental behaviour in Acrocephalus warblers
Authors: HOP HERBERT , KLEINDORFER SONIA , ILLE ROTRAUT , DITTAMI JOHN
Published: April 2008

This study examined the prey abundance at nesting sites of five different Acrocephalus warbler species. Intraspecific variations in prey density were analysed to determine the relative significance of this ecological factor for different mating systems and components of male parental behaviour. The Great Reed Warbler Acrocephalus arundinaceus, a facultatively polygynous species, nested in areas with the highest insect abundance. Its intraspecific variation in prey density (between different territories) was the highest while the male: female offspring feeding ratio was the lowest. At the other extreme, the monogamous Moustached Warbler Acrocephalus melanopogon and Reed Warbler Acrocephalus scirpaceus nested in areas with the lowest prey abundance and lowest intraspecific variation. Males of these species had the highest involvement in feeding young. In the Moustached Warbler and Marsh Warbler Acrocephalus palustris, an intraspecific comparison revealed a negative correlation between insect abundance and the male feeding component; a tendency in this direction was found for the Reed Warbler, while no correlation was evident in the polygynous Great Reed Warbler. These data demonstrate a general pattern relating prey abundance, mating systems and male parental investment on an interspecific level. However, intraspecific correlations revealed a net of complex interdependence. One of the factors which may be important is resource predictability. We found a significant correlation between certain vegetation types and insect abundance. The vegetation composition of territories is further influenced by interspecific dominance relationships whereby the dominant Great Reed Warbler occupies territories with the vegetation type which correlates with high prey abundance while the overlapping Moustached Warbler and Reed Warbler are restricted to areas with lower insect density.
Body size establishes the scaling of avian postnatal metabolic rate: an interspecific analysis using phylogenetically independent contrasts
Authors: WEATHERS WESLEY W. , SIEGEL RODNEY B.
Published: April 2008

The avian postnatal metabolic rate literature is reviewed using power equations,Y = aMb,to describe the relation between postnatal resting metabolic rate (RMR) and chick body mass (M) for 25 species. In altricial species, the relation between RMR andMfrom hatching to fledging can be described by a single power equation, whereas in most nonaltricial species two such equations are needed, one for chicks weighing less than about 25% of mature mass (Ma) and a second for larger chicks. For altricial chicks and larger nonaltricial chicks, the body‐mass exponent,b,of 25 intraspecific power equations ranged from 0.25 to 1.67 and varied inversely withMa. The scaling of postnatal RMR is thus unlike that of either adult or hatchling metabolism in that it is size dependent. We examined the relationship between intraspecificbandMausing Felsenstein's independent contrasts method to control for statistical complications due to the hierarchical nature of phylogenetic relationships. This “phylogenetic regression” technique yielded the relationb= 1.6Ma‐015, in which mature mass explained 38% of the variation inb.The mass exponent of this equation (‐0.15) did not differ significantly from that determined by nonphylogenetic methods (‐0.17).

In altricial chicks and larger nonaltricial chicks, the scaling coefficient,a,of the interspecific power equations varied with adult mass according to the phylogenetically determined relationa(kj/h) = 0.0052Ma0.65and was higher in fed than in fasted chicks. Equations derived in this analysis permit one to estimate the RMR of a growing chick from its mass and adult body mass and provide a basis for evolutionary and ecological comparisons.
Re‐mating between and within breeding seasons in the Greater Flamingo Phoenicopterus ruber roseus
Authors: CEZILLY FRANK , JOHNSON ALAN R.
Published: April 2008

Data on re‐mating between and within breeding seasons were collected between 1983 and 1994 as part of a long‐term study of the Greater Flamingo Phoenicopterus ruber roseus in the Camargue, southern France. Flamingos have bred in the Rhône delta for centuries and since 1972 have done so annually on an artificial island in the Etang du Fangassier. A sample of chicks has been ringed each year since 1977; many of these birds were later observed back at the breeding site and were used in this study. The mate‐switching rate between consecutive breeding seasons was 98.3%. This result is contrary to what has been reported from captive flocks where extensive mate fidelity occurred between consecutive breeding seasons. Mate‐switching also was observed in the Camargue within breeding seasons, following breeding failure, and seems to be linked to male breeding strategy in response to the need to synchronize hatching and the limited energy supply of breeding females. The absence of a long‐term pair bond in Greater Flamingos contrasts with current views on the evolution of mate fidelity in relation to longevity in birds.
Effects of a trawling moratorium on the breeding success of the Yellow‐legged Gull Larus cachinnans
Authors: ORO DANIEL , BOSCH MARC , RUIZ XAVIER
Published: April 2008

