scholarly journals Habitat and Sex Differences in Physiological Condition of Breeding Southwestern Willow Flycatchers (Empidonax Trailliiextimus)

The Auk ◽  
2005 ◽  
Vol 122 (4) ◽  
pp. 1261-1270 ◽  
Author(s):  
Jennifer C. Owen ◽  
Mark K. Sogge ◽  
Michael D. Kern

Abstract The Southwestern Willow Flycatcher (Empidonax traillii extimus; here- after “flycatcher”) is a federally listed endangered species that breeds in densely vegetated riparian habitats dominated by native and exotic plants, including introduced monotypic saltcedar (Tamarix ramosissima). Some workers have theorized that saltcedar is unsuitable habitat for the flycatcher, primarily because it generally supports a smaller and less diverse invertebrate community (the flycatcher's food base) than native habitats (e.g. Salix spp.). However, differences in insect communities between native and saltcedar habitats are not proof that saltcedar habitats are inferior. The only way to evaluate whether the habitats differ in dietary or energetic quality is to document actual food limitation or its manifestations. Measurements of an individual's body condition and metabolic state can serve as indicators of environmental stressors, such as food limitation and environmental extremes. We captured 130 flycatchers breeding in native and saltcedar habitats in Arizona and New Mexico and measured 12 variables of physiological condition. These variables included body mass, fat level, body condition index, hematocrit, plasma triglycerides, plasma free fatty acids and glycerol, plasma glucose and beta-hydroxybutyrate, plasma uric acid, total leukocyte count, and heterophil-to-lymphocyte ratio. We found substantial sex-based differences in the condition of male and female flycatchers. Ten of the 12 measures of physiological condition differed significantly between the sexes. In all cases where male and female condition differed (except mass), the differences suggest that males were in poorer condition than females. We found few habitat-based differences in flycatcher condition. Only 3 of the 12 physiological condition indices differed significantly between habitats. Our data show that, at least in some parts of the flycatcher's range, there is no evidence that flycatchers breeding in saltcedar habitats exhibit poorer nutritional condition or are suffering negative physiological affects. Diferencias entre Hábitats y Sexos en la Condición Fisiológica de Individuos Reproductivos en Empidonax traillii extimus

2010 ◽  
Vol 31 (4) ◽  
pp. 558-562 ◽  
Author(s):  
Rodica Plăiaşu ◽  
Tibor Hartel ◽  
Raluca Ioana Băncilă ◽  
Dan Cogălniceanu ◽  
Joost Smets

AbstractBody condition is important because it is correlated with population and habitat quality parameters. Since the direct measurements are either lethal or unreliable, a wide range of non-lethal body condition indices has been proposed. The aim of our study was to apply and compare three body condition indices (Fulton's index, relative body condition mass index and residual index) using body size indicator – body mass data for 24 populations of the yellow bellied toad (Bombina variegata). The condition index should be independent of body size indicator, in this case snout vent length (SVL). Therefore we tested all three indices for the statistical independence of SVL and for the normality of distribution. Fulton's index violated the independence assumption, whereas the relative body condition mass index did not have a normal distribution. Residual index was found both independent of SVL and normally distributed. Moreover, the residual index highlighted biological significant differences on the basis of altitude and season. Our results recommend the residual index as a useful tool in amphibian monitoring and conservation.


2021 ◽  
Author(s):  
Claudia Campanini ◽  
Marta Albo-Puigserver ◽  
Sara Gérez ◽  
Elena Lloret-Lloret ◽  
Joan Giménez ◽  
...  

