POPULATION,DIET AND THE ANNUAL CYCLE OF THE LAUGHING DOVE AT BARBERSPAN,PART 3: THE ANNUAL CYCLE

Dean, W. R. J. 1979. Population, diet and the annual cycle of the Laughing Dove at Barbers-pan, Part 3: The annual cycle. Ostrich 50:234-239.

Laughing Doves Streptopelia senegalensis were collected each month from July 1976 to June 1977. In each sample some males and females were breeding. Breeding and primary moult overlapped, and some birds began to moult after starting to breed, and began to breed after starting moult. Adult Laughing Doves require about 120 days to complete primary moult, and juveniles require about 90 days. Weights of moulting birds were not significantly different from those of non-moulting birds, and there were no seasonal trends in the weights of either group. The mean weight of 79 males was 101,6 g and of 39 females was 100,2 g.     

POPULATION,DIET AND THE ANNUAL CYCLE OF THE LAUGHING DOVE AT BARBERSPAN,PART 4. BREEDING DATA AND POPULATION ESTLMATES

Dean, W. R. J. 1980. Population, diet and the annual cycle of the Laughing Dove at Barber-span, Part 4: Breeding data and population estimates. Ostrich 51:80-91.

From 1974–1976, Laughing Doves Streptopelia senegalensis raised an observed total of 436 young in 619 nest attempts, giving a breeding success of 0,70 young per pair nest attempt, or an overall success of 0,35 young per egg. Breeding success, estimated by computing the probability of survival of an egg through the incubation period, and of a chick through the nestling period suggest that the breeding success is about 0,33 young per egg. Nests were found in every month of the year, though there was a tendency for breeding to be concentrated during the late rainy season and the dry season. The mean annual population size of the Laughing Dove in the study area was estimated at 221 adults and juveniles by one method and at 237 adults and juveniles by another method. The number of young produced each year is correlated with the estimated population size for each year.     

THE DIET OF THE CURLEW SANDPIPER AT LANGEBAAN LAGOON,SOUTH AFRICA

Puttick, G. M. 1978. The diet of the Curlew Sandpiper at Langebaan Lagoon, South Africa. Ostrich 49:158-167.

Nereid worms (mainly Ceratonereis erythraensis) and the hydrobiid gastropod Assiminea globulus were the most important prey items throughout the year for Curlew Sandpipers Calidris ferruginea feeding at Langebaan Lagoon. Other important items were the amphipod Urothoe grimaldi, the crabs Hymenosoma orbiculare and Cleistostoma edwardsii and dipteran larvae (Stratiomyidae). Immature Curlew Sandpipers took smaller prey items than adult birds. The diet of male and female birds differed in the proportion, sue and range of prey items taken.     

THE WINTER DIET OF GENTOO PENGUINS AT MARION ISLAND

La Cock, G. D., Hecht, T. & Klages, N. 1984. The winter diet of Gentoo Penguins at Marion Island. Ostrich 55: 188–191.

The diet of Gentoo Penguins Pygoscelis papua at Marion Island was studied during September 1982. Samples were obtained from 64 birds using a stomach-pump. Fish accounted for 70% of the diet by wet weight, and crustaceans 30%. Fishes occurred in 72% of the samples, crustaceans in 75%, cephalopods in 13%, and molluscs in 8%. Cephalopods and molluscs did not form a significant proportion of any single sample. Harpagifer georgianus was the predominant fish in the diet (92,7% of otoliths recovered), and Nauticaris marionis was the only crustacean.     

THE DIET OF RUFFS AND BLACKTAILED GODWITS IN SENEGAL

Tréca, B 1994. The diet of Ruffs and Blacktailed Godwits in Senegal. Ostrich 65: 256–263.

A study of the diet of Blacktailed Godwits Limosa limosa and Ruffs Philomachus pugnax by direct examination of stomach contents emphasizes the importance of rice, which accounted for over 80% of the items eaten. Rice was available at planting time in July-August and after the harvest in November-December. Thus fat deposition for migration, between January and April-May, is based on a rice diet (cultivated or wild rice). Very little animal matter was eaten. The choice of feeding ground will govern food choice among the available food. Birds which have eaten most are those which have found their preferred food.     

