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

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 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 499 nests of red-wattled lapwings (Vanellus indicus), a ground-nesting shorebird, to estimate a nest predation rate, and continuously monitored 231 of these nests for a sum of 2951 days to reveal how timing of predation changes over the day and season in a sub-tropical desert. We found that 324 nests hatched, 77 nests were predated, 38 failed for other reasons and 60 had unknown fate. Daily predation rate was 0.97% (95%CrI: 0.77% – 1.2%), which for a 30-day long incubation period translates into ~25% chance of nest being predated. Such predation rate is low compared to most other species. Predation events 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 upon when mid-day ground temperatures exceeded 45°C. Whether the activity pattern of predators indeed changes across the breeding season and whether the described predation patterns hold for other populations, species and geographical regions awaits future investigations.

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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.

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Using Video to Monitor Predation at Black-Capped Vireo Nests

The Condor ◽

10.1093/condor/105.2.348 ◽

2003 ◽

Vol 105 (2) ◽

pp. 348-357 ◽

Cited By ~ 12

Author(s):

Mike M. Stake ◽

David A. Cimprich

Keyword(s):

Nest Predation ◽

Molothrus Ater ◽

Time Lapse ◽

Predation Rate ◽

Video Monitoring ◽

Fire Ants ◽

Daily Survival Rate ◽

Nest Failure ◽

Fort Hood ◽

Mammalian Predators

AbstractWe monitored 142 Black-capped Vireo (Vireo atricapillus) nests at Fort Hood, Texas, from 1998 to 2001 using time-lapse infrared videocameras to identify nest predators. We recorded 59 predator visits (where at least some of the nest contents were removed or destroyed), resulting in 48 depredated nests. Snakes and fire ants (Solenopsis spp.) were the leading predators, accounting for 18 (38%) and 15 (31%), respectively, of all depredated nests. We also identified a variety of avian (19% of depredated nests) and mammalian predators (11% of depredated nests). Despite intensive Brown-headed Cowbird (Molothrus ater) removal at Fort Hood, we recorded nine predator visits by females of this species, but only one resulted in nest failure. Although predator visits occurred at all hours, most (58%) took place at night. The daily predation rate was higher during the nestling stage than during incubation, partly due to the apparent inability of fire ants to prey upon vireo eggs. We monitored 435 nests without video; field assistants checked the contents of these every 4–5 days. The daily survival rate of these nests was not higher than the rate of nests monitored with video, evidence that video monitoring does not increase nest predation relative to monitoring by human visits to nests.Uso de Video para Observar la Depredación de Nidos de Vireo atricapillusResumen. De 1998 al 2001 monitoreamos 142 nidos de Vireo atricapillus en Fort Hood, Texas. Utilizamos cámaras de video de luz infrarroja para identificar a los depredadores de los nidos. Logramos grabar 59 visitas de depredación (donde al menos parte del contenido de los nidos fue removido o destruido); en éstas, 48 nidos fueron depredados. Los principales depredadores de los nidos de V. atricapillus fueron las serpientes y las hormigas de fuego (Solenopsis sp.). Del total de nidos depredados, 18 (38%) fueron depredados por serpientes y 15 (31%) por hormigas. También identificamos otros depredadores como algunas especies de aves (19% de los nidos depredados) y mamíferos (11% de los nidos depredados). A pesar de la campaña intensiva de erradicación de Molothrus ater en Fort Hood, registramos 9 visitas de depredación por parte de hembras de esta especie, pero sólo una de estas visitas resultó en el fracaso del nido. Aunque las visitas de depredación se dieron en cualquier momento, la mayoría (58%) ocurrió durante la noche. La tasa diaria de depredación fue más alta durante la etapa de crianza que durante la etapa de incubación, en parte debido a la aparente inhabilidad de las hormigas de fuego para depredar los huevos de Vireo atricapillus. Durante nuestra investigación, monitoreamos 435 nidos sin cámara de video; los asistentes de campo revisaron el contenido de estos nidos cada 4 ó 5 días. La tasa de sobrevivencia diaria de estos nidos no fue más alta que la de los nidos monitoreados con cámaras, mostrando que el monitoreo con éstas no incrementa la depredación de nidos con relación al monitoreo por visitas personales a los nidos.

