DOCSLIB.ORG

FRONTISPIECE. Three-Striped Warblers (Basileuterus Tristriatus) Were Studied in the Northern Andes of Venezuela. Temperate and T

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
FRONTISPIECE. Three-Striped Warblers (Basileuterus Tristriatus) Were Studied in the Northern Andes of Venezuela. Temperate and T FRONTISPIECE. Three-striped Warblers (Basileuterus tristriatus) were studied in the northern Andes of Venezuela. Temperate and tropical parulids differ strongly in life histories. Three-striped Warblers have smaller clutches, longer incubation periods, lower nest attentiveness, longer off-bouts, and slower nestling growth rates than most temperate species. Water color by Don Radovich. Published by the Wilson Ornithological Society VOL. 121, NO. 4 December 2009 PAGES 667–914 The Wilson Journal of Ornithology 121(4):667–678, 2009 BREEDING BIOLOGY OF THE THREE-STRIPED WARBLER IN VENEZUELA: A CONTRAST BETWEEN TROPICAL AND TEMPERATE PARULIDS W. ANDREW COX1,3 AND THOMAS E. MARTIN2 ABSTRACT.—We document reproductive life history traits of the Three-striped Warbler (Basileuterus tristriatus) from 146 nests in Venezuela and compare our results to data from the literature for other tropical and temperate parulid species. Mean (6 SE) clutch size was 1.96 6 0.03 eggs (n 5 96) and fresh egg mass was 2.09 6 0.02 g. The incubation period was 15.8 6 0.2 days (n 5 23) and the nestling period was 10.5 6 0.3 days (n 5 12). Males did not incubate and rarely provided food for females during incubation. Females had 57 6 2% (n 5 49) nest attentiveness (% of time on the nest incubating), which caused egg temperature to commonly become cold relative to development. Both adults fed nestlings and feeding rates increased with nestling age. The growth rate constant for nestlings based on mass was K 5 0.490, which is slower than for north temperate warblers. Predation was the primary source of nest failure and only 22% of nests were successful based on a Mayfield daily predation rate of 0.048 6 0.006. Our literature review indicates parulids differ strongly in life histories between temperate and tropical/subtropical sites with species in the tropics having, on average, smaller clutches, longer incubation periods, lower nest attentiveness, longer off-bouts, and longer nestling periods. Received 11 October 2008. Accepted 6 June 2009. Life history strategies often show strong appear to show strong latitudinal patterns in life differences between north temperate versus sub- history traits (Martin et al. 2000, Martin 2002, tropical and tropical sites (Moreau 1944; Lack Auer et al. 2007). The wood-warbler genus 1947; Ricklefs 1976; Martin et al. 2000, 2006, Basileuterus, comprised of 20 species, is a 2007; Martin 2004), although the extent of particularly widespread group distributed from differences varies among phylogenetic groups Argentina to Mexico with records reaching as far (Fierro-Caldero´n and Martin 2007, Martin and north as southern Texas and Arizona (Dunn and Schwabl 2008). Wood-warblers (Parulidae) in- Garrett 1997). One species is endangered (B. clude a diversity of species across latitudes and griseiceps), but most others are common through- out their range and are of low conservation 1 Division of Biological Sciences, University of Missouri, concern (IUCN 2006). Little is known about the 105 Tucker Hall, Columbia, MO 65211, USA. life histories of most species despite their broad 2 USGS, Montana Cooperative Wildlife Research Unit, Avian Studies Program, 205 Natural Science, University of distribution and relative abundance. Basic infor- Montana, Missoula, MT 59812, USA. mation including nest descriptions and clutch size 3 Corresponding author; e-mail: [email protected] is lacking for many species (Curson et al. 1994). 667 668 THE WILSON JOURNAL OF ORNITHOLOGY N Vol. 121, No. 4, December 2009 Reproductive traits including incubation period, calculated following Mayfield (1961, 1975) and nest attentiveness, and nestling growth are Hensler and Nichols (1981). Nesting season described for even fewer members of Basileuterus length was estimated as the middle 90% of nest or other parulid genera (but see Skutch 1954, initiations (exclusion of earliest 5% and latest Ghalambor and Martin 2001, Martin 2002, Auer 5%) following Martin (2007). We used video et al. 2007). The dearth of information from the cameras to measure parental behavior for 6–8 hrs Tropics and the suggestion that Wood-warblers starting at dawn during incubation and nestling may show strong latitudinal patterns make them phases. Nest attentiveness (% of time on the nest an important group to study for improving our incubating) was calculated for each nest as the understanding of latitudinal patterns in life history number of minutes on the nest/total minutes traits. video-monitored. We calculated the incubation We describe the reproductive biology of the period as the number of days that lapsed between Three-striped Warbler (B. tristriatus) in northern the day the last egg was laid and when the first Venezuela. This warbler inhabits the understory egg hatched (Briskie and Sealy 1990). We of mature and second growth forests from 800 to calculated the nestling period as the number of 2,700 m elevation in Costa Rica, Panama, and in days that lapsed from when the first egg hatched the Andes from Venezuela to Bolivia (Hilty until the first nestling fledged. 