Short-term movement patterns, population estimates and breeding biology of an island endemic bird, the Tristan Thrush

The Tristan Thrush Turdus eremita is the only land bird that survived human colonisation of the main island of Tristan da Cunha and is listed as “Near Threatened”. Population estimates are confounded by the thrushes’ inquisitive and gregarious nature as well as limited information on their movements. We report the first measures of nest densities on Nightingale Island: 6 nests·ha-1 in Phylica arborea woodland and 4–5 nests·ha-1 in tussock habitat, which suggests that the population is approximately double the previous estimate. At Inaccessible Island, we individually color ringed 110 thrushes over two months to track their short-term movements and estimate the local population size. Individuals moved up to 950 m along the coast, but 96% of resightings were < 100 m. A Bayesian data augmentation approach estimated that some 260 thrushes visited the core study area, a 200-m stretch of cobble and boulder beach where birds come to drink, bathe and forage. This result suggests that the population on Inaccessible Island also is substantially larger than reported previously. We estimate the total population to be 8000–15,000 Tristan Thrushes. The main need is a population estimate for the nominate subspecies on the main island of Tristan.

The Tocantins-Araguaia Basin as a migratory route and a wintering area of Falco peregrinus (Aves, Falconidae)

The Peregrine Falco peregrinus, is an Nearctic migrant to Brazil where its status in central Brazil is still poorly known. Herein we present a compilation of records of the species from the state of Tocantins and comment on its use of a wintering site in the state of Goiás. These records show that the Tocantins-Araguaia River Basin is a migration route for the species, and therefore a mid-continental migration route through the interior of South America.

Fire management and aspects of the nesting biology of the Red-legged Seriema (Cariama cristata) in woodlands at Parque Nacional das Emas, central Cerrado

In the Brazilian Cerrado Biome, fire management within conservation units is usually restricted to burning grassland and woodland strips during the dry season to stop fires from spreading. Although it is a common practice, the impact of fire management on birds remains poorly investigated. This study aimed to examine the effects of fire management on nest-site selection by the Red-legged Seriema, Cariama cristata, and to describe nest-building characteristics at Parque Nacional das Emas (PNE). Nests were searched and monitored throughout 34 study sites between October and November 2006. These sites were 2.5-km strips of Campo Cerrado woodlands with (firebreaks) and without fire management, located at the interior and boundaries of the park. A total of 13 nests were found, all within firebreaks at the edge of the park. Nine (69%) of them were in fruiting Pouteria torta (Mart.) (Sapotaceae). Two or three white eggs were found in the nests. Nests had eggs and nestlings in October and no nestlings were found in November. Nests were usually in tree canopies and some of them were built nearly over the park’s fence. At PNE, breeding pairs of C. cristata are attracted to firebreaks located at the park’s boundaries. This is probably due to mobility through often burnt vegetation and ease in obtaining food from adjacent unsealed roads, exotic plantations and cleared areas. This study suggests that fire managers should: 1) avoid extinguishing natural fires initiated during the rainy season and 2) rotate controlled burning of patchy areas of Campo Cerrado woodlands. These two procedures should ensure the presence of suitable woodlands with short grasses in interior portions of PNE.

First record of death-feigning in Black Vultures (Coragyps atratus) (Cathartidae)

Death-feigning is a behavior ability with the purpose of allowing prey to evade from predators. Despite death-feigning is recorded on a wide variety of bird species, it has been recorded only once in vultures, more specifically on a Turkey Vulture (Cathartes aura) nest. In addition to this record, we report this behavior while manipulating an individual of Black Vulture (Coragyps atratus) in Brazil. This behavior is not usual in Cathartidae since adult vultures do not have a known natural predator.

GenTag: a package to improve animal color tagging protocol

The individual identification of animals by means of tagging is a common methodological approach in ornithology. However, several studies suggest that specific colors may affect animal behavior and disrupt sexual selection processes. Thus, methods to choose color tagging combinations should be carefully evaluated. However, reporting of this information is usually neglected. Here, we introduce the GenTag, an R package developed to support biologists in creating color tag sequence combinations using a random process. First, a single-color tag sequence is created from an algorithm selected by the user, followed by verification of the combination. We provide three methods to produce color tag sequences. GenTag provides accessible and simple methods to generate color tag sequences. The use of a random process to define the color tags to be applied to each animal is the best way to deal with the influence of tag color upon behavior and life history parameters.

