Nest Abandonment Research Articles

Nest Box Cameras Provide Insight into Causes of Nest Failure for American Kestrels

ABSTRACT Although nest failure is a common occurrence in birds, oftentimes the causes, or details, of the failure are unknown because nests cannot be monitored closely or continuously. This inability to monitor nests in ways that allow for a detailed understanding of nest failure can hamper our ability to conserve declining species, such as the American Kestrel (Falco sparverius). Here we describe previously unreported observations from continuous video monitoring in kestrel nest boxes and biweekly nest monitoring via an extendable fiber optic endoscopic camera. From continuous video monitoring we observed adult kestrels consume a kestrel egg with little to no development and a European Starling (Sturnus vulgaris) pierce and remove an abandoned kestrel egg from a nest box. From biweekly monitoring with a fiber optic camera, we inferred that nest abandonment by kestrels was associated with eggs not developing either from infertility or early-stage embryo death. Although it is unclear how common such occurrences may be across the broader range of kestrels, these observations may provide impetus to explore these causes of nest failure more closely.

Analysis of Public Comments on Experimental Regulations for Protecting Black Bass during The Spawning Period in Eastern Ontario Reveals Both Stakeholder Acceptance and Skepticism.

Recreational angling of nesting largemouth bass (Micropterus nigricans) and smallmouth bass (M. dolomieu) can greatly increase nest abandonment, and in the northern clines of their range, decrease recruitment. This is the case in eastern Ontario, where high levels of non-compliance and difficult to enforce regulations have impacted black bass (Micropterus spp.) conservation and management. Effective January 1, 2024 until December 31st, 2025, novel and experimental fishing sanctuaries were imposed on portions of Charleston Lake and Opinicon Lake that prohibit recreational fishing of all types from April 15th to the Friday before the first Saturday in July (encompassing the full bass reproductive season). As part of the formal process to institute these experimental regulations, public comments were collected on the Environmental Registry of Ontario. We examined those comments and identified supportive and non-supportive themes related to these experimental regulations. While a majority of stakeholders were in support of the new regulations, we also noted sub-themes that may hinder regulation acceptance. Those sub-themes include: a perceived lack of enforcement negating the potential benefits of the sanctuaries, under-estimation of the extent of non-compliance with existing regulations such that new regulations are unnecessary, misunderstanding and misinformation, as well as distrust of government and the academic research community. Understanding and addressing these stakeholder perspectives will help researchers studying the new sanctuary areas and managers understand any lack of compliance while informing future decisions about bass management in eastern Ontario and beyond.

Influence of prey availability on the movement pattern of breeding saker falcons (Falco cherrug) in Mongolia

Abstract As an apex predator in arid steppe, saker falcon plays a crucial role in maintaining ecosystem balance. Understanding their movement patterns concerning conspecific competition and prey availability is important for their conservation. We aim to understand how movement pattern of breeding saker falcons relates to prey availability. Twelve adult sakers were tracked during the breeding seasons, using satellite transmitters. Throughout the breeding season, sakers exhibited territorial behaviour, with minimal overlap in range use among neighbouring conspecifics. Males occupied larger areas (mean = 2,397 ha, median = 1,221 ha), compared to females (mean = 1,241 ha, median = 554 ha), and it remained consistent throughout breeding season. Female home range size increased notably during late nestling stage and post-fledging dependence periods, indicating release from brooding constraints. Notably, we found a negative relationship between male home range size and prey availability. In high rodent density areas, males occupied smaller areas (mean = 1,135 ha, median = 1,034 ha), contrasting with low rodent density areas (mean = 6,815 ha, median = 6,516 ha). However, no significant relationship was observed between female home range size and prey availability. We also noted instances of nest abandonment and early dispersal behaviour in some females, potentially influenced by a handicapping effect of tagging. Our findings offer valuable insight into how prey availability shapes saker falcon space use and defines their spatial requirements for successful breeding. This knowledge is crucial for the conservation and management of globally endangered saker falcons, informing targeted habitat protection and resource management strategies.

