Sex‐specific patterns in body condition and testosterone level changes in a territorial migratory bird: the Bluethroat <i>Luscinia svecica</i>

Geslin, Thomas; Chastel, Olivier; Eybert, Marie‐Christine

doi:10.1111/j.1474-919x.2004.00296.x

Cited by 17 publications

(8 citation statements)

References 72 publications

(101 reference statements)

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“…The significant negative correlation between urinary testosterone and body condition suggests that high levels of testosterone during breeding could lead to energy depletion in frogs thus contributing to a decrease in body condition. This negative correlation between testosterone and body condition has also been shown in some species of birds (Geslin et al, 2004).…”

Section: Discussionsupporting

confidence: 72%

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana)

Narayan¹,

Cockrem²,

Hero³

2013

Comparative Biochemistry and Physiology Part A: Molecular &

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Repeatability of physiological response variables, such as the stress hormone corticosterone, across numerous sampling occasions is an important assumption for their use as predictors of behaviour, reproduction and fitness in animals. Very few studies have actually tested this assumption in free-living animals under uncontrolled natural conditions. Non-invasive urine sampling and standard capture handling protocol have enabled the rapid quantification of baseline corticosterone and short-term corticosterone stress responses in anuran amphibians. In this study, established non-invasive methods were used to monitor physiological stress and urinary testosterone levels in male individuals of the terrestrial breeding Fijian ground frog (Platymantis vitiana). Adult male frogs (n = 20) were sampled at nighttime on three repeated occasions at intervals of 14 days during their annual breeding season on Viwa Island, Fiji. All frogs expressed urinary corticosterone metabolite responses to the capture and handling stressor, with some frogs showing consistently higher urinary corticosterone responses than others. Ranks of corticosterone values at 0, 4 and 8 h, and the corrected rank were highly significant (r = 0.75-0.99) between the three repeated sampling occasions. Statistical repeatabilities were high for baseline corticosterone (r = 0.973) and for corticosterone values at 2 h (r = 0.862), 4 h (r = 0.861), 6 h (r = 0.820) and 8 h (r = 0.926), and also for the total (inclusive of baseline corticosterone values) and the corrected integrated responses (index of the acute response) [r = 0.867 and r = 0.870]. Urinary testosterone levels also showed high statistical repeatability (r = 0.78). Furthermore, variation in baseline and short-term corticosterone stress responses was greater between individuals than within individuals. Baseline urinary corticosterone was significantly negatively correlated with the corrected integrated corticosterone response (r = -0.3, p < 0.001) but non-significantly with body-condition (r = -0.04) and baseline urinary testosterone (r = -0.07). In contrast, the corrected integrated corticosterone response was positively correlated (non-significantly) with baseline urinary testosterone (r = +0.04) and body-condition (r = +0.08). Urinary testosterone levels and body-condition were significantly negatively correlated (r = -0.23, p < 0.001). The results suggest that male frogs with higher levels of testosterone could have depleted energy reserve during the breeding period. The acute corticosterone responses help in replenishing energy that is needed for breeding and survival. The results also provide some support to the 'cort-fitness' hypothesis as highlighted by the negative correlation between baseline corticosterone and body-condition. It is most likely that the acute corticosterone response is adaptive and linked positively with reproductive fitness and survival in male anurans.

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Section: Discussionsupporting

confidence: 72%

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana)

Narayan¹,

Cockrem²,

Hero³

2013

Comparative Biochemistry and Physiology Part A: Molecular &

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“…We compared testosterone data from year‐round territorial species with those of socially monogamous northern songbirds that establish seasonal territories. In particular, we used data from bluethroats Luscinia svecica (Geslin et al 2004), common redpolls Carduelis flammea (Romero et al 1997), European blackbirds Turdus merula (Schwabl et al 1980), European stonechats Saxicola torquata rubicola (Schwabl et al 2005), Lapland longspurs Calcarius lapponicus (Hunt et al 1995), snow buntings Plectrophenax nivalis (Romero et al 1998), eastern song sparrows Melospiza melodia (Wingfield 1984), white‐crowned sparrows Zonotrichia leucophrys pugetensis (Wingfield and Farner 1978), blue tits Cyanistes caeruleus (Landys unpubl.) and great tits Parus major (Landys unpubl.).…”

