Showing papers in "Ringing and Migration in 1992"
TL;DR: A review of the use and effects of marks and devices on birds can be found in this paper, where the authors conclude that more attention should be given to these effects before the normal assumption of no influence on the biological parameters being studied can be made with confidence.
Abstract: This paper reviews the use and the effects of marks and devices on birds. Although most papers reporting research on birds make use of marks or devices, very few studies test for harmful effects or data biases caused by these. Many research projects have used marks and devices without encountering any harmful effects of these on the birds being studied. However, where assessments have been made it is clear that all of the methods of marking can have adverse effects, while most devices attached to birds do alter their behaviour to some extent. We conclude that more attention should be given to these effects before the normal assumption of no influence on the biological parameters being studied can be made with confidence. There is a need for careful tests of the effects of marking methods to be undertaken. We hope that this review will assist people studying birds to plan their use of marks and devices in such a way as to minimize problems caused by these research tools.
171 citations
TL;DR: The results indicate that several autumn migrating Garden Warblers and Blackcaps stopping over at Gotland have the energetic capability to almost cross continental Europe without refuelling.
Abstract: The migratory capacity of four Sylvia species was investigated during their initial phase of autumn migration in Sweden. Fat loads of individual birds were estimated by first determining approximately the fat‐free body masses for birds of different size (as judged from body mass ‐ fat index relationships). Individual fat loads varied considerably both inter‐ and intra‐specifically. The mean fat load (%fat mass of total body mass) of different species was: Lesser Whitethroat 9.3%, Whitethroat 7.2%, Garden Warbler 16.4% and Blackcap 13.2%. Comparatively low fat loads in the first two species may be because they probably commence their autumn migration in this area before the post‐juvenile moult is completed. Our results indicate that several autumn migrating Garden Warblers and Blackcaps stopping over at Gotland have the energetic capability to almost cross continental Europe without refuelling This contrasts with the Whitethroat and the Lesser Whitethroat of which many individuals would only be able to cro...
50 citations
TL;DR: In this article, capture-recapture data of 1985 Blackcap and 218 Robin migrants ringed during 6 winters were analyzed to describe the winter site fidelity and the year to year recurrence at Pilas, Seville, Spain.
Abstract: Capture‐recapture data of 1985 Blackcap and 218 Robin migrants ringed during 6 winters were analysed to describe the winter site fidelity and the year to year recurrence at Pilas, Seville, Spain. A higher percentage of Robins (31.6%) than Blackcaps (18.7%) were recaptured. Most of the recaptures were recorded within the same winter of ringing and especially within different months of the same winter. On average, a higher percentage of Robins (22.4%) than Blackcaps (11.3%) were retrapped within the same winter. These percentages varied significantly among years in Blackcaps but not in Robins. Although both species were ringed between the end of September and March, recaptures were only recorded between November and February which suggests that this is the real period of winter residency. The percentage of recoveries subsequent to the winter of ringing diminished with no statistical variation among species or periods. The longest period between the first and last capture was higher in Blackcaps (Syr) than i...
31 citations
TL;DR: In this paper, ring recovery data and observations of individually colour-ringed birds provided several lines of evidence suggesting that levels of immigration and emigration in the Great Skua population on Foula were very low.
Abstract: Ring recovery data were used to describe the dispersal of Great Skuas from Foula, Shetland, from 1963 to 1990. In general, the dispersal patterns and causes of recoveries had not changed since they were first described by Furness (1978) up to 1977. However, recoveries of 1–4year‐olds had increased since 1977 and recoveries of first‐year birds were greater after 1986 than for all previous years combined. Ring recovery data and observations of individually colour‐ringed birds provided several lines of evidence suggesting that levels of immigration and emigration in the Great Skua population on Foula were very low. Great Skuas also displayed a high degree of micro‐philopatry, generally choosing clubs and breeding sites within areas on the island from which they originated.
26 citations
TL;DR: The presence of simulated/feas around the entrance of a nestbox reduced the frequency of prospecting visits by birds.
Abstract: The presence of simulated/feas around the entrance of a nestbox reduced the frequency of prospecting visits by birds.
18 citations
TL;DR: An alternative method of age determination, based on wear and colouration of the longest tertial, inner secondary coverts and central tail feathers, is described and evaluated and shows significant increases in the extent of the white wing patch and in wing‐length when recaptured the following winter.