Water depth influences survival and predator-specific patterns of nest loss in three secretive marsh bird species.

Wetlands have become increasingly rare in the United States, negatively influencing wetland-dependent birds, and many remaining wetlands are intensively managed through seasonal dewatering mimicking historic flood pulses during spring and summer. However, water around nests may provide protection from terrestrial predators, and lowering water levels during the breeding season of wetland birds may increase predation risk and exacerbate marsh bird population declines. Understanding interactions between water depth, nesting marsh birds, and nest predators is critical to aid managers in developing a multi-species management approach in emergent wetlands. During the 2020 and 2021 breeding seasons, we examined nest survival of 148 marsh bird nests (American Coot, Fulica americana, n = 1; Common Gallinule, Gallinula galeata, n = 64; and Least Bittern; Ixobrychus exilis, n = 83) and installed cameras at 78 nests to identify predators at a large, restored floodplain wetland in Illinois where the primary management technique is seasonal water removal to stimulate germination of moist soil plants. We found nest predation of, and abandonment by, Least Bittern and Common Gallinule were related to shallower water, and early season, high volume dewatering. Least Bitterns nested more commonly along wetland edges and nests farther from the shore were more likely to survive. Similarly, we found mammalian depredation of nests and nest abandonment decreased when deeper water was present around nests. Alternatively, snake predation was observed earlier in the year prior to water removal from inundated emergent vegetation. Our results demonstrate water depth may be an important deterrent of nest predators, especially mammals, during the breeding season. Further, we recommend managers delay dewatering until after the nesting season at sites where management for conservation-priority marsh birds is a focus.

Emergence of games from ecological trade-offs: longevity changes strategies for extra-pair mating in birds

Each member of a breeding pair benefits if the other does more of the parental investment, so there is scope for behaviours that can be interpreted as both cooperative and competitive games between males and females. Extra-pair mating, widespread among socially monogamous birds, adds extra conflict but also potential opportunity to these social interactions. We analyse an individual-based model of a social environment with simple behavioural strategies where game-like patterns and cooperative outcomes emerge. The model focuses on three evolving traits: female propensity for extra-pair copulations and male investment in territorial behaviour and care. Male traits are reaction norms that use experienced within and extra-pair copulations as information input. We found that female extra-pair mating provided incentives for males to reduce territorial aggression and increase care for offspring. However, when adult survival was higher, male investment in care and territoriality changed from being negatively to positively correlated. This happened because longer life expectancy gave more behavioural opportunities for males, where nest desertion maximises lifetime male fitness when female extra-pair copulation is high. This outcome evolved gradually, with stable periods of intermediate extra-pair mating and low territoriality. These were punctuated by cycles of high extra-pair mating, nest desertion, reduced extra-pair mating and relapse to aggressive territoriality before a new stable phase was established. Each successive trait cycle was faster and smaller, indicating that through evolution of reaction norms, the gene pool has a long history that canalizes the evolution of behaviours, which can be interpreted as emergence and refinement of frequency-dependent games.Significance statementMost birds that mate in monogamous pairs engage in extra-pair copulations. Males of some species invest (in varying proportions) in offspring that are genetically related only to their social female. The great variability of extra-pair mating levels among different species and populations, supported by numerous field studies, indicates that social and ecological factors play a crucial role in shaping the behaviour. We analyse a computer model in which extra-pair mating evolves concurrently with male reproductive investments in territory defence and offspring care and show how common ecological trade-offs may change the social dynamics within a breeding population and lead to the emergence of complex social interactions between males, females and their neighbours.

