scholarly journals Nesting strategy and the niche partitioning in two socially monogamous songbirds

Author(s):  
Nao Ota

Niche partitioning is often vital for the coexistence of ecologically similar species under limited resources. Here I will report the nesting strategy of the two sympatric songbirds and the species differences, which have been overlooked in the past. Blue-capped and red-cheeked cordon-bleus are socially monogamous, biparental songbirds (family Estrildidae) that sympatrically inhabit East Africa. My field observation during their breeding season revealed that red-cheeked cordon-bleus build their nests near wasp nests more frequently than blue-capped cordon-bleus. Blue-capped cordon-bleus instead tended to take over weaver’s old nest more often or use a broader range of nesting materials compared to red-cheeked cordon-bleus. These nesting strategies are already described in the literature as common behaviors in both species. However, the species differences of the adopting strategies have never been reported. While Estrildid finches are one of the best well-studied bird families of their behavior under the captive condition, my finding suggests that we still have limited knowledge of their wild behaviors and ecological plausibility, which is required to understand the functions and evolution.

Phytotaxa ◽  
2018 ◽  
Vol 381 (1) ◽  
pp. 132 ◽  
Author(s):  
WEN-HONG CHEN ◽  
SIRILAK RADBOUCHOOM ◽  
HIEU QUANG NGUYEN ◽  
THAMARAT PHUTTHAI ◽  
LEONID V. AVERYANOV ◽  
...  

Due to the unavailability of specimens and publications in the past, some gaps exist in knowledge of similar species from various adjacent countries. After more recently detailed observations from field surveys and examinations on herbaria specimens, we confirmed the status of Begonia arboreta and B. sonlaensis as synonyms of B. garrettii and B. pseudodryadis from China and Thailand, and from China and Vietnam, respectively. The taxonomic treatment is based on the examination of both available herbarium specimens and living plants from different populations. Taxonomy revision of the allied species is very important for understanding plant diversity in the above neighboring countries.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuanxing Ye ◽  
Canshi Hu ◽  
Yiting Jiang ◽  
Geoffrey W. H. Davison ◽  
Changqing Ding

Abstract Background Interspecific competition is known to be strongest between those species that are both closely related and sympatric. Egrets are colonially nesting wetland birds that often overlap and can therefore be expected to compete in roosting and nesting habitat as well as in diet. According to the niche partitioning hypothesis, it is to be expected that these similar species would show differentiation in at least one of the main niche dimensions to reduce competition. We tested niche partitioning between the colonially nesting Little Egret (Egretta garzetta) and Cattle Egret (Bubulcus ibis) in temporal, spatial and trophic dimensions. Methods Field study was conducted in three mixed egret colonies in Yangxian County, southwest Shaanxi Province, central China. For each nest colony we recorded its spatial location, the height of nesting trees and of nests, the height of roosting trees and of roosting individuals within the trees. We determined the first egg-laying and first hatching dates of the two species. Craw dissection of storm-killed egret nestlings was used to measure the diet. Six transects were surveyed to study foraging habitat selection. Results We found that hatching time of Little Egrets peaked earlier (by about 1 month) than that of Cattle Egrets. Cattle Egrets nested and roosted higher than Little Egrets. The foraging habitats used by Little Egrets were dominated by river banks (73.49%), followed by paddy fields (13.25%) and reservoirs (10.84%), whereas Cattle Egret foraging sites were characterized by grasslands (44.44%), paddy fields (33.33%) and river banks (22.22%). Little Egrets consumed more fishes (65.66%) and Odonata larvae (13.69%) than Cattle Egrets, while Cattle Egrets were found feeding mainly on Coleoptera (29.69%) and Orthoptera (23.29%). Little Egrets preyed on larger mean biomasses of food items than Cattle Egrets. Conclusions Our results confirm the niche partitioning hypothesis as a mechanism for coexistence among ecologically similar species. In two coexisting egret species, niche partitioning is multidimensional, such that the two coexistent species occupy differing ecological space based on all three temporal, spatial and trophic niche dimensions.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 482
Author(s):  
Won Young Lee ◽  
Seongseop Park ◽  
Kil Won Kim ◽  
Jeong-Hoon Kim ◽  
Jong-Ku Gal ◽  
...  

Theory predicts that sympatric predators compete for food under conditions of limited resources. Competition would occur even within the same species, between neighboring populations, because of overlapping foraging habits. Thus, neighboring populations of the same species are hypothesized to face strong competition. To test the hypothesis that intra-specific competition is more intense than inter-specific competition owing to a lack of niche partitioning, we estimated the foraging area and diving depths of two colonial seabird species at two neighboring colonies. Using GPS and time-depth recorders, we tracked foraging space use of sympatric breeding Chinstrap and Gentoo penguins at Ardley Island (AI) and Narębski Point (NP) at King George Island, Antarctica. GPS tracks showed that there was a larger overlap in the foraging areas between the two species than within each species. In dive parameters, Gentoo penguins performed deeper and longer dives than Chinstrap penguins at the same colonies. At the colony level, Gentoo penguins from NP undertook deeper and longer dives than those at AI, whereas Chinstrap penguins did not show such intra-specific differences in dives. Stable isotope analysis of δ13C and δ15N isotopes in blood demonstrated both inter- and intra-specific differences. Both species of penguin at AI exhibited higher δ13C and δ15N values than those at NP, and in both locations, Gentoo penguins had higher δ13C and lower δ15N values than Chinstrap penguins. Isotopic niches showed that there were lower inter-specific overlaps than intra-specific overlaps. This suggests that, despite the low intra-specific spatial overlap, diets of conspecifics from different colonies remained more similar, resulting in the higher isotopic niche overlaps. Collectively, our results support the hypothesis that intra-specific competition is higher than inter-specific competition, leading to spatial segregation of the neighboring populations of the same species.