THE DIET AND IMPLICATIONS OF DIETARY CHANGE OF CAPE GANNETS ON BIRD ISLAND,ALGOA BAY

Batchelor, A. L. & Ross, G. J. B. 1984. The diet and implications of dietary change of Cape Gannets on Bird Island, Algoa Bay. Ostrich 55:45-63.

The diet of the Cape Gannet Sula capensis breeding on Bird Island, Algoa Bay, South Africa, was investigated. Approximately 2000 regurgitations representing 13300 prey items were examined. Twenty-three teleost and two cephalopod species were recorded in the diet. More than 90 % of the numerical composition consisted of the three species Pilchard Sardinops ocellata, Anchovy Engraulis capensis and Saury Scomberesox saurus. The proportions of these three species in the diet changed during the sampling periods. These changes were not related to the implied migration patterns of these species. Chick growth rates were investigated in conjunction with the dietary study. These results indicated that Cape Gannet chicks on a diet of Pilchard and/or Anchovy were more likely to fledge successfully than those on a diet of Stockfish Merluccius capensis or Saury. These observations were based on differences in growth rate, and peak and fledgling mass, The data suggest that Pilchard is a preferred prey species and its presence or absence in regurgitationsMayreflect a similar situation on the feeding grounds. The observed increase in the Bird Island gannet populationMaybe related to the availability of high-quality food and consequent reduced pre-breeding mortality. In the absence of historical dietary data, further detailed population dynamics studies are required to support this supposition.     

PREY SELECTION AND TEMPORAL VARIATION IN THE DIET OF SUBANTARCTIC SKUAS AT INACCESSIBLE ISLAND,TRISTAN DA CUNHA

Ryan, P.G., & Moloney, C.L. 1991. Prey selection and temporal variation in the diet of Subantarctic Skuas at Inaccessible Island, Tristan da Cunha. Ostrich 62:52-58.

More than 2 500 prey items of Subantarctic Skuas Cuthuructa anturcricu were identified from regurgitated pellets collected at a roost of non-breeding skuas during summer 1989–90 at West Point, Inaccessible'Is-land. Most prey items (96,5%) were birds, primarily burrow-nesting procellariiforms. Sixteen bird species were recorfed in the diet, but five secies accounted for 94,6% of identifiable prey remains: Whitebellied Storm Petrel Fieettu grullariu (53,5%), Whitefaced Storm Petrel Pelugodrorna marina 15,1%), Broad-billed Prion Pacaptilu vittutu (14,0%), Great Shearwater Puffinus gruvis (7,3%), and Iommon Diving Petrel Pelecunoids urinutrix (4,7%). Petrel chicks were important in the diet, particularly Great Shearwaters. The main non-avian prey were fish and goose barnacles Lepas sp., but their importance may have been underestimated. The remains of a rat Rattus sp. presumably were derived from the neighbouring island of Tristan da Cunha; rats are not known to occur on Inaccessible Island. Prey size affected seabird availability to skuas, and dietary composition vaned throughout the summer in relation to seabird breeding cycles. Both these factors reduce the value of skua diet as an indicator of the relative abundances of burrow-nesting petrels. There was no correlation between skua diet and estimates of breeding bird abundance, but this may be a consequence of studying non-breeding skuas. Subantarctic Skua diet in 1989–90 was similar to that recorded in previous years, with consistent seasonal trends between years.     

COMPARISON OF THE DIET OF BREEDING AND NONBREEDING CAPE GANNETS MORUS CAPENSIS

Berruti, A. 1991. Comparison of the diet of breeding and nonbreeding Cape Gannets Morus capensis. Ostrich 62:8-12.

The effects of breeding status on the diet composition of Cape Gannets Morus capensis were tested at two colonies in the western Cape, South Africa. At both colonies, there were no significant differences in the species composition of the diet, but the mean energy content of regurgitations of breeders was significantly greater. Although the regurgitations of breeders were heavier and contained more fish at both colonies, only the number of fish per regurgitation from breeders at one colony was significantly greater. Birds feeding chicks at Malgas Island took significantly shorter fish than nonbreeders. The small effect of breeding status on prey species composition shows that temporal and geographical variation in prey availability is more important than breeding status in affecting diet cornposition of the Cape Gannet.     

