Daily Nest Survival Probability Research Articles

Effects of nest site selection and nest concealment on nest survival of Gosling's Bunting (Emberiza goslingi)

Selecting nest sites that provide access to resources and reduce predation risk is crucial to maximizing fitness in breeding birds. Therefore, understanding what habitat features influence nest site selection and nest success is a key component of avian conservation because it allows for identification and protection of habitat that will promote population growth. We examined drivers of nest success in Gosling's Bunting (Emberiza goslingi) by evaluating variables that influence nest site choice and nest survival at 23 nests and an equal number of random, paired, non-nesting locations in a tropical savannah landscape in north-central Nigeria. Gosling's Buntings exhibited a nonrandom nest-placement pattern. Nests were either on or in proximity to large rock surfaces with nesting probability increasing when the immediate nesting area (100 m radius around the nest) consisted of 30–60% bare rock. Compared to random non-nesting sites, buntings selected areas that were low in litter cover and/or had short grass height. Daily nest survival probability was high (0.96) and was positively associated with the proportion of bare rock around the nest but negatively with the amount of litter cover. Although hatching success was 56.9%, only 30% of all nesting attempts successfully fledged a chick suggesting that nest failure occurred mostly at advanced stages of nesting (nestling phase) when renesting is less likely. Nest survival was higher at low concealment, but only significantly higher than nest failure within a restricted concealment range of 45–54%. Our findings show that microhabitat features could benefit reproduction and daily nest survival. Furthermore, by linking nest-site attributes with fitness indices, we highlight the potential importance of fitness measures as a key component of habitat quality assessment for these buntings in tropical savannahs.

Fine-scale plasticity in nest placement can compensate for poor quality junipers as nesting trees for gray vireos.

Understanding the interactions between behavior and habitat characteristics can have important implications for species of conservation concern. Gray vireos (Vireo vicinior) are one example of a species of conservation concern that is understudied in terms of nest survival probabilities and the habitat characteristics that influence them. Our objective was to determine if habitat features such as juniper density, juniper foliage density, or tree height influence nest survival probabilities, and if gray vireo nest placement can mitigate habitat risks. Based on previous work, we expected daily nest survival probabilities to be associated with nest height and surrounding vegetation. We monitored 89 nests in central New Mexico from 2016–2018 to estimate daily nest survival probabilities. We compared variation in nest placement, nest tree characteristics, and surrounding vegetation between failed and successful nests using logistic exposure models and Akaike Information Criteria. Daily and cumulative nest survival probability were 0.983 (95% CI [0.973–0.989]) and 0.575 (95% CI [0.444–0.702]), respectively. Top models predicting nest survival included a negative interaction between nest-tree foliage density and the distance of the nest from the edge of the nesting tree. This suggests that gray vireos can mitigate risks associated with low nest concealment by nesting closer to the interior of the nesting tree.

Descripción del nido y cuidado parental de Euphonia chlorotica (Aves: Fringillidae) en Santa Cruz, Bolivia

En este estudio se describen los primeros datos sobre aspectos reproductivos de Euphonia chlorotica en Bolivia mediante el monitoreo de un nido construido en un macetero colgante dentro una vivienda ubicada en la ciudad de Santa Cruz de la Sierra. El nido tenía forma globular con entrada lateral típica de la especie y fue construido en un lapso de 6 días en diciembre de 2019. Tres huevos de color blanquecino con manchas café oscuras fueron incubados durante 16 días exclusivamente por la hembra. Los pichones nacieron de forma sincrónica el 25 de enero de 2020 y luego de 16 días abandonaron el nido con sus plumajes totalmente desarrollados, excepto por el largo de las plumas de la cola, y con los picos aun con la comisura amarilla característica de los juveniles. La alimentación de los pichones fue realizada por ambos progenitores y la probabilidad de supervivencia diaria del nido y éxito de anidación fue del 100%, pese a encontrase en un ambiente altamente urbanizado.

Factors influencing productivity of eastern wild turkeys in northeastern South Dakota.

