Search results for "Cap"
showing 10 items of 8832 documents
Causes of mortality in depleted populations of Atlantic cod estimated from multi-event modelling of mark–recapture and recovery data
2017
Knowledge on mortality causes is key for an effective management of animal populations and can help to restore depleted fish stocks. Here we investigated the mortality dynamics of coastal Atlantic cod (Gadus morhua) in Skagerrak, southern Norway, by analyzing local mark–recapture and recovery data collected from 2005 to 2013 (N = 9360 fish, mean length = 41 cm, range = 16–93 cm). By applying multi-event models to the data, we could link field observations to multiple “dead states” and estimate the proportion of deaths associated with different fishing gears while controlling for unobserved mortality and detection errors. Deaths due to hand lines and fixed gear types were dominant compared …
Bycatch in gillnet fisheries - An overlooked threat to waterbird populations
2009
Bird mortality in fishing gear is a global conservation issue and it is recognised that bycatch in industrial longline and trawl fisheries threatens several seabird species. Little is known however about the effects of bycatch in small-scale gillnet fisheries on bird populations. Here we review 30 studies reporting bird bycatch in coastal gillnet fisheries in the Baltic Sea and the North Sea region in order to assess the magnitude of this problem and potential effects on bird populations. All species of diving birds that occur in the study region, including divers (loons), grebes, sea ducks, diving ducks, auks and cormorants, have been reported as dying in fishing nets. The cumulative bycat…
Species composition modulates seedling competitiveness of temperate tree species under hemiboreal conditions
2020
Abstract Mixed stands are advised for reduction of impacts of natural hazards, and species composition can largely affect sustainability and productivity of the stands. Early development of a stands after a stand-replacing disturbance can have considerable legacy effects on growth via alterations in the diversity-productivity relationships. Accordingly compatibility of growth and competitiveness of different species is one of the key issues for susceptibility of mixed stands. A two-year chamber experiment was conducted to assess early growth and intra- and inter-specific competition for light and soil resources among the seedlings of temperate tree species simulating the predicted effect of…
Patterns of movement of released female brown bears in the Cantabrian Mountains, northwestern Spain
2017
Between 2008 and 2013, 3 female brown bears (Ursus arctos; 2 cubs-of-the-year and 1 2-yr-old) were rescued, rehabilitated in captivity, radiotagged, and released back to the Cantabrian Mountains, northwestern Spain. We characterized their daily and seasonal movements post-release to gain insights into their movement strategies and the viability of bears released in human-dominated environments. The bears exhibited marked diurnal activity and were active throughout winter. Two bears demonstrated behaviors similar to those reported for wild bears, whereas one cub-of-the-year was recaptured after 21 days because she developed signs of habituation to humans.
Inter-specific nest re-use by Barn Swallows Hirundo rustica
2017
ABSTRACTCapsule: Reports of inter-specific nest re-use by Barn Swallows Hirundo rustica in Europe and North America are reviewed. Inter-specific nest re-use was rare but appeared opportunistic, possibly functioning as a time-saving mechanism or as a result of limited nest sites.
Behavior-modifying and insecticidal effects of plant extracts on adults of Ceratitis capitata (Wiedemann) (Diptera Tephritidae)
2018
The Mediterranean fruit fly Ceratitis capitata is a major pest of fruit orchards worldwide. In order to develop control methods based on natural products, particularly required in organic farming, a laboratory study was carried out to evaluate the response of adults to leaf extracts from four plant species: Ruta graveolens, Eriobotrya japonica, Rubus ulmifolius, and Ficus carica. Air-dried leaf powders were subjected to an ethanolic cold extraction. Chemical composition was assessed by GC/MS analysis. Extracts were tested in laboratory bioassays to assess the electroantennographic (EAG) response, attraction/repellence toward ovipositing females, and induced mortality toward adults. Among th…
First cases of polygyny for the Bearded Vulture Gypaetus barbatus in the central Pyrenees
2017
ABSTRACTWe report the first cases of polygyny for the Bearded Vulture Gypaetus barbatus in the central Pyrenees, Spain. Although polyandry is frequent in the study area (31.8% of all reproductive units in 2016), we only observed the occurrence of three cases of polygyny over the period 1994–2017. Polygyny in Bearded Vultures is possibly a consequence of habitat saturation.
Influence of Distance from the Host on Parasitisation by Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)
2019
The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited a…
Effects of Natura 2000 on nontarget bird and butterfly species based on citizen science data
2020
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30…
Local Recruitment in the Greater Flamingo: A New Approach Using Capture- Mark-Recapture Data
1997
International audience; Although the establishment of new individuals in the breeding component of a population is an essential feature of population regulation, only a few attempts have been made to test biological hypotheses about recruitment. Most previous studies rely on ad hoc calculations or are flawed with unwarranted assumptions about survival. We use a recently developed approach, based on capture-mark-recapture, in which analysis of local recruitment is similar to a time-reversed analysis of survival. The basic data set consists of capture histories viewed in reverse order, with initial capture at year of birth, and subsequent observations corresponding to years when the animal ha…