Environmental conditions and call-broadcast influence detection of eastern forest owls during standardized surveys

The Condor ◽  
2020 ◽  
Vol 122 (3) ◽  
Author(s):  
Kyle A Lima ◽  
Erynn M Call ◽  
Thomas P Hodgman ◽  
David S Potter ◽  
Susan Gallo ◽  
...  

Abstract Owls play crucial roles in the environment and provide ecosystem services making them important to monitor and study. However, standardized methods for most species do not exist, and we lack understanding of the effects of many environmental variables and call-broadcast on detection of owls during surveys. We performed a multispecies occupancy analysis of owl monitoring data collected from 2004 to 2013 across the state of Maine to examine the effects of environmental variables, conspecific and heterospecific call-broadcast, and general survey protocols on detection of 3 forest owls: Northern Saw-whet Owl (Aegolius acadicus), Barred Owl (Strix varia), and Great Horned Owl (Bubo virginianus). We found that environmental variables such as cloud cover, precipitation, temperature, time of night, and wind had species-specific effects on detection probability, and ambient noise decreased detection probability for all species. Snow cover did not affect detection of any species. We also found that conspecific call-broadcast increased detection of each species, while heterospecific call-broadcast had variable effects. Specifically, we found that Long-eared and Barred owl broadcast increased the detection of Northern Saw-whet Owl, and our results suggest additional heterospecific effects may exist. Our study showed that, compared to the protocol of the Maine Owl Monitoring Program, surveys simultaneously examining all 3 of our focal species can increase efficiency and lower disturbance by only broadcasting Long-eared and Barred owl calls during a 10-min survey. We recommend that future owl surveys take into account species-specific effects of conspecific and heterospecific call-broadcast, and use our results when designing survey protocols that include one or more of our focal species.

2021 ◽  
Author(s):  
Gerardo I. Zardi ◽  
Katy Rebecca Nicastro ◽  
Christopher D. McQuaid ◽  
Monique de Jager ◽  
Johan van de Koppel ◽  
...  

2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.


2017 ◽  
Vol 8 (10) ◽  
pp. 3587-3600 ◽  
Author(s):  
Linlin Wang ◽  
Lujun Hu ◽  
Qi Xu ◽  
Tian Jiang ◽  
Shuguang Fang ◽  
...  

Edible bifidobacteria exerted species-specific effects in relieving constipation.


PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0152113 ◽  
Author(s):  
Ana Z. Gonçalves ◽  
Rafael S. Oliveira ◽  
Paulo S. Oliveira ◽  
Gustavo Q. Romero

1994 ◽  
Vol 22 (6) ◽  
pp. 454-461
Author(s):  
Marga Oortgiesen ◽  
Ruud Zwart ◽  
Henk P.M. Vijverberg

The effects of nitromethylene heterocycle (NMH) insecticides on subtypes of nicotinic acetylcholine (nACh) receptors were investigated in locust thoracic ganglion neurons, mouse N1E-115 neuroblastoma cells, and mouse BC3H1 muscle cells by using electrophysiological techniques. In locust neurons, all of the six NMH insecticides tested induced transient inward currents resembling nicotinic ACh-induced inward currents, while, in the continued presence of the NMH compounds, the ACh-induced inward current was blocked. The amplitude of the inward current and the blocking effects of the NMH insecticides were enhanced by concentrations between 0.1 and 10μM. Cross-desensitisation with the ACh-induced inward current confirmed that the NMH-induced inward current was governed by the activation of nACh receptors. Mammalian endplate type nACh receptors in BC3H1 cells and mammalian neuronal type nACh receptors in N1E-115 cells were much less sensitive to the NMH insecticides than the locust neuronal nACh receptors. At a concentration of 10μM, which blocked 80–100% of the ACh-induced inward current in locust neurons, NMH insecticides only partially blocked the ACh-induced inward currents mediated by the two subtypes of mammalian nACh receptors. NMH insecticides also failed to induce significant agonist effects in the mammalian cells at this concentration. The results provide a possible explanation for the selectively greater toxicity of NMH insecticides to insects than to vertebrates, at the level of nACh receptor subtypes and, hence, demonstrate that this in vitro approach is valuable for the investigation of species-specific interactions of compounds at their target site.


Author(s):  
Carolin Boehlke ◽  
Sabrina Schuster ◽  
Lucas Kauthe ◽  
Oliver Zierau ◽  
Christian Hannig

AbstractAsian and African elephants show morphological adaptations to their ecological niche including the oral cavity. Variety and preferences of forage plants differ between both herbivorous elephant species. Diet can affect salivary enzymes. Asian elephants were shown to have a higher salivary amylase activity than African elephants. Species-specific differences were presumed to be influenced by feeding during collection procedure. This study aimed to determine the influence of feeding on enzyme activities in saliva of both elephant species to differentiate from species-specific effects. Additionally, season and housing conditions on salivary enzyme activities in non-fed elephants of both species were investigated. Salivary amylase (sAA), lysozyme (sLYS) and peroxidase (sPOD) activity were measured photometrically or fluorometrically. Results of this study reinforce previous observations of higher basic sAA activity in Asian elephants compared to African elephants. Salivary LYS and sPOD activity showed neither species-specific nor housing-specific differences. Independent from season, most elephants of both species revealed a lack of or low sPOD activity. Feeding caused a temporary decrease of sAA, sLYS and sPOD activity in both elephant species kept in four of eight tested zoos. Furthermore, sAA activity in Asian elephants was higher and sLYS activity lower in Spring than in Autumn. This study summarizes that sAA and sLYS are components of Asian and African elephant saliva in an active conformation in contrast to sPOD. Diet varying between season and zoos might influence sAA and sLYS activities primarily in Asian elephants but temporary low effects suggest sufficient buffer capacity of elephant saliva of both species.


2012 ◽  
Vol 39 (1) ◽  
pp. 76-89 ◽  
Author(s):  
Carolina E. Reisenman ◽  
Jeffrey A. Riffell ◽  
Kristin Duffy ◽  
Adrien Pesque ◽  
David Mikles ◽  
...  

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