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Many forest-dependent animals require complex branch and bole structural features as substrates for nesting, and these features may take decades or centuries to develop. In young forests, lack of suitable nest substrates may limit occurrence and abundance of arboreal rodents. To test this hypothesis, we measured the response of arboreal rodents to installation of 429 artificial nest platforms at 17 young forest sites in the Coast Range of Oregon, United States. We compared the percentage of 100-m2 plots at sites containing nests before and after installation of nest platforms, and examined 5 a priori hypotheses of spatial patterns of use using logistic regression. One year after installation, we observed a 5.8-fold increase (95% CI = 2.4–9.2) in plots containing nests of red tree voles (Arborimus longicaudus) and a 2.9-fold increase (95% CI = 1.3–4.4) of tree squirrels (Glaucomys oregonensis, Tamiasciurius douglasii). In addition, we captured 37 adult red tree voles (30 females, 7 males). Presence of conspecific nests < 75 m away increased the odds of use by red tree voles but not by tree squirrels. Our results support the hypothesis that lack of suitable nest substrates limits occurrence of red tree voles in young forests, but results were ambiguous for tree squirrels. Increasing the availability of nest substrates via installation of nest platforms may increase abundance of red tree voles in young forests. However, we do not know if this will allow red tree voles to persist in young forests that are subjected to repeated commercial thinning and clear-cut harvesting.

Studies of anthropogenic impacts on wildlife may produce inconclusive or biased results if they fail to account for natural sources of variation in breeding performance and do not use probabilistic sampling at a scale functional for management. We used stratified random sampling and generalized linear mixed models to test hypotheses on relationships of daily nest survival rate (DSR) and fledgling production with anthropogenic and environmental factors that influence reproduction in the ferruginous hawk (Buteo regalis). We conducted the study across ferruginous hawk range in Wyoming, USA, 2010–2012. We performed extensive field surveys of prey, vegetation, and nest substrates, and used spatially explicit data to quantify weather, and the most widespread forms of anthropogenic infrastructure (i.e., roads, oil and gas well pads) in ferruginous hawk territories. We found strong evidence that DSR and productivity were greater for nests on anthropogenic structures (i.e., artificial nest platforms, gas condensation tanks, abandoned windmill platforms, power poles) compared to natural substrates (i.e., trees, cliffs, rock outcrops). Additionally, ferruginous hawks produced more fledglings at territories with greater shrub cover and fewer severe storms during the June brood-rearing period. Amount of oil and gas development and prey was not associated with either measure of breeding performance. Our results suggest that artificial nest platforms are an effective tool to improve breeding success of ferruginous hawks and nesting on anthropogenic structures does not constitute an ecological trap for this species. Although ferruginous hawks nested in some areas with very little vegetative cover, territories with greater amounts of shrub cover produced more fledglings. The negative impact of severe spring storms on fledgling production illustrates the importance of including future weather scenarios in management planning for this species because storms are predicted to increase in frequency and intensity as a result of climate change. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The current work presents the preliminary results of the Cinereous Vulture ( Aegypius monachus ) releases in the Balkan Mountains in 2018–2022, aiming at the species re-introduction in Bulgaria, where it was listed as locally extinct since 1985. The first imports and releases of Cinereous Vultures in Bulgaria started in 2018. Until mid-2022, 72 individuals were released in the Eastern Balkan Mountains (Kotlenska Planina SPA and Sinite Kamani Nature Park) and Vrachanski Balkan Nature Park. Of them, 63 immatures imported from Spain were released from aviaries and nine juveniles captive-bred in European zoos were released by hacking (fledging from an artificial nest). We compared the success in survival and establishment between the different release sites and methods used to adjust the ongoing technics and tactics and to support knowledge improvement for future similar projects. From the nine Cinereous Vultures released by hacking, the results were as follows: 1.00 fledging success, but only 0.22 survival in the first six months – combined period of acclimation, first migration and the first winter. All survivors from that period reached maturity into the wild, but all emigrated from the release site and settled elsewhere. Of the 63 individuals released by aviaries, 32 individuals were released in the Eastern Balkan Mountains (18 individuals are still alive – 0.56 survival; 14 individuals settled in the area, which accounts for 0.44 of all released birds and 0.78 of the survivors). Thirty-one individuals were released in Vrachanski Balkan Nature Park (23 individuals are still alive – 0.74 survival; 22 individuals settled in the area – 0.71 of all released birds and 0.96 of the survivors). Based only on aviary method comparison, the settling of the individuals in the release area was alike in the two sites. However, the Vrachanski Balkan Nature Park performed better in survival – both in acclimation and establishment periods. While comparing the release methods – hacking and release from the aviary – the following results were observed: the survival rate during acclimation was 0.86. Due to more considerable losses during the first migration and dispersal in the individuals released by hacking, the survival rate of 0.22 was significantly lower compared to 0.73 for the birds released from the aviary. Additionally, in both methods, a similar pattern in the first winter and spring migration dispersal was observed. Although the survival was equal in the released-by-hacking or aviary birds after the first year onwards, it is essential to note that the emigration of the hacked birds from the release site was 1.00. In comparison, the birds released from aviaries largely remained and settled in the release area (> 0.77 of the survivors). The cost of release and related acclimation, settling, dispersal and the first winter was the greatest: 0.12–0.17 per period, or cumulatively, it was about 0.27. Survival increased and stabilised to > 0.90 after the first year in the wild and reached nearly 1.00 after two years in the wild onwards. Two distinct nuclei of the Cinereous Vulture were established along the Balkan Mountains – the Eastern Balkan Mountains with 18–23 individuals and four formed pairs using a territory of about 642.74 km 2 – 95% home range and 85.72 km 2 – 50% core area with center being the town of Kotel; and Vrachanski Balkan Nature Park with present 23–29 individuals, of which 2–3 pairs formed so far, using a territory of about 1,143.66 km 2 – 95% home range and 22.89 km 2 – 50% core area with center being the village of Zgorigrad. The species readily accepted breeding in artificial nest platforms built by professional arborists on different tree species – oak, beech, sycamore and pine. The only naturally built nests were on the ground (n = 2) (unsuccessful) and in Scots Pine (n = 1) (successful). In 2021 and 2022, in each of the two sites, the first successful reproductions were recorded, which marked the return of the Cinereous Vulture as breeding species – 28 years after the last occasional record of a single breeding pair in the country and 36 years after it was officially listed as locally extinct in Bulgaria.

