Find research datasets worth reusing

opencc-zeroDec 2022View details →

The role of reed management and habitat quality on brood parasitism and chick survival of the brood parasitic Common Cuckoo

Despite efforts on ecosystem restoration and management, biodiversity loss remains one of the major environmental concerns of our time. Beyond the focus on threatened species, animals that indicate regional biodiversity hotspots and population trends, such as brood parasites, should also be targeted by conservation actions. We studied how reed habitat quality and management influence brood parasitism rate and offspring survival in Common Cuckoos Cuculus canorus parasitizing nests of Great Reed Warblers Acrocephalus arundinaceus. In six reed habitats in an intensive agricultural landscape. Data collected from 45 sites over 13 years showed that the brood parasitism rate was highest on large canals and was positively influenced by the availability of potential perches (Cuckoo vantage points) and the height where host nests were built. Cuckoo chick survival decreased with water depth and was not affected by other factors. Our results suggest that the habitat-dependent detectability of host nests was central in brood parasitism rate and that water level was central in Cuckoo chick survival. Our study shows that a maintenance of intermediate water levels is the most optimal for maintaining Cuckoo populations in intensive agricultural landscapes. Because brood parasites are excellent bioindicators as their presence predicts regional hotspots of taxonomic and functional diversity as well as population trends in bird communities, knowledge on their habitat requirements is relevant in management targeting diverse bird communities.

Figure 14. Right-side mating Brettus cingulatus near a in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 14. Right-side mating Brettus cingulatus near a brood that has already molted to instar II. Photographed by Hemanth Kumar H M at Belur, Hassan district, Karnataka.

Figure 13 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 13. Cambodian Brettus cingulatus feeding on a large ant. Attribution and ©: 1-2, mark spicer.

Figure 10. Adult male Brettus cingulatus. 1 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 10. Adult male Brettus cingulatus. 1, Display with pedipalps extended to the sides. 2, Grooming, with fangs extended and chelicerae separated to reveal the endites and rostrum to the rear. Attribution and ©: 1-2, acharya_mr.

Figure 8 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 8. Sequence of selected (not consecutive) frames from a 30 fps video of the brooding female Brettus cingulatus shown in Figure 5. These represent a series of positions at which this female attached silk lines, mostly around the periphery of the nest. This entire sequence of attachment positions is diagrammed in frame 1410 (yellow circle to yellow circle). Note that the number of young in the nest at this stage was considerably smaller than the ~43 eggs deposited by this female.

Figure 6 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 6. Sequence of frames from a 30 fps video of the brooding female Brettus cingulatus shown in Figure 5. Here, as in Figures 7-8, total elapsed time is shown after frame number at the lower right of each frame. 1-5, The female removes remnants of the eggshell from an instar I spiderling (yellow arrow). 275-279, 682-686, The female masticated eggshell remnants (white arrow) with her chelicerae. 772-781, The female finished masticating the eggshell remnants, and then quickly flicked these remnants out of her nest with her feathery pedipalps. The high speed of this flick is indicated by the blurred image of the expelled material in frame 780 (streak marked by white arrow).

Figure 3. Three brooding Brettus cingulatus females. 1, Female guarding recently deposited eggs. 2 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 3. Three brooding Brettus cingulatus females. 1, Female guarding recently deposited eggs. 2, Female with first instar young, still with little pigmentation of the opisthosoma. Note that almost all covering silk, white flecks, and eggshell fragments were absent at this stage. 3, Later first instar young with full pigmentation of the prosoma and opisthosoma, as well as pigmentation of each femur I. The female (not shown) was still guarding the brood at this stage. Photographs by Arundathi Sambayya taken at Bhimanakone, Sangara Taluk, Shimoga District, Karnataka, India.

Figure 1. Brooding female Brettus cingulatus Thorell 1895. 1 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 1. Brooding female Brettus cingulatus Thorell 1895. 1, Guarding recently deposited cluster of eggs covered with silk fibers and white flecks. 2, Ten days later, guarding hatchlings (first instar). Larger white flecks represent eggshell fragments. 3, Three days later. All silk, white flecks, and eggshell fragments are gone, and except for their legs, the first instar young are now pigmented. Photographs by Abhijith A. P. C. at his Indraprastha Organic Farm, Kalalwadi Village, Karnataka, India.

Figure 7 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 7. Sequence of frames from a 30 fps video of the brooding female Brettus cingulatus shown in Figure 5. 1-15, Female masticating eggshell remnants with her chelicerae. 550-559, Female flicking eggshell remnant (red arrow) away from the nest with her pedipalps.

Figure 12 in Conversion of the egg nest to a brood nest by the female Brettus cingulatus (Araneae: Salticidae: Spartaeini)

Figure 12. Immature Brettus cingulatus feeding on late instar I (fully pigmented) B. cingulatus spiderlings in an untended nest. It appears that the female left this brood without converting the egg nest to a brood nest, and the instar I spiderlings, now exposed and vulnerable outside of that nest, had no guardian. At this stage (instar I) it is likely that the spiderlings were still completely blind. Photographs by Hemanth Kumar H M.

Figure 1 in Predation on the brood of a theridiid spider by a jumping spider (Araneae: Salticidae: Harmochirina: Bianor sp.)

Figure 1. Female Bianor sp., or B. cf. albobimaculatus (Lucas 1846), feeding on the brood within the brood sac (or egg sac) of a small theridiid spider at Gobichettipalam, Erode, Tamil Nadu. 1-2, Approaching and opening an unguarded brood sac near the edge of a web. 3, Removal of the brood sac from the web. 4-5, Feeding on the brood sac after its removal from the web.