Nest desertion as an anti-parasitism strategy in hosts selects for late egg-laying behavior in cuckoos

Studies have shown that brood parasites lay their eggs early in the egg-laying sequence of their hosts, providing them with the advantage of earlier hatching. However, common cuckoos (Cuculus canorus) appear to parasitize the nests of gray bushchat (Saxicola ferreus) during the late egg-laying stage. The bushchat often abandons parasitized nests in the early stages, but not in the late egg-laying stages, thus favoring late egg-laying by cuckoos. In this study, four experiments were conducted to determine whether gray bushchats employ a nest desertion strategy targeted at cuckoo parasitism. The results showed that nest desertion was significantly correlated with parasitism cues and occurred mainly during the hosts' early egg-laying stage. Our study provides the first experimental evidence that nest desertion is an anti-parasitic strategy used by hosts in response to cuckoos. Additionally, our experiments demonstrated that the nest desertion is influenced by the trade-offs of investments in different egg-laying stages.

To Flee or Not to Flee: How Age, Reproductive Phase, and Mate Presence Affect White Stork Flight Decisions.

Recognizing, assessing, and responding to threats is critical for survival in the wild. Birds, especially in their role as parents, must decide whether to flee or delay flight when threatened. This study examines how age, reproductive stage, and the presence of a mate influence flight initiation distance (FID) and nest recess duration in white storks. Analyzing the data with a generalized additive mixed model (GAMM), we found significant correlations between FID and age, reproductive stage, and presence of a mate. These results suggest that the trade-off between current and future reproduction shifts during critical breeding periods, such as incubation and nestling care. To increase breeding success, White Storks appear willing to take risks and extend their stay in the nest when offspring are most valuable and vulnerable. In the presence of a mate, individuals leave the nest earlier, suggesting possible sexual conflict over parental care. The duration of nest abandonment is consistent with FID, except for age. These results illustrate how parental age, brood value, vulnerability, and sexual dynamics influence white stork flight decisions in complex ways. Understanding these dynamics enriches our knowledge of bird behavior and adaptations to environmental challenges and highlights the complexity of parental decision making.

Evaluating blood, gill, and muscle biopsy methods on the behaviour, reproductive success, and survival of a wild freshwater fish

Non-lethal biopsy methods (including blood, gill, and muscle biopsies) have been used to study the health and physiological status of wild fishes. Nonetheless, concerns exist regarding the impact of non-lethal sampling on relevant welfare measures such as behaviour and survival. Here, nesting Smallmouth Bass (Micropterus dolomieu) were used as a model species to study in situ how fish respond to non-lethal sampling. Male Smallmouth Bass provide sole parental care and guard well-defined nests for a period of several weeks, providing a unique opportunity to assess behaviour, reproductive success, and survival in the wild. Fish were captured from their nests by angling and subjected to a biopsy (either blood, gill, or muscle), or a combination of all three biopsy methods prior to release. A control group that was captured but not biopsied as well as a non-angled control were also included. Nests were monitored for a period of four weeks or until the parental males either abandoned offspring, died, or raised a brood to independence. Single biopsies, regardless of the biopsy type, were found to have no impact on parental care and survival, but fish that received the combined treatment took longer to return to their nest and displayed a 6.5 times greater likelihood of nest abandonment. Mortality was only observed in fish that received the combined biopsy treatment. As such, this study reveals that it is possible to maintain the welfare status of Smallmouth Bass in the wild by using individual biopsies, thus emphasizing the importance of making careful decisions about which tissues are needed to achieve desired study objectives. This is one of the few studies to assess the behavioural and fitness consequences of increasingly common non-lethal biopsy methods and provides useful information on the relative consequences of different biopsy methods on wild fish.

