Breeding phenology and nest survival of Cinereous (Circus cinereus) and Long-winged (C. buffoni) Harriers in the agricultural landscapes of north-east Patagonia, Argentina

Abstract The population of the recently-described Whenua Hou diving petrel Pelecanoides whenuahouensis comprises c. 200 adults that all breed in a single 0.018 km2 colony in a dune system vulnerable to erosion. The species would therefore benefit from the establishment of a second breeding population through a translocation. However, given the small size of the source population, it is essential that translocations are informed by carefully targeted monitoring data. We therefore modelled nest survival at the remaining population in relation to potential drivers (distance to sea and burrow density of conspecifics and a competitor) across three breeding seasons with varying climatic conditions as a result of the southern oscillation cycle. We also documented breeding phenology and burrow attendance, and measured chicks, to generate growth curves. We estimated egg survival at 0.686, chick survival at 0.890, overall nest survival at 0.612, and found no indication that nest survival was affected by distance to sea or burrow density. Whenua Hou diving petrels laid eggs in mid October, eggs hatched in late November, and chicks fledged in mid January at c. 86% of adult weight. Burrow attendance (i.e. feeds) decreased from 0.94 to 0.65 visits per night as chicks approached fledging. Nest survival and breeding biology were largely consistent among years despite variation in climate. Nest survival estimates will facilitate predictions about future population trends and suitability of prospective translocation sites. Knowledge of breeding phenology will inform the timing of collection of live chicks for translocation, and patterns of burrow attendance combined with growth curves will structure hand-rearing protocols. A tuhinga whakarāpopoto (te reo Māori abstract) can be found in the Supplementary material.

Download Full-text

Breeding biology and population increase of the Endangered Bermuda Petrel Pterodroma cahow

Bird Conservation International ◽

10.1017/s0959270911000396 ◽

2012 ◽

Vol 22 (1) ◽

pp. 35-45 ◽

Cited By ~ 12

Author(s):

JEREMY MADEIROS ◽

NICHOLAS CARLILE ◽

DAVID PRIDDEL

Keyword(s):

Climate Change ◽

Population Size ◽

Breeding Success ◽

Reproductive Output ◽

Small Population ◽

Population Increase ◽

Storm Damage ◽

Breeding Phenology ◽

North East ◽

Rate Of Increase

SummaryThe Bermuda Petrel Pterodroma cahow was thought to have become extinct early in the 17th century due to a combination of hunting by human colonists and predation by introduced rats, cats, dogs and pigs. However, single individuals were found on four occasions during the first half of the 20th century, and in 1951 a small population was discovered breeding on several rocky islets in north-east Bermuda. Recovery actions began in 1962 when the population numbered just 18 pairs, dispersed among five small islets. Although rats extirpated one of these five colonies in 1967, the population has grown steadily to 56 breeding pairs in 2000. We investigated the breeding phenology, productivity and population size of the Bermuda Petrel between 2000/2001 and 2007/2008. Each year, the birds began arriving in Bermuda around mid-October. They departed on a pre-breeding exodus between 19 November and 14 December, returning after 32–56 days to lay a single egg between 31 December and 31 January. Eggs hatched from 16 February to 26 March after a mean (± SD) incubation period of 53 ± 2 days, and young fledged from 15 May to 25 June after a mean fledging period of 91 ± 5 days. Between 2000/2001 and 2007/2008, reproductive output ranged from 29 to 40 fledglings per annum. Mean annual breeding success (62%) was reasonably high relative to other Procellariiformes, largely due to the provision of artificial (concrete) nesting burrows. In 2008, the population numbered 85 breeding pairs. Monitoring since 1961 indicates the population has been increasing exponentially, doubling approximately every 22 years. This rate of increase, together with the increased incidence of storm damage, is making it progressively more impracticable to construct sufficient concrete burrows on the current nesting islets to accommodate all breeding pairs. The vulnerability of these sites to accelerating storm damage and erosion as a result of anthropomorphic climate change is now the greatest threat to the Bermuda Petrel.

