Chloephaga Picta Research Articles

Seasonal clutch size decline and individual variation in the timing of breeding are related to female body condition in a non-migratory species, the Upland Goose Chloephaga picta leucoptera

Several studies have shown that waterfowl females in good condition lay larger clutches and start egg-laying earlier in a breeding season. However, most of these studies lack corresponding data on individual condition and timing of breeding in different years. We analysed data on clutch size, egg size, hatching date and female body condition of a non-migratory species, the Upland Goose Chloephaga picta leucoptera, recorded in three seasons on New Island, Falkand Islands. We found a strong seasonal decline in both egg and clutch size. Egg size increased with clutch size. The mean egg volume and total clutch volume increased with female body condition and hatching date was earlier for females in higher body condition. Chicks hatched from nests with higher mean egg volume had higher early body condition. We also compared individual females between different study years and found that individual body condition showed a significant repeatability between years, whereas hatching date did not. While female aging did not systematically affect hatching date, females produced clutches that hatched earlier in years of higher body condition. We could thus show for the first time that the frequently reported negative relationship between female condition and hatching date also holds true on an individual basis. To our knowledge, this is the first study on seasonal clutch size decline in sheldgeese and one of a few in waterfowl comparing condition and timing of breeding within individuals between different years.

Variations in leucocyte profiles and plasma biochemistry are related to different aspects of parental investment in male and female Upland geese Chloephaga picta leucoptera

The analysis of plasma biochemistry and haematology to monitor the condition of birds in the wild has been found a useful tool in ecological research. Despite biparental investment in most wild birds studied, some studies of condition indices found sex differences, and attributed these to the costs of egg formation or brooding in females or a higher contribution of males to chick rearing. We studied the natural variation of haematological and plasma biochemistry parameters (namely leucocyte, lymphocyte and heterophil counts, H/L ratio and plasma concentrations of proteins, triglycerides and carotenoids) in relation to the different measures of parental investment in males and females in the Upland goose (Chloephaga picta leucoptera), a socially monogamous species. We found no sex differences in haematological and most plasma biochemistry parameters, but a relation to different aspects of parental investment in breeding male and female Upland geese. H/L ratios were related to body condition and capture date in males while leucocyte counts, plasma protein and plasma carotenoid concentrations varied with clutch measures and hatching date in females. Higher H/L ratios of males in a low body condition and later in the year may reflect stress associated with the investment into the establishment and defence of the breeding territory. Females with higher clutch volumes had lower total leucocyte and lymphocyte numbers and higher levels of plasma protein. Earlier hatching dates were associated with lower numbers of all leucocyte types and higher values of plasma carotenoid concentrations. This indicates that differences in health state are reflected in reproductive performance in female Upland geese. We also found sexual differences in the repeatability of haematological and plasma biochemistry parameters between years and therefore suggest that their potential as a measure of individual quality differs between male and female Upland geese. Finally, numbers of leucocyte counts and plasma triglyceride concentrations of pair partners were significantly related. No study so far investigated these parameters in pair partners and we discuss possible reasons for our finding.

Waterbird occurrence and abundance in the Strobel Plateau, Patagonia, Argentina

The Strobel Plateau is a conspicuous and representative basaltic plateau (“meseta”) in the Patagonian steppe, Argentina. This plateau is dotted with more than 1500 shallow lakes, which are regularly used by waterbirds and support one of the main breeding populations of the near threatened Hooded Grebe (Podiceps gallardoi). We collected data on bird presence and abundance in 41 shallow lakes, covering a wide spectrum of the wetland environmental variability found in the area. We conducted six surveys from spring to fall between 2004 and 2006. We recorded a total of 18 waterbird species, which represent 5 different families. Anatidae was the family most represented with 12 species, accounting for 85% of the observed waterbirds. Waterbird distribution among lakes was variable, from 2.4% occupied lakes for Wilson’s Phalarope (Steganopus tricolor) and Andean Ruddy-Duck (Oxyura jamaicensis) to 80% for Black-necked Swan (Cygnus melanocorypha), and abundance varied greatly both between species and seasons. The Hooded Grebe, in particular, was recorded in 14 lakes (1–81 individuals). Six species were detected breeding in the area: Hooded Grebe, Silvery Grebe (Podiceps occipitalis), Flying Steamer-Duck (Tachyeres patachonicus), Crested Duck (Anas specularioides), Upland Goose (Chloephaga picta), and White-winged Coot (Fulica leucoptera). The Hooded Grebe nested at four lakes, three of them not previously known to hold breeding birds. Results point to the need of further studies on the dynamic nature of waterbird lake use to adequately assess the importance of the Strobel Plateau as waterbird habitat.

