Intermittent breeding in the Herring Gull Larus argentatus and the Lesser Black-backed Gull Larus fuscus

Thirty-three percent and 37% of adult Herring Gulls Larus argentatus and 34% and 40% of adult Lesser Black-backed Gulls Larus fuscus , all with some previous breeding experience, failed to breed in 1993 and 1994, respectively. About half of these intermittent breeders of both species failed to breed in both years. Common amongst the intermittent breeders were smaller individuals, birds with low survival chances and relatively unsuccessful breeders.     

Genetic Affinities Within the Herring Gull Larus argentatus Assemblage Revealed by AFLP Genotyping

To date, the taxonomic status of circumpolar breeding populations of the Herring Gull Larus argentatus, the Lesser Black-backed Gull Larus fuscus, and the closely related Yellow-legged Gull Larus cachinnans has been based on differences or similarities in phenotype, morphology, and feeding and premating behavior. To shed some new light on the many taxonomic uncertainties surrounding these taxa, we describe the results of a large DNA study based on comparing the distribution of 209 biallelic markers among 109 gulls, representing 11 gull taxa of the Herring Gull assemblage and the Common Gull Larus canus. A detailed phylogenetic analysis failed to show clustering of individuals into groups representing either geographic origin or phenotype. Alternatively, birds were grouped into taxa defined on the basis of phenotype and geographic origin or phenotype alone. Genetic analyses revealed significantly different genetic distances between all pairs of taxa. However, based on these genetic distances, again no consistent phylogenetic tree could be constructed. Analysis of molecular variance indicated that about 77% of the total genetic variability among these gulls could be explained by within-taxon differences. Only 23% of the total genetic variability was due to genetic differences between taxa, irrespective of their species or subspecies status. Although this seems to challenge the current taxonomic treatment of the herring gull assemblage, our results are too premature and too incomplete to recommend a drastic change. Received: 27 January 2000 / Accepted: 18 September 2000     

Arterial system of the Herring gull (Larus argentatus)

Fourteen specimens of the Herring gull ( Larus argentatus ) were dissected and diagrams of the arterial system were prepared. Little individual variability in the larger arteries were noted; the origin, course, and number of smaller arteries, however, showed noticeable variation. In the neck and thorax region, the following arteries were relatively constant in origin and course: the common carotid, internal carotid, subclavian, sternoclavicular, ascending oesophageal, axillary, internal mammary (inner), pectoral, syringeobronchial, cervical cutaneous, comes nervi vagi, and subscapular artery. Individual variability was noted in the vertebral, accessory sternoclavicular, thyroid, and accessory oesophageal artery. In other regions of the body, as in the neck and thorax, the smaller arteries exhibited great individual variations. Additional studies are needed to clarify the phylogenetic significance of the vascular system in birds.     

Age Dynamics of Helminth Fauna of the Herring Gull (Larus argentatus) in Kola Bay,Barents Sea

Biology Bulletin - The influence of host age on the helminth fauna of the Herring Gull (Larus argentatus) captured in breeding colonies in Kola Bay in the Barents Sea was studied. The fauna of...     

A comparison of Herring Gull Larus argentatus and Lesser Black-backed Gull Larus fuscus nest sites: their characteristics and relationships with breeding success

Nest sites used by Herring Gulls and Lesser Black-backed Gulls in a mixed colony were compared. Correlations between features surrounding a nest and breeding success at different stages of the breeding cycle are presented. Lesser Black-backed Gulls nested on more vegetated and flatter areas than did Herring Gulls, even though the latter species had a lower hatching success at less vegetated sites. The difference in the general topography of nest sites between the species suggests that the Lesser Black-backed Gull, through an individual defence strategy, may be better adapted to use sites which are accessible to ground predators than the Herring Gull. The fledging success of Lesser Black-backed Gulls tended to increase with an increased proportion of relatively tall vegetation close to the nest. The Lesser Black-backed Gull may therefore be able to leave its young unattended and rely on their concealment for protection against predators. In contrast, the Herring Gull may rely more on parental vigilance to protect young. More frequent attendance by adult Herring Gulls at the nest site during chick rearing compared with Lesser Black-backed Gulls supports this hypothesis.     

Residues of DDE and PCB in Eggs from Herring Gull (Larus Argentatus) and Common Gull (Larus Canus) in Norway

In 1969 294 eggs from herring gull were collected from eight different localities in Norway. The eggshell thicknesses were measured, and 10 eggs from each locality were analysed by gas liquid chromatography for organochlorine insecticides and polychlorinated biphenyls (PGB). Residues of DDE were demonstrated in all eggs, the concentrations varying from 0.2 to 5.4 p.p.m. in herring gull, and from 0.2 to 3.5 p.p.m. in common gull. DDT occurred only in four eggs from herring gull and then only in concentrations of from 0.1 to 0.3 p.p.m. Other organochlorine insecticides were not detected. Residues of PGB were found in all eggs from herring gull in concentrations of from 0.2 to 3.8 p.p.m. PGB 10, and in six out of nine eggs from common gull, from trace to 0.8 p.p.m. PGB 10. The analysed material showed a positive correlation between amounts present of DDE and of PGB. There was a significant difference between localities concerning the contents of DDE and PGB in eggs from herring gull. This variance may be taken into consideration by using the herring gull as an indicator organism, since this bird, especially in the northern part of Norway, is migratory. The residue concentrations of DDE and PGB were markedly higher in eggs from herring gull than in eggs from common gull. It is suggested that this may be related to the difference between these species in their feeding habits. The residues of organochlorines demonstrated in this investigation do not seem to have had any effect on eggshell thickness in herring gull.     