Download Full-text

Preparing for translocations of a Critically Endangered petrel through targeted monitoring of nest survival and breeding biology

10.26686/wgtn.14607621.v1 ◽

2021 ◽

Author(s):

JH Fischer ◽

Heiko Wittmer ◽

GA Taylor ◽

I Debski ◽

DP Armstrong

Keyword(s):

Southern Oscillation ◽

Nest Survival ◽

Growth Curves ◽

Breeding Biology ◽

Source Population ◽

Breeding Phenology ◽

Chick Survival ◽

Egg Survival ◽

Dune System ◽

Burrow Density

The population of the recently-described Whenua Hou diving petrel Pelecanoides whenuahouensis comprises c. 200 adults that all breed in a single 0.018 km2 colony in a dune system vulnerable to erosion. The species would therefore benefit from the establishment of a second breeding population through a translocation. However, given the small size of the source population, it is essential that translocations are informed by carefully targeted monitoring data. We therefore modelled nest survival at the remaining population in relation to potential drivers (distance to sea and burrow density of conspecifics and a competitor) across three breeding seasons with varying climatic conditions as a result of the southern oscillation cycle. We also documented breeding phenology and burrow attendance, and measured chicks, to generate growth curves. We estimated egg survival at 0.686, chick survival at 0.890, overall nest survival at 0.612, and found no indication that nest survival was affected by distance to sea or burrow density. Whenua Hou diving petrels laid eggs in mid October, eggs hatched in late November, and chicks fledged in mid January at c. 86% of adult weight. Burrow attendance (i.e. feeds) decreased from 0.94 to 0.65 visits per night as chicks approached fledging. Nest survival and breeding biology were largely consistent among years despite variation in climate. Nest survival estimates will facilitate predictions about future population trends and suitability of prospective translocation sites. Knowledge of breeding phenology will inform the timing of collection of live chicks for translocation, and patterns of burrow attendance combined with growth curves will structure hand-rearing protocols. A tuhinga whakarāpopoto (te reo Māori abstract) can be found in the Supplementary material.

Download Full-text

Distribution, breeding phenology and time budget of Ruddy Shelduck Tadorna ferruginea during the annual cycle in the Hauts Plateaux, north-east Algeria

Ostrich ◽

10.2989/00306525.2013.821680 ◽

2013 ◽

Vol 84 (2) ◽

pp. 129-136 ◽

Cited By ~ 5

Author(s):

Mouloud Boulkhssaïm ◽

Abdallah Ouldjaoui ◽

Ahmed H Alfarhan ◽

Boudjéma Samraoui

Keyword(s):

Annual Cycle ◽

Time Budget ◽

Breeding Phenology ◽

North East

Download Full-text

Impact of Shiny Cowbird and botfly parasitism on the reproductive success of the globally endangered Yellow CardinalGubernatrix cristata

Bird Conservation International ◽

10.1017/s095927091400015x ◽

2014 ◽

Vol 25 (3) ◽

pp. 294-305 ◽

Cited By ~ 15

Author(s):

MARISOL DOMÍNGUEZ ◽

JUAN CARLOS REBOREDA ◽

BETTINA MAHLER

Keyword(s):

Reproductive Success ◽

Clutch Size ◽

Brood Parasitism ◽

Conservation Status ◽

Nest Survival ◽

Chick Survival ◽

Molothrus Bonariensis ◽

North East ◽

Conservation Actions ◽

The Impact

SummaryThe Yellow CardinalGubernatrix cristatais a globally endangered passerine endemic to southern South America. Although the conservation status of this species is alarming, there is no information about factors that affect its reproductive success. We studied the breeding biology of a Yellow Cardinal population in Corrientes province in north-east Argentina and report reproductive parameters, such as timing of breeding, clutch size, hatching success and chick survival and analyse factors influencing nest survival. The breeding season lasted from October to December with most nesting attempts occurring during the second half of November. Re-nesting after nest failure occurred in approximately 35% of pairs but we did not observe re-nesting after successful attempts. Modal clutch size was three eggs and successful nests fledged on average 1.6 chicks. We observed brood parasitism by Shiny CowbirdsMolothrus bonariensisin 33% of the nests. The main cost of brood parasitism was the puncture of cardinal eggs by cowbird females, which very often resulted in nest abandonment. Another factor reducing reproductive success was parasitism by botfliesPhilornissp., which occurred in 22% of the nests and reduced chick survival. We determined daily nest survival rate with MARK software and found that during the egg stage, it decreased with time of breeding and brood parasitism by Shiny Cowbirds. Our results indicate that Shiny Cowbird and botfly parasitism represent a threat for Yellow Cardinals. Conservation actions to protect the remaining populations of Yellow Cardinals should consider the impact of Shiny Cowbird parasitism.