The establishment of a two month commercial fishing moratorium, which overlapped each year with different stages of the breeding cycle of the Yellow‐legged Gull Larus cachinnans at the Ebro Delta, Spain, provided the opportunity of testing the effects of food limitation on the breeding success of this species. The study was carried out in 1993, when the chick rearing stage occurred with normal commercial fishing activity and in 1994, when the chick rearing stage overlapped with the trawling moratorium. We recorded diet of the chicks, breeding phenology, clutch size, egg volume, hatching success and productivity of adult birds. There was a highly significant difference in the diet of the chicks between the two years and significantly lower productivity in 1994, whilst the other parameters examined did not change. These results show that a dependence on discards from commercial fishing activities may be a limiting factor in the breeding success of this seabird.
Trade‐offs in nest site selection in coastal populations of Lapwings Vanellus vanellus
Authors: BLOMQVIST DONALD , JOHANSSON OLOF C.
Published: April 2008

In coastal populations of Lapwings Vanellus vanellus in southwestern Sweden, arable fields predominated as foraging habitat before laying. Females caught more large prey items on arable fields and shores than on pastures. Close to egg laying, females foraged mainly near their future nest sites. Arable land and pastures were used to a similar extent for nesting. We found no difference in nest predation between habitats. Egg volume varied among females and was correlated with wing‐length, body mass and condition. Mean egg volume also was positively correlated with feeding time on arable land before laying. Pairs nesting on arable fields therefore generally produced larger eggs than those on pastures. The distances between nests and chick foraging areas, however, were significantly longer for birds nesting on arable land than for those on pastures. Moreover, in 2 of 3 years, the proportion of hatched chicks that survived until fledging was negatively correlated with this distance. There was no difference in chick survival between broods hatched on arable fields and pastures. We suggest that nest site selection and offspring production involve a trade‐off between the benefits of nesting close to rich feeding grounds for adults and the costs of moving long distances between nest sites and chick‐rearing areas.
Plumage development and moult in the European Quail Coturnix c. coturnix: criteria for age determination
Authors: JALME M. SAINT , GUYOMARC'H J. C.
Published: April 2008

Sequence, rate and duration of moult were studied in captive bred European Quail Coturnix coturnix coturnix. The founder population originated from southwest France. The study was conducted between 1986 and 1989 on birds aged from 1 day to 2 years, exposed to a seasonal photoperiod corresponding to latitude 16°N during autumn and winter and latitude 48°N during the remainder of the year. Under these conditions, adult quail showed two annual moults with only the post‐breeding one being complete. The pre‐breeding moult essentially involved the throat feathers. Large interindividual variation was observed in the duration, timing and development of the post‐breeding moult: 60% of the studied birds suspended moult when they developed migratory restlessness and then finished renewing their feathers during the winter. The post‐juvenile moult was also suspended when 7–9 weeks old (3–6 primaries and 1–10 secondaries renewed). After this suspension, the length of which was related to the hatching date, the moult continued up to p7. The three outer primaries were kept for the first year and were replaced only during the post‐breeding moult. Based on the examination of wing patterns, our study provides reliable criteria for discriminating between age classes. The numbers of primaries and secondaries simultaneously in growth or renewed were different between the age classes. The secondaries of adults were renewed later in the moult stage than were the secondaries of juveniles. These criteria provide field researchers with a guide that enables them to age quail with reasonable accuracy.
A new species of nightjar from Ethiopia
Authors: SAFFORD R. J. , ASH J. S. , DUCKWORTH J. W. , TELFER M. G. , ZEWDIE C.
Published: April 2008

A new species of nightjar is described from a single wing salvaged from a road corpse in 1992 on the Nechisar Plains, Ethiopia. The species is unknown in life. The wing is highly distinctive, particularly because of the unusual position of the white patch on the primaries. Suggestions as to its nearest relatives must await description of an entire individual.
History of Shiny Cowbird Molothrus bonariensis brood parasitism in Trinidad and Tobago
Authors: CRUZ ALEXANDER , MANOLIS TIMOTHY H. , ANDREWS ROBERT W.
Published: April 2008