2003). Nest and clutch sizes have been described Egg temperatures (uC) were measured for B. in both Ecuador and Costa Rica (Greeney et al. tristriatus by inserting thermisters on the first or 2005, Jablonski et al. 2006), but no other second day of incubation into the center of one reproductive traits have been documented. We egg in each nest through a small hole sealed with provide detailed data based on 146 nests in a glue (Weathers and Sullivan 1989). The wire was montane cloud forest in Venezuela during 2002– threaded through the nest and connected to a 2006. We also present a review of the current HOBO Stowaway XTI datalogger (Onset Corpo- literature for all parulids and compare our results ration, Bourne, MA, USA) that recorded temper- to other species throughout North, Central, and atures every 12–24 sec for 5–7 days per nest South America. (Martin et al. 2007, Martin and Schwabl 2008). Ambient temperatures were measured over the METHODS same periods using a shaded probe near the nest. We searched for nests from March to July, We also measured egg temperatures for Red-faced 2002–2006, in Yacambu´ National Park in Lara, Warblers (Cardellina rubrifrons) in northern Venezuela (09u 429 N, 69u 429 W). This moun- Arizona using the same methodology (Martin et tainous park on the northernmost edge of the al. 2007). Andes is characterized by second growth and We searched the literature for life-history data mature tropical forest. The park ranges from 500 for all species in the Parulidae with which to to 2,200 m and our field sites occurred from 1,350 compare our results. We first consulted The Birds to 2,000 m elevation. We located nests via of North America data base (Poole 2005) and systematic and behavioral searches, and moni- supplemented these data with those from other tored them every 2–4 days, except at stage- literature. We calculated weighted means for changing events (laying, hatching, fledging) when clutch sizes, incubation periods (days), and we monitored nests daily or twice daily (Martin nestling periods (days) when multiple mean and Geupel 1993). Nest, egg, and nestling values and sample sizes were provided, or when measurements, and behavioral data were collected only raw data were available. We recorded a following Martin et al. (2000, 2006, 2007) and range of values when means could not be reliably Fierro-Caldero´n and Martin (2007). We measured calculated; these were excluded from analyses egg mass (g) and nestling growth using ACCU- when we compared temperate and tropical/ LAB (Elk Grove, IL, USA) portable electronic subtropical species. scales with an accuracy of 60.001 g during early Statistical Analysis.—Means are reported with incubation (days 0–2) for egg mass and every 61 standard error (SE) for all data and sample other day (starting on day 0 or 1) for nestling sizes reflect numbers of nests sampled. We used growth. Growth rates for non-experimental nests SPSS Version 15.0 (2006) for all statistical tests. were calculated following Remesˇ and Martin We used analysis of variance (ANOVA) to test for (2002), and nest predation and survival rates were temporal changes in nest attentiveness (% time on Cox and Martin N BREEDING BIOLOGY OF A TROPICAL WARBLER 669 FIG. 1. Temporal distribution of nest initiation dates (date the first egg is laid in a nest) for the Three-striped Warbler among weekly (7 day) intervals. the nest) and mean on- and off bouts during from 8 March to 25 June across years (Fig. 1). incubation by separating the stage into three Nests were usually initiated after 10 April (n 5 categories (early, 2–3 days; middle, 5–7 days; 103), although three nests were initiated in March; late, 12–14 days). We used least-significant two of these were from the same individual in difference tests (LSD) to conduct post hoc tests consecutive years based on color-banding. The when ANOVA results were significant (a # 0.05). median date of nest initiations was 16 May (Fig. 1). We used linear regression to test for relationships The nesting season lasted 68 days (Fig. 1). between temporal changes in parental behavior Eggs were white with irregular brown spots. during the nesting stage (e.g., brooding effort, Fresh egg mass (measured between day 0 and day feeding rates). We examined distributions of life- 2 of incubation) was 2.09 6 0.02 g (n 5 90), history trait data for temperate and subtropical/ which represented 17.7% of adult female body tropical warblers using a Shapiro-Wilks test. One mass (11.80 6 0.18 g, n 5 33). Five of 96 or both of the distributions departed from clutches had one egg (5%), one had three eggs normality for most life-history traits, so we used (1%), and the rest had two eggs (94%), yielding non-parametric Mann-Whitney U-tests to test for an average clutch size of 1.96 6 0.03 eggs.