Phytotaxa ◽  
2018 ◽  
Vol 365 (3) ◽  
pp. 295
Author(s):  
CHE-WEI LIN ◽  
CHI-HUNG LEE

Reknowned for its high biodiversity and endemism, over one third of the Bornean species of Phyllagathis were discovered in Sarawak over the past two years. In this study, we report an addition of a new species of Phyllagathis, namely P. stellata from southwestern Sarawak. In addition to the taxonomic account, color plates, line drawings, a distribution map, and comparisons with morphologically similar species are provided to aid in identification.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wade B. Worthen ◽  
Parker H. Morrow

In many communities of perching dragonflies (Odonata: Libellulidae), a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species:Celithemis elisa,C. fasciata, andC. ornata.Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing.Celithemis fasciatawas significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the largeC. fasciatawas attacked less frequently, and the smallC. ornatamore frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.


Author(s):  
Steven Lindberg ◽  
Matthew I. Campbell

Abstract Individual engineering design projects face different challenges depending on their scale. Instead of dealing with problems of complex multidisciplinary systems, small scale design must overcome issues of limited resources. The philosophy of agile software development has been highly successful in addressing similar issues in the software engineering realm over the past two decades. Through the design and prototyping of a low-budget desktop stereolithography printer, the application of agile principles to engineering design process is explored. The printer’s design is discussed in detail to provide examples of successes and failures when these agile principles are put into practice. The paper concludes with a discussion of how agile principles could be leveraged in engineering design. The approach taken in this paper is more of a longitudinal study of a single design process over a twelve-month period as opposed to rigorous experiments that engage multiple users in short design scenarios. Nonetheless, this case study demonstrates how the application of agile principles can inform, improve, and complement traditional engineering design processes.


2013 ◽  
Vol 71 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Nicholas R. Record ◽  
Andrew J. Pershing ◽  
Frédéric Maps

Abstract Record, N. R., Pershing, A. J., and Maps, F. 2014. The paradox of the “paradox of the plankton”. – ICES Journal of Marine Science, 71: 236–240. One of the central orienting questions in biodiversity theory and ecology is the “paradox of the plankton”, which asks how it is possible for many species to coexist on limited resources given the tendency for competition to exclude species. Over the past five decades, ecologists have offered dozens of solutions to the paradox, invoking game theory, chaos, stochastics, and many other concepts. Despite the plentitude of solutions to the paradox, ecologists continue to offer up novel solutions. Ocean modellers are now faced with the opposite paradox: given the overabundance and the diversity of solutions to the paradox, what is the appropriate way to build coexistence into ecosystem models? Ocean ecosystem models have a very standardized form—nutrient–phytoplankton–zooplankton (NPZ)-type systems of differential equations—where competitive exclusion is a common model behaviour. We suggest approaching the problem from the perspective of community-level patterns. We offer a prototype for building coexistence into NPZ models. The model allows for diverse assemblages of phytoplankton or zooplankton groups to persist and produces accurate community-level patterns. The approach is simple, adding only one additional parameter, and allows us to test the effects of trait distributions and environmental variables on diversity.


1989 ◽  
Vol 122 (3) ◽  
pp. 733-745 ◽  
Author(s):  
A. S. I. Loudon ◽  
J. A. Milne ◽  
J. D. Curlewis ◽  
A. S. McNeilly

ABSTRACT Non-domesticated seasonally breeding ungulates exhibit marked seasonal changes in metabolic rate, voluntary food intake (VFI), pelage growth and moult and hormone secretion. It is not known whether these seasonal rhythms are regulated by the same central processes which control the onset and termination of the breeding season. Here we compare two closely related deer species which have significantly different mating and calving seasons. Seasonal changes in VFI, liveweight, coat growth, plasma prolactin and tri-iodothyronine (T3), and the timing of the breeding season were examined over a 15-month period in six adult post-pubertal red and Père David's deer from January to April the following year. The timing of the seasonal changes in prolactin, T3, VFI and coat growth were all significantly advanced by 56, 23, 60 and 54 days respectively in the Père David's deer. The times of onset and termination of the breeding season of Père David's deer were also significantly advanced by 90 days, but in both species, the breeding season was of similar duration (160 ± 5 (s.e.m.) days). Changes in liveweight of adult red deer could be explained by changes in VFI rather than efficiency of utilization. This was not the case in Père David's deer and may indicate seasonal changes in the efficiency of energy utilization. In order to establish whether these species differences develop with age, we undertook a second study in which seasonal changes in VFI, growth, plasma prolactin concentrations and the timing of the onset of the breeding season were recorded for ten red deer and six Père David's deer from 6 to 18 months of age. Both species exhibited a similar decline in VFI in the first autumn of life. Subsequently, the Père David's deer exhibited an advance in the timing of the seasonal peak in VFI and prolactin (21 and 66 days respectively); puberty occurred 3 months earlier than in red deer. The earlier breeding season of the Père David's deer was associated with a significant advance in a range of seasonal endocrine and physiological parameters. These species differences may develop with age. Our data indicate that seasonal patterns of metabolism and growth may be closely linked to those mechanisms which also regulate the onset and termination of the breeding season. Journal of Endocrinology (1989) 122, 733–745


2017 ◽  
Vol 284 (1855) ◽  
pp. 20170546 ◽  
Author(s):  
Graham J. Slater ◽  
Jeremy A. Goldbogen ◽  
Nicholas D. Pyenson

Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the evolution of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary dynamics in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size evolution during the Plio-Pleistocene. This transition, from Brownian motion-like dynamics to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-driven upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean dynamics may have provided an ecological pathway to gigantism in multiple independent lineages.


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