In 2003 and 2004, we placed 41 floating nest platforms on Grassy Lake in southeastern Wisconsin (USA) to test the hypothesis that reproductive success of Black Terns (Chlidonias niger) is limited by the quality of suitable nesting habitat. Extreme differences in water levels between these 2 yr provided a natural experiment to evaluate the effectiveness of the nest platforms during a drought year (2003) when natural nesting substrate was abundant, and a flood year (2004) when natural substrate was limited during the peak nesting period. Terns nested on 27 of 41 (66%) of the platforms in 2003 and 26 of 41 (63%) in 2004. No difference in the occupancy rate of platforms and natural nests was evident in 2003, but the pattern of clutch initiations early in the season in 2004 indicated that platforms were preferred over natural substrates. In 2003, nest survival rates did not differ between nests placed on platforms and those placed on natural substrates, but platform nests had significantly higher hatching success and nest survival rates in 2004. Both the Kaplan-Meier and Apparent Nest Success methods of calculating nest survival provided similar estimates. In both years, eggs laid on platforms were significantly larger than those laid on natural substrates, suggesting that platforms were occupied by high-quality birds. Our study indicates that floating nest platforms can be an effective management tool to enhance nesting habitat for Black Terns and other aquatic birds that construct floating nests, primarily because platforms provide nest sites when natural sites are not available due to flooding. Nest platforms also may be useful for addressing questions concerning habitat selection and parental quality. /// De 2003-2004 colocamos 41 plataformas flotantes para poner aprueba la hipótesis que el éxito reproductivo de la gaviota Chlidonias níger, esta limitado por la calidad y lo apropiado del hábitat de anidamiento. El estudio se llevó a cabo en el Grassy Lake, Wisconsin. Extremos (bajos y altos) en los niveles de agua, causados por sequía (2203) y fuertes lluvias (2004) proveyeron el escenario adecuado para evaluar la efectividad de las plataformas. Las gaviotas anidaron en 27 (66%) de las 41 plataformas en el 2003 y en 26 (63%) de las 41 en el 2004. No se encontraron diferencias en la tasa de uso de las plataformas y áreas naturales en el 2003, pero el inicio de las camadas temprano en la temporada durante el 2004, dieron a indicar que las plataformas fueron preferidas a los lugares naturales. Durante el 2003, no hubo diferencia en la tasa de supervivencia de nidos en plataformas y o en áreas naturales. Sin embargo, durante el 2004 el éxito de eclosionamiento, de los nidos y la supervivencia fue mas alto en las plataformas. Tanto el método Kaplan-Meier como el \"Aparente Éxito de Anidamiento\", utilizados para calcular la supervivencia de los nidos, ofrecieron resultados similares. En ambos años el tamaño de los huevos fue mayor en las plataformas que en áreas naturales, lo que implica que las primeras fueron utilizadas por aves sumamente vigorosas o de alta calidad. El estudio indica que las plataformas flotantes pueden ser una herramienta de manejo adecuada para mejorar el hábitat de anidamiento de la gaviota estudiada, al igual que otras aves que construyen nidos flotantes. Las plataformas proveen de lugares de anidamientos cuando no hay disponible lugares naturales debido a inundaciones. Las plataformas de anidamiento muy bien pudieran proveer de información útil con respecto a la selección de hábitat y la calidad del cuidado parental.

