Blackcaps (Sylvia atricapilla) increase the whistle part of their song in response to simulated territorial intrusion

Ethology ◽  
2015 ◽  
Vol 121 (4) ◽  
pp. 403-409 ◽  
Author(s):  
Amy E. Leedale ◽  
Sarah A. Collins ◽  
Selvino R. de Kort
Keyword(s):  
Sylvia Atricapilla ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

Opposite Changes in Plasma Testosterone and Corticosterone Levels Following a Simulated Territorial Challenge in Male Great Tits

Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 451-467 ◽  
Author(s):  
Rianne Pinxten ◽  
Lutgarde Arckens ◽  
Els van Duyse ◽  
Marcel Eens ◽  
Veerle Darras
Keyword(s):  
Parus Major ◽  
Time Of Day ◽  
Behavioural Response ◽  
Egg Laying ◽  
Plasma Testosterone ◽  
Breeding Cycle ◽  
Territorial Defence ◽  
Breeding Stage ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

AbstractThe apparent ability of plasma testosterone (T) and corticosterone (B) levels to fluctuate rapidly in response to agonistic interactions, suggests that these hormones may play an important role in an animal's acute behavioural response during such interactions. In the present study, free-living male great tits, Parus major, were subjected to a simulated territorial intrusion (STI) during the egg laying, incubation and nestling stage of first broods. Plasma T and B levels of challenged males were compared to those of control males matched for breeding stage, day in breeding stage, and time of day. Plasma B levels were significantly higher in challenged males compared to control males during the egg laying and incubation stage but not during the nestling stage. On the other hand, challenged males had significantly lower plasma T levels than control males throughout the breeding cycle. While having low plasma T and elevated plasma B levels, challenged males showed a vigorous and unrelenting territorial response to the STI. Plasma T and B levels of challenged males did not correlate with the intensity of the behavioural response to the STI. These findings do not agree with the predictions of the 'challenge hypothesis' that males exposed to a territorial challenge while having breeding baseline T levels will respond with an increase in T or that T correlates with the intensity of aggression during a challenge. Together, our findings suggest a role for B rather than T in the regulation of territorial defence in male great tits.

Use of Stereo Duet Playback to Investigate Traditional Duet Playback Methods and Mechanisms of Cooperative Territorial Defence in Magpie-Larks

Behaviour ◽  
2004 ◽  
Vol 141 (6) ◽  
pp. 741-753 ◽  
Author(s):  
Helèna Harrington ◽  
Audrey Miller ◽  
Sarah Mcdowell ◽  
Amy Rogers ◽  
Joanne Panagos ◽  
...  
Keyword(s):  
Intraspecific Aggression ◽  
Same Sex ◽  
Territorial Defence ◽  
Male And Female ◽  
Single Speaker ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion ◽  
Australian Magpie ◽  
Response Variables

AbstractDuets are precisely coordinated acoustic displays, usually involving members of a mated pair. Studies investigating avian duet function often employ a single speaker playback system to compare response of focal pairs to simulated territorial intrusion by duetting and solo birds. It has recently been suggested that a 'stereo duet playback', in which male and female duet components are separated and broadcast through two different speakers, would provide a more realistic duet stimulus. We conduct the first comparison of a traditional single speaker versus a new stereo duet playback design and provide evidence that Australian magpie-larks, Grallina cyanoleuca, make significantly more flights towards duet playback presented in a more realistic stereo context. Male and female magpie-lark pairs did not split up and attack one 'intruder' each when presented with a stereo duet playback. Instead they moved towards the same speaker together as a united pair, showing a tendency to approach the speaker initiating the duet intrusion. Distance between the two speakers in a stereo duet design did not have a significant effect on the response variables measured. We conclude that magpie-larks can distinguish between use of a single speaker or stereo duet playback to broadcast a duet and suggest that cooperative defence against duetting intruders in magpie-larks is a result of joint territorial defence rather than intraspecific aggression against same-sex intruders.

scholarly journals Male White-shouldered Fairywrens (Malurus alboscapulatus) elevate testosterone when courting females but not during territorial challenges

2021 ◽  
Author(s):  
Jordan Boersma ◽  
John Anothny Jones ◽  
Erik D Enbody ◽  
Joseph F Welklin ◽  
Serena Ketaloya ◽  
...  
Keyword(s):  
Bird Species ◽  
Plasma Testosterone ◽  
Network Approach ◽  
Challenge Hypothesis ◽  
Agonistic Interactions ◽  
Causal Factors ◽  
Behavioral Traits ◽  
Social Network Approach ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

