John A. Smallwood

Seasonal shifts in sex ratios of fledgling American kestrels (Falco sparverius paulus): The Early Bird Hypothesis

We document a seasonal shift in the sex ratios of broods produced by resident southeastern American kestrels (Falco sparverius paulus) breeding in nest boxes in Florida. Early in the breeding season, most biased broods were biased towards males, whereas later in the season, most biased broods were biased towards females. Computer-simulated broods subjected to sex-biased egg and/or nestling mortality demonstrate that it is possible that differential mortality produced the pattern of bias that we observed. However, these simulations do not exclude the possibility that female kestrels were manipulating the primary sex ratio of the broods. We present evidence that this sex ratio shift is adaptive: for males we detected breeding as yearlings, all had fledged early the previous season. No such relationship between season and the probability of breeding as a yearling was found for females. We propose the Early Bird Hypothesis as the ecological basis for the advantage of fledg ing early in males. We hypothesize that pre-emptive competition among post-fledging, dispersing males for breeding sites confers an advantage to males fledged early in the season. This hypothesis may explain why a non-migratory population of the Eurasian kestrel (F. tinnunculus) and non-migratory American kestrels breeding in Florida (F. s. paulus) exhibit this seasonal shift in sex ratios, whereas migratory American kestrels (F. s. sparverius) breeding in Saskatchewan, Canada, do not. We discuss the relevance of the Early Bird Hypothesis for other animal species.

Why are American Kestrel (Falco sparverius) Populations Declining in North America? Evidence from Nest-Box Programs

Abstract Declines in American Kestrel (Falco sparverius) populations are widely reported, and Breeding Bird Survey (BBS) data suggest that the North American population declined significantly from 1984 to 2007. Potential causes include the spread of West Nile virus (WNV), increases in populations of Coopers Hawks (Accipiter cooperii), and loss of suitable habitat. We examined trends in the numbers of both migratory and resident kestrel populations that use nest boxes in eight study areas in Florida, Georgia, Virginia and Maryland, New Jersey, Massachusetts, Pennsylvania, Saskatchewan, and the Yukon Territory, 1984–2007. All eight populations underwent significant declines; the mean annual decline in nest-box occupancy rate was 3.0% and ranged from 0.6% in Pennsylvania to 4.7% in New Jersey. Except for the most recent nest-box program, established in 1995 and declining since 2002, all nest-box populations began to experience declines before WNV arrived in North America in 1999. To test whether changes in kestrel population densities generally are associated with the opposite trend in Coopers Hawks, we examined the 42 BBS physiographic regions for which trends for both species were available. No significant correlations were detected for the period 1966–2007, or for 1980–2007, more closely concurrent with our nest-box data. Christmas Bird Count data from 1959 through 1988 also failed to demonstrate a significant correlation. Finally, the habitat within our study areas still appears suitable, and the remaining kestrels appear healthy and have high reproductive success. Thus, the principal cause of the decline probably lies elsewhere, perhaps on the wintering grounds or along migration routes. Further, for both migratory and resident populations, the decline in nest-box occupancy may reflect regional declines, which would reduce the number of individuals available for replacing breeding birds that have died or dispersed.

Southeastern American Kestrels Respond to an Increase in the Availability of Nest Cavities in North-Central Florida

Abstract We conducted a nest-box study from 1989–93 in north-central Florida, in an effort to increase the population of the threatened Southeastern American Kestrel (Falco sparverius paulus) and to evaluate the effect of providing artificial nest sites on the local population. A total of 388 nest boxes were erected in the experimental area. Over 75% of these nest boxes were placed >250 m away from roadside transects we established. This enabled us to measure changes in population density without the potential bias associated with the concentration of kestrels at specific nest-box sites. Annual censuses were conducted along 20 16-km transects to quantify population density in the control (no nest boxes) and treatment zones. Breeding attempts in nest boxes increased during each year of the study. Kestrel densities along the experimental transects increased from 5.0 birds/100 km2 to levels equivalent to the control zone within 3 yr of nest box placement (32.3 vs. 34.9 birds/100 km2). Kestrels preferred nest boxes in sandhill habitats over those in hammock habitats, and nesting attempts in sandhills had greater hatching rates, more fledglings produced, and greater overall nesting success. Compared with sites with nest boxes that were not used by kestrels, sites with selected nest boxes were characterized by having more longleaf pine (Pinus palustris), cabbage palm (Sabal palmetto), and ground cover <10 cm in height, and less broadleaf deciduous trees, oaks (Quercus spp.), roadside berms, hayfields, water, and gravel.

