Literature type: Scientific
Journal: Ornis svecica
Volume: 31 , Pages: 125–138
Language: English
Download:Full reference: Liljebäck, N., Koffijberg, K., Kowallik, C., Månsson, J. & Andersson, Å. 2021. Use of foster parents in species conservation may cause conflicting objectives: Hybridization between Lesser White-fronted Goose Anser erythropus and Barnacle Goose Branta leucopsis. Ornis svecica 31: 125–138 https://www.dx.doi.org/10.34080/OS.V31.22430
Keywords: reintroduction, foster parents, Sweden, hybridization
Abstract:
Following the use of Barnacle Geese Branta leucopsis as foster parents in a conservation program for the endangered Lesser White-fronted Goose Anser erythropus in Sweden 1981–1999, mixed breeding pairs of the two species were established in the wild. We find indications that this was related to shared moulting habits of the two species in the Bothnian Sea during late 1990s. Starting in 2003, five mixed pairs produced at least 49 free-flying hybrid offspring until 2013, when the last breeding was confirmed. Reported numbers of hybrids did not increase in parallel to the production of young hybrids over time. After 2013, the number of hybrids started to decrease in Sweden and the Netherlands. Lower numbers of hybrids than expected can partly be explained by management actions taken, but may also be associated with low survival due to genetic outbreeding. Mixed pairs and their offspring entirely adopted the migratory habits of Barnacle Geese, overlapping very little with sites used by Lesser White-fronted Geese. We find no evidence that the hybrids ever posed a serious threat to Lesser White-fronted Geese breeding in Fennoscandia.
Literature type: Scientific
Journal: Environmental management
Volume: 54 , Pages: 1331–1341
DOI: 10.1007/s00267-014-0350-7
Language: English
Full reference: Guan, L., Wen, L., Feng, D., Zhang, H., & Lei, G. 2014. Delayed flood recession in central Yangtze floodplains can cause significant food shortages for wintering geese: results of inundation experiment. Environmental management 54: 1331–1341 https://www.dx.doi.org/10.1007/s00267-014-0350-7
Keywords: Carex, Gompertz growth curve, flood regimes, Three Gorges Dam, China, lake–river relationship, habitat management
Abstract:
Carex meadows are critical habitat for wintering geese in the floodplains of the middle and lower reaches of Yangtze River, China. These meadows follow a growth cycle closely tied to the seasonal hydrological fluctuation: as water levels recede in the fall, exposed mudflats provide habitat for Carex spp. growth. The seasonal growth of Carex overlaps the arrival of wintering geese and provides an important food source for the migrants. Recent alterations to the Yangtze's hydrology, however, have disrupted the synchronous relationship between water levels, Carex growth and wintering geese at Dongting Lake. In October 2012, we carried out an outdoor mesocosm experiment to investigate potential impacts of delayed water recession on the germination and growth of Carex heterolepis, the dominant Carex species at Dongting Lake, to understand how changes in hydrology might impact wintering goose habitat. Results showed that the delayed flood recession exerted significant impact on the first growth cycle of Carex growth. Prolonged inundation significantly lowered the intrinsic growth rate (P = 0.03) and maximum growth rates (P = 0.02). It also took significantly longer time to reach the peak growth rate (P = 0.04 and 0.05 for number of shoot and biomass, respectively). As a result, biomass accumulation was reduced by 45, 62 and 90 % for 10-day, 20-day and 30-day inundation treatments, respectively. These results indicate a severe risk of food shortage for wintering geese when water recession delayed. This potential risk should be taken into consideration when operating any hydrological control structures that alter the flood regimes in Dongting Lake.
Literature type: Scientific
Journal: Wildfowl
Volume: 34 , Pages: 153-162.
Language: English
Full reference: Hillgarth, N., Kear, J. & Horky, K. 1983. Mortality of the northern geese in captivity. Wildfowl 34: 153-162.
Keywords: longevity, mortality, age, death, cause, peritonitis, pneumonia, cardiac, aspergillosis, lead, trauma, seasonal
Number of results: 3