Lithium Transport in the Kidney of the Herring Gull Larus argentatus: Induction of Renal Li+ Net Secretion by a Salt Loading

To find out whether salt loading can induce Li⁺ net secretion in the kidney of the birds that have an extrarenal organ (the salt gland) for excretion of NaCl excess (earlier, such effect was revealed in the pigeon and chicken, the birds that do not have the salt gland), the effect of intravenous NaCl injections (4–5 injections of 14–20 mmol/kg at 20–30-min intervals) on Li⁺ transport in the gull kidney was studied. Prior to the salt loading, above 99% of the filtered Li⁺ were reabsorbed in the kidney: fractional excretion of Li⁺ (FE_Li) was 0.0024 ± 0.0007 (mean ± SD), the Li⁺ reabsorption occurring not only in the proximal, but also in the distal tubule. Under conditions of the salt loading, two essentially different regimes of the kidney functioning were observed: net Li⁺ reabsorption (FE_Li = 0.63 ± 0.26) and net Li⁺ secretion (FE_Li = 1.26 ± 0.12). In the absence of the salt loading, Li⁺ (due to its distal reabsorption) does not fit requirements of an indicator of proximal reabsorption of Na⁺ and water. However, in the regimes of the salt net reabsorption and the salt net secretion, FE_Li probably can serve as an indicator of delivery of these substances to the end of the proximal tubule (the lithium clearance method). If this suggestion is correct, transition from the net Li⁺ reabsorption (FE_Li < 1) to its net secretion (FE_Li > 1) with rise of the salt loading indicates the appearance of net Na⁺ secretion in the proximal tubule under these conditions. A comparison of the results for the gull and the chicken has shown that although the presence of the salt gland did not prevent transition of the kidney to the net Li⁺ secretion, its duration in the gull was significantly shorter. The comparative data are presented on parameters of renal function in the regimes of net Li⁺ secretion and net Li⁺ reabsorption. In both regimes, a linear correlation was observed between FE_Li and FE_Na; however, regression coefficients considerably differed. An abrupt break of the curve occurred at FE_Li 1.     

Adoption of Strange Chicks by Herring Gulls,Larus argentatus L

Adoption of young by unrelated adults is expected to be rare in natural populations, yet a high incidence was observed in a population of Herring Gulls on the Isle of May, Scotland. The means whereby rejection was avoided, and the resulting costs and benefits to adopting parents and adopted chicks, are described.     

Nitrite poisoning in herring gulls (Larus argentatus) and ring-billed gulls (Larus delawarensis)

Landfill disposal of a fertilizer manufacturing waste product was associated with a die-off of gulls in New Hanover County, North Carolina. An estimated 250 herring and ring-billed gulls were found dead at the site following the initial disposal of this material. Chemical analyses revealed that the fertilizer waste contained predominately calcium (12.0 to 22.2%) and nitrite (3.0 to 15.2%). Contents of the proventriculi and gizzards of dead gulls also contained calcium (3.0 to 10.9%) and nitrite (1,730 ppm). Fertilizer waste administered orally to 16-day-old domestic turkeys resulted in acute, progressive signs of depression, respiratory distress, pallor, convulsions and death. The mean percentage methemoglobin in blood from convulsing turkeys (90.6) was significantly increased from that of normal control turkeys (3.6). The ante-mortem signs and increased blood methemoglobin concentrations in the experimental turkeys support the conclusion that the toxic principle in the fertilizer waste was nitrite, and that nitrite poisoning was the cause of the die-off of gulls.     

Skull deformity in a herring gull chick (Larus argentatus)

A skull deformity resulting in death of a herring gull chick (Larus argentatus) is described in detail. The bones of the skull and upper jaw were twisted, asymmetrical and of unusual size or absent. The lower jaw had an almost "spoon-like" external appearance and lacked normal articular surfaces.     