Figure 2 in Predation on the brood of a theridiid spider by a jumping spider (Araneae: Salticidae: Harmochirina: Bianor sp.)

Figure 2. Female theridiids in their webs with brood sacs (egg sacs) between the branches of dry herbaceous plants at Gobichettipalam, Erode, Tamil Nadu (3 SEP 2022). 2, This female may have been accompanied by a much smaller male (arrow). 3, Note the distance between this female and one of her brood sacs.

opencc-zeroJan 2023View details →

Data for: The significance of Apis cerana cerana (Hymenoptera: Apidae) gnawing off the old brood cells

Apis cerana cerana has the biological characteristic of gnawing off the old brood cells for rearing multiple generations of workers. This study investigated the internal structure of newly built, old, and semi-rebuilt brood cells and their effects on the morphological development of workers to understand the significance of Apis cerana cerana gnawing off the old brood cells. The structural dimensions of the brood cells and the morphological characteristics of the newly emerged workers were measured. The results showed that Apis cerana cerana gnaw off the old brood cells mainly in two ways either by removing the whole cell or only the cell walls keeping the bases. The workers construct semi-rebuilt brood cells on the foundation of these old cell bases. The main shapes of the newly built, old, and semi-rebuilt brood cells are hexagonal prism, hexagonal prismatic table, and hexagonal prism having three rhombuses, hemisphere, and hemisphere-shaped bases, respectively. The average thickness of the newly built or semi-rebuilt brood comb was significantly smaller than that of the old brood comb (P<0.05), while it was almost the same for the newly built and semi-rebuilt brood combs (P>0.05). The depth of brood cells showed no significant difference between the three types of brood cells (P>0.05), but the brood cell volumes were significantly different (P<0.05). There was no significant difference among the three diameters (at the top, middle, and bottom positions) of newly built or semi-rebuilt brood cells (P>0.05), but these changed within the old brood cells (P<0.05). The top, middle, and bottom diameters of the newly built or semi-rebuilt brood cells were significantly larger than those of the old brood cells (P<0.05), but were almost the same between the newly built and the semi-rebuilt brood cells (P>0.05). The weight and base thickness of the cocoon were significantly greater in the old brood cells than those in the semi-rebuilt brood cells (P<0.05). Importantly, the birth weight, body length, and the tested 6 external morphological indices did not show a significant difference between the newly built and the semi-rebuilt brood cells (P>0.05), but were significantly larger than those of old brood cells (P<0.05). The size of brood cell and the external morphology of the workers showed a positive correlation. This study highlights the significance of Apis cerana cerana gnawing off the old brood cells providing a reference for its scientific breeding.

opencc-zeroJan 2023View details →

Why do parents produce small broods of offspring that have lower body mass, survival, and lifetime reproductive success? A case study in a long-lived bird

Numerous studies have examined the correlation between offspring quantity and quality, and many have found that the most common brood size is often smaller than broods with the highest offspring quality or production. However, the reasons why these small broods with lower offspring quality are produced, are still poorly explained. Using data spanning 29 years, we investigated the effects of brood size on nestlings' body mass and the lifetime fitness for those offspring as adults (as proxies of offspring quality) in the Crested Ibis (Nipponia nippon). We also examined the temporal variation of brood size. We found that overall offspring quality increases with brood size and that individuals from broods of three had the highest quality, as quantified by larger body mass, higher adult survival, and lifetime reproductive success. Furthermore, brood size of an individual pair significantly varied across years, and the proportion of broods containing two offspring increased while broods of three decreased after 2000 when the population dispersed to low-quality habitat. These findings indicate that spatiotemporal variation in resources may impact variation in brood size and subsequent fitness consequences, and that small broods are more common in resource-poor years or low-quality habitats. In contrast, parents with access to high-quality resources produce larger broods of nestlings that achieve higher body mass and subsequently experience higher adult survival and lifetime fitness. This study highlights how variation in life history traits can be influenced by resource condition, and provides an insight into particular habitat that need conservation for Crested Ibis.

Figure 5 in Brood nest of Piranthus planolancis (Araneae: Salticidae: Baviini)

Figure 5 (continued from previous page). Brood nest of Piranthus planolancis within a coiled Lychee (Litchi chinensis) leaf, photographed at the Indraprastha Organic Farm of the senior author (Abhijith), Kalalwadi Village, Mysuru, India. 6, Note that both sides of this leaf were coiled.

Figure 3 in Brood nest of Piranthus planolancis (Araneae: Salticidae: Baviini)

Figure 3 (continued from previous page). Adult male Piranthus planolancis at the Indraprastha Organic Farm of the senior author (Abhijith), Kalalwadi Village, Mysuru, India.

Figure 3 in Brood nest of Piranthus planolancis (Araneae: Salticidae: Baviini)

Figure 3 (continued on next page). Adult male Piranthus planolancis at the Indraprastha Organic Farm of the senior author (Abhijith), Kalalwadi Village, Mysuru, India.

Figure 2 in Brood nest of Piranthus planolancis (Araneae: Salticidae: Baviini)

Figure 2. Immature Piranthus planolancis at the Indraprastha Organic Farm of the senior author (Abhijith), Kalalwadi Village, Mysuru, India.

Figure 4 in Brood nest of Piranthus planolancis (Araneae: Salticidae: Baviini)

Figure 4 (continued from previous page). Three (1-3, 4-6, 7-8) adult female Piranthus planolancis at the Indraprastha Organic Farm of the senior author (Abhijith), Kalalwadi Village, Mysuru, India.