AbstractEuropean anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are crucial species for the marine ecosystem of the Northwestern Mediterranean Sea. They account for a high percentage of fish landings and they represent an important economic income. Concerns over their stock status are rising in recent years as biomass, growth, reproductive capacity and body condition of both species are declining. Therefore, there is an urgent need for a continuous and fast body condition monitoring scheme. Energy storage variability has important implications for both fish recruitment and population structure. Direct condition indices, such as bomb calorimetry, are highly reliable for measuring the energy content, but extremely time-consuming. Alternatively, fatmeter analysis and relative condition index (Kn) have been proposed as effective indirect methods. The aim of this study is to test the application of fatmeter as a surrogate of bomb calorimetry to infer the energy content of both small pelagic fishes. For the validation, fatmeter values were compared with both energy density (ED; via bomb calorimetry) and Kn values. Individuals of both species were sampled monthly in Barcelona harbor for a year in order to assess seasonal variations in energy content. Our results highlight that fatmeter measurements are strongly correlated with calorimetry for sardine, while a weaker but significant correlation was found for anchovy. The observed differences between the two species are related to their breeding strategies. Based on this study, fatmeter analysis appears to be a faster and suitable method to evaluate the energy content of both species routinely., In addition, we provide a linear model to infer ED from fatmeter values of both small pelagic fish. Eventually, these findings could allow for the avoidance of bomb calorimetry and could be used to implement body condition monitoring protocols, and to boost continuous large-scale monitoring.


2009 ◽  
Vol 78 (2) ◽  
pp. 65-75 ◽  
Author(s):  
Wenhua Xiong ◽  
Hong Liang ◽  
Xiaohui Yu ◽  
Lin Cong ◽  
Zhibin Zhang

Although food has been proposed as a possible factor on population regulation of small mammals, evidence of food restriction in field conditions is still lacking. Food restriction is generally thought to occur in high-density years of oscillating populations of small mammals. By using two body condition indices (muscle protein concentration and cleaned carcass index), we investigated variations of body condition of the greater long-tailed hamster (Tscherskia triton) and the striped hamster (Cricetulus barabensis) in the Raoyang County of the North China Plain during a population decline- and low-phase from 1998 to 2003. Our laboratory experiments showed that food restriction reduced muscle protein concentration and cleaned carcass index of greater long-tailed hamster. We found there were significant differences in body condition of hamsters over the six years. Both the muscle protein concentration and cleaned carcass index of T. triton were significantly and positively correlated with its yearly trap successes, which reflected yearly population densities. Muscle protein concentration of C. barabensis was positively correlated with the total yield of the wheat. This observation supported the hypothesis on the in-phase relation between food resources or availability and rodent abundances. During the four seasons, muscle protein concentration of two species was highest in autumn, and lowest in summer. These two body condition indices of wild T. triton in summer and in low phases were similar to 60% food restricted animals raised in the laboratory, but significantly lower than nonfood- restricted animals. Our results indicated that malnutrition occurred in summer when food was not abundant, and in low density years with low grain production (an index reflecting food abundance of rodents) in our study region. Therefore, we concluded that food limitation may play an important role in seasonal and inter-annual population fluctuation of these two hamster species.


2012 ◽  
Vol 39 (4) ◽  
pp. 301 ◽  
Author(s):  
Gina M. Morgan ◽  
Travis E. Wilcoxen ◽  
Michelle A. Rensel ◽  
Stephan J. Schoech

Context Anthropogenic disturbances induce physiological and behavioural responses in numerous species. The negative effects of human disturbance are of special concern to threatened and endangered species. Aims The present study aims to compare physiological stress measures and reproductive success of Florida scrub-jays (Aphelocoma coerulescens) living near roads with jays that live away from roads. Specifically, it aims to test whether roads are stressful. Methods We assessed physiological measures that can serve as indicators of ‘stress’ to determine whether a highway that bisects our study site had physiological effects on adult male Florida scrub-jays. We captured male breeders from three territory types, including scrub habitat that (1) bordered a highway with a grassy shoulder that created an ‘edge’ habitat (roadside), (2) bordered human-maintained habitat (a plowed firebreak of sand with adjacent pasture) that served as a control for the edge-effect of the road (pasture) and (3) contained only natural scrub habitat (interior). We measured baseline concentrations of the stress hormone corticosterone (CORT), body mass, and a suite of longitudinal body measures to generate a body condition index in males from each territory type over three breeding seasons. Key results Roadside jays had greater body mass than did interior and pasture jays, although there were no differences in overall baseline CORT concentrations or body condition among territory classes. There was no difference in clutch initiation date or size and nestling and independent-young survival. Conclusions Our results suggest that the road through our study site has physiological effects on Florida scrub-jays; however, there is mixed evidence as to whether it acts as a chronic stressor. Implications Our findings provide evidence that roads and road-associated disturbance has neutral or potentially beneficial physiological effects of roads on Florida scrub-jays. Knowledge of these effects of roads and disturbance on jays will hopefully provide additional opportunities to improve conservation of this species.