Primary moult and body-mass of the Cape Turtle Dove Streptopelia capicola,and its abundance relative to the Laughing Dove S. senegalensis,in the Western Cape

Underhill, L.G., Underhill, G.D. & Spottiswoode, C.N. 1999. Primary moult and body-mass of the Cape Turtle Dove Streptopelia capicola, and its abundance relative to the Laughing Dove S. senegalensis, in the Western Cape. Ostrich 70 (3&4): 196–199.

The duration of primary moult of adult Cape Turtle Doves Streptopelia capicola was estimated to be 192 days. 23 November was the estimated mean starting date, with 95% of birds starting within 88 days of this date. The mean body-mass of adults was 148 g and of first-year birds was 130 g. In residential areas, Cape Turtle Doves were trapped less frequently than Laughing Doves S. senegalensis; at most rural sites, Cape Turtle Doves comprised about two-thirds of the catch. On a dairy farm, where doves were attracted to cattle feed, 1 % of doves were Cape Turtle Doves. The emerging pattern is that Laughing Doves predominate at sites where food is provided on a long-term basis.     

DIET OF THE BLACK KORHAAN EUPODOTIS AFRA IN THE ORANGE FREE STATE AND NORTH-WEST CAPE

Kok, O. B. & Earle, R.A. 1990. Diet of the Black Korhaan Eupodotis afra in the Orange Free State and North-west Cape. Ostrich 61: 107–110.

Analysis of 135 stomach samples of Black Korhaans Eupodotis afra collected over a five year period showed this species to be omnivorous. More than two-thirds of the food items consisted of animal matter, mostly arthropods, the rest being plant material, mostly seeds. Three insect taxa, Isoptera (almost exclusively Hodotermes mossambicus), Coleoptera (largely Curculionidae beetles) and Orthoptera made up the bulk of the diet. Large numbers of harvester termites and grasshoppers were taken when these were available. The plant material in the diet reflects the ground-feeding habits of the birds in open and dry but often disturbed habitats.     

Behavioural and morphological characteristics of white doves in Osmaniye,Turkey identify the population as Laughing Doves (Streptopelia senegalensis)

Observation of an unusual population of white-plumaged doves in Osmaniye suggests that these birds are conspecific with the Laughing Dove (Streptopelia senegalensis, Linnaeus, 1766) population in the town. The white-morph is not found outside the urban area. Aside from colouration, the white doves shared identical morphological characteristics with wild-type brown Laughing Doves. Additionally, the white doves and wild-type Laughing Doves formed mixed flocks and readily paired. Based on the observations of four inter-morph pairings, the white morph appears to be a recessive, single autosomal locus mutation. It appears that the white colouration may have originated from one or more hybridization events between Laughing Doves and feral white Barbary Doves (Streptopelia risoria). This study not only identifies an anomalous population of birds in an urban setting, but highlights the importance of traditional knowledge in understanding biodiversity.     

A NEW AND PRACTICAL ARTIFICIAL DIET FOR THE COTTON BOLL-WORM*

Abstract A new and practical artificial diet for the cotton bollworm, Helicoverpa armigera (Hübner), containing canned tomato paste has been developed. The developmental duration of larvae fed on the diet was greatly shortened because most of them only went through 5 stadia before pupation. To add certain amount of mung bean flour to partly substitute for wheat germ in the diet was beneficial to the adult reproduction. During rearing period of 12 successive generations, 87. 5%-98. 7% of the larvae survived and only less than 5 % of the pupae failed to emerge. The number of egg laid by the adults of the 11th generation averaged about 1 000/female, with a hatching rate of 86. 5%. These results suggested that the vitality of the cotton bollworm did not decline obviously after reared with the diet for two years.     

