Varied Thrush (Ixoreus naevius) Science Article 2 abstract From a study of a partially albino female Varied Thrush, certain inferences are suggested with regard to sex coloration, principal of which is that, in Ixoreus, the sex difference in pigmentation is quantitative rather than qualitative. J. EUGENE LAW, THE CONDOR Vol. 23, 1931 Download article download […]
Category: Passeriformes
Migration patterns of two populations of Twite Carduelis flavirostris in Britain
Twite (Carduelis flavirostris) Science Article 1 abstract Following a recent large decline in range and numbers, the Twite Carduelis flavirostris is a red-listed bird of conservation concern. An understanding of the species’ movements between wintering and breeding areas is essential to underpin effective conservation. The migration patterns of two populations of Twite were examined: those […]
Natal philopatry and local movement patterns of Twite Carduelis flavirostris
Twite (Carduelis flavirostris) Science Article 2 abstract The Twite Carduelis flavirostris is classified as a red-listed bird of conservation concern in the United Kingdom. Successful conservation initiatives will depend on an understanding of local movement patterns and natal philopatry as these will be important in determining how likely the species is to colonise new nesting […]
MICROBES IN TREE SWALLOW SEMEN
Tree Swallow (Tachycineta bicolor) Science Article 15 abstract A frequently hypothesized but poorly studied cost of multiple mating in birds is thatexposure to pathogenic sexually transmitted microbes (STM’s) can lower reproductive success.Conversely, female birds may benefit from high frequencies of copulation and multiple copulationpartners if they receive cloacal inoculations of beneficial STM’s that can either […]
Tree Swallows (Tachycineta bicolor) are breeding earlier at Creamer’s FieldMigratory Waterfowl Refuge, Fairbanks, AK
Tree Swallow (Tachycineta bicolor) Science Article 4 abstract We examined the average annual lay, hatch, and fledge dates of tree swallows(Tachycineta bicolor) breeding in Creamer’s Field Migratory Waterfowl Refuge inFairbanks, AK from 2000 through 2008. From 2000 to 2008, lay and hatch dateexhibited a significant negative relationship, indicating that the timing of swallowreproduction has advanced […]
Age-related differences in plumage characteristics of male treeswallows Tachycineta bicolor: hue and brightness signal differentaspects of individual quality
Tree Swallow (Tachycineta bicolor) Science Article 11 abstract Age-related differences in plumage characteristics of birds can be the result of differential survival of more ornamented individuals, within-individual changes in plumage attributes with age, or a combination of both. In this study, we investigated age-class related differences in plumage attributes of male tree swallows Tachycineta bicolor […]
CAUSES AND CONSEQUENCES OF TREE SWALLOW(TACHYCINETA BICOLOR) DISPERSAL IN SASKATCHEWAN
Tree Swallow (Tachycineta bicolor) Science Article 12 abstract Poor breeding success often increases dispersal, but there is conflicting evidenceabout the putative adaptive benefi ts of dispersal behavior. Thus, observational and experimentaldata were analyzed to test whether breeding success (number of young fl edging) infl uencedbreeding and natal dispersal by Tree Swallows (Tachycineta bicolor), using information […]
Observations on the nesting and incubation behavior of the Tropical Gnatcatcher (Polioptila plumbea)
Tropical Gnatcatcher (Polioptila plumbea) Science Article 1 abstract OBSERVATIONS ON INCUBATION AND NESTING BEHAVIOR OF THE TROPICAL GNATCATCHER (POLIOPTILA PLUMBEA) IN EASTERN ECUADOR Erin C. Hannelly & Harold F. Greeney, Ornitologia Neotropical 15: 539-542 Download article download full text (pdf)
TIME AND ENERGY BUDGETS OF THE MOCKINGBIRD (MIMUS POLYGLOTTOS) DURING THE BREEDING SEASON
Tropical Mockingbird (Mimus gilvus) Science Article 2 abstract A time and energy budget of male and female Mockingbirds (Mimus polyglottos) in six phases of their breeding cycle was completed using the equivalent temperature model to predict perching metabolic rates. Recorded time-budget behaviors included perching, bipedal locomotion, flight, and the time spent in the sun and […]
Bigamy in a Male Mockingbird
Tropical Mockingbird (Mimus gilvus) Science Article 1 abstract Like many passerine species, the Mockingbird (Mimus polyglottos) is thought to be highly monogamous. Laskey (1935, Auk 52: 370), for example, reports perennial pair bonding between identified males and females, even though the female may leave for the fall and return to the same male during the […]