Breeding success of Cacicus haemorrhous (Linnaeus) (Aves: Icteridae) in different environments in an Atlantic Forest reserve in Southeast Brazil

Several factors, including the site where the colony was established and number of active nests can influence directly or indirectly the breeding success of colonial birds. The red-rumped cacique, Cacicus haemorrhous (Linnaeus, 1766), is a passerine (Icteridae) that breeds in colonies in different environments. The objective of this study was to evaluate the breeding success of red-rumped cacique in relation to three environments (lake edge, forest and swamp) in which colonies were established in an Atlantic Forest reserve in southeast Brazil. Seven colonies from the three environments were monitored during the breeding season of 2001. Overall probability of nest survival was 40.5%. We found that colonies established in the swamp presented higher nest survival than the others and the ones in the lake edge had lower survival. Nest predation was the most important cause of nest failure, representing 46.5% of all nest losses. Other failure causes were abandonment and fall of nests, representing 6.6% and 6.1% of the losses, respectively. Red-rumped cacique had higher success breeding in colonies located in the swamp.

Download Full-text

How Many Baskets? Clutch Sizes That Maximize Annual Fecundity of Multiple-Brooded Birds

The Auk ◽

10.1093/auk/118.4.973 ◽

2001 ◽

Vol 118 (4) ◽

pp. 973-982 ◽

Cited By ~ 8

Author(s):

George L. Farnsworth ◽

Theodore R. Simons ◽

J. Brawn

Keyword(s):

Clutch Size ◽

Breeding Season ◽

Nest Predation ◽

Reproductive Effort ◽

Nest Survival ◽

Survival Rates ◽

Season Length ◽

Deterministic Models ◽

Cavity Nesting ◽

Theoretical Issues

Abstract We developed deterministic models on the basis of nest survival rates and renesting behavior capable of predicting annual fecundity in birds. The models calculate probabilities of fledging from one to four nests within a discrete breeding season. We used those models to address theoretical issues related to clutch size. In general, birds require at least one day to lay an egg, and many species delay incubation until their entire clutch is laid. Because it takes longer to complete a larger clutch, and fewer such clutches can fit into a limited breeding season, there exists a clutch size for which annual fecundity is maximized. We asked, for a given amount of reproductive effort (i.e. a set number of eggs), does the age-old maxim “don't put all your eggs in one basket” apply? If so, in how many “baskets” should a nesting bird place its eggs? The answer depends on both likelihood of nest predation and length of the breeding season. Those results are consistent with the observed increase in clutch size with latitude (shorter breeding season length) and larger clutch sizes characteristic of cavity-nesting species (with higher nest survival rates). The models also predict that the size of replacement clutches should decrease as the breeding season progresses, and that intraseasonal decline in clutch size should be more pronounced when the breeding season is short.

Download Full-text

Diel timing of nest predation changes across breeding season in a subtropical shorebird

10.22541/au.162218472.26998411/v1 ◽

2021 ◽

Author(s):

Martin Sládeček ◽

Kateřina Brynychová ◽

Esmat Elhassan ◽

Miroslav Salek ◽

Veronika Janatová ◽

...

Keyword(s):