Multiparasitism and repeated parasitism by the great spotted cuckoo Clamator glandarius on its main host, the magpie Pica pica: effects on reproductive success, nest desertion and nest predation

Brood parasites are expected to lay only one egg per parasitized nest, as the existence of several parasitic nestlings in a brood increases competition and can lead the starvation of some of them. However, multiparasitism (laying of two or more eggs by one or more parasitic females in a single host nest) is surprisingly frequent. Here, we study multiparasitism by different females or by the same female (repeated parasitism) in the great spotted cuckoo Clamator glandarius, a non‐evictor brood parasite that mainly parasitizes the magpie Pica pica, and whose chicks may be raised together with host nestlings in the same nest. We used a total of 262 magpie nests found during four breeding seasons. Multiparasitism and repeated parasitism are very frequent because this brood parasite is less virulent than other cuckoo species and magpie hosts can successfully raise more than one parasitic nestling per nest. The total number of cuckoo chicks fledged was higher in multiparasitized nests than in single‐ or double‐parasitized magpie nests. Magpie breeding success (i.e. the proportion of eggs that produce young that leave the nest) did not differ between single‐, double‐, and multiparasitized magpie nests. These results suggest that multiparasitism is an adaptation in the great spotted cuckoo. The intensity of parasitism (number of cuckoo eggs per nest), after controlling for the potential effect of year, did not affect nest desertion or nest predation rate, neither during the incubation nor the nestling periods. This implies that nest concealment does not affect the susceptibility of one nest being parasitized and predated, as nest predation rate was similar regardless of the intensity of parasitism. Predation rate during the nestling phase did not vary according to intensity of parasitism, which does not support either the ‘mutualism' hypothesis or the ‘predation cost of begging' hypothesis.

Polyrhachis femorata (Hymenoptera: Formicidae) habitat and colony defensive immobility strategy

Many animal species ‘play dead’ or feign death (in some cases called tonic immobility) as a defence strategy against predators, including some ants, although triggers and durations are poorly understood. We repeatedly observed such death-feigning behaviour in Polyrhachis femorata ants that occupied pygmy-possum nest boxes deployed on Kangaroo Island following the 2019–2020 bushfires that burnt half of the island. Most of the 759 bat and pygmy-possum boxes (901 cavities) were on burnt ground. In 3312 box cavity checks on 13 diverse properties during monitoring visits, 28 of 40 P. femorata records (first for South Australia) occurred in unburnt Critically Endangered Narrow-Leaf Mallee Woodland community, seven in adjacent mallee community containing narrow-leaf mallee, three in cup gum unburnt habitat, and two in one box on burnt ground. Fire may have affected the abundance and re-establishment of the species. Polyrhachis femorata engages in a surprising defensive immobility strategy in boxes, since it is not only undertaken by individuals facing a potential predator, but also by entire colonies. The death-feigning behaviours were complemented by plugging box entrances. Nest boxes may be used to study this mysterious behaviour in this poorly known species, although frequent observation could lead to nest abandonment by the ant.

Variation in mesopredator abundance and nest predation rate of the endangered Strange‐tailed Tyrant (Alectrurus risora)

Nest predation is the main cause of nest failure in passerine birds and thus is a key determinant of breeding traits. Accordingly, nest predator community composition and abundance modulate nest predation rates. When top predators are absent, mesopredator populations may become unchecked, which in turn increases the predation pressure on their prey species. We evaluated whether nest predator abundance and breeding traits of an endangered grassland bird, the Strange‐tailed Tyrant Alectrurus risora, differed between two protected areas: Iberá National Park (INP), where top predators have been extinct for 50 years, and Reserva El Bagual (REB), where Pumas Puma concolor still have a stable population. We measured abundances of potential nest predator species and during the 2015–2018 breeding seasons we monitored Strange‐tailed Tyrant nests and set camera traps to identify nest predators. Mesopredator abundance was higher in INP, and foxes were identified as the main nest predators. Nest predation rate was also higher in INP, where the daily nest predation rate and cumulative probability of nest predation were 0.05 ± 0.006 and 0.81, whereas in REB they were 0.04 ± 0.004 and 0.70, respectively. The 10‐fold higher frequency of fox records in INP could explain the higher nest predation rate observed, suggesting that the extinction of top predators may increase nest predation rates of endangered grassland birds in protected areas through release of native mesopredator species. The lower nest predation observed in REB was compensated for by a higher nest abandonment rate, which resulted in a similar fledgling production in the two study sites. Clutch size, hatching success and number of nestlings did not differ between study sites. The low breeding success recorded for this endangered species despite its populations being in protected areas of high conservation value is alarming given the global decline that grassland bird populations are facing.