Download Full-text

Cross-seasonal weather effects interact with breeding conditions to impact reproductive success in an alpine songbird

10.1101/2021.08.06.455393 ◽

2021 ◽

Author(s):

Devin R de Zwaan ◽

Anna Drake ◽

Alaine F Camfield ◽

Elizabeth C MacDonald ◽

Kathy Martin

Keyword(s):

Reproductive Success ◽

Annual Cycle ◽

Environmental Conditions ◽

Nest Survival ◽

Breeding Site ◽

Weather Conditions ◽

Breeding Phenology ◽

Early Season ◽

Offspring Development ◽

Clutch Initiation

In alpine habitats, fluctuating early-season weather conditions and short breeding seasons limit reproductive opportunities, such that arriving and breeding earlier or later than the optimum may be particularly costly for migratory species. Given early-season energy limitations, the influence of environmental conditions across the annual cycle on breeding phenology may have pronounced fitness consequences, yet our understanding of cross-seasonal dynamics in alpine breeding organisms is severely limited. For an alpine-breeding, migratory population of horned lark (Eremophila alpestris) in northern British Columbia, Canada (54.8N latitude) we assessed how spatially explicit weather conditions from across the annual cycle influenced clutch initiation date and offspring development. We also addressed how cross-seasonal effects on breeding parameters interact to influence reproductive fitness. With 12 years of intensive breeding data and 3 years of migration data from archival light-level geolocators, we used a sliding window approach to identify critical points during the annual cycle where weather events most influenced breeding phenology and offspring development. Consequences for reproductive success were assessed using nest survival simulations. Average clutch initiation varied up to 11 days among years but did not advance from 2003 to 2019. Colder temperatures with greater precipitation at wintering habitats, as well as colder temperatures upon arrival at the breeding site delayed clutch initiation, independent of arrival time. Extreme cold (sub-zero temperatures) within a staging area just prior to arrival at the breeding site carried over to prolong offspring development rate, potentially by influencing parental investment. Nest survival decreased with both later clutch initiation and prolonged offspring development, such that females that nested earlier and fledged offspring at a younger age were up to 45% more likely to reproduce successfully. We demonstrate pronounced carry-over effects acting through mechanisms that influence breeding phenology and offspring development independently. We also highlight the potential importance of staging areas for alpine songbirds, particularly given that environmental conditions are becoming increasingly decoupled across seasons. Understanding the cross-seasonal mechanisms shaping breeding decisions in stochastic environments like the alpine enables more accurate predictions of future individual- and population-level responses to climate change.

Download Full-text

Preparing for translocations of a Critically Endangered petrel through targeted monitoring of nest survival and breeding biology

10.26686/wgtn.14607621 ◽

2021 ◽

Author(s):

JH Fischer ◽

Heiko Wittmer ◽

GA Taylor ◽

I Debski ◽

DP Armstrong

Keyword(s):

Southern Oscillation ◽

Nest Survival ◽

Growth Curves ◽

Breeding Biology ◽

Source Population ◽

Breeding Phenology ◽

Chick Survival ◽

Egg Survival ◽

Dune System ◽

Burrow Density

The population of the recently-described Whenua Hou diving petrel Pelecanoides whenuahouensis comprises c. 200 adults that all breed in a single 0.018 km2 colony in a dune system vulnerable to erosion. The species would therefore benefit from the establishment of a second breeding population through a translocation. However, given the small size of the source population, it is essential that translocations are informed by carefully targeted monitoring data. We therefore modelled nest survival at the remaining population in relation to potential drivers (distance to sea and burrow density of conspecifics and a competitor) across three breeding seasons with varying climatic conditions as a result of the southern oscillation cycle. We also documented breeding phenology and burrow attendance, and measured chicks, to generate growth curves. We estimated egg survival at 0.686, chick survival at 0.890, overall nest survival at 0.612, and found no indication that nest survival was affected by distance to sea or burrow density. Whenua Hou diving petrels laid eggs in mid October, eggs hatched in late November, and chicks fledged in mid January at c. 86% of adult weight. Burrow attendance (i.e. feeds) decreased from 0.94 to 0.65 visits per night as chicks approached fledging. Nest survival and breeding biology were largely consistent among years despite variation in climate. Nest survival estimates will facilitate predictions about future population trends and suitability of prospective translocation sites. Knowledge of breeding phenology will inform the timing of collection of live chicks for translocation, and patterns of burrow attendance combined with growth curves will structure hand-rearing protocols. A tuhinga whakarāpopoto (te reo Māori abstract) can be found in the Supplementary material.

Download Full-text

Hooded Warbler Nesting Success Adjacent to Group-Selection and Clearcut Edges in a Southeastern Bottomland Forest

The Condor ◽

10.1093/condor/104.2.366 ◽

2002 ◽

Vol 104 (2) ◽

pp. 366-377 ◽

Cited By ~ 5

Author(s):

Christopher E. Moorman ◽

David C. Guynn Jr. ◽

John C. Kilgo

Keyword(s):