Abstract: Several recent publications have indicated difficulties in ageing Snow Buntings wintering in Scotland because two races occur and characteristics based on plumage show overlap between age, sex and racial categories. An alternative method of age determination, based on wear and colouration of the longest tertial, inner secondary coverts and central tail feathers, is described and evaluated. In support of the technique, birds aged as one‐year‐olds showed significant increases in the extent of the white wing‐patch and in wing‐length when recaptured the following winter, while those aged as adults did not.
15 citations
TL;DR: Observations of colour‐ringed Common Sandpipers show that both parents are usually present during the first week of the chick's life, but one parent, usually the female, has often left before the chicks fledge at around three weeks.
Abstract: Observations of colour‐ringed Common Sandpipers show that both parents are usually present during the first week of the chick's life, but one parent, usually the female, has often left before the chicks fledge at around three weeks.
13 citations
TL;DR: Biometrie data of Irish Dippers were investigated over two years, and fully grown and nestling birds were found to be sexually dimorphic for wing length, tarsus length and weight.
Abstract: Biometrie data of Irish Dippers were investigated over two years. Wing length, tarsus length and weight were measured from fully grown and nestling birds across a number of sites in southern Ireland. Fully grown birds were found to be sexually dimorphic for wing length, tarsus length and weight. The degree of sexual dimorphism was less than expected, females being larger than reported from most other studies. Weight varied little between seasons, and the annual pattern of weight change was less than that shown for other studies. Nestling growth rate was similar to that of Welsh Dippers. These results are discussed in the context of the ecological niche of the Irish Dipper.
13 citations
TL;DR: One‐year olds were found to be much less faithful to their birth place than older birds were to their breeding place and the same pattern was found for dispersal distances.
Abstract: An examination was made of 521 ringing recoveries of Whinchats. Site fidelity (birds returning to within 1 km of the ringing locality), territory fidelity (returning to within 150 m of the ringing locality) and dispersal distances were calculated for adult males and females and for one‐year old birds of both sexes. One‐year olds were found to be much less faithful to their birth place than older birds were to their breeding place. Territory fidelity is most pronounced in old males, followed by old females and finally by one year old birds, which returned to their natal area. The same pattern was found for dispersal distances.
12 citations
TL;DR: Postjuvenile moult in Azure‐winged Magpies Cyanopica cyanea cooki was studied in free‐living and captive birds, and factors influencing the extent, timing and duration of moult are discussed.
Abstract: Postjuvenile moult in Azure‐winged Magpies Cyanopica cyanea cooki was studied in free‐living and captive birds. Most natal primary (99.7%) and secondary (81.2%) feathers were retained, but only 50% of rectrices. Estimates of individual moult duration in free living birds in the following feather tracts gave: 65 days for tertials, 13 days for greater coverts, 97 days for rectrices, and 30 days for the alula. Wing coverts were the first to begin moult, followed by tertials. Alula feathers were the last to start moult. Tertial moult commenced at an average age of 97 days, regardless of hatching date. In captive birds, body moult was initiated in dorsal and upper tail coverts at the end of July and culminated in the interramal region by the end of November, with a mean moult duration of 122 days. Data on plumage growth and development are presented, and factors influencing the extent, timing and duration of moult are discussed.
12 citations
TL;DR: A population of Whitethroats, breeding on the Saltfleetby‐Theddlethorpe Dunes N.N.R. at high density, was studied during 1981–90 by means of mist‐netting and post‐juvenile moult commenced before completion of post‐natal growth, or very shortly afterwards, and took about 36 days.
Abstract: A population of Whitethroats, breeding on the Saltfleetby‐Theddlethorpe Dunes N.N.R. at high density, was studied during 1981–90 by means of mist‐netting. The first adults returned from Africa in late April, with the majority arriving during May. Males were trapped on average eight days earlier than females, and adults of known age were caught slightly earlier on their second or later return than on their first return. Breeding commenced shortly after arrival with peak egg‐laying in the second‐half of May, declining steadily to late July. Recently‐fledged juveniles were trapped from 10 June to 1 September, with a clear peak during 16–30 June. Post‐nuptial moult commenced from late June, with most adults starting in July or early August; moult completion occurred from mid August to late September. Post‐juvenile moult commenced before completion of post‐natal growth, or very shortly afterwards, and took about 36 days. Some late‐fledged juveniles may have moulted more rapidly, retaining a higher proportion o...
TL;DR: The growth rate measured here is probably close to the maximum achievable in this habitat and possibly limited only to fully‐grown juveniles.