Testosterone mediates suites of physical and behavioral traits across vertebrates, and circulation varies considerably across and within taxa. However, an understanding of the causal factors of variation in circulating testosterone has proven difficult despite decades of research. According to the challenge hypothesis, agonistic interactions between males immediately prior to the breeding season produce the highest levels of testosterone measured during this period. While many studies have provided support for this hypothesis, most species do not respond to male-male competition by elevating testosterone. As a result, a recent revision of the hypothesis (challenge hypothesis 2.0) places male-female interactions as the primary cause of rapid elevations in testosterone circulation in male vertebrates. Here, we offer a test of both iterations of the challenge hypothesis in a tropical bird species. We first illustrate that male White-shouldered Fairywrens (Malurus alboscapulatus) differ by subspecies in plasma testosterone concentrations. Then we use a social network approach to find that males of the subspecies with higher testosterone are characterized by greater social interaction scores, including more time aggregating to perform sexual displays. Next, we use a controlled experiment to test whether males respond to simulated territorial intrusion or courtship interaction contexts by elevating testosterone. Males sampled during courtship had greater plasma testosterone both relative to flushed controls and males sampled during simulated intrusion. Ultimately, our results are consistent with challenge hypothesis 2.0, as males rapidly elevated testosterone following interactions with females, but not during territorial challenges.

scholarly journals Free-Living Male Mountain White-Crowned Sparrows Exhibit Territorial Aggression Without Modulating Total or Free Plasma Testosterone

The Condor ◽  
2007 ◽  
Vol 109 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Sharon E. Lynn ◽  
Thomas P. Hahn ◽  
Creagh W. Breuner
Keyword(s):  
Aggressive Behavior ◽  
Free Testosterone ◽  
Plasma Testosterone ◽  
Zonotrichia Leucophrys ◽  
Territorial Aggression ◽  
Testosterone Secretion ◽  
Corticosteroid Binding Globulin ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion ◽  
Free Plasma

Abstract Abstract In some species, expression of territorial aggression is accompanied by a rise in testosterone secretion, but in others aggressive behavior is expressed while testosterone levels remain unchanged. Corticosteroid binding globulin (CBG) binds both corticosterone and testosterone in avian plasma. Thus, increasing corticosterone may result in fluctuations in unbound (“free”) testosterone; this could result in greater biological activity of testosterone without an increase in testosterone secretion. We investigated whether such plasma interactions of testosterone, corticosterone, and CBG might result in alterations of free testosterone in male Mountain White-crowned Sparrows (Zonotrichia leucophrys oriantha). We conducted simulated territorial intrusions during incubation and compared total and free testosterone of males captured immediately following a simulated territorial intrusion with that of males captured passively. All experimental males showed aggressive behavior, but apparently did not modulate total or free testosterone relative to controls.

scholarly journals Defending as a unit: sex- and context-specific territorial defence in a duetting bird

2020 ◽  
Author(s):  
Lucia Mentesana ◽  
Maria Moiron ◽  
Ernesto Guedes ◽  
Enzo Cavalli ◽  
Bettina Tassino ◽  
...  
Keyword(s):  
Structural Equation Modelling ◽  
Latent Variable ◽  
Structural Equation ◽  
Bird Species ◽  
Correlation Pattern ◽  
Territorial Defence ◽  
Equation Modelling ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion ◽  
Context Specific

AbstractBehaviours such as territorial defence represent functionally integrated traits that underlie multiple behavioural variables such as physical and acoustic responses. Characterizing the multivariate structure of such traits is fundamental to understand their evolution. In bird species that form stable pair bonds and are territorial year-round, both sexes are expected to defend their territory; however, the role that each sex plays in defending their shared territory remains largely unknown. Evidence for the sex-roles during territorial defence is mixed and sex- and context-specific characterizations of territorial defence embracing the multivariate nature of the trait are currently lacking. Here we investigated sex- and context-specific variation in a hypothesised latent variable called “territorial defence” and tested whether duets were part of territorial defence in a wild population of rufous hornero (Furnarius rufus). To do so, we combined a simulated territorial intrusion approach during nest building and provisioning contexts with a structural equation modelling approach. Our results showed that, in males and females, the six measured behavioural variables were linked by a single latent trait, territorial defence, in both contexts. Flights over the decoy and duet songs were equally good proxies of territorial defence. Although males were defending more the territory than females, pair members showed a positive correlation in their behaviour. The structural equation modelling framework enabled us to capture a complex correlation pattern among behavioural variables, expanding upon a classic body of research on territorial defence. Thus, the combination of classical behavioural approaches with sophisticated statistical analyses brings new exciting possibilities to the field of behavioural ecology.Significance statementTerritorial defence is a key behaviour in territorial species as it plays a major role in an individual’s reproductive success and survival. Additionally, territorial defence has been proposed as one possible evolutionary driver of duetting behaviour, one of the most fascinating vocal behaviours in birds. As behaviours are evolutionary characters, they must be studied in a multivariate framework. In this study we focused on characterizing territorial defence during a simulated territorial intrusion in an integrative manner using a classical territorial intrusion framework. We did so in male and female rufous horneros (Aves: Furnaridae) across two breeding contexts, while simultaneously testing theoretical predictions about the role of duetting behaviour as key part of territorial defence. Overall, our study provides for the first time a sex- and context-comparison of the multivariate, latent variable “territorial defence” in duetting birds, while highlighting the potential of combining field behavioural approaches with structural equation modelling.