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Do Repugnant Scents Increase Survival of Ground Nests? A Test with Artificial and Natural Duck Nests

The Canadian Field-Naturalist ◽

10.22621/cfn.v121i2.439 ◽

2007 ◽

Vol 121 (2) ◽

pp. 150

Author(s):

Vanessa B. Harriman ◽

Justin A. Pitt ◽

Serge Larivière

Keyword(s):

Human Hair ◽

Nest Predation ◽

Survival Rates ◽

Olfactory Cues ◽

Artificial Nests ◽

Treatment Groups ◽

Mammalian Predators ◽

High Predation ◽

Ground Nesting ◽

Predation Rates

Ground-nesting birds typically experience high predation rates on their nests, often by mammalian predators. As such, researchers and wildlife managers have employed numerous techniques to mitigate nest predation. We investigated the use of scents as repellents to deter predators from both artificial and natural ground nests. Survival rates of artificial nests did not differ among six groups of substances (Wald ?2 df = 5 = 4.53, P < 0.48); however the chronology of predation among groups differed. A commercial Coyote urine based deterrent (DEER-D-TERTM), human hair, and Worcestershire sauce were depredated faster than the control (F4,5 = 40.3, P < 0.001). Nest survival of natural nests differed among those groups tested (Wald ?2 df = 2 = 11.8, P < 0.005); the eight mothball treatment decreased survival (Wald ?2 df = 1 = 11.5, P < 0.005), which indicated that novel smells may attract predators or result in duck nest abandonment when coupled with natural duck scent. Chronologies of predation events among treatment groups were not different for natural nests (F2,3 = 1.9, P = 0.22). These findings indicate an interaction between novel scents and predator olfactory cues.

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Visible marking of wader nests to avoid damage by farmers does not increase nest predation

Bird Conservation International ◽

10.1017/s0959270916000617 ◽

2017 ◽

Vol 28 (2) ◽

pp. 293-301 ◽

Cited By ~ 7

Author(s):

VÁCLAV ZÁMEČNÍK ◽

VOJTĚCH KUBELKA ◽

MIROSLAV ŠÁLEK

Keyword(s):

Czech Republic ◽

Nest Predation ◽

Agricultural Land ◽

Positive Experience ◽

The Czech Republic ◽

Trade Off ◽

Nest Protection ◽

Vanellus Vanellus ◽

The Impact ◽

Ground Nesting

SummaryOnly a few studies have assessed the predation risk on artificially marked nests, or have examined ways of marking nests to avoid destruction by machinery. Until now, however, neither type of study has directly addressed this apparent trade-off experimentally. The impact of marking the nests of Northern Lapwing Vanellus vanellus with thin 2 m-long conspicuous bamboo poles with the top end highlighted with reflective red or orange spray has been tested for three years in two breeding areas of waders in the Czech Republic. A total of 52 pairs of nests on agricultural land, with each pair consisting of one marked nest and one unmarked reference counterpart nest, were monitored for 2004 nest-days until hatching, agricultural operations or failure. The results proved that marking itself does not result in increased nest predation. The nests found in the early incubation stage were under higher threat of depredation, irrespective of the presence of marking. Our results show that it is possible to find a finely-tuned trade-off in nest marking of ground-nesting birds between risk of damage by agricultural machinery and risk of increased nest predation. Our positive experience with Northern Lapwing, and episodically with three other wader species in the Czech Republic, suggests that this direct nest protection could be used effectively for a wider variety of ground-nesting birds.

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Breeding Biology of Gray-Crowned Tyrannulet in the Monte Desert, Argentina

The Condor ◽

10.1093/condor/102.1.205 ◽

2000 ◽

Vol 102 (1) ◽

pp. 205-210 ◽

Cited By ~ 1

Author(s):

Eduardo T. Mezquida ◽

Luis Marone

Keyword(s):

Incubation Period ◽

Breeding Season ◽

Nesting Success ◽

Nest Failure ◽

East Central ◽

Male And Female ◽

Monte Desert ◽

Present Information ◽

Nestling Period ◽

Wet Tropics

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

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Factors Influencing Predation on Ovenbird (Seiurus Aurocapilla) Nests in Northern Hardwoods: Interactions Across Spatial Scales

The Auk ◽

10.1093/auk/123.1.82 ◽

2006 ◽

Vol 123 (1) ◽

pp. 82-96

Author(s):

Brady J. Mattsson ◽

Gerald J. Niemi

Keyword(s):

Nest Predation ◽

Spatial Scales ◽

Agricultural Practices ◽

Predation Rate ◽

Mean Values ◽

Core Habitat ◽

Litter Depth ◽

Seiurus Aurocapilla ◽

Forest Songbirds ◽

Main Effects

Abstract Microsite, patch, and landscape conditions may interact to influence nest predation. In northern Minnesota, silvicultural and agricultural practices may be involved in recent increases in nest predators and regional declines in several ground-nesting songbirds. To examine this problem, we evaluated 17 hierarchical models of predation on Ovenbird (Seiurus aurocapilla) nests that included microsite variables, distances to edges, and amount of core forest within a 2-km radius surrounding six study plots. During 2000 and 2001, 157 Ovenbird nests were monitored to estimate nest predation rates. A model that included the main effects of litter depth and core forest area and an interaction term between the two best described variation in predation on Ovenbird nests (AICc weight = 0.83). The nest predation rate from this model was 0.51 ± 0.01 (mean ± SE), assuming mean values of litter depth and amount of core forest. Shallow litter was associated with higher nest predation in three plots surrounded by less core habitat (40–60 ha), whereas there was no relationship in three plots surrounded by more core area (100–150 ha). Management that promotes deep leaf litter and the maintenance of large, intact forest tracts will likely benefit Ovenbirds and other forest songbirds. Factores que Influencian la Depredación de Nidos de Seiurus aurocapilla en los Bosques del Norte: Interacciones a través de las Escalas Espaciales