THE DIET OF DUCK AND COOT ON LAKE NAIVASHA

• 1 The diet of coot and duck on Lake Naivasha has been investigated to provide information on the duck/coot interaction.
• 2 Some 79 duck and coot were shot in a limited area over a period of 24 h, and their stomach contents preserved in 4% formalin.
• 3 The analysis of stomach contents was performed in two stages: large particles being completely identified and counted, small particles being sampled.
• 4 The results of the analyses are considered to be most usefully expressed as proportions of food component by number of particles.
• 5 Identification of components has been made by matching epidermal characters with collected plants, by matching shape and structures of seeds with collected seeds, and by recognition of such materials as arthropod exoskeletal fragments and molluscan shell. Some components have not been specifically identified.
• 6 A discussion has been presented on the problem of relating the results of stomach-content analysis to ecologically significant differences in feeding. The discussion hinges on four questions:

• (a) Is the result of a stomach-content analysis an accurate and appropriate indication of the stomach-contents of a bird when shot, and, if so, do the results presented indicate differences between stomach contents?
• (b) What is the relationship between stomach-contents at the time of shooting and food ingested over the immediately preceding period, and do differences between stomach contents indicate differences in food intake?
• (c) How far do differences in diet so deduced apply to the whole population of birds concerned in the study?
• (d) Are the differences in diet relatable to availability of food, and can any valid inferences be made concerning the birds' interaction?

• 7 It is concluded that at the time of the shooting, over the limited area examined, there was little overlap in diet for important components, and therefore probably little competition for food among the duck species and coot.
• 8 Some general observations have been made on the feeding biology of duck and coot, and it is pointed out that the feeding apparatus of coot differs from that of all duck species in having shearing edges. This difference is related to the dietary differences in a predictable manner.

     

Suitability of Asian citrus psyllid, Diaphorina citri, as prey for ladybeetles

Given the apparent importance ofladybeetles as biological control agents of theinvasive Asian citrus psyllid, Diaphorinacitri Kuwayama (Homoptera: Psyllidae), aseries of experiments were undertaken to assessthe nutritional suitability of this pest as aprey item. Five species of Coccinellidae wereshown to develop successfully on a diet ofpsyllid nymphs and four species produced viableeggs. Eggs of the flour moth, Ephestiakuehniella Zeller (Lepidoptera: Pyralidae)were used as a reference diet. Larvae of Curinus coeruleus Mulsant, Cyclonedasanguinea L., Exochomus childreniMulsant, Harmonia axyridis Pallas, andOlla v-nigrum Mulsant all had survival ona diet of D. citri nymphs not differentfrom 100%, although developmental times wereextended and adult dry weights were reducedrelative to the Ephestia egg diet. Species were ranked (highest to lowest) forlarval performance on the D. citri dietrelative to the Ephestia egg diet as:E. childreni, 0.85;O. v-nigrum,0.82; C. coeruleus, 0.80;H.axyridis, 0.71;C. sanguinea, 0.48. Most females of C. sanguinea ceasedoviposition on the second day followingtransferal to the D. citri diet, but thefecundity and fertility of females of the otherspecies were not different from those feedingon Ephestia eggs. Generation times onthe Ephestia egg diet at 24°C(time to egg hatch + larval developmental time+ pupation time + adult prereproductive period)were (mean ± SEM): C. coeruleus, 56.7± 1.32 d;C. sanguinea, 28.0 ±0.88 d;E. childreni, 60.8 ± 1.96 d;H. axyridis, 32.2 ± 1.47 d;O.v-nigrum, 25.8 ± 1.12 d. Adult females ofC. coeruleus, H. axyridis and O.v-nigrum consumed the most psyllids in oneh, C. sanguinea was intermediate, andE. childreni consumed the least.     