Breeding Season ◽

Nest Predation ◽

Predation Rate ◽

Diel Activity ◽

Limited Information ◽

Nest Failure ◽

Ground Temperatures ◽

Diel Activity Pattern ◽

Geographical Regions ◽

Ground Nesting

Predation is the most common cause of nest failure in birds. While nest predation is relatively well studied in general, our knowledge is unevenly distributed across the globe and taxa, with for example limited information on shorebirds breeding in sub-tropics. Importantly, we know fairly little about the timing of predation within a day and season. Here, we followed 444 nests of red-wattled lapwings (Vanellus indicus), a ground-nesting shorebird, for a sum of 7828 days to estimate a nest predation rate, and continuously monitored 230 of these nests for a sum of 2779 days to reveal how the timing of predation changes over the day and season in a sub-tropical desert. We found that 312 nests (70%) hatched, 76 nests (17%) were predated, 23 (5%) failed for other reasons and 33 (7%) had an unknown fate. Daily predation rate was 0.95% (95%CrI: 0.76% – 1.19%), which for a 30-day long incubation period translates into ~25% (20% – 30%) chance of nest being predated. Such a predation rate is low compared to most other avian species. Predation events (N = 25) were distributed evenly across day and night, with a tendency for increased predation around sunrise. Predation rate and events were distributed evenly also across the season, although night predation was more common later in the season, perhaps because predators reduce their activity during daylight to avoid extreme heat. Indeed, nests were never predated when mid-day ground temperatures exceeded 45°C. Whether the diel activity pattern of resident predators undeniably changes across the breeding season and whether the described predation patterns hold for other populations, species and geographical regions awaits future investigations.

Download Full-text

Return rates of nest-box breeding Pied Flycatchers Ficedula hypoleuca to their breeding site in subalpine birch forest in Swedish Lapland, during 1965–2018

Ornis Svecica ◽

10.34080/os.v29.20019 ◽

2019 ◽

Vol 29 ◽

pp. 53-68

Author(s):

N Erik I Nyholm

Keyword(s):

Breeding Season ◽

Breeding Success ◽

Nest Predation ◽

Breeding Site ◽

Ficedula Hypoleuca ◽

Return Rate ◽

Significant Part ◽

Northern Sweden ◽

Return Rates ◽

Local Factors

Return rates of 4,178 female and 1,565 male breeding Pied Flycatchers ringed in 1965–2017 were studied near the species’ upper elevation and climatic limit in northern Sweden. Female return rate was 7.5% in the season subsequent to the first breeding season. Having returned once, 37% continued to return the next three seasons. Corresponding return rates of males were 27% and 39%. Female return rate decreased with more than 30% during the study period whereas that of males did not decrease. This difference was probably due to increased mortality during the non-breeding season that selectively struck females after the 1970s. Local factors affected return rates in both sexes. Return rate was positively correlated with breeding success in females but negatively in males, whereas it was correlated with nest-predation in the opposite way. Predation by mustelids accounted for a significant part of female return rate. Females that had returned once were continuously faithful to the former breeding site. Males showed faithfulness only after having returned twice.

Download Full-text

Number of Close Spatial and Temporal Neighbors Decreases the Probability of Nest Failure and Shiny Cowbird Parasitism in Colonial Yellow-Winged Blackbirds

The Condor ◽

10.1093/condor/103.3.521 ◽

2001 ◽

Vol 103 (3) ◽

pp. 521-529 ◽

Cited By ~ 2

Author(s):

Viviana Massoni ◽

Juan Carlos Reboreda

Keyword(s):

