Sex- and age-related biometric variation of Black-headed Gulls<i>Larus ridibundus</i>in Western European populations

Palomares, Luis E.; Arroyo, Beatriz; Marchamalo, Javier; Sainz, J.J.; Voslamber, Berend

doi:10.1080/00063659709461066

Cited by 22 publications

(24 citation statements)

References 6 publications

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“…Rapid sexing of a bird would contribute to shortening handling time thereby allowing researchers to release birds quickly after a minimum of disturbance. Before applying this method to other populations or age classes, however, sexing accuracy requires further testing, especially since Laridae species show inter-colonial variation in external measurements (Threlfall & Jewer 1978;Jehl 1987;Evans et al 1993), as well as age related differences (Coulson et al 1981;Allaine & Lebreton 1990;Palomares et al 1997). The greater difference in size between the sexes found in the head region indicates that this region, especially the bill, may play an important role, probably in sexual display and territorial defence by males (Ingolfsson 1969).…”

Section: Discussionmentioning

confidence: 99%

“…Body mass was weighed to the nearest 0.1 g using an electrical balance. Several studies have found sexual dimorphism in body mass for Laridae species (Ingolfsson 1969;Ryder 1978;Threlfall & Jewer 1978;Hunt et al 1980;Fox et al 1981;Coulson et al 1983;Monaghan et al 1983;Bosch 1996;Rodriguez et al 1996;Palomares et al 1997 1994; Croxall 1995), sexual difference in body mass is not described here (Lorentsen & Røv 1994). Once these measurements were collected, birds were dissected and sexed based on their reproductive organs.…”

Section: Methodsmentioning

confidence: 99%

“…Finally, a discriminant function analysis was performed using HL and BD for sex determination of the gull, because these two measurements are readily taken during field studies (Fox et al 1981;Palomares et al 1997).…”

Section: Methodsmentioning

confidence: 99%

“…Visually assessing with certainty the sex of live seabirds, however, may be an impossible task when no obvious differences in plumage or body size exist between the two sexes. Several previous studies of Laridae species have shown that males are significantly larger than females (external measurements) and discriminant functions using measurements sex Laridae with great reliability (Shugart 1977;Ryder 1978;Fox et al 1981;Schnell et al 1985;Coulson et al 1983;Evans et al 1993;Bosch 1996;Rodriguez et al 1996;Palomares et al 1997).…”

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confidence: 99%

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Sexual differences in the external measurements of Black-tailed Gulls breeding on Rishiri Island, Japan

2002

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Sexual differences in the external measurements of Black-tailed Gulls breeding on Rishiri Island, Japan

2002

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“…However, the equation provided in this study included body mass, which exhibits substantial seasonal changes, varying greatly during migration (Zwarts et al, 1990;Meissner et al, 2011), moult (Zenatello et al, 2002;Fox and King, 2011), egg production, and incubation (Langseth et al, 2001;Jamieson, 2012), and which remains under the influence of weather conditions (Kelly et al, 2002;Robson and Barriocanal, 2008). This is why body mass is usually omitted in discriminant analyses when data outside the breeding season is taken into account (e.g., Palomares et al, 1997;Sikora and Dubiec, 2007;Jiménez et al, 2015). Hence, in this study, we propose a method for sexing Redshanks by linear measurements only, which may be applied not only in future research, but also to sex birds already measured in past studies.…”

Section: Introductionmentioning

confidence: 99%

Sexual size dimorphism and sex determination by external measurements in the Redshank Tringa totanus

Meissner¹,

Pinchuk²,

Karlionova³

et al. 2018

Turk J Zool

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The Redshank is a wader species that shows no sexual dimorphism in plumage, but some dimorphism in size. To propose a method for sexing birds of this species by linear measurements, a discriminant function analysis was applied to a set of morphometric traits in birds captured during the spring migration in southern Belarus. In total, 113 males and 75 females were measured and sexed molecularly. On average, females were larger in all measurements than males. The most sexually dimorphic trait was wing length, which was included in the discriminant function analysis. Jackknife cross-validation showed that the provided equation allowed the correct sexing of 67% of birds (81% of males and 52% of females). When identifying birds with this discriminant function, values lower than -0.96 indicated males, while those larger than 1.17 indicated females. This allowed the correct sexing of 95% of birds of each sex. The presented discriminant equation may be successfully used for sexing Redshanks when blood sampling is not possible, and could be applied to samples collected in the past, providing the opportunity to re-examine results of previous analyses.

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Intercolony variation in foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period

Jakubas

Indykiewicz

Kowalski³

et al. 2020

Ecology and Evolution

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Using GPS loggers, we examined the influence of colony, sex, and bird identity on foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period. We studied tracks of 36 individuals breeding in one urban and two rural colonies in Poland. Birds from both rural colonies performed the furthest flights (mean max distance 8–12 km, up to 27 km) foraging mainly in agricultural areas. Gulls from the urban colony performed shorter flights (mean 5 km, up to 17 km) visiting mainly urbanized areas and water bodies. We found that females performed longer flights and their flight parameters were less repeatable compared to males. Males from both rural colonies visited water bodies more frequently than females. In all colonies, males (but not females) used habitats unproportionally to their availability in the vicinity. Relatively low interindividual and relatively high intraindividual overlap in home ranges indicated considerable foraging site fidelity. Individuals specialized in the use of a particular type of habitat performed shorter foraging flights compared to individuals using diverse habitats during their foraging flights. Our results indicate diverse foraging strategies of black‐headed gulls, including generalists that explore various habitats and specialists characterized by high foraging site and habitat fidelity.

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Sex- and age-related biometric variation of Black-headed GullsLarus ridibundusin Western European populations

Cited by 22 publications

References 6 publications

Sexual differences in the external measurements of Black-tailed Gulls breeding on Rishiri Island, Japan

Sexual differences in the external measurements of Black-tailed Gulls breeding on Rishiri Island, Japan

Sexual size dimorphism and sex determination by external measurements in the Redshank Tringa totanus

Intercolony variation in foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period

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