Section: Methodsmentioning

confidence: 99%

Testosterone and year-round territoriality in tropical and non-tropical songbirds

Goymann¹,

Landys²

2011

Journal of Avian Biology

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Past studies have suggested a fundamental difference in testosterone concentrations between tropical and northern latitude male birds, with the convention being that males in the tropics express much lower levels of testosterone. However, recent comparative studies have shown that tropical males with a short and synchronous breeding season (i.e. a breeding season typical of northern species) express maximum testosterone levels similar to those of northern latitude birds. Here, we ask the converse: do northern latitude songbirds that express a defining life‐history characteristic typical of the tropics, i.e. year‐round territoriality, have an annual testosterone profile similar to that of tropical songbirds? For the few year‐round territorial species for which data are available, we found that seasonal testosterone profiles and seasonal maxima in plasma testosterone were similar between males of tropical and non‐tropical species. For example, males of both groups expressed seasonal maxima during the period when females were fertile, and testosterone levels at this time were similar. In contrast, this and other studies show that species with seasonal territories typically express maximum testosterone levels earlier in the breeding cycle, when territories are first being established. Taken together, we suggest that specific life‐history traits may play a more important role in determining testosterone profiles of tropical and non‐tropical birds than breeding latitude and encourage further studies to allow for more formal comparisons.

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“…To determine the body condition of birds, we first calculated a synthetic index of body size using the first axis (PCI) of a principal component analysis performed on the wing, tarsus and tail lengths (see Chastel and Kersten 2002;Geslin et al 2004). The first axis explained 56.27% of the overall variance in body size.…”

Section: Index Calculationmentioning

confidence: 99%

Morphological differences along a chronological gradient of urbanisation in an endemic insectivorous bird of New Zealand

Amiot

Harmange

2021

Urban Ecosyst

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Urbanisation constitutes one of the most rapid human-induced environmental changes, developing at the expense of natural and semi-natural habitats. It often implies alterations of many abiotic and biotic factors and contributes to create new environmental conditions, including temperature, food resources, competition and predation. Despite increasing empirical evidence of intra-specific divergence in phenotypic traits (e.g., physiological, behavioural or morphological) between urban and rural individuals, such patterns have often remained disconnected from the underlying mechanisms involved. In the current study, we tested for divergence in functional morphological traits that are related to feeding ecology (i.e., bill morphology, body mass and condition) and/or to the locomotory performance in escaping from predators (i.e., wing, tarsus and tail morphology, body mass and condition) along a chronological gradient of urbanisation (old urban, recent urban and rural areas), using the New Zealand fantail, an endemic insectivorous passerine species. We found divergences in phenotypic traits related to bill morphology along the urban-rural gradient: birds inhabiting the old urban area had stubbier bills (i.e., shorter, deeper and wider bills) than those inhabiting the recent urban and rural areas. We did not detect any difference in locomotion-related morphological traits. Our results suggest the urbanisation-induced alteration in food resources may drive morphological divergence in bird populations. We emphasized the need for mechanistic and experimental studies, with a particular focus on resource-based mechanisms, to identify more precisely the morphological responses of urban populations to changes in food composition, and the resulting implications for communities in urban ecosystems.

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Sex‐specific patterns in body condition and testosterone level changes in a territorial migratory bird: the Bluethroat Luscinia svecica

Cited by 17 publications

References 72 publications

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana)

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana)

Testosterone and year-round territoriality in tropical and non-tropical songbirds

Morphological differences along a chronological gradient of urbanisation in an endemic insectivorous bird of New Zealand

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