scholarly journals Territorial Movements of Black-throated Blue Warblers in a Landscape Fragmented by Forestry

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 544-549 ◽  
Author(s):  
Rebecca J. Harris ◽  
J. Michael Reed
Keyword(s):  
Bird Species ◽  
Small Scale ◽  
Neotropical Migrant ◽  
Dendroica Caerulescens ◽  
Alarm Calling ◽  
Second Year ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion ◽  
Song Playback ◽  
Older Males

Abstract Many forest bird species show inhibition to entering open areas, including crossing habitat gaps. We examined the responses of Black-throated Blue Warblers (Dendroica caerulescens) to conspecific song playback within forest, at clearcut-forest ecotones, and across logging roads to assess movements of this Neotropical migrant into open areas. Males responded readily to song playbacks in all areas, and moved significantly farther into clearcuts than they did within intact forest (40.4 ± 2.9 m and 17.1 ± 1.2 m, respectively). Their singing, aggressive trilling, and alarm-calling rates were highest in response to playback from clearcuts, intermediate during road-crossings, and lowest within forest. Males moved farthest into the oldest regenerating clearcuts (>15 years old), indicating that vegetation structure also influences their movement into open areas. Second-year males were more responsive than older males, moving farther to reach speakers in all areas, and showing a nonsignificant trend of moving farther into clearcuts. We found that extensive movements into open areas occur in response to simulated territorial intrusion, indicating that small-scale habitat fragmentation by forestry may not disrupt territorial movements of that species.

scholarly journals Ignoring the challenge? Male black redstarts ( Phoenicurus ochruros ) do not increase testosterone levels during territorial conflicts but they do so in response to gonadotropin-releasing hormone

2011 ◽  
Vol 278 (1722) ◽  
pp. 3233-3242 ◽  
Author(s):  
Beate Apfelbeck ◽  
Wolfgang Goymann
Keyword(s):  
Breeding Season ◽  
Gonadotropin Releasing Hormone ◽  
Plasma Testosterone ◽  
Releasing Hormone ◽  
Social Challenges ◽  
Testosterone Levels ◽  
Territorial Conflicts ◽  
Territory Defence ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

Competition elevates plasma testosterone in a wide variety of vertebrates, including humans. The ‘challenge hypothesis’ proposes that seasonal peaks in testosterone during breeding are caused by social challenges from other males. However, during experimentally induced male–male conflicts, testosterone increases only in a minority of songbird species tested so far. Why is this so? Comparative evidence suggests that species with a short breeding season may not elevate testosterone levels during territory defence. These species may even be limited in their physiological capability to increase testosterone levels, which can be tested by injecting birds with gonadotropin-releasing hormone (GnRH). We studied two populations of black redstarts that differ in breeding altitude, morphology and the length of their breeding season. Unexpectedly, males of neither population increased testosterone in response to a simulated territorial intrusion, but injections with GnRH resulted in a major elevation of testosterone. Thus, black redstarts would have been capable of mounting a testosterone response during the male–male challenge. Our data show, for the first time, that the absence of an androgen response to male–male challenges is not owing to physiological limitations to increase testosterone. Furthermore, in contrast to comparative evidence between species, populations of black redstarts with a long breeding season do not show the expected elevation in testosterone during male–male challenges.

scholarly journals Not one hormone or another: Aggression differentially affects progesterone and testosterone in a South American ovenbird

2018 ◽  
Author(s):  
Nicolas M. Adreani ◽  
Wolfgang Goymann ◽  
Lucia Mentesana
Keyword(s):  
Parental Care ◽  
Social Interactions ◽  
Breeding Cycle ◽  
South American ◽  
Male Behavior ◽  
Free Living ◽  
Mating Period ◽  
Territorial Aggression ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

AbstractBehaviors such as territorial interactions among individuals can modulate vertebrate physiology and vice versa. Testosterone has been pointed out as a key hormone that can be rapidly affected by aggressive interactions. However, experimental evidence for such a link is mixed. In addition, behaviors can elicit changes in multiple hormones, which in turn have the potential to synergistically feedback to behavior. For example testosterone and progesterone can act interdependently in modulating male behavior. However, if aggression can affect progesterone levels in males remain unknown and – to the best of our knowledge – no one has yet tackled if and how aggressive behavior simultaneously affects testosterone and progesterone in free-living animals. We addressed these questions by performing simulated territorial intrusion experiments measuring both hormones and their ratio in male rufous horneros (Aves, Furnarius rufus) during the mating and parental care periods. Aggression affected testosterone and progesterone differentially depending on the period of testing: challenged birds had higher levels of progesterone during the mating period and lower levels of testosterone during parental care compared to controls. Challenged individuals had similar progesterone to testosterone ratios during both periods and these ratios were higher than those of control birds. In summary, territorial aggression triggered hormonal pathways differentially depending on the stage of the breeding cycle, but equally altered their ratio independent of it. Our results indicate that multiple related hormones could be playing a role rather than each hormone alone in response to social interactions.

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