- New
- Research Article
- 10.3390/birds7010010
- Feb 6, 2026
- Birds
- Sarah L Foltz
Many cemeteries include large amounts of greenspace and so have substantial potential to support urban plant and wildlife communities. However, the physical structure and design of these human-focused greenspaces may ultimately determine which species successfully inhabit these areas. Here, I studied the relationship between grave markers, a unique and ubiquitous feature of cemeteries that vary widely in shape and structure within and between burial areas, and the behavior of cemetery avian communities. I hypothesized that areas with greater structural heterogeneity of markers would be used by a larger diversity of species and that species would alter their behavior and interactions with markers based on marker structure. I assessed avian abundance and species richness in areas with varied upright and homogenously flat grave markers and observed behaviors exhibited by four common species in relation to grave markers and other structural features. While I found no relationship between grave marker heterogeneity and avian species richness or abundance, there is evidence for species-specific behavior and interactions with grave markers, suggesting that marker design is an important and relevant landscape feature for birds. These results have practical applications for cemetery design at a time when there is both increased public interest in environmentally friendly burials and growing competition for land in increasingly heavily developed urban areas.
- New
- Research Article
- 10.3390/birds7010007
- Feb 2, 2026
- Birds
- Roshan Tailor + 4 more
Illegal wildlife trade exerts severe pressure on wild parrot populations, and confiscated parrots often end up in rescue centers where they are rehabilitated for release. However, parrots kept in captivity often develop potentially maladaptive behaviors, including attraction to humans. This behavior can increase the risk of recapture. We modified and tested a previously published human aversion training (HAT) protocol designed to reduce human attraction in confiscated Amazona parrots. The HAT consisted of observers either on the ground or on a ladder, offering food to a single individual and then feigning capture of birds that approached or failed to move away from the observer. Twelve Yellow-naped Amazons (Amazona auropalliata) underwent 36 sessions of HAT over a 14-week period. Ten additional birds were held without training as a control. All birds were evaluated through food offer tests (FOTs) before, during, and after the experiment (FOT scores ranged from 1 when the bird approached the observer to 6 when the bird flew away). Over the training period, both groups showed increased aversion to people. However, contrary to our predictions, aversion scores were not higher for the group given aversion training. Aversion training also did not have a strong impact on fate post-release: within a month of release, 40% of the 22 birds were recaptured in a nearby village, including 4 treatment and 5 control birds. Overall, these results suggest that holding these birds in monospecific groups increased aversion to humans. However, the intense training aversion protocol did not further increase the fear of humans in these Amazona parrots, many of which may have been pets for years before entering the program. This study suggests that rehabilitation and release projects should regularly evaluate the impacts of their training programs and improve or eliminate costly protocols that do not achieve stated objectives.
- New
- Research Article
- 10.3390/birds7010005
- Jan 14, 2026
- Birds
- C T Shifa + 8 more
Sympatric species are closely related taxa that coexist within the same habitat through niche partitioning, and kingfishers serve as an ideal group for studying such ecological mechanisms. The present study examined the perch height in relation to foraging behaviour and hunting success of five kingfisher species: Common Kingfisher (Alcedo atthis), White-throated Kingfisher (Halcyon smyrnensis), Pied Kingfisher (Ceryle rudis), Stork-billed Kingfisher (Pelargopsis capensis), and Black-capped Kingfisher (Halcyon pileata). The study was conducted between 2021 and 2023, across seven habitat types in Kerala, India (Kadalundi–Vallikkunnu Community Reserve (KVCR) mangroves, Kallampara mangroves, Vadakkumpad mangroves, Vazhakkad agroecosystem, Mavoor wetland, Sanketham wetland, and Elathur beach). A generalized linear mixed model (GLMM) with a binomial distribution and logit link function was used to analyze hunting success across species. The model indicated that the effect of perch height on hunting success varied among species, though neither perch height nor species identity alone had a significant effect. Most species favored mid-height perches (2–5 m) for foraging, with the Common Kingfisher exhibiting moderate success across all heights and habitats. The Pied Kingfisher showed significantly reduced success at higher perches, while the Stork-billed Kingfisher achieved the highest success at mid-heights (2–5 m). The White-throated Kingfisher showed a non-significant negative association with capture success, whereas the Black-capped Kingfisher exhibited a neutral to positive relationship across perch heights. Among all variables tested, prey availability emerged as the sole significant predictor of hunting success, indicating that prey abundance is the principal determinant of foraging efficiency in tropical wetlands, rather than environmental conditions. Our findings confirm a pattern of vertical stratification in resource partitioning among sympatric kingfisher species and underscore the importance of conserving habitats that retain natural perch sites of varying heights.