Author(s):  
Danise Benatti ◽  
Luis Felipe Andrietti ◽  
José Flávio Cândido Júnior ◽  
Alexandre Vogliotti ◽  
Marcela Figueirêdo Duarte Moraes ◽  
...  

Abstract Rodents are small mammals that can be parasitized by various helminths. This study aimed to identify and describe the ecological indicators of infection in rodents captured in fragments of the Atlantic Forest in the western region of Paraná State, Brazil. Sixty-eight specimens of five rodent species were collected, necropsied, and inspected in search of helminths. The parasites were stored in 70% ethanol, morphologically identified, and counted for calculation of infection indicators. Fourteen species of helminths and one species of Crustacea were recorded: ten in Akodon montensis, four in Mus musculus, two in Thaptomys nigrita, two in Oligoryzomys nigripes, and one in Euryoryzomys russatus. The registered species of parasites were: Rodentolepis akodontis, Angiostrongylus sp., Protospirura numidica criceticola, Trichuris navonae, Syphacia alata, Syphacia criceti, Syphacia evaginata, Trichofreitasia lenti, Stilestrongylus aculeata, Stilestrongylus eta, Stilestrongylus gracielae, Stilestrongylus franciscanus, Stilestrongylus moreli, Stilestrongylus sp., and Pentastomida gen. sp. A positive correlation between the intensity of infection of T. navonae and T. lenti was observed with the body condition index of the host A. montensis. For all species, this study represents a new register of locality, and for eight of them a new host.


2016 ◽  
Vol 2 (1) ◽  
pp. 67-76
Author(s):  
Yasser Ahmed ◽  
Armin Fabritzek ◽  
Neviaty P. Zamani ◽  
Karen Von Juterzenka ◽  
Mark Lenz

Pergerakan organisme dipengaruhi oleh penyebaran alami dan aktivitas manusia.Beberapa spesies yang terbawa, memiliki sebaran yang melebihi distribusi batas normal oleh pengaruh tertentu (vector).Penelitian ini melakukan pengujian pada skala laboratorium untuk melihat survival rate yang terkait dengan body condition index selama diberikan stress suhu yang terkait perubahan iklim dan ini juga dapat dijadikan sebagai simulasi transportasi kapal, sehingga dapat diketahui pergerakan organisme.Distribusi organisme tersebut mempengaruhi kemampuan bertahan hidupselama transportasi.Oleh karena itu, perlu dilakukan penelitian dengan mengekspose grup pra-stress dan grup non stress sebelum masuk ke fase stress dan membandingkan survival rate dan body condition index (BCI) pada organisme tersebut. Organisme yang dipilih adalah Kerang Hijau (P. viridis) dengan menggunakan stress suhu.Pengukuran respon variabel dari organisme tersebut yaitu survival rate dan body condition index (BCI).Penelitian ini menunjukkan bahwa survival rate dan body condition index memiliki korelasi linier.


2020 ◽  
Vol 21 (8) ◽  
Author(s):  
AGUS INDARJO ◽  
Gazali Salim ◽  
MUFRIDA ZEIN ◽  
DODDY SEPTIAN ◽  
STEPHANIE BIJA

