Birds, Lower Sangay National Park, Morona-Santiago, Ecuador

Sangay National Park is located at the mid-eastern Andean foothills of the Cordillera Oriental of Ecuador. We present a preliminary avifauna inventory corresponding to the lower zone of the Sangay National Park (SNP). One-hundred and twenty-seven bird species belonging to 39 families were recorded, including noteworthy records that represent range extensions for four species, Phaetornis hispidus (Gould 1846) (White-bearded Hermit), Ramphastos ambiguus Swainson 1823 (Black-mandibled Toucan), Phylloscartes orbitalis (Cabanis 1873) (Spectacled Bristle Tyrant), and Microcerculus bambla (Boddaert 1783) (Wing-banded Wren). We also obtained information on threatened species such as Aburria aburri (Lesson 1828) (Wattled Guan), Phlogophilus hemileucurus Gould 1860 (Ecuadorian Piedtail), and Dendroica cerulea (Wilson 1810) (Cerulean Warbler) and reproductive data on one species, Patagioenas speciosa (Gmelin 1789) (Scaled Pigeon). To our knowledge this is a first ornithological survey carried out at this specific site of the SNP.

Within-Territory Habitat Use and Microhabitat Selection by Male Cerulean Warblers (Dendroica Cerulea)

Although most habitat characteristics are known to be continuously variable in space, practicality dictates that most habitat-selection studies at the spatial scale of the territory treat within-territory habitat as essentially homogeneous. However, the limitations associated with such a compromise have remained largely unexamined. Male Cerulean Warblers (Dendroica cerulea) exhibit nonrandom space- use patterns within their territories, in that all territories contain areas of intensive use or core areas. In addition to documenting territory-wide habitat and behavioral use patterns in this species, we asked two specific questions about core-area structure and function. (1) Are core-area habitats distinct in their vegetative composition and structure from the rest of the territory? (2) What behavioral mechanisms underlie the nonrandom space-use patterns? On a territory-wide basis, males used trees in proportion to their availability; however, core areas were predominantly composed of bitternut hickory (Carya cordiformis), which was a highly preferred song-post tree. Core areas were not consistently associated with any other habitat feature, including canopy gaps. Core areas were singing centers; song-post densities within core areas were 10× higher than in noncore areas. In our study area, bitternut hickories have significant delayed leaf-out patterns, potentially offering minimal acoustic hindrance to song transmission until late in the breeding season. These singing centers may be strategically placed to simultaneously maintain vigilance over social nests and maximize communication with conspecifics. Core areas are potentially as important to males as nesting habitat is to females, and their provision should be taken into account when implementing conservation or management strategies. Uso de Hábitat en los Territorios y Selección de Microhábitats por los Machos en Dendroica cerulea

Cerulean Warbler (Dendroica Cerulea) Microhabitat and Landscape-Level Habitat Characteristics in Southern West Virginia

The Cerulean Warbler (Dendroica cerulea) is a species of conservation concern in eastern North America, where declines in its population have been documented over the past several decades. A high proportion of the population occurs in forested areas of southern West Virginia, where it may be threatened by loss and degradation of forested habitat from mountaintop mining and valley fill (MTMVF). We examined, from a landscape perspective, the effects of forest fragmentation (in particular, effects of fragment size and response to edges) on Cerulean Warblers, using territory mapping techniques and geographic information system (GIS) technology in portions of four counties in southwestern West Virginia. We quantified landscape characteristics from digitized aerial photographs and measured microhabitat characteristics on spot-mapping plots. Territory density of Cerulean Warblers was 4.6 territories per 10 ha in intact forest and 0.7 territories per 10 ha in fragmented forest. The best habitat model included both landscape and microhabitat variables and indicated that territory density increased with increasing snag density, percentage of canopy cover >6–12 m and >24 m in height, and distance from mine edge. Models for predicting microhabitat use at the territory level were weak, indicating that microhabitat characteristics of territories were similar to habitat available on spot-mapping plots. The species did not appear to avoid internal edges, such as natural canopy gaps and open-canopy or partially open-canopy roads. Territory placement on ridges was greater than expected, and in bottomlands (ravines) and midslopes less than expected, given availability. Fifty percent of all territories were on ridges. Preference for ridges suggests that MTMVF may have a greater effect on Cerulean Warbler populations than other sources of forest fragmentation, given that ridges are removed in MTMVF. Our data indicate that Cerulean Warblers are negatively affected by mountaintop mining from loss of forested habitat, particularly ridgetops, and from degradation of remaining forests, as evidenced by lower territory density in fragmented forests and lower territory density closer to mine edges.

Geographic variation in prevalence and parasitemia of Haemoproteus paruli in the cerulean warbler (Dendroica cerulea)

Although host–parasite interactions can affect the ecology and distribution of species, virtually nothing is known about range-wide variation in haematozoan levels in North American birds. We investigated haematozoan prevalence and parasitemia in 112 adult male cerulean warblers (Dendroica cerulea (Wilson, 1810)) in six populations throughout this species' breeding range. Thirty-six birds were infected with Haemoproteus paruli at low parasitemia (mean ± 1 SE, 6.18 ± 1.27 parasites/2000 erythrocytes). Prevalence did not differ between age classes, and there was no significant relationship between parasitism and body condition. However, prevalence and parasitemia were significantly higher in southern populations and further study is required to elucidate factors underlying regional differences in cerulean warbler haematozoan levels.