American Kestrel Breeding Habitat: The Importance of Patch Size

Abstract Previous studies have examined vegetative cover and land use immediately surrounding American Kestrel (Falco sparverius) nest sites. However, the relationship of landscape-level habitat structure to nest-site selection has received little attention. Between 1995 and 2007, we erected nest boxes in pastures and meadows in northwestern New Jersey. The number of breeding pairs in boxes ranged from 2 in 1995 to 59 in 2002. We used a Geographic Information System to model habitats used by kestrels (open areas dominated by herbaceous vegetation) and delineated patches of contiguous suitable habitat within the study area and statewide. Nest boxes available in large (>1000 ha) patches of suitable habitat were occupied by kestrels at rates significantly higher than those in medium (250–1000 ha) or small (<250 ha) patches. Large patches exhibited relatively high occupancy rates every year, medium patches were most likely to be occupied during years when kestrels were abundant in the study area, and small patches were used infrequently, regardless of how many breeding pairs were present in the study area. That kestrels disproportionately select nest sites in contiguous patches sufficiently large to include many breeding territories has important implications for conservation strategies. We currently are using information on patch size to implement a statewide nest-box program for kestrels in New Jersey.

Habitat fragmentation reduces occupancy of nest boxes by an open-country raptor

Despite the recent rapid decline of many grassland bird species, the relative importance of habitat configuration to population persistence is unclear. We used Southeastern American Kestrels Falco sparverius paulus in north-central Florida as a model system to explore the relative influence of landscape structure components on site occupancy patterns at two spatial scales, and for two different time periods. We focused on the dynamic processes of site-level population expansion or contraction. We modelled the occupancy of 131 American Kestrel nest boxes with Bayesian state-space dynamic occupancy models that considered both the partially observed process of true occupancy and the probability of detection of occupancy. We used reversible jump Markov chain Monte Carlo (RJMCMC) algorithms to identify variables that described the continued occupancy of nest boxes, or ϕ, and the probability of colonisation of nest boxes between time periods, or γ 3 . Changes in open habitat patch isolation at a fine scale, as estimated by the variability of nearest neighbour distance, predicted site colonisation between decades, and patch shape variability was related to ϕ during the early time period (1992–93). We found no strong effects of landscape structure on ϕ during the later time period (2008–2010). We also found no evidence for effects of loss of open habitat on box occupancy or colonization. Our results indicate that continued habitat fragmentation would be deleterious for this threatened subspecies. Additionally, certain land cover management practices recommended for the Florida sandhills, such as frequent low-intensity controlled burns, will likely help conservation attempts.

Ectoparasites of American Kestrels in Northwestern New Jersey and Their Relationship to Nestling Growth and Survival