Vulnerability of ground-nesting waterbirds to predation by invasive American mink in the Cape Horn Biosphere Reserve, Chile

Biological invasions constitute one of the most important threats to biodiversity. This is especially true for “naïve” birds that have evolved in the absence of terrestrial predators in island ecosystems. The American mink ( Mustela vison) has recently established a feral population on Navarino Island (55°S), southern Chile, where it represents a new guild of terrestrial mammal predators. We investigated the impact of mink on ground-nesting coastal waterbirds with the aim of deriving a vulnerability profile for birds as a function of different breeding strategies, habitat, and nest characteristics. We compared rates of nest survival and mink predation on 102 nests of solitary nesting species ( Chloephaga picta, Tachyeres pteneres), on 361 nests of colonial birds ( Larus dominicanus, Larus scoresbii, Sterna hirundinacea), and on 558 artificial nests. We calculated relative mink and bird densities at all nest sites. Nests of colonial species showed the highest nest survival probabilities (67–84%) and no predation by mink. Nest survival rates for solitary nesting species were lower (5–20%) and mink predation rates higher (10–44%). Discriminant analyses revealed that mink preyed upon artificial nests mainly at shores with rocky outcroppings where mink were abundant. High nest concealment increased the probability for predation by mink. Conservation planning should consider that invasive mink might severely affect the reproduction success of bird species with the following characteristics: solitary nesting, nesting habitat at rocky outcrop shores, and concealed nests. We recommend that work starts immediately to control the mink population with a priority in the nesting habitats of vulnerable endemic waterbirds.

Non-invasive measurement of faecal glucocorticoid metabolites in Upland Geese Chloephaga picta

Glucocorticoid (GC) hormones rise in response to stressors, including natural events including weather or predator presence, and human activities, such as hunting, scientific research or recreational visits. However, because blood sampling itself causes stress and is dangerous or even impossible in some wildlife species, feedback-free methods for GC determination are needed to assess stress in these animals. Faecal GC analyses have thus gained interest. Here, we validate a non-invasive method to estimate the physiological stress in the Upland goose Chloephaga picta. An adrenocorticotropin hormone (ACTH) challenge was conducted in captive adults (female and male), and droppings were collected before, during and after the experiment. Corticosterone metabolite (CM) secretion in response to the ACTH challenge was measured with several enzyme immunoassays (EIA) to find the most appropriate test. We used CM levels during the periods before and after the experiment as control data. An EIA for 11-oxoetiocholanolone achieved the highest response to the ACTH challenge and also reflected a stress response to unfamiliar environment. Furthermore, CM concentrations of dry samples were highly correlated with the corresponding non-dried (frozen) samples. The data suggest that this method is appropriate to measure the stress in Upland geese, and that samples can be stored either frozen or dry form.

Estudio del parasitismo gastrointestinal y externo en caiquén Chloephaga picta Gmelin, 1789 (Aves, Anatidae) en la región de Magallanes, Chile

The parasites of 16 Magellan geese (Chloephaga picta picta: 8 females and 8 males), captured in May 2002 in the Commune of Rio Verde, Province of Magallanes, XII Region, Chile, were studied. All the birds from this study were found positive for the endoparasitic nematode Heterakis dispar. In one of the birds, proglotides were found which, from a morphological analysis, belong to the family Hymenolepidae. The total number of specimens of H. dispar was greater in male geese than in females. The female/male ratio was 1.22. The larva/adult ratio was 0.41. No parasites were found in a study of goose faeces. An 87.5% of the birds were parasitised by one or more of the following louse species: Holomenopon brevithoracicum, Anaticola marginella, Anatoecus dentatus and Anatoecus icterodes, all of them belonging to the Order Phthiraptera. All these species represent new louse records from Magellan geese for Chile, as well as a new host-louse record for A. dentatus on C. picta.