Simulating the brain-body-environment trinity in closed loop is an attractive proposal to investigate how perception, motor activity and interactions with the environment shape brain activity, and vice versa. The relevance of this embodied approach, however, hinges entirely on the modeled complexity of the various simulated phenomena. In this article, we introduce a software framework that is capable of simulating large-scale, biologically realistic networks of spiking neurons embodied in a biomechanically accurate musculoskeletal system that interacts with a physically realistic virtual environment. We deploy this framework on the high performance computing resources of the EBRAINS research infrastructure and we investigate the scaling performance by distributing computation across an increasing number of interconnected compute nodes. Our architecture is based on requested compute nodes as well as persistent virtual machines; this provides a high-performance simulation environment that is accessible to multi-domain users without expert knowledge, with a view to enable users to instantiate and control simulations at custom scale via a web-based Graphical User Interface. Our simulation environment, entirely open source, is based on the Neurorobotics Platform developed in the context of the Human Brain Project, and the NEST simulator. We characterize the capabilities of our parallelized architecture for large-scale embodied brain simulations through two benchmark experiments, by investigating the effects of scaling compute resources on performance defined in terms of experiment runtime, brain instantiation and simulation time. The first benchmark is based on a large-scale balanced network, while the second one is a multi-region embodied brain simulation consisting of more than a million neurons and a billion synapses. Both benchmarks clearly show how scaling compute resources improve the aforementioned performance metrics in a near-linear fashion. The second benchmark in particular is indicative of both the potential and limitations of a highly distributed simulation in terms of a trade-off between computation speed and resource cost. Our simulation architecture is being prepared to be accessible for everyone as an EBRAINS service, thereby offering a community-wide tool with a unique workflow that should provide momentum to the investigation of closed-loop embodiment within the computational neuroscience community.

Cabot's tragopan Tragopan caboti, a pheasant that inhabits subtropical montane forests in south-east China, is categorized as Vulnerable on the IUCN Red List. Nesting in trees, it routinely makes use of natural platforms and the old nests of other species, both of which may sometimes be in short supply. This study was designed to test how much use would be made of artificial nest platforms, and to identify factors influencing their occupation. Basketry platforms made of bamboo were erected in parts of Wuyanling National Nature Reserve, Zhejiang Province, China. The tragopans used 16 platforms (8%) in 2002 and 12 (5%) in the following year. A census of the population in spring suggested that a high proportion of the females (41% in 2002, 36% in 2003) in the study area made use of the platforms. There were significant preferences for platforms in mixed conifer/broadleaf forest, as opposed to pure stands, as well as for sites on the upper part of hill slopes. Principal component scores were used to represent variation in 11 variables measured at each platform site. Binary logistic regressions employing these scores as predictors for each year separately did not reveal a consistent model for distinguishing used from unused platforms, although short distances to the forest edge were associated with use in both years. These nest platforms are cheap and easy to erect, and may have the potential to halt or reverse a perceived downward population trend for this species across the whole of its fragmented range. Further trials are therefore advocated.