- Research Article
- 10.3390/birds7010001
- Dec 25, 2025
- Birds
- Adiv Gal + 5 more
Intraspecific brood parasitism (IBP), where one female lays eggs in another’s nest, is considered rare in raptors, including typically monogamous and solitary or semi-colonial falcons. The Lesser Kestrel (Falco naumanni) is a colonial falcon with a usual clutch size of one to five eggs, yet two independent cases of anomalously large clutches consistent with suspected IBP are described from long-term studies in Greece and Israel. In central Greece (Armenio; 39°29′ N, 22°41′ E), a nest box colony monitored since 1998 produced a clutch of eight unhatched eggs in 2017; egg volumes formed two statistically distinct groups (V1 = 850.74 ± 27.72 vs. V2 = 926.78 ± 18.87 mm3; t = 4.146, p = 0.006), suggestive of contributions from two females. In Israel (Alona District; 32°35′ N, 35°05′ E), a nest under an asbestos roof contained a mixed clutch of eight eggs laid over two seasons (2003–2004), with four new eggs added to four unhatched eggs from the previous year; only one egg hatched and the chick was subsequently predated by a Little Owl (Athene noctua). Given the species’ typical clutch size and the occurrence of double clutches, these cases are interpreted as rare instances of parasitic egg-laying. Their extreme rarity—only one event over more than 20 years of monitoring ~120 pairs annually in Greece—underscores how uncommon IBP appears to be in Lesser Kestrels and how easily such events may be overlooked without intensive, long-term monitoring. The results emphasize the need to combine detailed field observations with molecular parentage analyses, quantify IBP frequency, and clarify the ecological and evolutionary relevance of alternative reproductive strategies in this and other colonial raptors.
- Research Article
- 10.3390/birds7010002
- Dec 25, 2025
- Birds
- Valeria López-Hernández + 9 more
The Military Macaw is a Neotropical psittacid that is endangered in Mexico. It faces significant threats due to habitat loss and the illegal pet trade. However, little is known about the nutritional characteristics of the plant resources available to this species throughout its annual cycle. This study aimed to characterize the nutritional profile of the fruits consumed by macaws in the Alto Balsas Basin, Mexico, and to infer potential seasonal patterns in the availability of the fruits they feed on in relation to the Macaws’ reproductive phenology. We identified 13 plant species that have been consistently reported as components of the diet of the macaws within the Alto Balsas Basin using a literature review, field observations, and local interviews. We conducted bromatological analyses to assess the content of moisture, protein, lipids, carbohydrates, and fiber for the pulp and seeds of all 13 identified plant species. Although we did not measure quantitative food intake, we integrated these data with reproductive phenology and resource availability to infer potential patterns of nutritional use. The results revealed significant differences in nutritional content among the different species, as well as seasonal variation in the nutritional profiles of available resources that coincide with the physiological demands of the macaw life cycle. During the non-breeding season, the availability of species whose fruits have high lipid and carbohydrate contents, such as Bursera spp., hackberry and madras thorn, may provide essential energy. Conversely, during the breeding season, resources with higher lipid and protein content (such as Mexican kapok tree and red mombin) could support the increased energetic investment associated with courtship, egg production, and chick provisioning. Although our study did not directly quantify the amount of each food item consumed, the integration of nutritional and ecological data provides a preliminary view of how resource quality may influence seasonal foraging patterns, offering valuable insights for the conservation and management of this species.
- Research Article
- 10.3390/birds6040064
- Dec 9, 2025
- Birds
- Momoyo Fujioka + 2 more
Corvids exhibit avoidance behaviour when foraging in the presence of potentially risky stimuli, yet it remains unclear how stimulus characteristics influence the strength of such responses. In this paper, we present wild-caught Large-billed Crows (Corvus macrorhynchos) with five conditions: no visual stimulus, a cardboard box (non-biological, stationary), an immobile owl decoy (biological, stationary), a continuous-motion owl decoy (biological, moving), and a sensor-activated-motion owl decoy (biological, moving, and sudden). Avoidance was quantified using feeding latency, landing frequency, total time spent in the feeding area, and food consumption. Compared with the condition with no visual stimulus, the presence of any visual stimulus elicited increased latency, indicating that crows detect and respond to objects near food. Among the four objects, the sensor-activated-motion owl decoy produced stronger avoidance responses of the crows than the non-biological and stationary object (cardboard box). This indicates that they evaluate not only the presence of an object but also its motion characteristics and/or perceived biological cues when adjusting their foraging behaviour. Although sample size and individual variation impose limitations, these findings suggest that both the presence of visual stimuli and/or the complexity of their appearance play key roles in shaping avoidance behaviour in corvids.