Load more

Recommended publications
  • Birdlife International for the Input of Analyses, Technical Information, Advice, Ideas, Research Papers, Peer Review and Comment
    UNEP/CMS/ScC16/Doc.10 Annex 2b CMS Scientific Council: Flyway Working Group Reviews Review 2: Review of Current Knowledge of Bird Flyways, Principal Knowledge Gaps and Conservation Priorities Compiled by: JEFF KIRBY Just Ecology Brookend House, Old Brookend, Berkeley, Gloucestershire, GL13 9SQ, U.K. June 2010 Acknowledgements I am grateful to colleagues at BirdLife International for the input of analyses, technical information, advice, ideas, research papers, peer review and comment. Thus, I extend my gratitude to my lead contact at the BirdLife Secretariat, Ali Stattersfield, and to Tris Allinson, Jonathan Barnard, Stuart Butchart, John Croxall, Mike Evans, Lincoln Fishpool, Richard Grimmett, Vicky Jones and Ian May. In addition, John Sherwell worked enthusiastically and efficiently to provide many key publications, at short notice, and I’m grateful to him for that. I also thank the authors of, and contributors to, Kirby et al. (2008) which was a major review of the status of migratory bird species and which laid the foundations for this work. Borja Heredia, from CMS, and Taej Mundkur, from Wetlands International, also provided much helpful advice and assistance, and were instrumental in steering the work. I wish to thank Tim Jones as well (the compiler of a parallel review of CMS instruments) for his advice, comment and technical inputs; and also Simon Delany of Wetlands International. Various members of the CMS Flyway Working Group, and other representatives from CMS, BirdLife and Wetlands International networks, responded to requests for advice and comment and for this I wish to thank: Olivier Biber, Joost Brouwer, Nicola Crockford, Carlo C. Custodio, Tim Dodman, Roger Jaensch, Jelena Kralj, Angus Middleton, Narelle Montgomery, Cristina Morales, Paul Kariuki Ndang'ang'a, Paul O’Neill, Herb Raffaele and David Stroud.
    [Show full text]
  • American Redstarts
    San Antonio Audubon Society May/June 2021 Newsletter American Redstarts By Mike Scully At the time of this writing (early April), the glorious annual spring migration of songbirds through our area is picking up. Every spring I keep a special eye out for one of my favorite migrants, the American Redstart (Setophaga ruticilla). These beautiful warblers flutter actively through the foliage, tail spread, wings drooped, older males clad in black and orange, females and second year males in shades of gray, olive green and yellow. For years, the American Redstart was the only species remaining in the genus Setophaga, until a comprehensive genetic analysis of the Family Parulidae resulted in this genus being grouped with more than 32 species formerly placed in the genus Dendroica and Wilsonia. The name Setophaga was applied to the whole by virtue of seniority. Though now grouped in a large genus, the American Redstart remains an outlier, possessing proportionately large wings, a long tail, and prominent rictal bristles at the base of the relatively wide flat beak, all adaptations to a flycatching mode of foraging. Relatively heavy thigh musculature and long central front toes are apparently adaptations to springing into the air after flying insects. The foraging strategy of redstarts differs from that of typical flycatchers. Redstarts employ a more warbler-like maneuver, actively moving through the foliage, making typically short sallies after flying insect prey, and opportunistically gleaning insects from twigs and leaves while hovering or perched. The wings are frequently drooped and the colorful tail spread wide in order to flush insect prey.