Clutch Size ◽

Group Selection ◽

Molothrus Ater ◽

Nest Survival ◽

Agricultural Landscapes ◽

Nesting Success ◽

Edge Type ◽

Wilsonia Citrina ◽

Arundinaria Gigantea ◽

Bottomland Forest

Abstract During the 1996, 1997, and 1998 breeding seasons, we located and monitored Hooded Warbler (Wilsonia citrina) nests in a bottomland forest and examined the effects of edge proximity, edge type, and nest-site vegetation on nesting success. Successful Hooded Warbler nests were more concealed from below and were located in nest patches with a greater abundance of >0.5-m-tall switchcane (Arundinaria gigantea) stems than unsuccessful nests. Daily nest survival rates, clutch size, and number of fledglings per successful nest did not differ between nests near edges of selection-harvest openings within the bottomland and nests near edges of clearcuts adjacent to the bottomland. Daily survival rate, clutch size, and number of fledglings per successful nest did not differ among nests 0–50 m, 51–100 m, and >100 m from the nearest edge, and probability of nest survival was not related to proximity to either edge type. However, probability of parasitism by Brown-headed Cowbirds (Molothrus ater) was higher near clearcut edges, and parasitism reduced clutch size and numbers of fledglings per successful nest. The combined effects of edge, especially edge created by the relatively small (≤0.5 ha) group-selection openings, on Hooded Warbler nesting success were minimal. However, our study was conducted in a primarily forested landscape, so cowbird abundance or negative edge effects may have been low relative to agricultural landscapes in the South. Éxito de Anidación de Wilsonia citrina en Sitios Adyacentes a Bordes de Claros Formados por Extracción de Árboles Seleccionados y por Tala Rasa en Bosques Ribereños del Sureste Resumen. Durante las épocas reproductivas de 1996, 1997 y 1998, ubicamos y monitoreamos nidos de Wilsonia citrina en un bosque de ribereño y evaluamos los efectos de la proximidad al borde, el tipo de borde y la vegetación del sitio de anidación sobre el éxito reproductivo. Los nidos exitosos estuvieron más escondidos desde abajo y se ubicaron en parches de bosque con una mayor abundancia de tallos de Arundinaria gigantea de más de 0.5 m de alto que los nidos no exitosos. Las tasas de supervivencia diaria de los nidos, el tamaño de la nidada y el número de polluelos emplumados por nido exitoso no difirieron entre nidos ubicados cerca de bordes de aperturas de cosecha selectiva dentro del valle ribereño y nidos cerca de bordes de sitios completamente talados adyacentes al valle. La tasa de supervivencia diaria, el tamaño de la nidada y el número de polluelos emplumados por nido exitoso no difirió entre nidos ubicados a 0–50 m, 51–100 m y >100 m del borde más cercano, y la probabilidad de supervivencia de los nidos no estuvo relacionada con la proximidad a ningún tipo de borde. Sin embargo, la probabilidad de parasitismo por Molothrus ater fue mayor cerca de bordes de tala rasa, y el parasitismo redujo el tamaño de la nidada y el número de polluelos emplumados por nido exitoso. Los efectos combinados de borde sobre el éxito de anidación de W. citrina fueron mínimos, especialmente aquellos de los bordes creados por los claros relativamente pequeños (≤0.5 ha) formados tras extraer grupos de árboles seleccionados. Sin embargo, nuestro estudio fue realizado en un paisaje principalmente forestal, de modo que la abundancia de M. ater o los efectos de borde negativos pueden haber sido menores en relación a paisajes agrícolas del sur.

Download Full-text

Globalisation and Agricultural Landscapes

10.1017/cbo9780511844928 ◽

2009 ◽

Cited By ~ 23

Keyword(s):

Agricultural Landscapes

Download Full-text

Ras al Khaimah: further archaeological discoveries

Antiquity ◽

10.1017/s0003598x00150070 ◽

1976 ◽

Vol 50 (200) ◽

pp. 216-222

Author(s):

Beatrice De Cardi

Keyword(s):

United Arab Emirates ◽

The State ◽

Focused Attention ◽

North East ◽

The North ◽

History Of ◽

The City

Ras a1 Khaimah is the most northerly of the seven states comprising the United Arab Emirates and its Ruler, H. H. Sheikh Saqr bin Mohammad al-Qasimi, is keenly interested in the history of the state and its people. Survey carried out there jointly with Dr D. B. Doe in 1968 had focused attention on the site of JuIfar which lies just north of the present town of Ras a1 Khaimah (de Cardi, 1971, 230-2). Julfar was in existence in Abbasid times and its importance as an entrep6t during the sixteenth and seventeenth centuries-the Portuguese Period-is reflected by the quantity and variety of imported wares to be found among the ruins of the city. Most of the sites discovered during the survey dated from that period but a group of cairns near Ghalilah and some long gabled graves in the Shimal area to the north-east of the date-groves behind Ras a1 Khaimah (map, FIG. I) clearly represented a more distant past.

Download Full-text