Abstract American Kestrel (Falco sparverius) populations have been declining throughout much of North America during recent decades. To determine if the ectoparasite burdens of nestlings may be a contributing factor, we examined broods of kestrels in nest boxes in northwestern New Jersey. Our objectives were to identify and quantify the arthropod ectoparasites of nestlings, and to determine if removing these parasites from nestlings would increase kestrel nesting success. Of 26 broods we examined, we randomly chose 13 and manually removed from the nestlings all visible arthropods during three visits, when nestlings were age 5–7, 10–12, and 15–17 d old; we handled the 11 control broods similarly but did not remove arthropods. Both the experimental and control broods were measured and banded at age 20–22 d, and all visible arthropods were collected from both groups. Of 1767 arthropod specimens collected, 1679 (95.0%) were Carnus hemapterus (Diptera: Carnidae). Our observation of the next most abundant parasite, Ornithonyssus sylviarum (northern fowl mite, Acari: Macronyssidae; 46 specimens), was apparently the first record of the American Kestrel as host. The remaining 42 specimens included 9 other kestrel parasites (4 species) and 33 nonparasites (19 species). C. hemapterus loads increased as nestlings aged, were highest at age 10–12 d, and declined thereafter. At age 20–22 d, control broods had significantly higher loads of C. hemapterus and other parasites. However, we detected no significant differences in nestling wing length, tail length, body mass, body mass/wing length (an index of nestling condition), or nestling survival. Thus, we found no evidence that ectoparasite removal would be an effective strategy in increasing the nesting success of American Kestrels in this study area. ECTOPARÁSITOS DE FALCO SPARVERIUS EN EL NOROESTE DE NUEVA JERSEY Y SU RELACIÓN CON EL CRECIMIENTO Y LA SUPERVIVENCIA DE LOS POLLUELOS Durante las últimas décadas, las poblaciones de Falco sparverius han disminuido a lo largo de la mayor parte de América del Norte. Para determinar si la carga de ectoparásitos de los pichones puede ser un factor que contribuye a la disminución, examinamos las nidadas de F. sparverius en nidos caja en el noroeste de Nueva Jersey. Nuestros objetivos fueron identificar y cuantificar los ectoparásitos artrópodos de los polluelos y determinar si la remoción de estos parásitos de los pichones incrementa el éxito de nidificación de la especie. De las 26 nidadas que examinamos, escogimos 13 al azar y quitamos manualmente todos los artrópodos visibles de los pichones durante tres visitas, cuando las edades de los polluelos eran de 5–7, 10–12 y 15–17 días. Manipulamos las 11 nidadas de control de manera similar pero no les quitamos los artrópodos. Tanto la nidada experimental como la de control fueron medidas y anilladas a los 20–22 días de edad y todos los artrópodos visibles fueron colectados en ambos grupos. De 1767 especímenes de artrópodos colectados, 1679 (95.0%) pertenecieron a la especie Carnus hemapterus (Diptera: Carnidae). La observación del siguiente parásito más abundante, Ornithonyssus sylviarum (Acari: Macronyssidae; 46 especímenes) fue, aparentemente, el primer registro para F. sparverius como hospedador. Los 42 especímenes restantes incluyeron otros nueve parásitos de F. sparverius (4 especies) y 33 individuos no parásitos (19 especies). Las cargas de C. hemapterus aumentaron a medida que los pichones crecían hasta los 10–12 días de edad y a partir de entonces disminuyeron. A la edad de 20–22 días, las nidadas de control presentaron cargas significativamente mayores de C. hemapterus y de otros parásitos. Sin embargo, no detectamos diferencias significativas en el largo del ala de los polluelos, el largo de la cola, la masa corporal, la masa corporal/el largo del ala (un índice de la condición del polluelo) o la supervivencia de los pichones. De este modo, no encontramos evidencia de que la remoción de ectoparásitos pueda ser una estrategia efectiva para incrementar el éxito de nidificación de F. sparverius en el área de estudio.

Breeding-site Fidelity of Southeastern American Kestrels (Falco sparverius paulus)

Resumen La fidelidad a los sitios de cria en las rapaces ha sido estudiada principalmente en las poblaciones migratorias, sin embargo, se sabe relativamente poco sobre las poblaciones no migratorias. Examinamos la fidelidad a los sitios de cria en la especie no migratoria Falco sparverius paulus en el centro-norte de Florida. Las hembras exhibieron una mayor tendencia que los machos a cambiar territorios en anos consecutivos; la ocupacion de los machos cambio en 4 de 10 (40%) casos, mientras que la ocupacion de las hembras cambio en 21 de 28 (75%) casos (P  =  0.055). En todos los casos donde los nidos fallaron, la propiedad territorial en el ano siguiente cambio; sin embargo, tanto para los machos como para las hembras los cambios en la ocupacion de territorios no se relacionaron significativamente con el resultado de los nidos, debido probablemente al tamano pequeno de la muestra. Las diferencias entre los sexo en la fidelidad a los sitios de cria en nuestra area de estudio fueron mayores que aquellas d...

