Male Common Loons Signal Greater Aggressive Motivation By Lengthening Territorial Yodels

  title={Male Common Loons Signal Greater Aggressive Motivation By Lengthening Territorial Yodels},
  author={John N. Mager and Charles Walcott and Walter H. Piper},
Abstract We examined two critical predictions of the hypothesis that male Common Loons (Gavia immer) communicate greater aggressive motivation by increasing the number of repeat syllables within their territorial yodels. We observed (from >3,500 hrs of field observations of 58 males) the probability that territorial interactions escalated from territorial flyovers by intruders to stereotyped ‘social gatherings’ to escalated fights between residents and intruders was positively correlated to the… Expand
The social context of a territorial dispute differentially influences the way individuals in breeding pairs coordinate their aggressive tactics
It is found that, when facing intruders that pose a greater threat, residents adjust levels of aggressive output in response to the number of vocalizations produced by their breeding partner, and this ability reflects an adaptive mechanism that allows individuals to fine-tune territorial tactics to reduce overall costs of aggression. Expand
Dynamics of an Aggressive Vocalization in the Common Loon (Gavia immer): A Review
Abstract. Unlike most waterbirds, Common Loons (Gavia immer) have a dynamic vocal repertoire that includes the high-amplitude wail, tremolo, and yodel. This paper is a review of the acousticExpand
Contextual variations in calls of two nonoscine birds: the blue petrel Halobaena caerulea and the Antarctic prion Pachyptila desolata
Vocal plasticity in nonlearning birds has been greatly underestimated and the expression of different motivations through vocal variations and the ability to produce frequency variations in species with genetically coded vocalizations is highlighted. Expand
Aging male loons make a terminal investment in territory defense
It is found that males, but not females, suffered a decrease in survival rate and ability to hold a territory after age 14, and territorial males older than 14 behaved more aggressively and were more apt to give a territorial yodel call towards territorial intruders. Expand
Common loon parents defend chicks according to both value and vulnerability
Findings lent clear support to the vulnerability hypothesis, as males with two-chick broods were almost three times more likely to yodel than males with singleton chicks and the value hypothesis was supported. Expand
Investment in territorial defence relates to recent reproductive success in common loons Gavia immer
This data is interpreted to suggest that loons with recent success offset the cost of increased intrusions by adopting a more efficient strategy for territorial defence (e.g. limiting investment in resource defence until the time of the season when it is most critical). Expand
Variation in the Vocal Behavior of Common Loons (Gavia immer): Insights from Landscape-level Recordings
It is revealed that this species calls when abiotic conditions are ideal for long-range signaling, demonstrating that wail, yodel, and tremolo calls transmit significantly farther at night than during the day. Expand
All signals are not equal: acoustic signalling of individuality, sex and breeding status in a cooperative breeder
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Testing the maintenance of natural responses to survival-relevant calls in the conservation breeding population of a critically endangered corvid (Corvus hawaiiensis)
Results are encouraging, showing that ‘alalā exhibit relevant, species-specific behaviors despite generations under human care, but they do illustrate, however, that not all individuals respond appropriately, so vocal response may be an important factor to consider in determining the release suitability of individuals. Expand
Animal choreography of song and dance: a case study in the Montezuma oropendola, Psarocolius montezuma
A case study of free-living Montezuma oropendolas, Psarocolius montezuma, a polygynous songbird that performs a dramatic song and dance is explored, finding that two elements of this display are each choreographed with the song's loudest note (dBmax) and lowest peak frequency (LPF), respectively. Expand


Communication of Intentions in Agonistic Contexts By the Pigeon Guillemot, Cepphus Columba
This observational study of communication behavior of the pigeon guillemot (Cepphus columba) in agonistic contexts studied two questions: (1) What factors influence the outcome of interactionsExpand
Male common loons, Gavia immer, communicate body mass and condition through dominant frequencies of territorial yodels
An acoustic playback experiment indicated that potential receivers vocalized sooner and more often in response to low-frequency yodels, a possible indication that dominant frequencies of the yodel may communicate condition-dependent fighting abilities. Expand
Nest platforms increase aggressive behavior in common loons
This study is one of a few to show that tools used to mitigate habitat loss can negatively impact reproductive fitness in a threatened species. Expand
Strophe Length in Spontaneous Songs Predicts Male Response to Playback in the Hoopoe Upupa epops
Results show that strophe length reflects some component of the competitive ability of males (either physical strength or aggressiveness) in the hoopoe, which together with previous results regarding its role for female choice, show that it is a sexual signal with dual function. Expand
There is a suggestion that changes in the yodel may be related to territory and mate switching, indicating that individuality in theYodels may be linked to female choice. Expand
Do Blackbirds Signal Motivation to Fight with Their Song
Conflicts about resources can be solved with physical fights, but animals will in general try to avoid them due to the costs and risks associated with fighting. Fight outcome depends on the fightingExpand
Prospecting in a solitary breeder: chick production elicits territorial intrusions in common loons
One striking finding was the tendency of territorial breeders to conceal chicks from flying intruders, perhaps to avoid future territorial takeover. Expand
Do little blue penguins signal their intentions during aggressive interactions with strangers?
  • J. Waas
  • Psychology
  • Animal Behaviour
  • 1991
Abstract A model of an intruder was used to determine whether burrow-dwelling little blue penguins, Eudyptula minor , signal their intentions during aggressive interactions with strangers. WhenExpand
Common Loons can differentiate yodels of neighboring and non-neighboring conspecifics
Although previous studies have identified elements of the yodel calls of male Common Loons (Gavia immer) that might be important for neighbor/non-neighbor discrimination, no one to date hasExpand
Testing hypotheses of social gatherings of common loons (Gavia immer)
Three hypotheses are tested to explain the function of common loon social gatherings: Cooperative Foraging, Familiarity, and Reconnaissance. From 1993 to 1999, I studied social gatherings throughExpand