Population growth is highly sensitive to changes in reproductive rates for many avian species. Understanding how reproductive rates are related to environmental conditions can give managers insight into factors contributing to population change. Harvest trends of eastern wild turkey in northeastern South Dakota suggest a decline in abundance. We investigated factors influencing reproductive success of this important game bird to identify potential factors contributing to the decline. We monitored nesting rate, nest survival, renesting rate, clutch size, hatchability, and poult survival of 116 eastern wild turkey hens using VHF radio transmitters during the springs and summers of 2017 and 2018. Heavier hens were more likely to attempt to nest than lighter hens, and adult hens were more likely to renest than yearling hens. Nest survival probability was lowest in agricultural fields relative to all other cover types and positively related to horizontal visual obstruction and distance to the nearest road. Daily nest survival probability demonstrated an interaction between temperature and precipitation, such that nest survival probability was lower on warm, wet days, but lowest on dry days. Egg predation was the leading cause of nest failure, followed by haying of the nest bowl and death of the incubating hen. Poults reared by adult hens had a greater probability of survival than poults reared by yearling hens. Our estimate of survival probability of poults raised by yearling hens was low relative to other studies, which may be contributing to the apparent regional population decline. However, there is little managers can do to influence poult survival in yearling hens. Alternatively, we found nest survival probability was lowest for nests initiated in agricultural fields. Wildlife‐friendly harvesting practices such as delayed haying or installation of flushing bars could help increase productivity of eastern wild turkey in northeastern South Dakota.

Factors influencing nesting phenology and nest success of the Rufous-winged Sparrow (Peucaea carpalis) at the center of its distribution in Sonora, Mexico

We determined the effect of the seasonal distribution of summer rainfall and associated seasonal changes in vegetation on the timing of reproduction and reproductive success of the Rufous-winged Sparrow (Peucaea carpalis) in the plains of central Sonora, Mexico, and influence of exotic buffelgrass (Pennisetum ciliare). We monitored 302 nests twice weekly from early July to early October of 2012–2014. We fitted Bayesian logistic-exposure models for nest survival data using covariables year, nest stage, date, normalized difference vegetation index, shrub cover, buffelgrass cover, and nest height. Mean daily nest survival probability equaled 95.9% (95% CRI 95.1%–96.1%), with nest survival probability averaging 36.3% (95% CRI 30.2%–42.5%) during the nesting season.We found evidence that daily nest survival probability differed between nest stages but variation in environmental explanatory variables among nests did not explain variation in daily nest survival probability, despite suggestive evidence of a positive association between NDVI and daily nest survival probability. Daily nest survival probability seemed unaffected by the habitat alteration in buffelgrass prairies, suggesting that the Rufous-winged Sparrow may be resilient to habitat transformation in the center of its distribution.

Interactive effects between nest microclimate and nest vegetation structure confirm microclimate thresholds for Lesser Prairie-Chicken nest survival

AbstractThe range of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) spans 4 unique ecoregions along 2 distinct environmental gradients. The Sand Shinnery Oak Prairie ecoregion of the Southern High Plains of New Mexico and Texas is environmentally isolated, warmer, and more arid than the Short-Grass, Sand Sagebrush, and Mixed-Grass Prairie ecoregions in Colorado, Kansas, Oklahoma, and the northeast panhandle of Texas. Weather is known to influence Lesser Prairie-Chicken nest survival in the Sand Shinnery Oak Prairie ecoregion; regional variation may also influence nest microclimate and, ultimately, survival during incubation. To address this question, we placed data loggers adjacent to nests during incubation to quantify temperature and humidity distribution functions in 3 ecoregions. We developed a suite of a priori nest survival models that incorporated derived microclimate parameters and visual obstruction as covariates in Program MARK. We monitored 49 nests in Mixed-Grass, 22 nests in Sand Shinnery Oak, and 30 nests in Short-Grass ecoregions from 2010 to 2014. Our findings indicated that (1) the Sand Shinnery Oak Prairie ecoregion was hotter and drier during incubation than the Mixed- and Short-Grass ecoregions; (2) nest microclimate varied among years within ecoregions; (3) visual obstruction was positively associated with nest survival; but (4) daily nest survival probability decreased by 10% every half-hour when temperature was greater than 34°C and vapor pressure deficit was less than −23 mmHg during the day (about 0600–2100 hours). Our major finding confirmed microclimate thresholds for nest survival under natural conditions across the species' distribution, although Lesser Prairie-Chickens are more likely to experience microclimate conditions that result in nest failures in the Sand Shinnery Oak Prairie ecoregion. The species would benefit from identification of thermal landscapes and management actions that promote cooler, more humid nest microclimates.

