Territory Quality and Dispersal Options in the Acorn Woodpecker, and a Challenge to the Habitat-Saturation Model of Cooperative Breeding

1987 ◽  
Vol 130 (5) ◽  
pp. 654-676 ◽  
Author(s):  
Peter B. Stacey ◽  
J. David Ligon
Keyword(s):  
Cooperative Breeding ◽  
Saturation Model ◽  
Territory Quality ◽  
Habitat Saturation

Does year-round territoriality rather than habitat saturation explain delayed natal dispersal and cooperative breeding in the carrion crow?

2005 ◽  
Vol 74 (5) ◽  
pp. 842-851 ◽  
Author(s):  
VITTORIO BAGLIONE ◽  
JOSE M. MARCOS ◽  
DANIELA CANESTRARI ◽  
MICHAEL GRIESSER ◽  
GUIDO ANDREOTTI ◽  
...  
Keyword(s):  
Cooperative Breeding ◽  
Natal Dispersal ◽  
Carrion Crow ◽  
Habitat Saturation

Exploring territory quality in the North American red squirrel through removal experiments

1995 ◽  
Vol 73 (6) ◽  
pp. 1115-1122 ◽  
Author(s):  
Karl W. Larsen ◽  
Stan Boutin
Keyword(s):  
North American ◽  
Poor Quality ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrel ◽  
Territory Quality ◽  
The North ◽  
Removal Experiments ◽  
Habitat Saturation ◽  
Removal Studies ◽  
North American Red Squirrel

If territory quality affects the fitness of its holder, then relatively unsuccessful individuals should relocate if given the opportunity to appropriate a higher quality territory. Relocation by these animals, however, may be prevented by habitat saturation, poor competitive ability, or the costs of relocating. We conducted two removal studies that created numerous territory vacancies in a population of the North American red squirrel (Tamiasciurus hudsonicus), thus providing favourable conditions for relocation. In both experiments, we tested whether nonbreeding females were more likely to relocate than breeding females, presumably because they (the nonbreeders) occupied relatively poor-quality territories. In our first experiment we permanently removed most of the squirrels from a study site and monitored the relative proportions of the remaining nonbreeding and breeding females that relocated. In our second experiment we monitored the response of squirrels to vacant territories that had been previously held by nonbreeding and breeding females, as well as by males. We also monitored the behaviour of squirrels that did not hold territories (dispersing offspring), as these individuals would not experience the same costs of relocation as adults. Our experiments showed that neither category of female was likely to relocate, regardless of the type of territory available. Both residents and dispersing offspring displayed no biases towards vacant territories that previously belonged to nonbreeding or breeding females or to males. Relocation does not appear to be a strategy for a female in this system to increase her reproductive opportunities. This suggests that either territory quality is inconsequential or the costs of relocation are prohibitive. Dispersing offspring also may be unable to select certain territories because of the premium placed on acquiring a territory, regardless of its quality.

scholarly journals Experimental vacancies do not induce settlement despite habitat saturation in a cooperative breeder

2020 ◽  
Vol 16 (3) ◽  
pp. 20190757
Author(s):  
Lyanne Brouwer ◽  
Andrew Cockburn
Keyword(s):  
Experimental Evidence ◽  
Cooperative Breeding ◽  
Ecological Constraints ◽  
Multiple Group ◽  
Risk Of Predation ◽  
Group Members ◽  
Habitat Saturation ◽  
Crucial Test

The paradox of cooperative breeding, whereby individuals assist others instead of reproducing independently, is generally explained through ecological constraints, but experimental evidence is scant. Here we performed the crucial test of the role of habitat saturation through the experimental creation of vacancies and found that, despite abundant presence of potential mates, subordinates are reluctant to disperse into suitable vacant habitat where conspecifics are absent. We argue that sudden disappearance of multiple group members might indicate a heightened risk of predation. Thereby the results of this study are consistent with the ‘perceptual trap’ hypothesis: the avoidance of habitats because cues do not accurately reflect their quality. Interestingly, this hypothesis can also explain previous findings, which were widely interpreted as evidence for ecological constraints as a driver of cooperative breeding. Our results can have considerable implications for conservation as they mean that opportunities for colonization might go unexploited.

Female Choice in Middendorff's Grasshopper-Warbler (Locustella Ochotensis)

The Auk ◽  
1986 ◽  
Vol 103 (4) ◽  
pp. 694-700 ◽  
Author(s):  
Hisashi Nagata
Keyword(s):  
Mate Choice ◽  
Female Choice ◽  
Morphological Characteristics ◽  
Female Mate Choice ◽  
Food Abundance ◽  
Territory Size ◽  
Territory Quality ◽  
Female Mate ◽  
Nest Sites ◽  
Grasshopper Warbler

Abstract Morphological and territorial factors that influence female mate choice were examined in the monogamous Middendorff's Grasshopper-Warbler (Locustella ochotensis) on an islet near Fukuoka, Japan. I assumed that pairing date corresponded with female mate choice. Pairing date was correlated with both territory size and food abundance but was not correlated with selected morphological characteristics of males. Territorial quality was assumed to be correlated with territory size because preferable food resources and nest sites were distributed randomly. I conclude that female mate choice was influenced by territory quality rather than by the morphological characteristics of males.

scholarly journals Cooperative breeding behaviors in the Hawaiian Stilt ( Himantopus mexicanus knudseni )

2021 ◽  
Author(s):  
Arleone Dibben‐Young ◽  
Kristen C. Harmon ◽  
Arianna Lunow‐Luke ◽  
Jessica L. Idle ◽  
Dain L. Christensen ◽  
...  
Keyword(s):  
Cooperative Breeding ◽  
Himantopus Mexicanus

scholarly journals Transient rhyolite melt extraction to produce a shallow granitic pluton

2021 ◽  
Vol 7 (21) ◽  
pp. eabf0604
Author(s):  
Allen J. Schaen ◽  
Blair Schoene ◽  
Josef Dufek ◽  
Brad S. Singer ◽  
Michael P. Eddy ◽  
...  
Keyword(s):  
Time Scales ◽  
Explosive Eruptions ◽  
Upper Crust ◽  
Saturation Model ◽  
Granitic Pluton ◽  
Melt Extraction ◽  
High Silica ◽  
Melt Segregation ◽  
Zircon Saturation

Rhyolitic melt that fuels explosive eruptions often originates in the upper crust via extraction from crystal-rich sources, implying an evolutionary link between volcanism and residual plutonism. However, the time scales over which these systems evolve are mainly understood through erupted deposits, limiting confirmation of this connection. Exhumed plutons that preserve a record of high-silica melt segregation provide a critical subvolcanic perspective on rhyolite generation, permitting comparison between time scales of long-term assembly and transient melt extraction events. Here, U-Pb zircon petrochronology and 40Ar/39Ar thermochronology constrain silicic melt segregation and residual cumulate formation in a ~7 to 6 Ma, shallow (3 to 7 km depth) Andean pluton. Thermo-petrological simulations linked to a zircon saturation model map spatiotemporal melt flux distributions. Our findings suggest that ~50 km3 of rhyolitic melt was extracted in ~130 ka, transient pluton assembly that indicates the thermal viability of advanced magma differentiation in the upper crust.

Sign in / Sign up

Export Citation Format

Share Document