Nest entry shape change may cause nest abandonment in urban cavity-nesting species: a case study of the Tree Sparrow Passer montanus

The threat of predation is the main cause of bird nest abandonment, with such behaviour imposing considerable energetic costs on breeding birds. However, for several species, nest abandonment can be a less costly alternative to complete brood failure. In this study, we examined nest abandonment among Eurasian Tree Sparrows (Passer montanus) by surveying 71 Tree Sparrow nests with various types of entry holes and conducted artificially manipulating some of the entrance shapes. We found that nest abandonment was caused by changes to the nest entry shape in seven cases and by human interference in two cases. Nest abandonments occurred throughout the breeding season, and breeding pairs attempted to breed again immediately after nest abandonment. The results of the artificial nest entry shape manipulation experiment showed that nine of twelve nests (75.0%) were abandoned where the nest entrance holes were widened, and six of eleven nests (54.5%) were abandoned where the nest entrance holes were narrowed. However, none of the nests were abandoned where the entry shape was unchanged. Thus, nest abandonment by Tree Sparrows is correlated with nest entry shape manipulation and is more likely to occur when the energy cost of breeding again is less than that of abandoning the nest.

Surplus feeding reverses worker ovarian suppression and disrupts social cohesion in queen-right wasp colonies

Nutrition is an important component of oogenesis and ovarian development in insects. In social insect colonies where a large proportion of females are sterile, suppression of reproduction caused by differential acquisition and retention of nutrition has been hypothesized to cause worker sterility. This study, using the primitively eusocial wasp Ropalidia marginata (Lepeletier) (Hymenoptera: Vespidae), show that worker ovarian development in naturally foraging colonies is more similar to experimentally food-limited colonies than to surplus-fed colonies, indicating nutritional castration in workers whose ovaries are inhibited by food availability. Further, experimental provisioning of surplus nutrition led to higher ovarian development in workers as compared to naturally foraging and food-limited workers. Surplus feeding also led to higher nest desertion by workers, leading to a breakdown of the colony’s social structure, whereas food-limited colonies retained workers.

Nest abandonment by Little Eagles Hieraaetus morphnoides: A comment on Rae et al. (2023)

Rae et al. (2023, Australian Field Ornithology 40, 17–19) suggested that a pair of Little Eagles Hieraaetus morphnoides might have abandoned their nest because of infestation of the nest by dermestid beetles. Here the context of their observations is discussed, leading to the conclusion that the nest abandonment might have alternative explanations.

Breeding ecology of the laughing dove (Streptopelia senegalensis) in the Taif City, Kingdom of Saudi Arabia.

The Laughing Dove (Streptopelia senegalensis) is a columbid bird commonly found throughout most of Africa, the Middle East, Central Asia, India and Australia. Its preferred habitat includes scrubland, agricultural lands, and human settlements. Despite this species' extensive breeding range, very little information is available regarding its breeding ecology. The main objective of this study was to investigate the breeding features of the Laughing Dove in Taif City, Saudi Arabia between March and May 2018 and December 2018 and May 2019. The results indicate that this species constructs its nests at a mean height of 2.74 ± 0.1 m from the ground. The average number of nesting materials used for building a Laughing Dove nest was 109.3 ± 11.25. This study recorded that this species starts breeding in the middle of February. A clutch of two eggs comprised 72% of all the nests, with a mean of 1.75 ± 0.06 eggs per clutch. The average egg size was 25.27 ± 0.43 mm x 20.25 ± 0.19 mm, with an average egg volume of 5.01 ± 0.13 cm3. In total, 39.5% of the eggs hatched, and 64.7% of hatchlings reached the fledgling stage, resulting in an overall breeding success of 25.6%. This study suggested that nest desertion and predation were the major factors contributing to nest failure.

