Ecology and Evolution最新文献

Understanding temporal behavioural patterns in animals can be crucial to their conservation management. Emergence timing in bats, that is, the decision on when to depart day-roosts for foraging, is one such example and is well studied in Northern Hemisphere bats. The emergence timing of New Zealand long-tailed bats (Chalinolobus tuberculatus) is not yet fully understood, including when and where they may be vulnerable to threats. We investigated factors influencing long-tailed bat emergence timing in the Kinleith Forest (exotic plantation, 38° S) and the Eglinton Valley (native beech forest, 45° S). We recorded emergence times during late pregnancy through post-lactation (October to March), to determine whether the month, temperature at sunset, tree density, cloud cover, presence of rain and the number of bats within a roost influenced emergence timing. Most long-tailed bats emerged after sunset in the Kinleith Forest, whilst 80% of first emerging bats departed before sunset in the Eglinton Valley where nights are much shorter in summer, reducing foraging time. Month, temperature at sunset, and roost population size were the most important predictors of emergence timing at both sites. Long-tailed bats in the Kinleith Forest also emerged earlier as tree density increased, a pattern potentially associated with predator defence. The factors influencing long-tailed bat emergence timing are likely context dependent, namely latitude and habitat structure, which has implications for roost protection protocols, timing of bat surveys and interpretation of bat acoustic monitoring data.

Beach mass stranding events of marine organisms, widely documented worldwide, are triggered by a range of biotic and abiotic environmental factors, often unexplained. Such occurrences among pelagic crustaceans are less frequent, yet not uncommon. Here we studied mass mortality events of hyperiid amphipods—abundant members of pelagic zooplankton, commonly associated with gelatinous organisms. Our study examined consecutive mass die-off and stranding events of free-living hyperiids in the Red Sea during 2023 and 2024. We investigated three potential causes: semelparous reproduction, thermal stress, and physical oceanographic conditions. To place our findings in a broader context, we further performed a global review of hyperiid swarming and mass mortality events from scientific literature and a citizen science repository. Morphological and molecular analyses confirmed that the hyperiid species in the die-off events at the Red Sea was Anchylomera blossevillei (Phrosinidae). The balanced male: female sex ratio (0.99), combined with the absence of gravid or brooding females, led to the rejection of semelparity as a driving factor. The environmental data did not indicate thermally stressful conditions, and no evidence of parasitic infection was found. Nonetheless, previous studies have shown that under weak wind conditions, as measured during the stranding events, coherent cyclonic eddies with diameters of 5–6 km are developed in the northern Gulf of Aqaba, persisting for about a day. These eddies can exceed velocities of 100 cm s⁻¹ and may have facilitated the hyperiid stranding events. Future research should unveil the impacts of such events on marine ecosystems.

Pseudotsuga sinensis is a distinctive plant species endemic to China, predominantly found in areas affected by varying degrees of rocky desertification. Despite its wide distribution, the physiological mechanisms underlying its adaptation to harsh environments remain unclear. In this study, we investigated 16 leaf traits, including the morphological, anatomical, and chemical characteristics of the leaves of P. sinensis across forests with mild, moderate, severe, and extremely severe rocky desertification to elucidate the adaptive strategies of P. sinensis in response to arid conditions and nutrient-poor soils. Our findings revealed that P. sinensis leaves from forests with mild and moderate rocky desertification exhibited higher specific leaf area (SLA) and magnesium concentrations but lower leaf dry matter content (LDMC), abaxial epidermis thickness, and adaxial epidermis thickness than in those from forests with severe and extremely severe desertification. Principal component analysis indicated that forests with mild to moderate desertification employ resource acquisition strategies characterized by greater SLA and magnesium concentrations than those in forests with severe and extremely severe desertification. In contrast, forests with severe to extremely severe desertification adopted resource-conserving strategies, as evidenced by higher LDMC, epidermal thickness, and calcium concentrations than those in forests with mild to moderate desertification. The N:P ratio of P. sinensis across all desertification levels was consistently below 14, suggesting nitrogen limitation in P. sinensis in regions with rocky desertification. Thus, these results provide valuable reference for guiding vegetation restoration under degraded habitats.