Effects of glucose-supplemented diets on food intake, nymphal development, and fecundity of glucose-averse, non-glucose-averse, and heterozygous strains of the German cockroach,Blattella germanica

Life history parameters were determined for glucose-averse (glu/glu), wild-type (glu+/glu+) and heterozygous (glu/glu+) genotypes of Blattella germanica (L.) (Blattodea: Blattellidae) fed diets supplemented with glucose. Glu/glu nymphs consumed less glucose-supplemented diet, gained less weight, developed slower and had a lower rate of survival than glu/glu nymphs fed the same diet without added glucose, or glu+/glu+ and glu/glu+ fed either diet. Prior to formation of the first oötheca, female glu/glu consumed less glucose-supplemented diet per day than glu+/glu+ and glu/glu+, which presumably delayed egg case production. Oötheca-bearing glu/glu and glu/glu+ females consumed less glucose-supplemented diet than glu+/glu+ females. Despite a difference in female total diet intake, there was no effect of diet or genotype on fecundity. However, the intrinsic rate of increase (r) for glulglu on unsupplemented diet was less than that of glu+/glu+ and glu/glu+, suggesting that individuals with both glu alleles may be at a selective disadvantage in environments lacking diets containing glucose plus a toxicant.     

Comparison of prey consumption by Dicyphus tamaninii reared conventionally, and on a meat-based diet

The zoophytophagous predator Dicyphustamaninii Wagner (Heteroptera: Miridae) hasbeen successfully reared for more than fivegenerations on a meat-based diet, and in theabsence of a plant as a substrate foroviposition and feeding. We compared thepredation efficiency of D. tamaniniiproduced on this diet with those rearedconventionally on Ephestia kuehniellaeggs (Zeller) (Lepidoptera: Pyralidae) andtobacco plants. Their performances wereevaluated on two prey, the greenhouse whiteflyTrialeurodes vaporariorum Westwood(Homoptera: Aleyrodidae) and the cotton aphidAphis gossypii Glover (Homoptera: Aphididae). Their tendency to cannibalisticbehaviour was also evaluated.Nymphs of D. tamaninii produced on themeat diet consumed a similar number ofgreenhouse whitefly pupae after 24 and 48 hoursto nymphs reared by the conventional method.Diet-reared females consumed significantly morewhitefly pupae after 24 and 48 hours thancontrol females. When the cotton aphid wasoffered, diet-reared D. tamaninii nymphsand females consumed similar numbers of prey tocontrol D. tamaninii. There was nosignificant increase in cannibalistic behaviourof diet-reared D. tamaninii after 3 and 5days of interaction.These results show that, after fivegenerations, the predation efficiency and thetendency to cannibalism of meat-reared D.tamaninii is similar to that ofconventionally-reared individuals.     

Dietary constraints on sexual activity, mating success, and survivorship of male Delia antiqua

The effects of protein-deprivation on the sexual activity and reproductive fitness of male onion flies, Delia antiqua (Meigen) (Diptera: Anthomyiidae), were investigated under laboratory conditions. The percentage of males inseminating gravid females, the magnitude of ovipositional response, and the total numbers of eggs deposited in 1:1 or 1:10 male:female matchings over two days was unaffected by deprivation of dietary protein. The LT₅₀'s (median survival time) for solitary males provided proteinaceous, sucrose, or water diets were 38.0, 25.8, and 6.0 days, respectively. Yet independent of diet effects, males lost 50% of their wing tissue by fragmentation after 26 days, suggesting that wing condition is more important in determining male reproductive fitness than longevity. Male mating frequency in single pairings with previtellogenic females deprived of proteinaceous diet for ten days was similar to that of gravid, protein-fed females. In no-choice and choice mating bioassays at a 10:1 female:male ratio, however, males inseminated significantly fewer previtellogenic than gravid females over 24 h. Despite evidence for male autogeny, removal of exogenous protein resources in the Allium agroecosystem may have important effects on the reproductive competency and fecundity of D. antiqua.     

INCORPORATION OF A EUROPEAN WEED INTO THE DIET OF A NORTH AMERICAN HERBIVORE

Populations of the butterfly Euphydryas editha living within a 30 times 100–km region on the eastern slope of the Sierra Nevada range were compared for oviposition preference and ability of larvae to grow and survive on two host plants, Collinsia parviflora and Plantago lanceolata. Since its introduction approximately 100 years ago, P. lanceolata has been incorporated in the diet of E. editha in one of the study populations. The populations differed in oviposition preference; only the population that uses P. lanceolata contains some individuals that prefer P. lanceolata. Larvae from two populations, one using both P. lanceolata and C. parviflora, the other using only C. parviflora, were not found to differ in relative abilities to grow or survive on P. lanceolata. The potential for E. editha to use P. lanceolata appears in populations that have had no prior exposure to this plant, while oviposition preference for this plant has evolved in the population in which the plant now grows.     