In attempting to evaluate the evolutionary stability of the reproductive strategies of an avian brood parasite, it is important to know whether or not the observed levels of parasitism on host species have changed through time and whether or not new host species are being used in the region under study. In this regard, the islands of Trinidad and Tobago provide an excellent opportunity because they are ornithologically well known and the expansion of the parasitic Shiny Cowbird Molothrus bonariensis into the West Indian region is thought to have originated from Trinidad and Tobago. On the whole, host choice has remained remarkably stable over the past 50–60 years. The three hosts (House Wren Troglodytes aedon, Red‐breasted Blackbird Leistes militaris and Yellow‐hooded Blackbird Agelaius icterocephalus) known to be heavily parasitized historically remain heavily parasitized today. Only one instance of parasitism of a new host (Tropical Kingbird Tyrannus melancholicus) is recorded. In the case of one intensively studied host, the Yellow‐hooded Blackbird, cowbird parasitism had a minimal negative effect on the host's reproductive success. Reproductive equilibrium in this study seemed to be maintained by behavioural adaptations of host and parasite to each other. The stable pattern of host choice by Shiny Cowbirds in Trinidad and Tobago may not develop elsewhere in the West Indian region. Before the cowbird's expansion in the West Indies, potential hosts had no prior experience of brood parasites. Consequently, the island bird populations are unlikely to have evolved defensive strategies and thus may be more vulnerable to reproductive failure as a result of cowbird parasitism, precluding the development of a stable system at this point in time.
Changes in the muscle condition of female Zebra Finches Poephila guttata during egg laying and the role of protein storage in bird skeletal muscle
Authors: HOUSTON DAVID C. , DONNAN DAVID , JONES PETER , HAMILTON IAN , OSBORNE DAN
Published: April 2008

Samples of pectoral muscle tissue from Zebra Finches Poephila guttata were taken from birds at various stages of egg laying. As egg laying progressed, there was a significant loss of both water‐soluble and alkali‐soluble proteins. Gel filtration of the water‐soluble proteins showed three peaks, only one of which changed significantly during the laving cycle. This was a high‐molecular‐weight protein that declined in concentration during the period of egg laying. This protein may function as a reserve, enabling female birds to provide amino acids for egg protein production from their muscle tissue without impairing normal muscle function.
Differences in reproductive success and parental qualities between habitats in the Great Tit Parus major
Authors: RIDDINGTON R. , GOSLER A. G.
Published: April 2008

Reproductive success and parental attributes of Great Tits Parus major nesting in good and poor habitats were compared to investigate whether they differed and, if so, whether parental or environmental variation contributed most to the differences.

Monitored over 3 years, clutches in mature woodland were started earlier, were larger and produced larger broods of heavier chicks than those in marginal habitats such as gardens and hedgerows. Fledging success was significantly higher in woodland in 2 of the 3 years although egg weights were lower. Parents nesting in different habitats were very similar in body‐size although those in woodland were in better condition. The prey delivered to nestlings in woodland was of significantly higher quality than that delivered in marginal habitats. Furthermore, the heritability of body‐size (tarsus‐length) was higher in woodland, suggesting that the environment limits nestling growth in poorer habitats. Reproductive success was considerably lower in poor habitats and appears to be constrained primarily by environmental quality, although this may operate partly through its affect on parental body condition.
Measurement and mapping of avian diversity in southern Africa: implications for conservation planning
Authors: HARRISON JAMES A. , MARTINEZ PETER
Published: April 2008

The potential and problems of using species diversity information, derived from the Southern African Bird Atlas Project (SABAP), are examined. Atlas data were analysed and the problem of uneven sampling effort was ameliorated through an application of an index of diversity. Maps of diversity for various suites of species are considered in relation to their implications for conservation planning. An approach to the identification of high‐priority areas for conservation, based on an index of diversity, is described and called the Compatible Sets Approach. Birds in the grassland biome are used to illustrate the principles of the approach.
A method of assessing seabird vulnerability to surface pollutants
Authors: WILLIAMS J. M. , TASKER M. L. , CARTER I. C. , WEBB A.
Published: April 2008

