Topic
Selasphorus
About: Selasphorus is a research topic. Over the lifetime, 92 publications have been published within this topic receiving 2232 citations.
Papers published on a yearly basis
Papers
TL;DR: Comparisons of feeding territories of S. rufus and other nectarivorous birds indicate similarities which suggest that these systems may be subject to similar economic constraints.
Abstract: Migrant Rufous Hummingbirds (Selasphorus rufus) arrive in eastern Arizona in late summer and establish feeding territories from which other hummingbirds are excluded. Territories vary 100-fold in area and 5-fold in number of flowers. A simple cost-benefit model accounts for observed variation in territory size and number of flowers defended. Both sexes defend territories, but d d utilize denser flowers than Y Y. These differences appear to be related to sexual dimorphism in wing disc loading. Selasphorus rufus appears to have sacrificed efficient flight for aggressive ability as a strategy for competing with resident hummingbird species during its migration. Comparison of feeding territories of S. rufus and other nectarivorous birds indicate similarities which suggest that these systems may be subject to similar economic constraints.
360 citations
TL;DR: The findings tentatively suggest that, in response to short-term variations in food availability, migrant hummingbirds are capable of adjusting territory size and time budgeting in a manner consistent with maximizing daily net energy gain.
Abstract: While migrating southward each summer along the Sierra Nevada Mountain Range in California, nectar-feeding rufous hummingbirds (Selasphorus rufus) establish feeding territories within isolated meadows. We investigated the effect of variable food density upon territory area and time budgeting by controlled removals and additions of flowers of Castilleja linariaefolia within the territories of immature birds. The experiments were replicated three times with generally consistent results. Within one day following a 50% decrease in flower density: (1) territory area usually about doubled, resulting in (2) the number of defended flowers remaining similar to the premanipulation value; (3) foraging time increased significantly from about 21% to about 26% of the day as the result of (4) a significant increase in foraging bout duration, with (5) bout frequency remaining unchanged; (6) daily sitting time decreased significantly from about 76% to about 71% of the day; and (7) daily defense time did not change signifi...
184 citations
TL;DR: This field study of female and immature migratory rufous hummingbirds (Selasphorus rufus) reveals that their feeding territories are closely regulated in size to maintain environmental reserves of energy per individual.
Abstract: This field study of female and immature migratory rufous hummingbirds (Selasphorus rufus) reveals that their feeding territories are closely regulated in size to maintain environmental reserves of ...
129 citations
TL;DR: The foraging ecology of rufous hummingbirds, Selasphorus rufus, suggests that this species may have good spatial memory capabilities, and information about rewarded and non-rewarded locations was combined to direct sampling behaviour towards flowers the birds had not yet encountered.
94 citations
TL;DR: In this paper, an inverse hyperbolic relationship between territory size and flower density indicates that territory size is regulated to maintain food supply: individual hummingbirds make daily adjustments in their territories.
Abstract: Postbreeding migrant rufous hummingbirds (Selasphorus rufus) establish feeding territories in alpine meadows. An inverse hyperbolic relationship between territory size and flower density indicates that territory size is regulated to maintain food supply: individual hummingbirds make daily adjustments in their territories. These adjustments maintain food supplies from day lo day and improve them over what they would be if no adjustments were made. The ability of individuals to maintain territory quality, however, and the length of time they remain in the meadows, is affected by their age and sex and by the level of competition for food by conspecifics. Territoriality, therefore, must be considered in relation to factors operating beyond the local food environment, both in terms of effects on and effects of the short-term dynamics of energy regulation. This has important implications for hummingbird migration.
80 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 8 |
| 2019 | 1 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 2 |