Egg retrieval behavior in hosts within avian brood parasitism systems was found to be regulated by the motivation to reject parasitic eggs. However, due to the limitations in the research systems, there is a lack of effective validation regarding the adaptation mechanisms of cuckoo hosts to the conflict between retrieving their own eggs outside the nest and rejecting parasitic eggs. This study uses Daurian redstarts (Phoenicurus auroreus), a secondary cavity-nesting host parasitized by common cuckoos (Cuculus canorus), to verify the adaptive decision-making of the host between egg retrieval and egg rejection by simulating the occurrence of eggs outside the nest. The results showed that Daurian redstarts ignored 60.6% of highly mimetic conspecific eggs, with a retrieval rate of only 18.2%. Additionally, Daurian redstarts rejected 21.2% of conspecific eggs. However, non-mimetic budgerigar (Melopsittacus undulatus) and white model eggs were more likely to be directly rejected (75% and 86.4%, respectively) with no retrieval events. Our findings suggest that egg retrieval behavior in Daurian redstarts is likely influenced by the cognitive process of rejecting parasitic eggs, leading to occasional over-identification and difficulty in decision-making between egg retrieval and egg rejection, especially in the context of conflicting motivations.

Offspring predation is one of the greatest obstacles to an organism's reproductive success, but parents vary in the strength of their response to potential predators. One explanation for this variable investment is that defending current offspring has the potential to lower future reproductive success if the predator is also capable of injuring or killing the parent. Northern house wrens (Troglodytes aedon) are cavity-nesting songbirds that defend against multiple species of nest predators including small mammals, birds of prey, and snakes. Here, we used three different predator decoys: two nest predators—an eastern chipmunk (Tamias striatus) and an eastern ratsnake (Pantherophis alleghaniensis)—as well as a predator of both offspring and adults—a juvenile Cooper's hawk (Accipiter cooperi)—to elicit nest defense and test whether females use risk assessment to modulate their antipredator behavior. We found that antipredator behaviors were not significantly different between the two nest predators, which posed a high risk to the nestlings, but lower risk to the parents, as neither species frequently captures adult wrens outside the nest box. However, female wrens never dove at or attacked the Cooper's hawk, while they frequently attacked both the snake and chipmunk decoys. Neighboring house wrens from adjacent territories were also less likely to respond to the hawk, but more heterospecifics mobbed the hawk than the snake decoy. Collectively, these results show that risk assessment and the strength of the antipredator response varies substantially both within and among species. Female house wrens exhibit plasticity in their nest defense behavior, and they respond to different types of predators in a way that could maximize lifetime fitness while risking the loss of their current offspring.

Agonistic and affiliative interactions with group members dictate individual access to resources, and investment in competing for resources is often traded off with other needs. For example, reproductive investment can reduce body condition and, thereby, an individual's ability to win future agonistic interactions. However, group members may also alter their behaviour towards reproductive individuals, such as becoming more or less aggressive. Here, we investigated the social consequences of reproduction in female vulturine guineafowl Acryllium vulturinum, a plural breeder in which females disperse and are subordinate to males. We found opposing patterns for within- and between-sex dominance interactions experienced by females from before to after breeding. Specifically, breeding females became far less likely to win dominance interactions with non-breeding females after breeding than before breeding, but received considerably fewer male aggressions than non-breeding females after breeding. Despite a limited sample size, our study reveals that reproduction can have nuanced trade-offs with dominance and suggests that the study of dominance may benefit from explicitly considering variation in interaction rates as an additional factor affecting individuals.

The Yarlung Zangbo River (YLZB), the world's highest plateau river, possesses a particularly fragile ecosystem, making it highly vulnerable to global climate change. Understanding changes in YLZB habitat quality and their driving mechanisms is crucial for ecological protection and sustainable development in the region. Based on land use data from 2000 to 2020, we conducted a quantitative study on the spatiotemporal changes and driving mechanisms of habitat quality in the YLZB. This study employed habitat quality model, Land Use Transition Matrix, optimal parameter geographical detector, and partial least squares structural equation model (PLS-SEM). The results show that: (1) Forests, grasslands, and unused land account for 94.14% of the basin area. The areas of unused land, forest land, and water bodies have continuously increased, while the areas of grasslands, permanent glaciers, and snowfields have continuously decreased. The decline was most pronounced from 2005 to 2010. (2) The habitat quality in the study area is higher in the southeast and lower in the west. The area of degraded habitats is significantly larger than that of improved habitats. (3) NDVI, elevation, and annual average temperature are key factors affecting changes in habitat quality. Elevation indirectly affects NDVI by influencing climate conditions, leading to a decline in habitat quality. This study provides a scientific basis for understanding ecological trends in YLZB habitat quality, it provides new insights into the intrinsic driving mechanisms in high-altitude regions, and it offers theoretical support for relevant departments to implement sustainable management and conservation efforts.