Breeding Season ◽

Brood Parasitism ◽

Nest Predation ◽

Dilution Effect ◽

Temporal Aggregation ◽

Nest Failure ◽

Negatively Associated ◽

Molothrus Bonariensis ◽

Colonial Nesting ◽

Nest Desertion

Abstract We investigated whether the synchrony and proximity of nests of Yellow-winged Blackbirds (Agelaius thilius) provided protection against nest predation or brood parasitism by Shiny Cowbirds (Molothrus bonariensis). We analyzed the effect of the temporal aggregation of nests on the daily probability per nest of predation, desertion, egg punctures, and parasitism throughout the breeding season. The probabilities of nest predation and nest desertion increased through the breeding season. The temporal aggregation of nests was negatively associated with the probability of nest desertion, egg punctures, and parasitism, but there was no association with the probability of nest predation. We also analyzed the effect of the number of close neighbor nests on the daily probability per nest of predation, desertion, egg punctures, and brood parasitism. The spatial aggregation of nests was negatively associated with the probability of nest failure and brood parasitism, but there was no association with the probability of egg punctures. We discuss whether dilution effect or group defense, two mechanisms proposed to explain the antipredatory advantages of colonial nesting, are likely to apply to our system. El Número de Vecinos Espaciales y Temporales Disminuye la Probabilidad de Pérdida del Nido y de Parasitismo por Molothrus bonariensis en Colonias de Agelaius thilius Resumen. Se investigó si la sincronía y la proximidad de nidos del Agelaius thilius proveyó protección ante la depredación del nido y el parasitismo de cría por Molothrus bonariensis. Se analizó el efecto de la agregación temporal de nidos sobre la probabilidad diaria por nido de depredación, abandono, picaduras y parasitismo a lo largo de la temporada reproductiva. Las probabilidades de predación y abandono del nido aumentaron a medida que avanzó la temporada reproductiva. La agregación temporal de nidos estuvo negativamente asociada con la probabilidad de abandono, picaduras y parasitismo pero no se observó asociación de ésta con la probabilidad de predación. También se analizó el efecto del número de nidos vecinos cercanos sobre la probabilidad de pérdida del nido y de parasitismo de cría. La agregación espacial de nidos estuvo asociada negativamente con la probabilidad de pérdida del nido y de parasitismo de cría pero no se observó una asociación de ésta con la probabilidad de picadura de huevos. Se discute si el efecto de dilución o la defensa grupal, dos mecanismos propuestos para explicar los beneficios antipredatorios de la nidificación colonial, son probables de ocurrir en este sistema.

Download Full-text

Mercury deposition through litterfall in an Atlantic Forest at Ilha Grande, Southeast Brazil

Chemosphere ◽

10.1016/j.chemosphere.2006.04.053 ◽

2006 ◽

Vol 65 (11) ◽

pp. 2477-2484 ◽

Cited By ~ 38

Author(s):

Emmanoel V. Silva-Filho ◽

Wilson Machado ◽

Rogério R. Oliveira ◽

Silvia M. Sella ◽

Luiz D. Lacerda

Keyword(s):

Atlantic Forest ◽

Mercury Deposition ◽

Southeast Brazil

Download Full-text

Low reproductive success of the endangered Iberá Seedeater in its only known breeding site, the Iberá Wetlands, Argentina

The Condor ◽

10.1093/ornithapp/duab008 ◽

2021 ◽

Author(s):

Melanie Browne ◽

Sheela P Turbek ◽

Constanza Pasian ◽

Adrián S Di Giacomo

Keyword(s):

Breeding Season ◽

Migratory Birds ◽

Nest Survival ◽

Breeding Site ◽

Grassland Management ◽

Nest Site Selection ◽

Breeding Biology ◽

Cumulative Probability ◽

Conservation Area ◽

Northeastern Argentina

Abstract Subtropical grasslands are highly susceptible to habitat conversion and number among South America’s most threatened ecosystems. The grasslands of northeastern Argentina have been identified as a priority conservation area for threatened capuchino seedeaters because they constitute the main breeding area of these migratory birds. The Iberá Seedeater (Sporophila iberaensis) is a newly described species in the Iberá Wetlands in Argentina whose biology is still poorly understood. The endangered species inhabits grasslands but has only been reported to breed in the Iberá Wetlands ecoregion of northeastern Argentina. To explore the species’ association with grassland vegetation, we studied the breeding biology (clutch size, hatching success, and fledgling production) of the Iberá Seedeater and the main parameters that influence nest survival and nest-site selection. We conducted nest searches and banded adults and nestlings in Iberá National Park during the breeding seasons of 2016–2018. The breeding season of the Iberá Seedeater was highly synchronous and the cumulative probability of nest survival was 0.16. The daily nest survival rate decreased as the breeding season advanced, survival was lower for nests supported by Rhynchospora corymbosa than Paspalum durifolium, the two main nest substrates, and the main causes of nest failure were nest predation and strong winds. Additionally, the population exhibited male-biased site fidelity and a low female return rate. In contrast to other capuchinos, whose breeding biology is associated with upland grasslands, the Iberá Seedeater nested exclusively in flooded lowland grasslands on marsh plants. Thus, effective lowland grassland management is key to maintain the vegetation structure required for reproduction in the Iberá Seedeater.

Download Full-text