Abstract: One hundred and six Little Tern chicks have been weighed and had their wing length measured in the colony at Gronant, Clwyd, Wales, in two different years. Forty of them were re‐measured on dates at least six days later and growth rates calculated. There were big differences in the weather in the two years of this study but no difference in growth rate. Chicks put on weight quickly and reached close to their full weight at an age of about 10 days. After an initial period of two or three days with little growth, wing length increased approximately linearly at a rate between 6.5 and 7.5 mm/day, with a mean of 6.8 ± 0.2 mm/day. Chicks could just fly at 14 or 15 days of age, with wing lengths of about 100 mm, some 70 mm shorter than the mean wing lengths of fully‐grown juveniles. They were fed on small fish, mainly sandeels and Whitebait’, and satiated chicks were frequently seen to refuse food. The growth rate measured here is probably close to the maximum achievable in this habitat and possibly limited only...
TL;DR: The natal dispersal and site fidelity in breeding Red‐throated Divers is described from retraps of ringed birds of known sex and males bred very closely to their natal site, whilst females dispersed widely.
Abstract: The natal dispersal and site fidelity in breeding Red‐throated Divers is described from retraps of ringed birds of known sex. Males bred very closely to their natal site, on average within 2.17 km, whilst females dispersed widely, on average 37.79 km. Oncea bird had bred on a loch it rarely changed site and then only over a short distance.
TL;DR: It is suggested that a pre‐breeding population of Lesser Whitethroats arrives each spring, comprising principally first‐year birds, probably returning to the general area of their birth and then selecting breeding sites for the coming season.
Abstract: Over a 20 year period the average annual return rate of adult Lesser Whitethroats was 23%. Recaptures of these birds at the site of ringing totalled 88%, which suggests a strong fidelity to breeding area. The number of birds breeding each year at the study site was mainly dependent on the return of previously ringed adult birds. When these did not return either breeding did not take place, or the population was very low. Juvenile birds commenced dispersal at the start of post‐juvenile moult and were more sedentary during mid‐moult. Migration appeared to commence as moult neared completion. Returns of juvenile birds in subsequent years was very low (0.8%), but the two birds that did return had been ringed in moult stage 2/3 and were probably not reared at the study site. It is suggested that a pre‐breeding population of Lesser Whitethroats arrives each spring, comprising principally first‐year birds, probably returning to the general area of their birth and then selecting breeding sites for the coming season.
TL;DR: Turnstone numbers on Sanday and North Ronaldsay, in the north-east of Orkney, increased considerably in late April and remained high well into May; large gains in mass were attained over this period and the proportion of adults caught was higher than that recorded on OrkNEY in winter as mentioned in this paper.
Abstract: Patterns of change in numbers and mass of Turnstones in two parts of Orkney during winter and spring were compared. On Mainland and South Ronaldsay, Turnstone numbers were generally stable during winter and then tended to decline in April, leaving few birds still present in May; prior to emigration an associated modest gain in mass occurred. In contrast, Turnstone numbers on Sanday and North Ronaldsay, in the north‐east of Orkney, increased considerably in late April and remained high well into May; large gains in mass were attained over this period and the proportion of adults caught was higher than that recorded on Orkney in winter. The possibility is discussed that Turnstones wintering on Mainland and South Ronaldsay migrate north in spring via staging posts in Iceland, whereas birds staging on Sanday and North Ronaldsay may fly directly to Greenlandic breeding grounds.
TL;DR: Based on a knowledge of the extent of juvenile autumn partial moult, it is found that the colouration of the primary coverts is the best ageing character using plumage, allowing the separation of young birds until their second autumn moult.
Abstract: This paper describes clear differences in the colouration of some feather groups in juvenile and adult Dartford Warblers. Based on a knowledge of the extent of juvenile autumn partial moult, it is found that the colouration of the primary coverts is the best ageing character using plumage, allowing the separation of young birds until their second autumn moult. In addition, age‐related variation in the iris and orbital‐ring colour is described, and was found to be a reliable ageing method at least until spring.
TL;DR: In this article, the authors examined 40 Common Sandpipers at a stopover site on a small island in the central Mediterranean during the spring migration and found that birds had very low mean body mass, indicating that they were probably at the end of one of the most arduos part of their journey.
Abstract: Forty two Common Sandpipers were examined at a stopover site on a small island in the central Mediterranean during the spring migration. Some details about the timing of passage and body conditions are given. Birds had very low mean body mass, indicating that they were probably at the end of one of the most arduos part of their journey, although none of them appeared exhausted. The absence of information about body mass at more southerly latitudes precludes assessment of the role of insular stopover sites in relation to the species’ overall migration strategy. A hopping strategy, at least during spring Mediterranean crossing, seems possible.