Substantial information on the offshore distribution of seabirds exists for the North Sea and nearby areas. This information is extensive but is not easily applicable to management problems, such as oil pollution incidents. A quantitative oil vulnerability index has been developed, based on four easily scored factors, to assess the vulnerability of seabird species to surface pollution. The index has been applied to calculate area vulnerability scores for 15′ latitude x 30′ longitude rectangles in the North Sea by combining the species vulnerability scores with information on seabird densities. Maps of vulnerable concentrations of seabirds for each month of the year have been published with interpretative text. These maps can be used as a management tool, for example, in assessing potential risk or in the event of an oil pollution incident.
Action Plans for United Kingdom and European rare, threatened and internationally important birds
Authors: WILLIAMS GWYN , HOLMES JOHN , KIRBY JEFF
Published: April 2008

Action Plans provide an invaluable mechanism for translating scientific knowledge into conservation action. By assisting the effective targeting of the resources available to the conservation movement towards the most urgent priorities, the adoption of this approach should result in more effective attainment of conservation goals. This paper describes the approach adopted by the Joint Nature Conservation Committee, The Royal Society for the Protection of Birds and The Wildfowl & Wetlands Trust in the production of Species Action Plans for birds on the United Kingdom's Red Data List.
Diagnosing causes of bird population declines
Authors: GREEN R. E.
Published: April 2008

The value to bird conservation of determining the causes of population declines is considered and the diagnostic methods available are reviewed, with examples. Diagnosis of the cause or causes of a decline in bird numbers is likely to be helpful in deciding the priority of conservation actions, though actions which aim to reverse the changes in external conditions which caused the decline need not be the most effective in initiating recovery.

The methods for diagnosing causes of declines in bird numbers with the widest application make use of comparisons between geographical areas or time periods with different trends. Correlations between trends in numbers and measurements of external factors are examined across areas or periods or both. The danger of spurious correlations is minimized by drawing up a list of plausible causes based on studies of the natural history of the species. The effects of all of these candidates should be examined, subject to availability of data. The consistency of observed changes over time, or differences among areas, in survival rate or breeding success with the postulated demographic mechanism of the decline should be examined.

Conclusions based on correlations across geographical areas between trends in numbers and external factors may be misleading if birds are able to move between the areas selected for comparison and if their pattern of settlement depends upon external factors thought to be implicated in the decline.

Manipulative experiments should be carried out to test conclusions drawn from correlative studies. However, it must be recognized that the capacity of birds to move between areas means that experiments may measure effects of manipulations on settlement patterns or distribution rather than population size. Experiments that appear well designed in terms of controls and replication may be misleading when applied to the conservation of bird populations if their geographical scale is inappropriate.
Habitat fragmentation: island v landscape perspectives on bird conservation
Authors: WIENS JOHN A.
Published: April 2008

Fragments of habitat are often viewed as islands and are managed as such; however, habitat fragmentation includes a wide range of spatial patterns of environments that may occur on many spatial scales. Fragments exist in a complex landscape mosaic, and dynamics within a fragment are affected by external factors that vary as the mosaic structure changes. The simple analogy of fragments to islands, therefore, is unsatisfactory. Understanding how birds respond to these complexities of fragmentation requires mechanistic studies focused on habitat selection and movement behaviour. Conservation efforts must be based on viewing fragmentation as a range of conditions that occurs in a landscape mosaic, and management should be directed toward the mosaics rather than focusing solely on reserves.
Eggs, egg formation and the timing of breeding
Authors: PERRINS C. M.
Published: April 2008

The eggs of birds contain all the nutrients necessary for the developing embryo. The female has to obtain these nutrients, and while in some species these may be gathered and stored over a period of time, in many species they seem to be obtained on a daily basis. Obtaining the calcium necessary for the eggshell may pose special problems for some species, which may have to give up valuable feeding time in order to search for calcium.