GENETIC VARIABILITY OF BLOOD PLASMA PROTEINS IN WILD AND DOMESTIC GEESE

Abstract An analysis of variability of blood plasma proteins in domestic Rein geese (Anser anser domesticus) and four species of wild geese [Anser albifrons (Se), A. indica (Lath.), A. caerulescens (L.), Chloephaga picta (Cmelin)] applying Polyacrylamide gel electrophoresis was performed. A comparative analysis revealed that natural and artificial selection caused evident differentiation not only among domestic and wild species, but among wild geese species as well. A slow homozygous form AlSS of locus. Al was very frequent among A. albifrons (Se) and A. anser domesticus geese, while among other species of geese this genotype was not found. 100% heterozygosis of Al and Pa loci was established in the population of Chloephaga picta (Cmelin). Most of the examined species possessed heterozygous genotypes of transferin loci, homozygous Tf DD and EE genotypes were found in no one of the examined species, and TfE alleles were found only in A. caerulescens (L.) geese with the frequency of 0.15. Artificial selecti...

Feeding and Spatial Ecology of Felis geoffroyi in Southern Patagonia

Geoffroy's cat (Felis geoffroyi) is distributed from southern Bolivia and the Parana Basin of southern Brazil to the southern tip of Patagonia in Chile and Argentina (Cabrera, 1957; Ximenez, 1975). In 1980, this spotted cat became the most commonly traded felid species in the world (MacMahan, 1986) with more than 450,000 skins exported from 1976 to 1980 from Argentina alone (Fujita and Calvo, 1982). Despite its economic importance, almost nothing is known about the biology and ecology of the species, especially in its native South American habitat. In Chile, where Geoffroy's cat is classified as endangered, research on this species is considered to be a priority (Glade, 1988). The only published field study was the report of the home range of one subadult female in Paraguay based on 12 radiotelemetry relocations (Berrie, 1978). The goal of our study was to obtain basic ecological information on Geoffroy's cat in the southern portion of its distribution. Specific objectives were to describe home-range sizes and distribution patterns, habitat use, activity patterns, and food habits of Geoffroy's cat. The study was conducted from 1986 through 1989 in the eastern part of Torres del Paine National Park (51*3'S, 72*55'W), an International Man and Biosphere Reserve located in the eastern foothills of the Andean mountain range in southern Chile. The park encompasses 2,400 km2 and provides almost undisturbed habitat for wildlife. The park has a high heterogeneity of plant associations and habitats from glacier-covered mountains to dense Nothofagus deciduous forest and grassland. Approximately 70% consists of a steppe biome, or pre-Andean, dry-shrub association, and the remainder is a mosaic of lakes, forests, and aridmountain alpine zones. The steppe is characteristic of the pampa of southern South America, found in Chile and Argentina at elevations <500 m (Pisano, 1973, 1974). The locally dominant species of this biome (or association) is mata barrosa (Mulinum spinosum), a spiny, dome-shaped shrub, common in thin, rocky upland, and rapidly draining soils and mata negra (Verbena tridens), a 1to 1.5-m shrub covering large areas. Other common species are senecio (Senecio patagonicus), calafate (Berberis buxifolia), and paramela (Adesmia boronoides). The woodland areas are dominated by two medium-sized species of trees, fiirre (Nothofagus antarctica) and lenga (N. pumilio). The dominant grass species in the study area are Festuca gracillina, Anarthrophyllum patagonicum, and F. palliscens, in order of decreasing cover (Ortega and Franklin, 1988; Pisano, 1973, 1974; Texera, 1973). The park has a high diversity of mammalian species (Johnson et al., 1990). Potential mammalian prey species included the introduced European hare (Lepus capensis) and several cricetine rodents such as Auliscomys micropus, Oryzomys longicaudatus, Phyllotis darwini, Reithrodon physodes, and several species of Akodon. Numerous avian species also were potential prey items for Geoffroy's cat, such as the upland goose (Chloephaga picta), austral parakeet (Enicognathus ferrugineus), and eared dove (Zenaida auriculata). The puma (Felis concolor), culpeo fox (Dusicyon culpaeus), chilla fox (D. griseus), Patagonia hog-nosed skunk (Conepatus humboldtii), Patagonia weasel (Lyncodon patagonicus), and several raptors, including the great-horned owl (Bubo virginianus) and black-chested buzzard-eagle (Geranoaetus melanoleucus), were potential competitors. There are two general climatic periods, a relatively cold, dry, typically windless season from May through September (July mean temperature = 0.20C) and a relatively warm, windy, rainy season from October through April (January mean temperature = 12.60C). Mean annual precipitation is 550 mm, with 60% falling from January to May (Pisano, 1974). Adjacent mountains and ice fields create local weather patterns as reflected by a large variability in precipitation (Pisano, 1974). Geoffroy's cats were captured either in padded leg-hold traps (Victor no. I1? soft-catch coil spring) or in trees by use of trained hunting dogs and immobilized with ketamine hydrochloride (Ramsden et al., 1976)