Proceedings Of The Ninety-Second Annual Meeting

The Ninety-sixth Annual Meeting of The Wilson Ornithological Society was held in joint conference with the Association of Field Ornithologists and the Society of Canadian Ornithologists-Societe des ornithologistes du Canada, from Wednesday, 15 July, through Sunday, 19 July, 2015, on the campus of Acadia University in Wolfville, Nova Scotia, which hosted the meeting. Dave Shutler of the Department of Biology, Acadia University, chaired the Committee on Local Arrangements, which also included Colleen Barber, Andrew Boyne, Carina Gjerdrum, Andrew Horn, Marty Leonard, Mark Mallory, Cindy Staicer, and Phil Taylor, with help from Terry Aulenbach, Avery Bartel, Brenda Bigelow, Morgan Brown, Duane Currie, Tammy Gregory, Kayoung Heo, Christine Kendrick, Katrien Kingdon, Sarah Klapstein, Sarah MacDougall, Emma McIntyre, Karissa Reischke, Brent Robicheau, Dave Schultz, Larissa Simulik, Richard Stern, Dan Sweeney, Lisa Taul, Allison Walker, Jake Walker, Nicole Weisner, and Brett VanBlarcom. The Council met from 13:08 to 17:14 on Wednesday, 15 July, and again from 08:37 to 12:16 on Thursday, 16 July, in the Acadia Room of the K. C. Irving Environmental Science Centre, Acadia University. That evening (Thursday) there was an icebreaker opening reception for the conferees and guests at Fountain Commons. The scientific program began on Friday morning in Festival Theater with the WOS Margaret Morse Nice Plenary Lecture, cosponsored by SCO-SOC, delivered by the 2015 Margaret Morse Nice Medal recipient, Erica (Ricky) Dunn, Research Scientist Emeritus, Environment Canada, and titled “Bird observatories: diversity and opportunity.” On Saturday morning James F. Dwyer, Research Scientist, EDM International, presented the AFO plenary lecture, “Range sizes and habitats of nonbreeding Crested Caracaras: implications for the evolution of communal roosting.” The scientific program also included 98 papers organized into 12 sessions; 20 papers organized into three symposia on the ecology and conservation of landbird species at risk: Rusty Blackbirds (Euphagus carolinus) and Canada Warblers (Cardellina canadensis), measuring the impact of bird conservation programs, and bird migration in Atlantic Canada and the Gulf of Maine; and 68 poster presentations. On Friday and Saturday morning, before the plenary sessions, the Local Committee hosted field trips to local birding spots, including Miner’s Marsh and Evangeline Beach. On Sunday, conferees enjoyed longer outings, including a trip to Brier Island to observe pelagic birds and whales, a visit to Cape Split on the Bay of Fundy, and a tour of four local wineries. On Saturday evening there was a social gathering prior to the annual banquet. The evening events included dinner and afterwards Acting WOS Secretary Lindsey Walters, on behalf of all assembled, thanked the Local Committee for a successful conference. She then commended retiring WOS President Bob Curry for his many contributions to the society thus far, as the society looks forward to his continued service in his new role as First Past-President. The following WOS awards, grants, and commendations were presented at the banquet:

Proceedings of the Ninetieth Annual Meeting

The ninetieth annual meeting of the Wilson Ornithological Society (WOS) was held in joint session with the Association of Field Ornithologists (AFO) from Thursday, 9 April, through Sunday, 12 April 2009 at the Hilton Pittsburgh in Pittsburgh, Pennsylvania at the invitation of the National Aviary and Powdermill Nature Reserve, Carnegie Museum of Natural History, in partnership with the Three Rivers Bird Club, Audubon Society of Western Pennsylvania, Duquesne University, University of Pennsylvania, Pennsylvania Game Commission, Western Pennsylvania Conservancy, and the American Birding Association. Todd Katzner, Director of Conservation and Research at the National Aviary, chaired the local committee, which also included Anthony Bledsoe, Jim Bonner, Tammy Colt, Jean Deo, Erin Estell, Mike Kuzemchak, Steven Latta, Andrew Mack, Brady Porter, Brian Shema, Poly Singh, Jack Solomon, Samara Trusso, and James Valimont. The Council met from 0916 to 1708 hrs on Thursday, 9 April, in the Brigade Room of the Hilton Pittsburgh. That evening there was an ‘‘ice-breaker’’ reception for the conferees and guests. The opening session on Friday convened in the Grand Ballroom at 0814 with welcoming remarks from Todd Katzner, WOS President James D. Rising, and AFO President David N. Bonter. After several items of information for the conferees, David Bonter concluded the opening ceremony by introducing the plenary speaker, Bruce Beehler, who delivered a wonderfully thought-provoking presentation, ‘‘The forgotten science—a role for natural history in the 21st Century.’’ The scientific program included 54 contributed papers and 62 contributed posters, which were organized into eight paper sessions, a poster session, and a symposium on remote and automated technologies for monitoring birds. In addition, WOS hosted the Margaret Morse Nice Lecture, presented by the 2009 Nice Medal recipient, Sidney A. Gauthreaux Jr., ‘‘Radar ornithology at different spatial scales.’’ The evening program on Friday included a reception at the National Aviary, which coincided with the poster session. The Three Rivers Bird Club hosted birding forays in the vicinity of the conference site each morning from Thursday through Sunday. In addition, longer trips were scheduled for Sunday to: (1) Powdermill Nature Reserve, the biological research station of Carnegie Museum of Natural History with a trip to Frank Lloyd Wright’s Fallingwater; (2) the Pittsburgh Zoo and view of downtown Pittsburgh from an amphibious tour vehicle; (3) the University of Pittsburgh campus, home of a breeding pair of Peregrine Falcons (Falco peregrinus), and a tour of the Carnegie Museum of Natural History; (4) the Pymatuning Laboratory of Ecology in northwestern Pennsylvania; and (5) Moraine State Park and Lake Arthur. The attendees enjoyed a social hour prior to the annual banquet, which was held in the Kings Garden Room of the Hilton Pittsburgh. The evening festivities included an enjoyable dinner, and afterwards WOS President Rising and AFO President Bonter joined those assembled in thanks to the many persons whose hard work had resulted in a successful conference. President Rising also thanked the three elected members of Council who had completed their terms of office, Carla Dove, Greg H. Farley, and Daniel Klem Jr., and welcomed the three newly elected members of Council, Mary Bomberger Brown, Mary Garvin, and Mark S. Woodrey, who will serve the 2009– 2012 term, and another newly elected member of Council, Mia R. Revels, who will serve the remainder of a vacated 2007–2010 term. The following WOS awards and commendations also were presented:

