scholarly journals SEASONAL BODY MASS CHANGES IN PIED FLYCATCHER (FICEDULA HYPOLEUCA) AT TWO STOPOVER SITES IN MOROCCO.

2019 ◽  
Vol 7 (7) ◽  
pp. 479-486
Author(s):  
Souad Zerdouk ◽  
The Auk ◽  
2001 ◽  
Vol 118 (3) ◽  
pp. 698-708 ◽  
Author(s):  
Regine Schwilch ◽  
Lukas Jenni

Abstract For various reasons, migrating birds may not refuel and gain mass immediately after they have arrived at a stopover site. That led to the concept of a search-settling time after arrival with a low or negative initial refueling rate, but its existence has not been clearly demonstrated in field studies. Body-mass changes resulting from capture–recapture data can be misleading if used for the estimation of a natural low initial refueling rate because (1) it is usually unknown whether the day of first capture is also the first day of stopover, and (2) handling at first capture may have an adverse effect on subsequent body-mass development. To circumvent those problems we increased probability of catching birds shortly after arrival by inducing landfall by tape-luring, and we estimated body-mass change without previous handling effects from concentration of two metabolites in blood plasma. In the Eurasian Reed-Warbler (Acrocephalus scirpaceus) studied at a stopover site in Switzerland, there was no difference in plasma-metabolite concentrations between a group of mostly newly arrived individuals and a group with few newly arrived birds. Similarly, there was no difference in those parameters between birds that had been handled before and birds at first capture. However, the analysis of capture–recapture data from two other Swiss stopover sites with longer handling times indicated that mean body mass of Eurasian Reed-Warblers and European Robins (Erithacus rubecula) dropped after capture and reached initial values only after one to several days. We concluded that mass loss after capture depended mainly on lost foraging time and that natural low initial refueling rate after arrival at a stopover site is not detectable under the conditions of this study.


2020 ◽  
Author(s):  
Barry Taylor ◽  
David Christie

The Auk ◽  
1984 ◽  
Vol 101 (1) ◽  
pp. 47-52 ◽  
Author(s):  
A. Allan Degen ◽  
Berry Pinshow ◽  
Peter J. Shaw

Abstract The Chukar subspecies Alectoris chukar sinaica inhabits the Negev desert, which is characterized by hot, dry summers, and little winter rainfall. Vegetation is dry and dormant during the summer and autumn; green, succulent vegetation is available following winter rain. We studied whether or not and under what dietary conditions Chukars require drinking water. Four groups of Chukars in an outdoor aviary received either a dry ration + water, a dry ration + green vegetation, a dry ration + green vegetation + water, or green vegetation only. The birds offered only greens lost 15% of their body mass in the first 8 days and 2.9% over the next 6 days, while birds on the other three treatments maintained body mass. The birds receiving only greens had the highest total body water to body mass ratio and the highest water influx. We concluded that the Chukars receiving only green vegetation met their water requirements but not their maintenance energy requirements. Chukars fulfilled both their water and energy requirements on a dry ration + green vegetation (without drinking water); the green vegetation comprised approximately 60% of their total fresh matter intake, or 26% of their total dry matter intake. Our analysis suggests that wild desert Chukars do not require drinking water from early winter to late spring, when succulent forage is available, but probably need free water during summer and autumn, when the bulk of their diet is seeds.


2009 ◽  
Vol 9 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Szymon Skoczen ◽  
Marcin Surmiak ◽  
Wojciech Strojny

2006 ◽  
Vol 37 (6) ◽  
pp. 555-560 ◽  
Author(s):  
Juan Moreno ◽  
Judith Morales ◽  
Elisa Lobato ◽  
Santiago Merino ◽  
Gustavo Tomás ◽  
...  

1988 ◽  
Vol 19 (1) ◽  
pp. 31 ◽  
Author(s):  
Rauno V. Alatalo ◽  
Karin Gottlander ◽  
Arne Lundberg

2016 ◽  
Vol 24 (2) ◽  
pp. 109-126 ◽  
Author(s):  
Andrea Harnos ◽  
Péter Fehérvári ◽  
Imre Sándor Piross ◽  
Zsolt Karcza ◽  
Nóra Ágh ◽  
...  

Abstract Ornithological studies often rely on large temporal scale ringing datasets as source of information. However, basic descriptive statistics of collected data are rarely provided. In order to fill this gap, here we present the first item of a series of exploratory analyses of migration timing and body size measurements of the most frequent Passerine species at a ringing station located in Central Hungary (1984–2015). First, we give a concise description of foreign ring recoveries of the Pied Flycatcher in relation to Hungary. We then shift focus to data of 2860 individuals deriving from the ringing station, where birds have been trapped, handled and ringed with standardized methodology since 1984. Timing is described through annual and daily capture and recapture frequencies and their descriptive statistics. We show annual mean arrival dates within the study period and we present the cumulative distribution of first captures with stopover durations. We present the distributions of wing, third primary, tail length and body mass, and the annual means of these variables. Furthermore, we show the distribution of individual fat and muscle scores, and the distribution of body mass within each fat score category. We distinguish migration periods (spring and autumn), age (i.e. juveniles and adults) and sex groups. Our aim is to provide a comprehensive overview of the analysed variables. However, we do not aim to interpret the obtained results, merely draw attention to interesting patterns, that may be worth exploring in detail. Data used here are available upon request for further analyses.


Sign in / Sign up

Export Citation Format

Share Document