    [Show full text]
  • Spring Migration of Blackpoll Warblers Across North America
    VOLUME 15, ISSUE 1, ARTICLE 17 Covino, K. M., S. R. Morris, M. Shieldcastle, and P. D. Taylor. 2020. Spring migration of Blackpoll Warblers across North America. Avian Conservation and Ecology 15(1):17. https://doi.org/10.5751/ACE-01577-150117 Copyright © 2020 by the author(s). Published here under license by the Resilience Alliance. Research Paper Spring migration of Blackpoll Warblers across North America Kristen M. Covino 1,2,3,4, Sara R. Morris 2,3,4,5, Mark Shieldcastle 6 and Philip D. Taylor 7 1Biology Department, Loyola Marymount University, Los Angeles, California, USA, 2Appledore Island Migration Station, Portsmouth, New Hampshire, USA, 3Shoals Marine Laboratory, University of New Hampshire, Durham, New Hampshire, USA, 4Braddock Bay Bird Observatory, Hilton, New York, USA, 5Canisius College, Buffalo, New York, USA, 6Black Swamp Bird Observatory, Oak Harbor, Ohio, USA, 7Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada ABSTRACT. The awe-inspiring seasonal migrations of birds between breeding and wintering grounds has long attracted the interest of casual naturalists and professional ornithologists alike. Although new technologies improve our ability to follow individual migrants throughout their annual cycle, the scale and detail provided by banding records remain incredibly valuable. The focus of avian migration studies is often the most physiologically challenging migratory feats that sometimes leaves certain species or seasons relatively understudied. The Blackpoll Warbler (Setophaga striata) is well-known for its transoceanic migratory flight during fall migration, the season in which it is best studied, yet the details of its spring migration are not well known, at least not at a continental scale.
    [Show full text]
  • Toxic Birds Not of a Feather
    Commentary Avian chemical defense: Toxic birds not of a feather Paul J. Weldon Conservation and Research Center, Smithsonian Institution, 1500 Remount Road, Front Royal, VA 22630 n 1992, Dumbacher et al. (1) substan- Itially altered prevailing views of avian physiology, biochemistry, and chemical ecology with their report of the potent neurotoxin homobatrachotoxinin in feathers and other tissues of several spe- cies of New Guinean passerine birds of the genus Pitohui. Their discovery was signif- icant not only for suggesting a protective mechanism rarely considered for birds (i.e., chemical defense) but for the nature of the compound they discovered, a struc- turally complex alkaloid that binds Naϩ channels and depolarizes electrogenic membranes. Alkaloids in tetrapods gen- erally had been thought to be confined to amphibians, whose skins have long been acknowledged as arsenals of these biolog- Fig. 1. Hornets (Vespa orientalis) attacking a freshly skinned carcass of a laughing dove (Steptopelia ically active compounds (2). Indeed, be- senegalensis)(Left) while ignoring that of a pied kingfisher (Ceryle rudis). This observation prompted H. B. fore its discovery in Pitohui, homobatra- Cott (4) to undertake an extensive investigation of avian chemical defense. [Reproduced with permission chotoxinin, a member of a family of from ref. 4 (Copyright 1947, The Zoological Society of London).] steroidal alkaloids called batrachotoxinins (BTXs), had been found only in skin se- cretions of Central and South American dichrous), the most toxic of the birds they An additional enigma described by poison-dart frogs (Dendrobatidae) of the examined, is aposematic and may be Dumbacher et al. (3) is the profound genus Phyllobates.