Biases in nest survival associated with choice of exposure period: A case study in North American upland game birds

ABSTRACT Estimated probability of daily nest survival is commonly used to derive cumulative nest survival for a specified nest-exposure period. For many species of birds, the presence of a parent is an important cue used by researchers to locate nests, but in some cases nest detection rates are reduced during egg laying, when parents spend a greater amount of time away from the nest. As a result, sample size becomes limited during the laying stage. Researchers must then choose between 2 alternative strategies for deriving cumulative nest survival, based on either (1) exposure length for only the incubation period or (2) exposure length for laying plus incubation. Both approaches carry implicit assumptions, the violation of which can result in bias. We reviewed recent literature and describe the extent to which these 2 strategies were used in studies of galliform birds (including grouse, quail, and Wild Turkey [Meleagris gallopavo]) in North America. We then evaluated the theoretical potential for bias und...

Observer effects strongly influence estimates of daily nest survival probability but do not substantially increase rates of nest failure in Greater Sage-Grouse

ABSTRACT Researchers have long recognized that the process of observing nests may influence nest success by increasing depredation risk or causing females to abandon nests. The effects of observer-related nest abandonment may also reduce estimates of daily nest survival when time to nest fate is reduced and the average nest exposure period within the sample becomes shorter. We used an 8-yr record of observer visitations of nesting female Greater Sage-Grouse (Centrocercus urophasianus) in central Nevada, USA, to assess whether observers influenced either the probability of daily nest survival or the overall probability of nest success. Because nest success is influenced by factors other than visitation, we also accounted for the overall quality of a nest (i.e. probability of success in the absence of observer effects) based on potential confounding factors. Nest visitation (no flushing) had no effect on daily nest survival, regardless of nest quality or female age. Flushing a female from a nest substantial...

Variability of daily nest survival and breeding success in relation to characteristics of Eurasian magpie (Pica pica) nests

Size and structure of birds’ nests can arise from evolutionary trade-offs between benefits, such as insulation from unfavourable conditions, maintenance of eggs or chicks, security against predation, and costs, such as energy spent in construction of the nest and the risk of predation in more visible nests. The relationships between nest characteristics and breeding success and survival probabilities of Eurasian magpie (Pica pica) eggs and nestlings were studied in Baghbadaran, central Iran during the 2008 and 2010 breeding seasons. Nesting success was modelled to assess the relationships between nest parameters and the probability of daily nest survival. Mean clutch and brood size, hatching, fledging and breeding success did not vary significantly between the two years. Mean internal diameter, external diameter, distance to feeding location and distance to open areas varied significantly between the two study years. Daily nest survival rate for both years (2008 and 2010) was 0.98 ± 0.002. Nest size and status of nests, defined as old or newly established nests, were the best factors predicting probabilities of nest survival. Nests with small internal diameters had higher overall nest productivity. Nest height was positively correlated with both fledging success and breeding success. Our results agree with previous findings that have shown that magpie pairs with large nests provided their nestlings with higher quality food compared with pairs with smaller nests and so nest size was an indicator of parental ability. Nest height is also recognized as an important determinant of nest predation, mostly because it may affect nest detectability and accessibility.

Experimental removal of woody vegetation does not increase nesting success or fledgling production in two grassland sparrows (Ammodramus) in Pennsylvania