Ground nesting birds in roadside borders of the Argentine Pampas: habitat use and predation risk of artificial nests

Habitat loss and fragmentation have led to grassland bird declines, with ground nesters particularly vulnerable. Roadsides could provide habitat, although their suitability depends on several roadside and field characteristics. Vegetation structure determines foraging and nesting site availability. In addition, road delimits sharp edges where the activity of nest predators is usually higher, whereas herbaceous vegetation determines ground nest concealment. Trees could provide lookouts to predators, and modified habitat and woodlands in surrounding fields could offer additional resources to predators. Our objective was to assess habitat suitability for ground nester birds in roadsides belonging to one modified grassland of the Argentine Pampas. We surveyed birds (90 plots) and monitored artificial nests (60 plots) in different road types: unpaved, paved of one-lane per side, and paved of two-lanes per side. Within each road type, we evaluated the relationship that ground nesters abundance had with vegetation structure of roadsides and surrounding fields. In addition, we related predation of artificial nests with the proximity to the road, roadside vegetation, and modified land and woodlands of surrounding fields. We made 2832 records of 84 species using roadsides, including 1083 records of 13 ground nesting species. Abundance of ground nesters increased with tall grass cover of roadsides and decreased with the number of native trees within roadsides. Roughly half (31/60) of the artificial nests were predated and 82.6% of the identified egg-marks were of mammal teeth. Nest predation decreased with nest proximity to the road. Our results emphasize the importance of tall grass cover of roadsides for the conservation of ground nesting species, and the necessity of monitoring natural nests in order to clarify the effect of trees, proximity to the road, and other environmental variables on nest success.

Nest, eggs and nestling description of the Silvery-flanked Antwren Myrmotherula luctuosa (Pelzeln, 1868) in the Atlantic Forest of northeast Brazil

In the present study, we describe the nest, eggs, and nestlings of the Silvery-flanked Antwren, Myrmotherula luctuosa. One nest was found on 08 May 2017 on the edge of one of the forest fragments of the Serra de Itabaiana National Park, in the state of Sergipe, northeast Brazil, and was monitored until 21 May 2017. The nest, presented the following dimensions: external height: 7.6 cm; outside diameter: 21 × 19 cm; internal diameter: 13.3 × 11 cm; depth of the oologic chamber: 4.7 cm; and height in relation to the ground: 84 cm. The two eggs found in the nest were white with reddish-brown dots, patches and stripes and weighed 1.7 and 1.5 g. Incubation was performed by both the male and female, as well as feeding of the nestlings. A single egg hatched, giving rise to a 3.9 cm, 3.7 g nestling. According to our estimates, the young fledged with about 11 days. This is the first study to present information about the reproductive biology of the Silvery-flanked Antwren.

Three bird species new to Brazil from the Serra da Mocidade, a remote mountain in Roraima

From 15 January to 06 February 2016, we conducted an expedition to the Serra da Mocidade, a remote and previously unexplored mountain range in extreme northern Amazonian Brazil. There we encountered three bird species never before documented in Brazilian territory: Grallaria guatimalensis (Grallariidae) was photographed, audio recorded, video recorded and a single specimen collected; Catharus aurantiirostris (Turdidae) was similarly documented and a series of specimens collected; and a single individual of Parkesia motacilla (Parulidae) was photographed. All were found in the understory of montane forest at 1000–1550 m elevation. We interpret each of these as most likely representing a regularly occurring population on Mocidade. However, each had probably been overlooked in Brazil for a different reason and represents a distinct distributional pattern. Adding these novelties to Brazil’s previously published total of 1919 species clearly expresses the country’s position among the most bird-rich in the world, perhaps the richest, and suggests that further exploration of Brazil’s Amazonian mountains will yield more discoveries.

Nesting biology of the Aplomado Falcon (Falco femoralis) at Parque Nacional das Emas, central Brazil

Te objective of this study was to investigate aspects of the nesting biology of the Aplomado Falcon, Falco femoralis (Temminck, 1822), at Parque Nacional das Emas, Brazil. Woodland (Campo Cerrado) frebreaks were searched for nests in October 2006 and October 2009 by driving a vehicle along a road adjacent to these fre managed vegetation strips. Most (62%) of the eight nests found were in canopies of fruiting Pouteria torta trees. Nests were at 2.2–3.8 m above ground. Invariably, clutch size was of three cream eggs and nestlings had a white plumage in the frst days of life. For two active nests, adults also defended an additional empty nest located in the surroundings. No evidences of nest destruction or predation were detected. Falco femoralis successfully uses frebreaks for breeding at Parque Nacional das Emas.

Reproductive behavior of White-tailed Kites (Elanus leucurus) in the Pampas of Argentina

The White-tailed Kite (Elanus leucurus) is a raptor that has been less studied in the Neotropics than in the Nearctic region, especially in relation to its reproductive behavior. In this study, we report information about the phenology and activity patterns of this raptor at the Pampas of Argentina. We found that White-tailed Kites have a prolonged breeding season, from October to May. Time-activity budgets of mating pairs indicated a pronounced division of roles in parental care between sexes. Females devoted most of their time to nest construction, incubation and chick care (80% of total time) and males to food provisioning and vigilance (70% of total time). We registered 11 cases of prey transfer from the male to the female. In four cases the transfer occurred in flight and in the remaining seven cases while individuals were perched. Our results agree with general patterns on breeding behavior of White-tailed Kites from North America, suggesting a consistent behavioral pattern throughout the species’ distribution.