DIET,HOME RANGE,HUNTING AND REPRODUCTIVE BEHAVIOUR OF A PAIR OF DICKINSON'S KESTREL FALCO DZCKZNSONZ IN THE KRUGER NATIONAL PARK,SOUTH AFRICA

Summary

BENN, G.A. &; KEMP, A.C. 1995. Diet, home range, hunting and reproductive behaviour of a pair of Dickinson's Kestrel Falco dickinsoni in the Kruger National Park, South Africa. Ostrich 66: 81–91.

During July-December 1992, the diet, home range, hunting and reproductive behaviour of a pair of Dickinson's Kestrel Falco dickinsoni was recorded in the Kruger National Park, South Africa. Numerically, for both sexes combined, invertebrates formed the majority (56%) of the diet, while separately the female caught 75% and the male 49% invertebrate prey. During courtship and incubation the male supplied the female with primarily vertebrate prey and both provisioned mainly vertebrates to the nestlings (male = 80%; female = 57%). The non-breeding home range of the female was 27.8 km², and the breeding home range of the male was 26.3 km2. Both utilised their home ranges differentially, the area within a 2 km radius of the nest (12.6 km²) being used proportionally more than the remaining area. The home range of the female was compared to that of other Falco spp. and was larger than would be expected based on body weight. Perch-hunting was the only technique utilised by both sexes, with 79–80% of observed strike attempts from dead trees. During the day, the 9.emale spent 87% and the male 77% of the time perch-hunting, with respective hunting success rates of 69% and 58%. During courtship, the female spent much of her time (94%) close to the nest, where the male supplied her with prey. During incubation, the male spent 95% of his time within 2 km of the nest tree, where he hunted to supply the female with prey at a rate of 0.3 items.hr^?1 and assisted in nest defence. On occasion the male entered the nest to relieve the female, and remained in the cavity on average for 134 min (n = 5). As the young got older, the female spent less time at the nest and provisioned more items to the nestlings. Overall, there was an increase in the rate of prey provisioning to the nestlings from 0.45 items.hr^?1 (10 days old) to 0.85 items.hr^?1 (21 days old). The male initially passed prey to the female but provisioned directly to older nestlings.     

Growth of a pupal ectoparasitoid, Diapetimorphaintroita, on an artificial diet: stimulation of growth rate by a lipid extract from host pupae

An artificial diet used to rear the ectoparasitoid,Diapetimorpha introita, was supplemented withlipids extracted from pupae of the host, Spodoptera frugiperda (J. E. Smith). The diet alsowas sequentially supplemented with four fatty acids(arachidonic, linoleic, -linolenic and oleic),flax oil and Lipid Concentrate^® which is used in cellculture. Pupae were homogenized and extracted withchloroform:methanol (2:1 v/v) and after drying downthe chloroform and methanol phases separately, theresidues from each solvent phase were evaluated in theartificial diet. Growth-promoting activity wasobserved in the chloroform phase containing lipids. Diet supplemented with lipid stored at –80 °C, andinsects reared on diet with fresh 1× and 2× extractsdeveloped significantly faster than those reared onthe artificial diet but slower than those reared onhost pupae. The fresh 1× and the 2× extracts alsoenhanced the average weight of the males and females,respectively. Storing the lipids at –20 °C resultedin a loss of activity. A lipid extract from Galleria mellonella pupae increased the averageweight of male and females but did not increase theirdevelopmental rate. Adult emergence was not improvedby any of the dietary additives. None of thecommercial lipid treatments significantly reduceddevelopmental time; however, the -linolenicacid-supplemented diet significantly increased theaverage weight of females. TLC analyses of the lipidextract from S. frugiperda revealed lipidsrepresenting four classes of neutral lipids in theextract: triolein, cholesterol, diacylglycerol, andphospholipid. Data from this study indicate thatoptimization and successful utilization of anartificial diet to rear D. introita depends onidentification of host factors required by theparasitic for growth and development.