Abstract. Indarjo A, Salim G, Zein M, Septian D, Bija S. 2020. The population and mortality characteristics of mangrove crab (Scylla serrata) in the mangrove ecosystem of Tarakan City, Indonesia. Biodiversitas 21: 3856-3866. The mangrove crab is an iconic species of Tarakan City and is often is used as a souvenir. However, the high demand for this species can cause its population to decline. This study aimed to characterize the mangrove crab (Scylla serrata) population in the mangrove ecosystem of Tarakan City, North Kalimantan, Indonesia. This study was designed using a quantitative descriptive method with a case study model. The samples of mangrove crabs were obtained from 6 different stations using a purposive sampling method. The mangrove crab specimens were caught using 35-50 units of crab traps known as the ambau brackets. The primary data included carapace length, carapace width, carapace thickness, sex, and the total weight of each mangrove crab specimen. The results showed that male mangrove crabs have positive allometric growth when the condition index was fat. However, female crabs exhibited negative allometric growth when the condition index was thin. The Von Bertalanffy growth model analysis showed that the maximum carapace length of male mangrove crab in the mangrove ecosystem of Tarakan City was approximately 11.1118 cm for 189 days, while the female length was 9.6474 cm for 80 days. The total mortality value of male and female crabs was 120.01% and 154.94%, the mortality due to fishing was 84.69% and 135.75%, and natural mortality was 35.32% and 19.2%, respectively. The estimated rate of exploitation of both male and female crabs was 70.57% and 87.61%, respectively. The exploitation of S. serrata in the mangrove ecosystem of Tarakan City was evident, hence, conservation efforts are urgently required.


2007 ◽  
Vol 55 (4) ◽  
pp. 249 ◽  
Author(s):  
Louise Mortimer ◽  
Alan Lill

Some birds facing energy ‘bottlenecks’ display elevated oxidative metabolism and oxygen delivery to tissues and could be particularly susceptible to chronic stress. We examined whether there was evidence for such trends in little penguins (Eudyptula minor) over the period from breeding to the post-moulting stage and particularly during the onshore moult-fast. Penguin parents contribute equally to incubation, brooding and brood provisioning. A few weeks post-breeding, adults undergo a protracted, terrestrial moult-fast and then make brief visits to the colony during the post-moulting stage. Provisioning nestling(s) and moulting could theoretically be particularly energetically and nutritionally demanding. We determined for adults whether mass, a body condition index and blood parameters influencing vascular oxygen carrying capacity (hematocrit, Hct; whole blood haemoglobin, Hb) and indicating chronic stress (leukocyte count, WBC; heterophil/lymphocyte ratio, H/L) varied from August to May in a manner reflecting likely variation in energy and nutrient demand. Female mass and body condition index decreased significantly between the incubation and guard stages, before returning to incubation levels between the guard and post-guard nestling stages. Both parameters declined to their lowest levels between the post-guard and moult stages, before increasing to levels comparable with those during nestling care between the moult and post-moult stages. Blood parameters in both sexes exhibited temporal variation similar to that in female mass and body condition index, declining to their lowest levels during moult and increasing after the moult to levels comparable with those during breeding. Results indicated that the period of most intense provisioning of nestlings was associated with a decrease in blood oxygen carrying capacity, but no pronounced change in chronic stress indicators. However, the penguin’s moult-fast involved a loss of female body condition and, in both sexes, a reduction in body mass, vascular oxygen carrying capacity and possibly specific immune competence. Thus, regulation of human disturbance in accessible little penguin colonies may be particularly important during moult.


<em>Abstract</em>.—U.S. Game and Fish agencies and farm-pond owners throughout the United States use commercially produced channel catfish <em>Ictalurus punctatus </em>fingerlings transported from the southern United States for supplemental stocking. We conducted six trials to examine whether pathogen load, body condition, and select environmental factors influence fingerling survival following transport and cage stocking. Fingerlings were sampled prior to stocking and weekly for the following 3 weeks. Weights and lengths were measured, and a relative condition index was used to quantify body condition. Skin scrapings and gill clippings were examined microscopically for pathogens, and posterior kidney was assayed for <em>Aeromonas hydrophila</em>. Mortality was either less than 10% (four trials) or catastrophic (two trials). A Columnaris disease epizootic was associated with ~50% mortality in one trial, and a red sore disease epizootic was associated with ~80% mortality in another. Body condition or other pathogens, present initially or acquired in study ponds, were not associated with high mortality. The first week appears to be critical for the survival of channel catfish fingerlings following transport.


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