The influence of vegetation structure on the probability of daily nest survival (DNS) for grassland passerines has received considerable attention. Some correlative studies suggest that the presence of woody vegetation lowers DNS. Over 3 years (2009–2011), we monitored 215 nests of the Grasshopper Sparrow (Ammodramus savannarum) and Henslow's Sparrow (A. henslowii) on 162 ha of reclaimed surface-mine grasslands in Pennsylvania. We removed shrubs from treatment plots with ≤36% areal coverage of woody vegetation in a before-after-control-impact-pairs (BACIP) design framework. Daily nest survival (95% CI: 0.94–0.96) was as high as previous studies have reported but was not associated with woody vegetative cover, proximity to woody vegetation, or woody stem density. Variation in DNS was best explained by increasing nonwoody-vegetation height. Grasshopper Sparrow fledgling production on treatment plots in 2010 (95% CI: 3.3–4.7) and 2011 (95% CI: 3.8–5.0) was similar to baseline conditions of treatment plots (95% CI: 3.4–4.9) and control plots (95% CI: 3.2–4.5) in 2009. Fledgling production was associated with thatch depth (β ± SE = 0.13 ± 0.09) and bare ground (β ± SE = -2.62 ± 1.29) adjacent to the nest and plot woody vegetative cover ( ± SE = -3.09 ± 1.02). Our experimental research suggests that overall reproductive success of Grasshopper and Henslow's sparrows on reclaimed surfacemine grasslands is driven by a suite of largely nonwoody—vegetation components, and both species can successfully nest and produce young in habitats with greater amounts of scattered woody vegetation than has generally been considered.

Variations in breeding success and daily nest survival of Whiskered Tern (Chlidonias hybrida) at two Iranian colonies

Variations in breeding success of the Whiskered Terns (Chlidonias hybrida) were studied in two wetlands; Anzali (2005 and 2008) and Zarivar (2007–2008) in north and west Iran. Nesting success was modeled and compared using information-theoretic approach implemented in program Mark in order to assess effects of colony locations, years and nest initiation dates on the probability of daily nest survival. Clutch size did not vary between colonies and years. Breeding success varied between colonies (Zarivar > Anzali), and years only in Anzali (2005 > 2008). Overall daily nest survival was 0.977. (95% LCI 0.973, UCI 0.981), equivalent to a Mayfield nest survival of 0.317. (95% LCI 0.255, UCI 0.387). Egg-laying periods and colony site were important covariates affecting the daily survival rates (Σωi = 0.86 and Σωi = 0.83, respectively), while, the support for the effect of year was less (Σωi = 0.41). We concluded that Lake Zarivar provides a more favorable nesting location for Whiskered Terns probably because of little changes in rainfall and water depth during the breeding seasons which influence breeding performance.

Nest-Site Selection and Nest Survival of Early Successional Birds in Central Pennsylvania

Abstract We studied nest-site selection and nest survival of early successional birds at the Barrens Grouse Habitat Management Area in central Pennsylvania in 2006 and 2007. We compared vegetation at nests to that at sites 30 m distant to examine microhabitat characteristics related to nest-site selection and which characteristics were associated with nest survival. Daily nest survival probability was 0.968 ± 0.006 (SE) for Chestnut-sided Warblers (Dendroica pensylvanica), 0.935 ± 0.014 for Field Sparrows (Spizella pusilla), 0.955 ± 0.011 for Indigo Buntings (Passerina cyanea), and 0.960 ± 0.005 for all species combined. Nest-site selection was best characterized by high woody stem density for Chestnut-sided Warblers, Indigo Buntings, and all species combined. Nest survival increased with woody stem density, indicating that nest-site preferences may be adaptive. Ground cover best predicted nest placement for Field Sparrows but no measured variable affected nest survival for this species. We suggest that s...

Incubation success of released hand‐reared pheasants Phasianus colchicus compared with wild ones

We investigated previously observed but unexplained differences in incubation success between wild and hand‐reared common pheasants Phasianus colchicus. Hand‐reared birds are widely released in late summer in Britain and elsewhere to supplement wild stocks for shooting purposes. We radio‐tracked 53 wild and 35 previously released reared female pheasants occupying simultaneously the same areas on a game‐keepered estate in eastern England between February and mid July 1999 and 2000. Predation of adult birds was comparatively low for both wild and reared birds, and overall survival did not differ between years or between groups. However, of 52 nests incubated by wild females 49% hatched, whereas of 30 nests incubated by reared pheasants only 22% hatched. Mayfield estimates of daily nest survival probability thus differed significantly between groups. However, predation of eggs was similar for both wild and reared birds. Instead the observed difference in hatch rates was due to nest abandonment, with more reared females (41%) deserting apparently unmolested nest sites than wild females (6%).