TL;DR: It is suggested that adult breeding mortality may be high, particularly in males, but that males may be better able to survive migration and overwintering.
Abstract: A total of 4654 Goldcrests was ringed at the Calf of Man Bird Observatory during 1989. This total consisted of 1344 ‘spring’ birds ringed between 17 March and 17 May, one odd bird on 15 June and 3309 ‘autumn’ migrants between 19 July and 7 November. The highest daily total was 728 on 17 March and the highest autumn daily total was 382 on 26 September. Among the spring migrants the overall sex ratio was very close to unity, but there was a higher proportion of males early on and later more females. In autumn the juvenile/immature females tended to migrate earlier than the juvenile/immature males, but there was not a similar difference between the sexes of the adult birds. Very few adults returned in autumn and of those that did few migrated early. In autumn, among both first year and adult birds, there were significant excesses of females. It is suggested that adult breeding mortality may be high, particularly in males, but that males may be better able to survive migration and overwintering. Marked hetero...
TL;DR: In this article, the authors made a detailed analysis of 246 ringing recoveries of Pied Wagtail nestlings found during their first autumn and winter and found that birds from south of 52° 00' started to move later, and even by 120 days, few had taken part in distant movements.
Abstract: Analysis was made of 246 ringing recoveries of Pied Wagtail nestlings found during their first autumn and winter. Some birds from north of 54° 00’ had moved up to 50 km by only 30 days after ringing. Birds from north of 52° 00’ made more distant movements but only after 90 days. Birds from south of 52° 00’ started to move later, and even by 120 days, few had taken part in distant movements. Southern fledglings dispersed widely and over a longer time period than birds from farther north. The latter dispersed randomly until about 90 – 108 days after ringing, beyond which their dispersal followed “preferred” orientations.
TL;DR: Yellowhammers caught in North Yorks and Cleveland were photographed concentrating on tail feathers, and a plumage feature on the outer tail feathers allowed 97% (n=100) of birds to be aged correctly.
Abstract: Yellowhammers caught in North Yorks and Cleveland were photographed concentrating on tail feathers. A plumage feature on the outer tail feathers allowed 97% (n=100) of birds to be aged correctly. During March 5% of birds were noted moulting some tail feathers.
TL;DR: An examination of 212 House Martins in SW Spain indicates that the majority are in active flight feather moult when departing on autumn migration, and appear to lack the ectoparasites that are associated with British HouseMartins.
Abstract: An examination of 212 House Martins in SW Spain indicates that the majority are in active flight feather moult when departing on autumn migration. They appear to lack the ectoparasites that are associated with British House Martins.
TL;DR: It is concluded that Bardsey frequently intercepts the passage of Greenland/Iceland Wheatears in spring, though the proportions from these two destinations is not yet known.
Abstract: An analysis is made of wing lengths and weights of 141 male and 127 female Wheatears caught on Bardsey in the springs of years 1970–1989. Birds were caught mainly at the lighthouse (63%) and in mistnets (28%). Wing lengths ranged 92–116 mm in males and 90–110 mm in females. Mean wing length (in both sexes) was longer in April and May than in March, and graphical separation of normal distributions indicated the presence of two subspecies ‐ 23% nominate oenanthe (males mean wing length 95.8 mm, females 92.9) and 77% leucorhoa (males mean wing length 105.1 mm, females 101.4). Weights ranged 21–46g in males and 19–44g in females. Time of day did not affect greatly the median weights, but medians for May were 8g higher (males) and 5g higher (females) than in March. It is concluded that Bardsey frequently intercepts the passage of Greenland/Iceland Wheatears in spring, though the proportions from these two destinations is not yet known.
TL;DR: Nest sites and nesting success of the Wren in farms of NE Spain were examined and some of the factors which may induce Wrens to seek the vicinity of man are discussed.
Abstract: Nest sites and nesting success of the Wren in farms of NE Spain were examined. Nests were found: inside human habitations in abandoned platforms of Swallows (41%); in bundles of rope, cloth or other soft materials (31%); and in cavities (28%). Nests occupied and not occupied by females did not differ significantly in relation to nest sites. The nesting success of 42 occupied nests was 93% with no predation. Some of the factors which may induce Wrens to seek the vicinity of man are discussed.