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Pattern Of Skin Diseases In A Rural Village Development Community Of Nepal

Nepal Journal of Dermatology Venereology & Leprology ◽

10.3126/njdvl.v12i1.10595 ◽

2016 ◽

Vol 12 (1) ◽

pp. 41-44 ◽

Cited By ~ 2

Author(s):

R Shrestha ◽

DP Shrestha ◽

L Lama ◽

D Gurung ◽

I Rosdahl

Keyword(s):

Health Services ◽

Skin Disease ◽

Skin Diseases ◽

Age Group ◽

Limited Information ◽

Disease Category ◽

Common Cause ◽

Rural Village ◽

Common Skin

Introduction: Skin diseases are a common cause of morbidity in Nepal as per the health services report. There is limited information on the prevalence and pattern of skin diseases in the community. The objective of this study was to determine the pattern of skin diseases in a rural village development community of Nepal. Materials and methods: Two dermatologic health camps were conducted, during which, the villagers were examined by dermatologists. The skin diseases diagnosed were recorded in a proforma. Results: There were 433 individuals examined and 359 (male-47.9%; female-52.1%) had skin disease identified clinically (camp prevalence- 83%). The age of patients ranged from 1 to 80 years (mean-24.5; SD±15.9), with majority in the age group of 10-19 years. The most common skin disease category was eczemas (36.4%), followed by infections (28.4%), acne (22%), pigment disorders (34%) and urticaria (12.3%). Conclusion: Skin diseases were common in the community. The five most common Skin disease categories were eczemas, infections, acne and pigment disorders were the more common conditions. DOI: http://dx.doi.org/10.3126/njdvl.v12i1.10595 Nepal Journal of Dermatology, Venereology & Leprology Vol.12(1) 2014 pp.41-44

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Laboratory Protocol for Induction of Sporulation in Phytophthora cajani causing Phytophthora Blight in Pigeonpea

Legume Research - An International Journal ◽

10.18805/lr-4310 ◽

2020 ◽

Author(s):

G. Jadesha ◽

Mamta Sharma ◽

P. Narayan Reddy

Keyword(s):

Incubation Period ◽

Culture Conditions ◽

Fluorescent Light ◽

Limited Information ◽

Phytophthora Blight ◽

Phytophthora Spp ◽

Tomato Extract ◽

Culture Plate ◽

Laboratory Protocol

Background: Phytophthora blight (PB), caused by Phytophthora cajani is a prominent disease in the low laying areas combined with intermittent rainfall. Induction of zoospores and sporangia of P. cajani in culture plate is troublesome and also limited information is available on the protocol for sporulation of sporangia and zoospores in the laboratory, The study developed and validated the protocol for induction of sporangia and zoospore of P. cajani. Methods: The Protocol using 5-7 days old culture, diluted tomato extract broth and other culture conditions like the temperature of 30oC, alternate 12 hours of fluorescent light (2000 Lx) and dark can induce abundant sporangia and zoospores in vitro. Result: The study developed and validated the new protocol for uniform and profuse induction of sporangia and zoospores of P. cajani. Diplanetism mechanism of Phytophthora spp. was recorded with P. cajani the findings are the first of its kind. Additionally, the study revealed the concentration of 1x10-5 zoospores/ml is optimum to develop the infection in plants with the shortest incubation period of 24 hours.

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Nestling begging calls increase predation risk by corvids

Animal Biology ◽

10.1163/15707563-20181058 ◽

2019 ◽

Vol 69 (2) ◽

pp. 137-155

Author(s):

Magne Husby

Keyword(s):