- Research Article
- 10.3390/birds6040063
- Dec 4, 2025
- Birds
- Dajana Davitkov + 5 more
Parasitic infections represent an important health challenge in falcons (Falconidae), where they may negatively influence survival, reproduction, and performance. This study is the first investigation in Serbia assessing the prevalence and diversity of endoparasites in captive falcons, with special emphasis on Serratospiculum spp. A total of 145 live birds (hybrid falcon, Falco peregrinus, F. cherrug, F. rusticolus) and 1 dead individual were examined. Diagnostic procedures included necropsy, coprological analysis, and molecular detection. Endoparasites were confirmed in 55.2% of fecal samples. The most frequent were Caryospora spp. (41.4%), followed by Porrocaecum spp. (18.6%), Capillaria spp. (3.4%), and Serratospiculum spp. (2.8%). Statistically significant differences were observed between sexes, locations, and preventive health management. Falcons kept under preventive measures showed a markedly lower prevalence compared with those lacking such care. These findings highlight the persistent occurrence of endoparasites in Serbian falcons and underscore the importance of preventive programs. Regular deworming, strict hygiene, and vector control represent essential strategies for minimizing infections, particularly of Serratospiculum spp., which poses a serious respiratory health threat.
- Research Article
- 10.3390/birds6040062
- Nov 21, 2025
- Birds
- Remo Probst + 1 more
Raptors wintering in temperate regions face strong energetic constraints due to low temperatures and limited prey availability. Understanding how intrinsic traits and environmental conditions shape hunting performance helps to clarify the mechanisms underlying winter foraging efficiency. We studied wintering Hen Harriers (Circus cyaneus) in Austria over five consecutive winters (2020/21–2024/25) to quantify touchdown attempt rate and outcome in relation to sex, age, territorial status, and weather. Using generalized linear mixed models, we analyzed 1829 recorded touchdowns with individual identity as a random effect. Territorial females showed slightly higher attempt rates than males, whereas non-territorial females exhibited a tendency toward lower touchdown success. Adult males achieved the highest per-attempt efficiency, but age alone had no significant effect. Touchdown outcomes improved under cloud cover and declined with wind speed, while temperature showed no influence. Attempt rate was unaffected by any environmental variable. These results demonstrate that both intrinsic and extrinsic factors jointly determine winter foraging performance: males, with their smaller body size and agility, can persist even in vole-poor habitats by compensating through efficient flight and prey capture; territorial females benefit from stable access to vole-rich patches; and non-territorial females remain constrained by competition and limited access to prey. The findings highlight the need to maintain open farmland and vole-rich habitat to support diverse overwintering strategies.
- Research Article
- 10.3390/birds6040061
- Nov 11, 2025
- Birds
- Seon-Ju Lee + 2 more
Nest defense is a key component of avian reproductive success, yet its intensity and expression often depend on ecological and social contexts. We investigated the nest defense behaviors of Saunders’s Gulls (Saundersilarus saundersi) breeding in Incheon Bay of South Korea in 2022 in relation to nest density and perceived threats. Using decoy presentations of three heterospecifics, Oriental Magpie (Pica serica; diurnal avian nest predator), common raccoon dog (Nyctereutes procyonoides; nocturnal mammalian nest predator), and Little Tern (Sternula albifrons; neutral co-nester), we quantified latency to respond, bombing attack rate, and the number of mobbing individuals at high- and low-density nesting sites within a breeding colony. Mixed models revealed that latency to respond and attack rates varied strongly with stimulus type, with diurnal predator magpies eliciting the fastest and most intense responses, followed by nocturnal predator raccoon dogs and co-nester terns. Nest density influenced the number of mobbing individuals, which was significantly greater at high-density sites. Principal Component Analysis reduced the three behavioral metrics into a composite score, which correlated negatively with latency and positively with bombing attack rate and mobbing intensity. This score varied with both nest density and stimulus type. Our findings demonstrate that Saunders’s Gulls adjust their nest defense strategies according to both the social context and predator type, highlighting the importance of density-dependent collective nest defense in colonial breeders.
- Research Article
- 10.3390/birds6040059
- Nov 5, 2025
- Birds
- Monica Guerrini + 4 more
The Red-legged Partridge (Alectoris rufa, Phasianidae) is a non-migrant gamebird endemic to southwestern Europe that was introduced into Mediterranean and Atlantic islands in historical times. This is the case for Madeira, Portugal, where a population morphologically assigned to A. r. hispanica has been present since the XV century. We assessed its genetic identity using 2248 (Cytochrome-b, Cyt-b + Control Region, CR) and 297 bp-long (CR) mitochondrial DNA sequences obtained from modern and archival (1900–1964, including Caccabis rufa maderensis syntypes) partridges, respectively. These sequences were compared against an already published dataset covering the entire Iberian A. rufa range. We found that all the haplotypes of modern birds from Madeira were private to this island. The putative subspecies was confirmed, and northern Portugal with northwestern Spain turned out to host the closest mainland populations. This result was in line with the origin of the first human settlers of Madeira from, among other historical provinces, Douro Litoral and Minho, the latter neighboring Galicia. Despite relatively recent A. rufa importations from continental Europe, we did not find any significant change over time in the haplotypic pattern of Madeiran partridges as well as any evidence for maternal introgression from species such as the congeneric Chukar Partridge (A. chukar). Studies relying on genome-wide markers and including the only captive-bred population of Madeira are needed to gain more comprehensive information for the management of the local A. rufa.