Egg size varies considerably, even within species, and the reasons for this are not clear. In the Great TitPants major,large eggs produce nestlings which have a higher chance of hatching, surviving to fledging and surviving after fledging. However, large eggs require the female to acquire more nutrients to form them, and large chicks may sometimes be at a disadvantage. The amount of energy required to form a larger egg often seems small unless the metabolic costs of egg formation are taken into account.
Three fundamental contributions of molecular genetics to avian ecology and evolution
Authors: AVISE JOHN C.
Published: April 2008

Studies in molecular genetics are having revisionary impact in at least three broad areas of avian ecology and evolution: mating systems, geographic population structure and gene flow, and phylogenetic relationships among species and higher taxa. With regard to mating systems, genetic analyses of maternity and paternity have revealed unexpectedly high frequencies of extra‐pair fertilization and intraspecific brood parasitism in numerous avian species (including those thought to be socially monogamous), and these discoveries are prompting a fundamental reshaping of mating system theory for birds. With regard to genetic structure, molecular markers have uncovered a great variety of depths and patterns in the phylogeographic histories of conspecific populations, and these findings provide novel perspectives on historical gene flow regimes and species concepts. With regard to evolutionary relationships among higher avian taxa, molecular findings have suggested several phylogenetic realignments, thus prompting renewed interest in the cross‐comparative aspects of molecular and morphological evolution as well as of alternative procedures for molecular analysis.
Interspecific kleptoparasitism in Audouin's Gull Lams audouinii at the Ebro Delta, northeast Spain: a behavioural response to low food availability
Authors: ORO DANIEL
Published: April 2008

Kleptoparasitism of Audouin's Gull Lams audouinii on other seabirds, a foraging behaviour previously unrecorded for the species, was studied in the Ebro Delta, northeast Spain, during 1992. The relationship between kleptoparasitism and trawler activity was assessed through changes in the availability offish discards brought about by a trawling moratorium. When trawlers are not active, Audouin's Gulls use different feeding strategies, such as interspecific kleptoparasitism. Audoin's Gulls appeared to prefer to kleptoparasitize terns rather than gulls, but the success rate on gulls was higher. Most of the attacks rather than gulls, but the success rate on gulls was higher. Most of the attacks were performed by single Audouin's Gulls, although success per attack improved with group size. During the trawling moratorium, the existence of large seabird colonies in the Ebro Delta acted as a buffer for Audouin's Gull through kleptoparasitism, compensating partly for the reduced food supply.
Winter survival and breeding success of dominant and subordinate Willow Tits Parus montanus
Authors: Koivula Kari , Orell Markku , Rytkönen Seppo
Published: April 2008

We studied the effect of winter rank on survival rate and reproductive success in Willow Tits Parus montanus, a resident passerine living in dominance‐structured flocks during the nonbreeding season, in 6 years. Winter survival was dependent on both the birds' age and rank. Adults survived better than first‐year birds, and within first‐year males, dominants survived better than subordinates. In other sex and age classes, rank did not contribute to survival. Although first‐year males were in excess among nonbreeders, no connection existed between breeding status and rank. Female rank did not explain the variation in the start of laying, clutch size, number of fledglings or recruit production. We conclude that social status in Willow Tits affects individual fitness mainly through rank‐dependent survival. Acquiring a high rank position seems to be most important for first‐year birds, especially first‐year males.
Food availability and the male's role in parental care in double‐brooded Treecreepers Certhia familiaris
Authors: Kuitunen Markku , Jäntti Ari , Suhonen Jukka , Aho Teija
Published: April 2008

The aim of this work was to examine differences in paternal and maternal care in a double‐brooded, monogamous species, the Treecreeper Certhia familiaris, in relation to food availability. As a measure of parental care, we recorded the hourly feeding activity of parents when the nestlings from their first and second breeding attempts were 7 and 12 days old. Feeding frequency of the first brood increased with the age of the nestlings and also with the brood size when 12 days old. While the feeding activities of the females were similar with respect to the first and second broods, the males were less active and failed to provide any food to their nestlings in 15 cases out of 28 second broods. In spite of this, the fledglings from the second broods were heavier than those in the first. Such a pattern of male behaviour was possible without being a disadvantage to the chicks because the food supply increased during the breeding season and the female could provide food for the young alone. Thus paternal care was particularly important in times of poor food supply, i.e. during the first brood, where the extent of these males' activity in feeding the 7‐day‐old nestlings was positively correlated with the average mass of the nestlings. Our results support the idea that the male of monogamous, altricial bird species often makes important contributions to raising the young, especially during periods when it is difficult for the female to do so alone. Males show flexibility in their pattern of parental care, and male Treecreepers change their contribution to the first and second broods within the same season.