Progressively higher atmospheric nitrogen (N) deposition increasingly affects soil ecosystems' elemental cycling and stability. Biochar (BC) amendment has emerged as a possible means of preserving soil system stability. Nevertheless, the pattern of soil–microbial nutrient cycling and system stability in response to BC after high N deposition in ecologically sensitive regions remains uncertain. Therefore, we investigated the effects of high N (9 g N·m⁻²·a⁻¹), BC (0, 20, 40 t·ha⁻¹), and combinations of the treatments on soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP), microbial entropy (q_MB), and stoichiometric imbalance (C_imb:N_imb:P_imb). We found that high N addition decreased topsoil (0–20 cm) TP, C:N, q_MBN, and C_imb:N_imb values and increased TN, C:P, N:P, q_MBP, C_imb:P_imb, and N_imb:P_imb values. However, BC addition increased 0–40 cm soil q_MBC and N_imb:P_imb values and decreased q_MBN, C_imb:N_imb, and C_imb:P_imb values. Meanwhile, high BC additions attenuated BC's promotion of soil–microbial nutrients. We observed that a mixture of high N and BC increased the 0–40 cm SOC and TP content, promoted the accumulation of MBN and MBP in the subsoil (20–40 cm), and decreased the topsoil C_imb:P_imb and N_imb:P_imb values compared to high N additions. The impact of high N and BC additions on N and P elements varied significantly between the different soil depths. In addition, redundancy analysis identified C:N, MBC, MBN, and C:P as pivotal factors affecting alterations in soil q_MB and stoichiometric imbalance. Overall, adding BC reduced the negative impacts of high N deposition on the stability of soil–microbial systems in the Loess Plateau, suggesting a new approach for managing ecologically fragile areas.

Ferranti, M. P., I. Azzena, E. Batistini, D. Caracciolo, M. Casu, M. Chiantore, S. Ciriaco, V. Firpo, L. Intini, C. Locci, M. Montefalcone, A. Oprandi, D. Sanna, F. Scarpa, and M. Segarich. 2024. “Handling of the Bivalve Pinna nobilis, Endangered and Pathogen-Affected Species, for Controlled Reproduction: Precautions Taken.” Ecology and Evolution 14, e70565. https://doi.org/10.1002/ece3.70565.

In the “Discussion” section on page 10 (in the second column of the tenth line of the second paragraph), the unit of measurement of “400–800 mm” is incorrect, to be corrected with “400–800 μm.”

We apologize for this error.

Why animals migrate is a fundamental question in biology. While the adaptive significance of some animal migrations is well understood (e.g., to find food, to pursue more-favorable habitats, to spawn, or to give birth), others remain unknown. The adaptive significance of whale migration, for example, is unresolved and multiple hypotheses have been proposed to explain it. One recently proposed hypothesis that challenges the long-standing “feeding-breeding” whale migration model is a “feeding-molting” model, where whales undertake latitudinal migrations to warmer waters to molt skin. In July 2019, we attached satellite-tracking tags to northern bottlenose whales (Hyperoodon ampullatus) in the Canadian Arctic. One of these tagged whales completed a round-trip movement between the Arctic and the temperate western North Atlantic, traveling 7281 km in 67 days (and spanning 27° of latitude). The whale was tagged in sea-surface temperatures of ~4°C, but migrated south, reaching ~23°C surface waters, where it remained for 7 days before returning to the Arctic. The whale's occupancy of warm water was accompanied by a distinct shift in dive behavior, remaining near the ocean's surface. Four other tagged whales initiated similar long-distance movements. We conclude that feeding or breeding were unlikely reasons for this movement and that northern bottlenose whales migrate to warmer latitudes to molt skin.