Dabbling Duck Eggs Hatch after Nest Abandonment in the Wild

In most birds, parental incubation of eggs is necessary for embryo development and survival. Using a combination of weekly nest visits, temperature dataloggers, infrared video cameras, and GPS tracking of hens, we documented several instances of duck eggs hatching after being abandoned by the incubating female. Of 2826 Mallard (Anas platyrhynchos) and Gadwall (Mareca strepera) nests monitored 2015–2019 in Suisun Marsh, California, 48 (1.7%) were abandoned during late incubation (≥ 20 days). Of these, we identified six (12.5%) where at least one egg hatched 2–9 days after abandonment. In all six cases, eggshell membranes were found in the nest (indicating hatch), and ducklings were observed at three nests. Abandoned nests were unattended for an average of 5.9 days before eggs hatched; during this time, mean nest temperatures (23.6°C–29.0°C) were substantially lower than before nest abandonment (31.7°C–36.4°C). We estimated that abandonment resulted in a 9% longer time period between clutch completion and hatch (0–4 days longer) and a lower rate of egg hatching success (36%). Our results provide evidence that some older embryos (≥ 20 days) in mild climates can survive without parental incubation for several days and continue to develop (at a reduced rate) to the point of successfully hatching.

High density and successful breeding of Turtle doves Streptopelia turtur in Moroccan olive groves.

The turtle dove is a migratory species that has suffered a rapid decline principally across its Northern ranges, despite pronounced conservation measures. Consequently, it has been categorized as 'Near Threatened' in Europe. Degradation of breeding habitats and a decrease in food resources are listed as principal causes of this decline. Despite its importance, the productivity of the North African population is widely unknown. Here we present the first estimation of the density of the breeding population and the superior reproductively of Streptopelia turtur arenicola in Morocco and entire North Africa. This study was carried out for two seasons 2018-2019 in the Saïss plain, central Morocco. Based on previous data, doves were monitored weekly, from early March to late August, in aquatic ecosystems (two dams and one river) and farmlands (cereals and orchards). The breeding population was censused using the "point-count" method, following a walked transect of 5 km in orchards, 7 km in cereal fields, and 3 km along the river. Equally, nests were searched in natural habitats counting riparian trees, forests, and ornamental trees, and in orchards based on the Common Birds Census (CBC) methodology, in which the singing doves, mating pairs, nesting, and/or feeding behavior were the most monitored signs to discover nests. In orchards, nests were searched line-by-line based on the rows of fruit trees. For each recorded nest, we note the breeding chronology, clutch size and incubation period, success and failure factors, dimensions, and vertical placement on trees. To evaluate the predictors of doves' occurrence, we noted at each site the presence of cereals, water, human disturbance, presence of nesting trees, and predators. In total, 3,580 turtle doves (22.37 birds/ha), including 240 breeding pairs, were documented. Nesting occurred mainly in olive groves, cereals were used for forage, and aquatic ecosystems for water sources. The nesting period lasted from late April to July (last fledglings). All nests were located on olive trees at a height of 225.30 ± 48.87 cm. The clutch size was 1.98 ± 0.13 (laid eggs/built nests), the incubation period lasted 14.16 ± 1.32 days, and the rearing period lasted 16.54 ± 1.76 days. The breeding success among the 240 monitored nests accounted for 73.84% during the nesting phase and 87.42% during the incubation phase; 71.5%% of nestlings have fledged, which is the highest success rate for turtle doves in Europe and Northwest Africa. Clutches were aborted mostly due to predation from snakes (7.5% of nests, 16.12% of eggs, and 5.63% of chicks), nest desertion (9.16% of nests and 5.37% of eggs), and marginally by the destruction of nests through farming activities. These findings are important for conservation plans, to restore turtle doves' habitats in Europe, where the species is widely declining.