Sheld-geese and man in the Falkland Islands

Abstract The history of the association between sheld-geese (upland geese Chloephaga picta and ruddy-headed geese C. rubidiceps) and man in the Falkland Islands is described from the time when they were used as food by early settlers, to the conflict with the sheep industry. Geese were found to be extremely abundant when man first settled. A bounty scheme was instigated by sheep farmers in 1905 and claimed 74 000 geese annually between 1905 and 1912. Far fewer (25 000 annually) were killed in the late 1970s because fewer shepherds lived in the remote houses of sheep stations, and the bounty did not increase in proportion with wage increases. The population of geese remains large despite this toll and recent studies of the annual cycle, movements and population dynamics give reasons for the failure of the bounty scheme to reduce numbers. Information on food intake and densities of geese on different vegetation types has indicated that the geese populations take only 1·5% of the total annual organic matter production of herbage. This represents 7% of what is eaten by all the herbivores. However, most of this consumption is restricted to a few vegetation types with a relatively small area (e.g. ‘greens’ and reseeded pastures). It is the consumption from reseeds that causes the biggest problem to the sheep industry. Methods of control are discussed and the value of destruction of geese questioned.

The life cycle of the Upland Goose Chloëphaga picta in the Falkland Islands

Upland Geese Chloëphaga picta were studied between 1977 and 1980, primarily around Darwin, East Falkland, in order to describe their breeding biology, moulting and adult survival. The population of breeding birds in a valley reached a peak from mid‐September to late November when nesting took place. The average territory length was 240 m in five valleys. Breeding adults generally returned to breed in the same territory each year and with the same mate. Nests were on the ground, usually amongst whitegrass Cortaderiapilosa. The mean clutch size was 6‐1, brood size was 5‐1 and fledged family 3–9. Incubation took 30 days and the fledgling period was about 70 days. Most broods were raised in the nesting territory. Growth of goslings is described. The breeding success between laying and fledging was 0–34 (in 1977) and 0–29(in 1978), giving an annual production of 21 and 1–8 young per breeding pair. Fledglings remained in family parties through the autumn and winter and were evicted by their parents in early spring. Some siblings stayed together for short periods and then joined other non‐breeders. Females started pairing at ten months of age and most were paired at 17–18 months. Some bred for the first time at 23 months. Males started pairing at about 20 months of age. Flightless moult (shedding) took place at ponds or in sheltered inlets of the sea, in flocks of up to several hundred birds. Flightless birds were found between 14 November and 11 February, though 50% were flightless between 26 November and 2 January. Individuals were flightless for 36 days. First‐year birds were more synchronized in shedding than adults. The percentage of first‐year males (in the male component) varied from 16‐5 to 45‐9% in shedding flocks, and significantly more males were present in some flocks. The flocks were composed of first‐year and second‐year birds too young to breed and failed breeders. The percentage of a shedding population which returned to the same site in successive years was 25‐3 and 15‐1% at two localities. The moult of other feather tracts is described. The annual survival rate of breeding adults was 82%. A model of the population dynamics is presented. The current level of culling to control the goose population is less than the number which must die each year to maintain a stable population.

Moult‐skipping by Upland Geese Chloëphaga picta in the Falkland Islands

IbisVolume 125, Issue 2 p. 262-266 Moult-skipping by Upland Geese Chloëphaga picta in the Falkland Islands Ronald W. Summers, Ronald W. Summers Grasslands Trials Unit, Port Stanley, Falkland Islands1Search for more papers by this author Ronald W. Summers, Ronald W. Summers Grasslands Trials Unit, Port Stanley, Falkland Islands1Search for more papers by this author First published: April 1983 https://doi.org/10.1111/j.1474-919X.1983.tb03110.xCitations: 9 MAFF, Tangley Place, Worplesdon, Surrey. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume125, Issue2April 1983Pages 262-266 RelatedInformation

Diet, Feeding Behaviour and Food Intake of the Upland Goose (Chloephaga picta) and Ruddy-Headed Goose (C. rubidiceps) in the Falkland Islands

Diet, Feeding Behaviour and Food Intake of the Upland Goose (Chloephaga picta) and Ruddy-Headed Goose (C. rubidiceps) in the Falkland Islands