Does photo-monitoring affect nest predation?

We examined predation rates on natural and artificial Common Wood-Pigeon (Columba palumbus) nests with camouflaged cameras, with uncamouflaged cameras, and without cameras in Villatobas, Central Spain. Total daily nest survival probability was considerably higher in uncamouflaged-camera nests than in the two other types of nests, while there were no differences between the camouflaged-camera and the control nests. Survival probability of natural nests was similar to that of camouflaged-camera and control nests and significantly lower than that of uncamouflaged-camera nests. Any significant differences among nest types applied only to predation by Black-billed Magpies (Pica pica); predation rates by the garden dormouse (Elyomis quercinus) were similar in all experimental treatments. The results suggest that the presence of an uncamouflaged camera can affect Black-billed Magpies, which may become wary and avoid nests equipped with uncamouflaged cameras. The influence of photographic equipment on predation intensity in different species is an important factor that should be taken into account in studies using artificial nests. The use of control nests is recommended to evaluate the potential effects of the camera.

Avian Nest Success and Community Composition in a Western Riparian Forest

Riparian cottonwood (Populus angustifolia) forests provide avian habitats that are of high conservation value throughout western North America. We compared avian nest success, brood parasitism, species richness, and species abundance among 24 cottonwood forest patches representing a range of sizes and shapes. We randomly selected patches in 3 ranges of size, small (0.1-0.6 ha), medium (1.2-2.5 ha), and large (4.0-6.2 ha); and 2 ranges of shape, compact (1.00-1.83) and edgy (1.87-3.30). We measured pathch shape using the Patton Diversity Index. We monitored 313 nests of 20 species over 2 years. Only American robin (Turdus migratorius) nests exhibited a negative relationship between distance from edge and probability of daily nest survival. We found no relationship between the probability of nest parasitism and patch size, patch shape, or nest distance from edge. Point counts revealed that both richness and abundance of forest-interior bird species increased with patch size. Forest-interior species abundance also increased with decreasing Patton Diversity Index. Our results suggest that patch edginess has a negative effect on the abundance of forest-interior birds. Although our results do not show that patch edginess has a negative effect on nest success, they emphasize the importance of species autecology in relation to the effects of edge on avian nesting success.

Nest predation and reproductive traits in small passerines: a comparative approach

Nest predation can be a decisive factor in the evolution of bird reproduction strategies. This paper compares several reproductive traits in small passerines on the Iberian Peninsula (n=31) with the probability of daily nest survival from predation. We consider the phylogenetic relationships between species by means of an analysis according to three models of evolutionary change: Brownian, punctuational and Grafen's arbitrary. In this comparative evolutionary scenario, clutch size, egg volume and incubation period appear not to change in relation to nest predation, while the nestling phase duration is a positively-related parameter to daily nest survival from predation. These results are consistent for all models of evolutionary change. Thus, from the perspective of nest predation, the nestling period is the most important evolutionary parameter in small passerines. A hypothetical influence of nest predation on passerine clutch and egg size should only be regarded as an indirect factor, linked to the relationship between these parameters and the duration of the nestling period.

Nesting Success of Northern Pintails on the Coastal Yukon-Kuskokwim Delta, Alaska

We studied nesting chronology and success of Northern Pintails (Anas acuta) on the coastal Yukon-Kuskokwim Delta, Alaska during the summers of 1991-1993. We found a total of 795 nests during three annual searches of a 27.4 km 2 area. Minimum nest density averaged 9.67 nests per km 2 . Nesting success varied among years and ranged from 43.12% in 1991 to 10.74% in 1993 (average 23.95%). Most nest loss was the result of predation and tidal flooding. Daily nest survival probability declined with nest initiation date in all three years and also varied with nest age in 1992. Clutch size averaged 7.63 ± 0.067 (SE) eggs per nest and was larger than reported for other populations of Northern Pintails. Clutch size declined during the 44-47 day nesting interval at a greater rate than reported for other populations of Northern Pintails. We conclude that sub-arctic and prairie nesting Northern Pintails have similar reproductive potentials.