Nest Predation ◽

Predation Rate ◽

Artificial Nest ◽

Auditory Cues ◽

Artificial Nests ◽

Breeding Failure ◽

Nestling Begging ◽

Real Costs ◽

Insight Into ◽

Nest Predators

Abstract Despite nest predation being the most common cause of breeding failure in open-nesting birds, we have little insight into the cues used by nest predators when they search for nests. So far we have assumed that nest-predating birds are visually oriented while mammal predators to a large extent use scent and auditory cues like nestling begging calls. To evaluate how important nestling begging calls are for corvid nest predators searching for nests, I used artificial nests, which made it possible to find the real costs of the begging without mitigation by parental and nestling behavior. I used paired artificial nests, one with and one without nestling begging call playback. Within 10 days, 62.9% of the nests were predated. The analyses showed that nests with begging calls suffered a significantly higher predation rate than nests without begging calls, especially when the nests were placed close to corvid nests. Moreover, nests with begging calls were predated significantly earlier than nests without begging calls. In artificial nest pairs with both nests predated but on different days, nests with begging calls were predated first. In nest pairs with only one predated nest, nests with begging calls were predated most often. This experiment shows that nestling begging calls imply a cost in terms of increased and earlier nest predation, and that corvids use nestling begging calls as a cue to find and depredate bird nests, challenging earlier expectations.

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Predation on Real and Artificial Nests in Shrubsteppe Landscapes Fragmented by Agriculture

The Condor ◽

10.1093/condor/104.3.496 ◽

2002 ◽

Vol 104 (3) ◽

pp. 496-506 ◽

Cited By ~ 7

Author(s):

W. Matthew Vander Haegen ◽

Michael A. Schroeder ◽

Richard M. DeGraaf

Keyword(s):

Nest Predation ◽

Survival Rates ◽

Predation Rate ◽

Future Research ◽

Fragmented Landscape ◽

Corvus Corax ◽

Artificial Nests ◽

Fragmented Landscapes ◽

Eastern Washington ◽

Predation Rates

Abstract Clearing of shrubsteppe communities for agriculture has created a highly fragmented landscape in eastern Washington, a condition that has been shown to adversely affect nesting success of birds in some forest and grassland communities. We used artificial nests monitored by cameras to examine relative effects of fragmentation, distance to edge, and vegetation cover on nest predation rates and to identify predators of shrubsteppe-nesting passerines and grouse. Predation rate for artificial nests was 26% (n = 118). Fragmentation had a strong influence on predation rates for artificial nests, with nests in fragmented landscapes about 9 times more likely to be depredated as those in continuous landscapes. Daily survival rate (± SE) for 207 real nests of 4 passerine species also was greater in continuous (0.978 ± 0.004) than in fragmented (0.962 ± 0.006) landscapes, although pattern of predation between real and artificial nests was not consistent among sites. Artificial nests were depredated by Common Ravens (Corvus corax), Black-billed Magpies (Pica hudsonia), Sage Thrashers (Oreoscoptes montanus), least chipmunks (Tamias minimus), and mice. Most nests in fragments were depredated by corvids (58%), whereas only Sage Thrashers and small mammals depredated nests in continuous landscapes. Increased predation by corvids and lower nest success in fragmented landscapes may have played a part in recent declines of some shrubsteppe birds. Future research should measure annual reproductive success of individual females and survival rates of juveniles and adults. Depredación de Nidos Naturales y Artificiales en Paisajes de Estepa Arbustiva Fragmentados por Agricultura Resumen. El reemplazo de estepa arbustiva por campos de cultivo ha creado un paisaje altamente fragmentado en el este de Washington, afectando adversamente el éxito de nidificación de aves en algunas comunidades de bosque y pastizal. Usamos nidos artificiales monitoreados por cámaras para examinar los efectos relativos de la fragmentación, la distancia al borde y la cobertura de la vegetación sobre las tasas de depredación de nidos, y para identificar los depredadores de paserinos y gallinas silvestres (Phasianidae) que nidifican en la estepa arbustiva. La tasa de depredación de los nidos artificiales fue del 26% (n = 118). La fragmentación tuvo una fuerte influencia en las tasas de depredación de nidos artificiales, ya que los nidos en paisajes fragmentados tuvieron una probabilidad de ser depredados 9 veces mayor que aquellos en paisajes continuos. La tasa de supervivencia diaria (± EE) de 207 nidos naturales pertenecientes a 4 especies de paserinos también fue mayor en paisajes continuos (0.978 ± 0.004) que fragmentados (0.962 ± 0.006), aunque el patrón de depredación entre nidos naturales y artificiales no fue consistente entre sitios. Los nidos artificiales fueron depredados por Corvus corax, Pica hudsonia, Oreoscoptes montanus, Tamias minimus y ratones. La mayoría de los nidos en fragmentos fueron depredados por C. corax (58%), mientras que sólo O. montanus y pequeños mamíferos depredaron nidos en paisajes continuos. Un incremento en la depredación por parte de C. corax y un menor éxito de los nidos en paisajes fragmentados puede haber jugado un rol en la disminución de algunas aves de la estepa arbustiva. Futuras investigaciones deberían medir el éxito reproductivo anual de hembras individuales y las tasas de supervivencia de juveniles y adultos.

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