Proceedings Of The Eighty-Ninth Annual Meeting

The eighty-ninth annual meeting of the Wilson Ornithological Society (WOS) was held Thursday 17 April, through Sunday, 20 April 2008 at the Mobile Convention Center, Mobile, Alabama in joint session with the Association of Field Ornithologists (AFO), at the invitation of the University of Southern Mississippi (USM) Migratory Bird Research Group and sponsored by the Gulf Coast Bird Observatory, Mississippi Coast Audubon Society, University of Southern Mississippi, Dauphin Island Sea Laboratory, University of California Press, USM Coastal Research and Extension Center, and the Grand Bay National Estuarine Research Reserve (NERR). Frank R. Moore, Director of the USM Migratory Bird Research Group, chaired the local committee, which also included Robert Diehl, John Dindo, Jennifer Owen, and Mark Woodrey. The WOS Council met from 1307 to 1802 hrs on Thursday, 17 April, in Room 105-B of the Mobile Convention Center. That evening there was a social at the Center for the conferees and guests. The Council met again from 1121 to 1306 hrs the following day. The opening session on Friday convened in a large space at the Center known as Room 210-BCD at 0806 hrs with welcoming remarks from Frank R. Moore, WOS President James D. Rising, and AFO President Cecilia M. Riley. Timothy J. O’Connell, Chair of the WOS Student Travel Awards Committee, offered comments on those awards, and Mark Woodrey of the local committee provided information concerning field trips. The opening ceremony continued with a presentation by Edward H. Burtt Jr. on Margaret Morse Nice, which led to his introduction of Jerome A. Jackson, who concluded the opening ceremony by delivering the Margaret Morse Nice Plenary Lecture, ‘‘Thinking like a mountain, seeing like a woodpecker: behavioral ecology and conservation of woodpeckers.’’ The scientific program included 58 contributed papers and 47 contributed posters, which were organized into eight paper sessions, a poster session, and a symposium on migration and coastal ecology. In addition, WOS hosted the Margaret Morse Nice Lecture, and the Association of Field Ornithologists hosted the AFO Plenary Lecture, ‘‘How phylogenies can guide research in other fields: examples from hummingbirds,’’ presented by J. Van Remsen. On Friday evening the poster session was held in conjunction with a reception at the Center. In addition to self-guided bird-watching opportunities in the vicinity of the Mobile Convention Center, the local committee organized several longer field trips. These included two trips each to Dauphin Island and the Pascagoula River, and a post-conference trip to Grand River National Estuarine Research Reserve. The conferees enjoyed a 60-min reception prior to the annual banquet, which was held in a very large space at the Center known as Room 201-ABCD. After an enjoyable dinner, WOS President James D. Rising introduced the new AFO president, David N. Bonter. President Bonter led those assembled in an expression of gratitude to Frank R. Moore, Chair of the local committee, and the many persons who had worked hard to make the conference a success; this expression took the form of a collective bout of exuberant hand clapping. After presenting AFO awards, President Bonter returned the podium to WOS President Rising, who in turn thanked the three elected members of the WOS Council who had completed their terms of office, Robert L. Curry, Daniel Klem Jr., and Douglas W. White, and welcomed the three newly elected members of Council, Jameson F. Chace, Sara R. Morris, and Margaret A. Voss. The following WOS awards and commendations also were presented: