The effect of timber stand improvement practices on the abundance of Pileated Woodpeckers

Abstract only availableThe Pileated Woodpecker (Drycopulus pileatus) is a large woodpecker that requires large dead trees within a mature forest. I investigated how forest management practices affect the Pileated Woodpecker. Timber stand improvement (TSI) is the practice of girdling live trees to allow adjacent trees more space and light in which to grow. Areas treated with TSI have more dead snags which may be used by pileated woodpeckers. I surveyed total snag abundance and woodpecker density in these TSI areas compared to unmanaged (control) areas to determine the effect of TSI on Pileated Woodpeckers.Missouri Ozark Forest Ecosystem Projec

On the road again: Corridor effects on nesting passerines in Missouri forests [abstract]

Abstract only availableRoads and other linear corridors may have profound ecological consequences. Direct mortality of adult birds by vehicle collisions is well documented, but increased nest predation along road corridors has not been shown in passerines. I tested the hypothesis that nests proximal to unimproved roads (<10 m) suffer greater nest predation than those further from roads (11+ m) due to a predator-corridor effect. Nests from four sites in Missouri were found, monitored, and filmed during the spring and summer of 2007. Roadside shrub-nesting passerines did not experience significantly lower nest success than those nesting far from roads. Acadian Flycatchers experienced significantly higher nest success than did birds of the shrub-nesting guild as a whole. Initial predator identifications are presented

Conserving Migratory Land Birds in the New World: Do We Know Enough?

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas. Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird\u27s life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk. Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human population growth, acid deposition, climate change, and exotic diseases are global concerns with uncertain consequences to migratory birds and even less-certain remedies. Despite enormous gaps in our understanding of these birds, research, much of it occurring in the past 30 years, has provided sufficient information to make intelligent conservation efforts but needs to expand to handle future challenges

The effects of even-aged cutting on density and pairing success of Worm-eating Warblers

Abstract only availableIt is important for researchers to be aware of how timber management practices affect songbird populations. Certain forest management techniques can cause declines in breeding habitat of Neotropical migrant songbirds that require mature forest. The worm-eating warbler (Helmitheros vermivorus) is a common mature forest-dwelling species that may experience a decline in density due to habitat alterations such as clear cutting and selection cutting. As regeneration of the clear cuts occurs, mature forest-dwelling species may be able to utilize these areas as suitable habitat. This summer was the first year that worm-eating warblers settled on the 8 year old clear cuts on the sites of the Missouri Ozark Forest Ecosystem Project. We compared the relative abundance of worm-eating warblers that inhabited even-aged sites with those that inhabited control sites by using point counts of each site. In order to determine pairing success, we followed a singing male until the bird was seen interacting with a female or for 90 minutes if no interaction was seen. We hypothesized that the worm-eating warblers will have lower pairing success on even-aged sites (clear cuts) than control sites. We also hypothesized that the densities of worm-eating warblers would be the highest on the control sites and the lowest on the uneven-aged (selection cuts) sites, with the density of the even-aged sites falling slightly below that of the control sites.Missouri Ozark Forest Ecosystem Projec

Population trends of forest birds in Missouri, USA: Comparison of point count data with predictions from the BBS [abstract]

Abstract only availableLong-term population size trends of Neotropical migrants and other forest birds are of primary concern for conservation biologists. The Breeding Bird Survey (BBS) has become an important tool for biologists in estimating population trends, but because surveys are conducted only along roads, its utility for forest interior species may be limited. We analyzed a long term (1991-2006) point count data set from the interior of three forested sites in central Missouri and compared our trend estimates to BBS trends for the state of Missouri. Using a mixed model analysis of variance with year as a fixed effect and point as a random effect, we generated trend estimates for thirteen species. Results/Conclusions Five species (38%) exhibited statistically significant negative trends indicating species decline, four species (31%) exhibited positive trends indicating that populations increased, three species (23%) exhibited no significant trend, and data from one species did not adequately fit the model. Of the nine species with significant trends in our point count data, seven (78%) had trends that were qualitatively similar to those generated from BBS data. However, for both of the species with contrasting trends, model predictions were strongly different. Our results suggest that the accuracy of BBS trends for forest interior birds may be species specific. We hope to strengthen our conclusions by incorporating point count data from other field sites and by controlling for observer effects in future analyses.NSF Undergraduate Mentoring in Environmental Biolog

Effect of clearcutting on the habitat within the clearcut and the surrounding forest and its relationship to the presence of wood thrush (Hylocichla mustelina) in the Current River Conservation Area

Abstract only availableWood thrush were one of the few species of forest birds that increased in density on sites that received even-aged management as part of the Missouri Ozark Forest Ecosystem Project (MOFEP). One hypothesis is that this may be caused by shifts in vegetation structure, leaf litter production, and relative moisture level between regenerating clearcuts and the surrounding forest. I compared these habitat characteristics for five clearcuts in the Current River Conservation Area. Three clearcuts had adjacent wood thrush territories and two did not. For each clearcut, 5-meter radius vegetation plots were established at six randomly selected points—two within the clearcut, two at a distance of 30 meters from the clearcut's edge, and two at a distance of 60 meters. Habitat characteristics tested at each plot include average leaf litter depth, stem size distributions, horizontal foliar density, percent coverage by five types of ground cover, and relative soil moisture. These parameters serve as a basis of comparison between the clearcuts with and without wood thrushes to indicate what kind of habitat is preferred by these birds when breeding.Missouri Ozark Forest Ecosystem Projec

Long-term decline of a winter-resident bird community in Puerto Rico

Despite concern expressed two decades ago, there has been little recent discussion about continuing declines of migrant bird populations. Monitoring efforts have been focused almost exclusively on the breeding grounds. We describe the long-term decline of a winter-resident bird population in Guánica Commonwealth Forest, Puerto Rico, one of the last remaining tracts of high-quality tropical dry forests in the Caribbean. The winter bird community has exhibited dramatic declines, with constant-effort mist netting now capturing about one-third as many birds as it did 20 years ago. Population estimates for the three most common species have declined dramatically, even though survival rates have remained constant, and other species are now virtually absent from a site where they once were fairly common. Although explanations for these declines are speculative, particularly because they involve multiple species, we argue that the strength and duration of these declines in well-preserved dry forest within a biosphere reserve should stimulate renewed discussion of migrant population trends and comparison with other recent monitoring activities.Keywords: Ovenbird, Partners in Flight, Black-and-white Warbler, Songbird population declines, American Redstar

On the mating system of the cooperatively breeding saddle-backed tamarin ( Saguinus fuscicollis )

This paper reports on 5 years of observatiors of individually marked saddle-backed tamarins ( Saguinus fuscicollis , Callitrichidae). Although callitrichids have long been presumed to have a monogamous social system, this study shows that the breeding structure of saddle-back tamarin groups is highly variable. Groups most commonly include two or more adult males and a single reproductive female, but occasionally contain only a single pair of adults, or less often, two reproductively active females and one or more males. Data on group compositions, group formations, intergroup movements and copulations show that the social and mating systems of this species are more flexible than those of any other non-human primate yet studied. Infants (usually twins) were cared for by all group members. There were two classes of helpers: young, nonreproductive individuals who helped to care for full or half siblings, and cooperatively polyandrous males who cared for infants whom they may have fathered. The observations suggest that non-reproductive helpers may benefit from their helping behavior through a combination of inclusive fitness gains, reciprocal altruism, and the value of gaining experience at parental care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46874/1/265_2004_Article_BF00295541.pd