    [Show full text]
  • Birds of the East Texas Baptist University Campus with Birds Observed Off-Campus During BIOL3400 Field Course
    Birds of the East Texas Baptist University Campus with birds observed off-campus during BIOL3400 Field course Photo Credit: Talton Cooper Species Descriptions and Photos by students of BIOL3400 Edited by Troy A. Ladine Photo Credit: Kenneth Anding Links to Tables, Figures, and Species accounts for birds observed during May-term course or winter bird counts. Figure 1. Location of Environmental Studies Area Table. 1. Number of species and number of days observing birds during the field course from 2005 to 2016 and annual statistics. Table 2. Compilation of species observed during May 2005 - 2016 on campus and off-campus. Table 3. Number of days, by year, species have been observed on the campus of ETBU. Table 4. Number of days, by year, species have been observed during the off-campus trips. Table 5. Number of days, by year, species have been observed during a winter count of birds on the Environmental Studies Area of ETBU. Table 6. Species observed from 1 September to 1 October 2009 on the Environmental Studies Area of ETBU. Alphabetical Listing of Birds with authors of accounts and photographers . A Acadian Flycatcher B Anhinga B Belted Kingfisher Alder Flycatcher Bald Eagle Travis W. Sammons American Bittern Shane Kelehan Bewick's Wren Lynlea Hansen Rusty Collier Black Phoebe American Coot Leslie Fletcher Black-throated Blue Warbler Jordan Bartlett Jovana Nieto Jacob Stone American Crow Baltimore Oriole Black Vulture Zane Gruznina Pete Fitzsimmons Jeremy Alexander Darius Roberts George Plumlee Blair Brown Rachel Hastie Janae Wineland Brent Lewis American Goldfinch Barn Swallow Keely Schlabs Kathleen Santanello Katy Gifford Black-and-white Warbler Matthew Armendarez Jordan Brewer Sheridan A.
    [Show full text]
  • REGUA Bird List July 2020.Xlsx
    Birds of REGUA/Aves da REGUA Updated July 2020. The taxonomy and nomenclature follows the Comitê Brasileiro de Registros Ornitológicos (CBRO), Annotated checklist of the birds of Brazil by the Brazilian Ornithological Records Committee, updated June 2015 - based on the checklist of the South American Classification Committee (SACC). Atualizado julho de 2020. A taxonomia e nomenclatura seguem o Comitê Brasileiro de Registros Ornitológicos (CBRO), Lista anotada das aves do Brasil pelo Comitê Brasileiro de Registros Ornitológicos, atualizada em junho de 2015 - fundamentada na lista do Comitê de Classificação da América do Sul (SACC).
    [Show full text]
  • A Description of Mixed-Species Insectivorous Bird Flocks in Western Mexico’
    The Condor 89~282-292 0 The Cooper Omithologml Society 1987 A DESCRIPTION OF MIXED-SPECIES INSECTIVOROUS BIRD FLOCKS IN WESTERN MEXICO’ RICHARD L. HUTTO Department of Zoology, Universityof Montana, Missoula, MT 59812 Abstract. Insectivorousbird flockswere observed in all typesof forestedhabitats during the nonbreedingseason in westernMexico. The speciescomposition of flockschanged markedlyand predictablyamong five categoriesof habitat type. The averagenumber of speciesper flockin lowlandhabitats was 4.7, while a mean of 18.6 speciesparticipated in highlandflocks, ranking the latter amongthe most species-richflocks in the world. The meanproportion of the localinsectivorous species that participatedin mixed-speciesflocks wassignificantly greater in the highlands(6 1.3%)than in the lowlands(24.6%). About half of the flock participantsin both undisturbedlowland and highlandhabitats were north temperatemigrants, ranking west Mexican flocks among the mostmigrant-rich in the world as well. In highlandflocks, the maximum numberof individualsper attendantspecies was generallytwo to three,but therewere often six to twelveindividuals belonging to eachof severalnuclear species. The lowlanddeciduous forest flocks seemed to lack nuclearspecies. Key words: Mixed-speciesflocks; insectivorousbirds; Mexico; migratory birds;pine-oak woodlands;tropical deciduous forests. INTRODUCTION mixed-speciesflocks in 26 sites(Appendix I) that Mixed-speciesinsectivorous bird flockshave been were distributed among various habitats described from temperate and tropical areas throughout western Mexico. The habitat types worldwide (Rand 1954), and are known to occur that I surveyed can be roughly classified (after in practically every habitat type (Powell 1985). Pesman 1962) as belonging to either lowland Although mixed-species flocks are quite com- (tropical deciduous and tropical evergreen) or mon in north temperate regions during the non- highland (oak, pine-oak, and boreal) forests.