Difficulties in the ageing of the Herring Gull and Lesser Black-backed Gull

Annual Report Of The Edward Grey Institute

Report On The Nest Record Scheme, 1956, by J. F. Burton

Buzzard Survey, by N. W. Moore     

The blood vascular system in the head of the herring gull (Larus argentatus)

The structure and development of the blood vascular system in the head of the herring gull (Larus argentatus) have been studied using injection techniques and histological sections. Three different but interconnected divisions of the arterial system are recognized in the adult: the cerebral carotid artery system, the external ophthalmic artery system, and the external carotid artery system. Embryologically, the arterial system is characterized by changes in the relative development of these three divisions; the cerebral carotid system being the most prominent in the first half of the embryonic period. The venous system is divided into two parts, the rostral cephalic system and the caudal cephalic system, which drain separate regions of the head. The Rete ophthalmicum, which is an arteriovenous network associated with the external ophthalmic artery system, can be identified from the fifth day of incubation, and its development appears to be coupled with changes in the arterial supply to the eye. The possibility of a homology between the Rete ophthalmicum of birds and the Rete caroticum of mammals is briefly discussed.     

Hybridization of glaucous gull (Larus hyperboreus) and herring gull (Larus argentatus) in Iceland: mitochondrial and microsatellite data

Large white-headed gulls provide an interesting group of birds for studies of hybridization. The group is composed of 20 species of recent origin, often with weak reproductive barriers. Here we report the results from a study on the glaucous gull Larus hyperboreus, an Arctic species which has been breeding in Iceland for centuries, and the herring gull Larus argentatus which has a wide distribution in Europe but colonized Iceland in 1920s. Previous studies, based on morphological variation indicated hybridization between the two species in Iceland, have been questioned as it may just reflect variation within the species. Here we evaluate whether hybridization has occurred between the two species in Iceland by studying variation in microsatellites and mtDNA. The analysis is based on feathers taken from wings sampled in Iceland over a period of 40 years. The results are compared with samples obtained from East Greenland and published sequences of samples obtained throughout Europe. The genetic analysis reveals a distinctive grouping of the two species, although they present a shallow genealogy and an extensive sharing of the genetic variants between the two species. Several individuals show admixture for molecular markers, which may result from an incomplete lineage sorting although geographical patterns of both mtDNA haplotypes and microsatellites strongly indicate a recent hybridization in Iceland.     

Induced minisatellite germline mutations in herring gulls (Larus argentatus) living near steel mills

Despite widespread industrial release of genotoxic contaminants, little is understood of their role in inducing germline mutations in natural populations. We used multilocus DNA fingerprinting to quantify germline minisatellite mutations in families of herring gulls (Larus argentatus) in three nesting categories: (a) near cities with large steel mills operating coking ovens; (b) near cities without steel mills; and (c) in rural locations removed from point sources of contamination. Gulls nesting near integrated steel mills showed significantly higher mutation rates than gulls from rural locations (Fisher's exact, P=0.0004); urban sites without steel mills fell midway between steel and rural sites (difference from rural; Fisher's exact, P=0.19). Distance of the nesting location of herring gulls from the steel industries' coking ovens was negatively correlated with minisatellite mutation rate demonstrating significant risk for induced germline mutations in cities with steel operations (Kendall Tau; tau=0.119; P<0.0001).     

Weaning and Parent-Offspring Conflict in the Domestic Dog

Weaning and signs of a parent-offspring conflict were studied in four females of the Swedish Dachsbracken breed of domestic dog and their pups. The animals were observed from the second to the seventh week of age of the pups. In addition to regular weighing, measurements of milk and solid food intake per pup and meal were also made, and samples of milk from the mothers were collected and analysed. The most important mechanism for weaning seemed to be on the behavioural level. The time that the mother spent with her pups decreased continuously from week 2 to week 7, as did the number of sucklings per hour. Furthermore, both duration of suckling and the number of sucklings initiated by the mother decreased during the period, while the proportion of sucklings where the mother was standing increased steadily. The weights of mothers stayed rather constant during the period and there was no difference in the amount of milk given per suckling or in the composition of milk between the early and late weeks of lactation. Consequently, costs for the mother, in terms of loss of weight, were negligible as she was able to compensate for the increased energy demand of lactation with an increased food intake. There was a tendency for care-giving behaviour to decrease and aggression from the mother to increase at the same time as there was a tendency for care-seeking and contact-seeking behaviour from the pups to increase. These changes, together with the less frequent initiation of suckling by the mother, could perhaps be seen as signs of conflict. Conflict was defined according to TRIVERS' theory (1974) and referred to the disagreement between the female and her pups about the amount of care given. However, although the animals were kept in a way that allowed them to perform as much as possible of their natural behaviour, the good nutritional conditions, one of the characteristics of captive life, may have reduced overt parent-offspring conflict.     

Hematologic and hematochemical characteristics of the herring gull (Larus argentatus) and the buzzard (Buteo buteo)

Some hematological and hematochemical parameters in eight herring gulls (Larus argentatus) and in six buzzards (Buteo buteo) were checked. The buzzards were fed with ovine meat exclusively, while the herring gulls were fed with fish and ovine meat. Considerable differences between the two species were noted, particularly as far as the hematological and lipidic parameters are concerned. These differences are probably related to the aquatic life of the herring gull.