Artificial manipulations of habitat, such as those that incorporate adding nesting boxes or platforms for birds, often enhance the breeding success of threatened animals. However, such alterations are likely to have unintended behavioral and ecological effects that might negatively impact the target species or others in its community. We conducted a controlled study to investigate the effect of artificial nesting platforms on aggressive behavior and reproductive success of male common loons (Gavia immer). Males residing on territories to which platforms were added produced longer territorial “yodels” (reflecting willingness to escalate a contest), experienced increased levels of confrontation and aggression with territorial intruders, and experienced increased rates of territorial displacement by intruders. Surprisingly, males of treatment territories also experienced lower productivity. Therefore, in addition to providing novel empirical support of sequential assessment models of animal contests that predict contest escalation with increasing resource quality, this study is one of a few to show that tools used to mitigate habitat loss can negatively impact reproductive fitness in a threatened species.

After a critical decline in the late 1970s, the white stork population in Europe is currently stable and may be increasing in size. The use of electric utility towers as nest sites is discussed.

Plastics are widely distributed in all ecosystems with evident impacts on biodiversity. We aimed at examining the topic of plastic occurrence within bird nests. We conducted a systematic search on three social media platforms (Facebook, Instagram, and Twitter) to fill the gap of knowledge on plastic nests worldwide. As a result, we observed nests with plastics mostly belonging to synanthropic species inhabiting riverine habitats, mainly in Europe, North America, and Asia, with an increase in occurrence over the years. Two common and generalist freshwater species (Eurasian Coot Fulica atra and Swans Cygnus sp.) showed the highest frequency of occurrence of plastic debris. We suggest plastics in bird nests as a proxy for debris occurring in the environment. However, our data may be biased, due to our sample’s low representativeness. Therefore, more data are necessary to have more information on plastic distribution. In conclusion, social media might be pivotal in indicating plastic hotspot areas worldwide and being an indicator of plastic pollution within the environment.

With data accumulating from a growing pool of chimpanzee field studies, new behaviors as well as novel variants on common behaviors continue to be described. Nest construction is a universal behavior in wild great apes. Among chimpanzee populations, reported variation in nest building behavior mostly reflects environmental constraints. Despite the ubiquity of nest making by chimpanzees, only ground nesting has been recognized as a behavioral variant, potentially determined by both environmental and social factors. In a study of nests made by chimpanzees (Pan troglodytes schweinfurthii) in Bulindi, Uganda, I identified a hitherto undescribed nest construction technique, termed ‘nest tying’. Five observed nests lacked strong weight-bearing structures beneath them, such as large branches or a supporting trunk. Instead, the nests appeared ‘tied’ (or ‘tethered’) to an adjacent trunk by looping leafy stems or palm fronds around it and interweaving these into the nest mattress, securing the nest against the trunk; thus, nest tying presumably functions to provide added stability and support. This preliminary report presents a description of the observed nests. Irrespective of whether nest tying constitutes true knot making—commonly considered absent in wild great apes—this nest construction technique would seem to require advanced dexterity and a sophisticated understanding of the mechanical properties of the plants used. Forest fragments in Bulindi are highly degraded. Thus, nest tying—and construction of integrated nests (i.e., utilizing multiple plants, often small trees and shrubs) generally—may be promoted by a relative paucity of suitable nesting trees at this site. Still, insofar as nest building is learned in chimpanzees, different construction techniques including nest tying are potentially acquired through social learning. Further investigation is required to ascertain the prevalence and acquisition of this nest construction technique at Bulindi, and to verify its presence or absence in other habitats.