Brood parasitism of Hooded Warblers by Brown-headed Cowbirds: Severe impact on individual nests but modest consequences for seasonal fecundity and conservation

Abstract Brood parasitism by Brown-headed Cowbirds (Molothrus ater) often has pronounced negative effects on host nests. However, the extent to which parasitism reduces annual reproduction and presents conservation challenges for host species is unclear. We address this issue with data from a color-banded population of Hooded Warblers (Setophaga citrina) in Pennsylvania, where Hooded Warblers have increased dramatically despite frequent nest parasitism. Our analysis is based on both an extensive dataset (8 years, 847 nests) on the per-nest impacts of cowbird parasitism and female-based stochastic simulations that accurately reflect the reproductive biology and parasitism rate (30%) of our study population. Cowbird parasitism has multiple negative consequences for Hooded Warbler nests, including (1) reduced host clutch size; (2) increased nest abandonment; (3) increased risk of complete failure due to predation; and (4) in surviving nests increased egg loss, hatching failure, and nestling mortality. We estimate that parasitism reduces success of Hooded Warbler nests 68%, from 1.29 to 0.41 fledglings per nest. For females and populations, however, the consequences of nest parasitism are considerably less extreme; female annual fecundity decreases 25% for each nesting attempt parasitized, and population-level fecundity drops 5.6% for each 10% increase in the frequency of parasitism. These more modest impacts are attributable to (1) steep declines in rates of cowbird parasitism as the nesting season progresses, (2) rapid renesting following abandonment or failure of parasitized nests, and (3) regular double brooding, with second broods initiated in late June and July when the incidence of cowbird parasitism is low. Our results help resolve the paradox of how cowbird parasitism can have both severe consequences for individual host nests but more modest and sustainable conservation impacts on the seasonal fecundity of females and populations. They further underscore the importance of determining population-level effects of brood parasites before investing in costly management efforts.

Multi-scale nest survival analysis suggests new cavities improve nest success for the Green-barred Woodpecker, but not the Campo Flicker, in a threatened woodland of Argentina

Abstract Understanding factors affecting nest survival of woodpeckers in threatened landscapes is a key tool for land managers, particularly when conservation depends on public policies. However, information of Neotropical woodpeckers breeding in southern temperate forests is noticeably sparse despite the worrying conservation status of these ecosystems and woodpeckers’ key role as cavity providers. Our objective was to assess the relationship between tree cavity features, vegetation structure, and landscape configuration on the nest survival of the Green-barred Woodpecker (Colaptes melanochloros) and the Campo Flicker (C. campestris). We monitored nests of these woodpeckers during 3 breeding seasons from 2015 to 2018 in a woodland of east-central Argentina threatened by selective tree logging and soil material extraction. We recorded features that presumably influence nest survival at a micro-scale (cavity, cavity-tree features, and foliage cover around the cavity) and a macro-scale (forest cover and shape index within a 500-m circle around the nest). We did not find support for a relationship between daily nest survival rates (DSR) and cavity features, vegetation structure, or landscape configuration. However, new cavities were more successful than reused ones for the Green-barred Woodpecker. We also found a surprisingly high rate (~33% of nest failures) of nest abandonment for both species. Abandonment may be a factor regulating this population and causes of abandonment warrants further investigation. Given the importance of new cavities to the success of Green-barred Woodpeckers, our results indicate the preservation of medium-size trees (20 cm < diameter at breast height [DBH] < 50 cm) with wood softened by degradation processes (preferred by the species to excavate cavities) would facilitate persistence both of this woodpecker and the cavity nesting community. Effective audit of soil material extraction and controlled selective timber logging practices (including preservation of mature trees) in compliance with existing regulations could contribute to this type of habitat maintenance.

Evidence of nest abandonment in Grass Wrens Cistothorus platensis suggest that non-breeding nests are not structures that differ in function from breeding nest

Evidence of nest abandonment in Grass Wrens Cistothorus platensis suggest that non-breeding nests are not structures that differ in function from breeding nest