    [Show full text]
  • Ne:Otropigalmigr:Ant Landbird Monitoring Program for Maineand..New' Brunswick: Assessing Coastal Importance and Management Strategies
    NE:OTROPIGALMIGR:ANT LANDBIRD MONITORING PROGRAM FOR MAINEAND..NEW' BRUNSWICK: ASSESSING COASTAL IMPORTANCE AND MANAGEMENT STRATEGIES Norman Famous, Wildlife Ecologist PROJECT SUMMARY Populations of many Neotropical migrant landbirds and shorebirds have shown both long­ and short-term declines in the Northeastern U.S. and adjacent Canada. The causes of these declines are not entirely understood and vary among species. A cooperative initiative linking Federal and Provincial agencies, private landowners, conservation organizations, industry and field ornithologists was implemented in 1993 to monitor breeding and migratory bird populations in structurally stable boreal forests, pine-spruce woodlands, bogs and fens in the Bay of Fundy ecological zone in Maine and coastal New Brunswick, as well as the Acadian Peninsula in NW New Brunswick. Careful selection of monitoring sites and control of observer expertise are being exercised. Most sites are relatively free from future habitat fragmentation, large changes in habitat structure, human disturbances and insect infestations. The distribution of birds and vegetation characteristics are being mapped within fixed­ diameter point count circles along 25 new census routes located within 0.5 km of the coast or on larger islands. Birds were censused and mapped along 13 BBS routes in the region. Twenty-two boreal bogs and fens were surveyed. Habitat use by birds and habitat changes over time will be evaluated in addition to long term population trends in both new routes and BBS routes. Breeding season bird use and vegetation change in nine mined peatlands undergoing natural and human-induced restoration are being monitored in Maine and New Brunswick. (Comment, the habitat work was not completed during subsequent years due to insufficient funds.) Seventy-eight fall migration fixed-diameter area-search point count circles were censused every ten days from August through October at six coastal sites.
    [Show full text]
  • Observations on New Or Unusual Birds from Trainidad, West Indies
    474 SHORT COMMUNICATIONS SUMMARY CLAUSEN, G., R. SANSON, AND A. STORESUND. 1971. The HbO, dissociation curve of the fulmar and Blood respiratory properties have been compared in the herring gull. Respir. Physiol. 12 :66-70. antarctic birds. Blood hemoglobin content, hemato- DANZER, L. A., AND J. E. COHN. 1967. The dis- crit, and mean corpuscular hemoglobin concentration sociation curve of goose blood. Respir. Physiol. (MCHC) are higher in three species of penguins 3:302-306. than in the Giant Fulmar and the antarctic Skua. HOLMES, A. D., M. G. PIGGOT, AND P. A. CAhwmLL. Penguin chicks show lower hemoglobin values than 1933. The hemoglobin content of chicken blood. adults. HbO, dissociation curves show higher affin- J. Biol Chem. 103:657. ity in diving than nondiving birds. Among penguins, LENFANT, C., AND K. JOHANSEN. 1965. Gas trans- the Chinstrap Penguin, practicing longer and deeper port by the hemocyanin containing blood of the dives, has blood with higher O? affinity than the other cephalopod, Octopus dofleini. Amer. J. Physiol. species. The Bohr effect is similarly higher in diving 209:991-998. than nondiving birds. The adaptive value of the blood LENFANT, C., G. L. KOOYMAN, R. ELSNER, AND C. M. respiratory properties is discussed in the context of DRABEK. 1969. Respiratory function of blood behavior and mode of life of the species studied. of the adelie penguin, Pygoscelis adeliae. Amer. ACKNOWLEDGMENT J. Physiol. 216: 1598-1600. LUTZ, P. L., I. S. LoNchrmn, J. V. TUTTLE, AND K. This work was supported by the National Science SCHMIDT-NIELSEN. 1973. Dissociation curve of Foundation under grants GV-25401 and GB-24816 bird blood and effect of red cell oxygen consump- to the Scripps Institution of Oceanography for opera- tion.
    [Show full text]
  • Macgillivrays Warbler
    Wyoming Species Account MacGillivray’s Warbler Geothlypis tolmiei REGULATORY STATUS USFWS: Migratory Bird USFS R2: No special status USFS R4: No special status Wyoming BLM: No special status State of Wyoming: Protected Bird CONSERVATION RANKS USFWS: No special status WGFD: NSS4 (Bc), Tier II WYNDD: G5, S4 Wyoming Contribution: LOW IUCN: Least Concern PIF Continental Concern Score: 11 STATUS AND RANK COMMENTS MacGillivray’s Warbler (Geothlypis tolmiei) does not have any additional regulatory status or conservation rank considerations beyond those listed above. NATURAL HISTORY Taxonomy: Two subspecies of MacGillivray’s Warbler are recognized and known to breed in the United States: G. t. tolmiei and G. t. monticola 1. In Wyoming, G. t. monticola is the known subspecies; it breeds east of the Pacific slope, in the Rocky Mountains and Great Basin, and winters in higher elevations of central and southern Mexico, occasionally in southern California 2, 3. Two additional subspecies of G. tolmiei are not recognized by the American Ornithologists’ Union (AOU): G. t. intermedia and G. t. austinsmithi. The distinguishing characteristic is reported to be a shorter tail length in G. t. austinsmithi and there are specimens of said subspecies from western Wyoming 1, 4. Recent molecular phylogeny efforts concluded that MacGillivray’s Warbler is more closely related to the genus Geothlypis 5. The AOU approved the genus change in 2011 6. Prior to this, the species was placed in the genus Oporornis. Description: The species is a small wood-warbler in the Parulidae Family. MacGillivray’s Warbler is identifiable in the field during the breeding season. Male upperparts are olive green and underparts are yellow.
    [Show full text]
  • The Influence of Agriculture on Avian Communities Near Villavicencio
    GENERAL NOTES 381 By day 35 foot span already averaged 99% of adult size. Rapid attainment of adult foot size likely reflects the importance of the many tasks the foot performs (e.g., perching, climb- ing, feeding). At hatching, bill width was already 49.4% of adult size, although, at day 35, bill width was closer to adult size than length or depth. This was the result of a more rapid development in width before hatching, since the growth rates of all bill dimensions were about the same throughout nestling development. Since bill width was measured at the base of the bill, it is about equivalent to gape width. The rapid increase of gape width in other species (Dunn, Condor 77:431-438, 1975; Holcomb, Nebraska Bird Rev. 36:2232, 1968; Holcomb and Twiest, Ohio J. Sci. 68:277-284, 1968; Royama, Ibis 108:313347, 1966) has been interpreted (OConnor,’ Ibis 119:147-166, 1975) as important in increasing parental feeding efficiency because it allows the young to consume larger food items. Young Monk Parakeets are fed by regurgitation. This material was described as a white, milky fluid (Alexandra 1977). Ac- cordingly, the ability to consume large food items may be of little value to nestlings. Since food is provided by the parents in a rather processed form, there would be little advantage in rapid bill growth for the purpose of processing food items. Fledglings, too, are fed by regurgitation, although they soon begin to do some foraging for themselves. Yet, as Portmann (Proc. 11th Int. Omithol. Congr. 138-151, 1955) has shown, as the brain develops early, the skull must develop similarly to accommodate it.
    [Show full text]
  • Brown-Headed Cowbird (Molothrus Ater) Doug Powless
    Brown-headed Cowbird (Molothrus ater) Doug Powless Grandville, Kent Co., MI. 5/4/2008 © John Van Orman (Click to view a comparison of Atlas I to II) Brown-headed Cowbirds likely flourished Distribution Brown-headed Cowbirds breed in grassland, alongside the Pleistocene megafauna that once prairie, and agricultural habitats across southern roamed North America (Rothstein and Peer Canada to Florida, the Gulf of Mexico, and 2005). In modern times, flocks of cowbirds south into central Mexico (Lowther 1993). The followed the great herds of bison across the center of concentration and highest abundance grasslands of the continent, feeding on insects of the cowbird during summer occurs in the kicked up, and depositing their eggs in other Great Plains and Midwestern prairie states birds’ nests along the way. An obligate brood where herds of wild bison and other ungulates parasite, the Brown-headed Cowbird is once roamed (Lowther 1993, Chace et al. 2005). documented leaving eggs in the nests of hundreds of species (Friedmann and Kiff 1985, Wild bison occurred in southern Michigan and Lowther 1993). The evolution of this breeding across forest openings in the East until about strategy is one of the most fascinating aspects of 1800 before being hunted to near-extinction North American ornithology (Lanyon 1992, across the continent (Baker 1983, Kurta 1995). Winfree 1999, Rothstein et al. 2002), but the Flocks of cowbirds likely also inhabited the cowbird has long drawn disdain. Chapman prairies and woodland openings of southern (1927) called it “. a thoroughly contemptible Michigan prior to the 1800s (Walkinshaw creature, lacking in every moral and maternal 1991).
    [Show full text]