Hedd, A., Gales, R. & Brothers, N. 1998. Shy's and hooks: Overlap of Australian Shy Albatrosses and longline fisheries. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 237.

Longline fishing is the most serious threat facing albatrosses globally. In Australian waters Shy Albatrosses Diomedea cauta are killed in large numbers on foreign and domestic longlines. Shy Albatrosses are endemic to Australia, breeding in three colonies off Tasmania: Albatross Island to the north and Pedra Branca and Mewstone to the south. Our five-year satellite tracking program has identified the foraging zones of breeding birds from all colonies, and examined intra- and inter-annual variation in foraging ranges. The migratory paths of fledglings were also studied. Inter-annual consistency in adult foraging zones and the sedentary nature of adult flight paths translate into differential vulnerability of these three populations to longline fisheries. Adult albatrosses from Albatross Island ranged locally, both during and outside the breeding season. The overlap of these adult birds with longline fisheries is minimal. Shy Albatrosses breeding south of Tasmania, however, overlapped extensively with longline fisheries. The highly migratory nature of juveniles from all three populations also exposes them to extensive fishing pressures. The complexity of the nature of interactions with longline fisheries confounds efforts to measure its impact at the population level. Urgent attention to the widespread application of mitigation measures must therefore be a priority.

Key words: Diomedea cauta, longline fishing, satellite tracking, at-sea distribution, seabird-fisheries interactions

Arroyo, B., Salamolard, M. & Bretagnolle, V. 1998. Evaluating the long-term efficiency of conservation practices of Montagu’s Harrier Circus pygargus. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 238.

Montagu’s Harriers breed mainly and increasingly in agricultural habitats in Europe (as their original grassland habitats become scarcer). They are thus very vulnerable to human-related activities and agricultural policies, because agricultural practices have direct (at harvesting) and indirect (through affecting food and habitat availability) effects on reproduction. France and Spain hold currently more than 70% of the European (excluding Russian) population. Many conservation programmes are currently in practice in these countries, based mainly on protection of nests from harvesting activities. These measures are expensive, time consuming, and their long-term efficiency remains unevaluated. We have studied Montagu’s Harrier populations in four areas located in France and Spain. Data from these medium-term studies (4 to 11 years) include productivity, breeding and harvesting phenology, survival, sex ratio, age at first breeding, phyllopatry and dispersion, mating systems and coloniality. We use these data to model the population dynamics in order to evaluate the efficiency (in terms of probability of maintaining stable population numbers) of nest protection practices and land use changes. We conclude that land use changes have a potentially larger effect than harvesting. We suggest new potential conservation measures and ways to optimise the still-necessary nest-protection effort, working only in good food years and in traditional colonies.

Key words: conservation, Circus pygargus, population dynamics

Gubin, B.M. 1998. Modern state of Houbara Bustard population in Kazakhstan and problems with their conservation and use. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 238.

The Houbara Bustard Chlamydotis undulata in Kazakhstan numbers 3000 to 4000 individuals from a minimum of two populations. They are limited to the desert and semi-desert zones in the southern half of Kazakhstan. Eastern and Western houbara populations are delimited by the line of Western Aral seacoast. Distribution is irregular and is known from about 20 areas with relatively high population density (0.1 to 2.0 individuals per km²) and 200 to 1000 individuals. Houbara breed in April to June, with one clutch of two to five eggs (average 3.2) with a brood size of one to four (average 2.7 chicks per female). The main losses are from predation, and breeding success ranges from five to 80%. The houbara is not utilized in Kazakhstan, while during migration and wintering they are killed extensively by falconry in Pakistan, Afghanistan, Syria and other countries. In the last two to three years hunting has spread in Uzbekistan and Turkmenistan. This creates a paradoxical situation, when the country in which about 77% of the world population breed, does not receive reward for its conservation efforts. Kazakhstan is enveloped by economic crisis and practically all scientific research on animals has stopped, including work on rare and vulnerable species. To correct this situation, prompt international co-operation must form the basis of houbara’s study, conservation and harvesting.

Key words: conservation, breeding success, Chlamydotis undulata

Maloney, R.F., Seddon, P.J. & Paillat, P. 1998. Reintroduction of Houbara Bustards: The process of establishing a resident breeding population. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 239.

Reintroduction of species using captive-bred stock is a slow and often unsuccessful method of establishing populations. A recent review suggests that successful projects, with self-sustaining populations, are longer term (mean of 11.8 years) and release more birds (mean of 726) than unsuccessful ones (means of 4.7 years and 336 birds released). Reintroduction projects have several intermediate points where the progression towards self-sustainment can be assessed. These points are: (1) Producing captive-bred stock for release. (2) Releasing birds. (3) Obtaining initial survival. (4) Establishing a resident population. (5) Achieving regular breeding and finally (6) Recruiting sufficient wild-born juveniles to support the wild population. We report the progress in establishing a population of Houbara Bustards Chlamydotis undulata in a reserve in Saudi Arabia. It took six years to successfully raise stock for release, trial release methods and to achieve a 30 to 50% initial juvenile survival. Confirmation of the establishment of a resident population of approximately 30 adult Houbara from 180 birds released took two more years. In a further three years, six fledged young from 30 nesting attempts were produced. However, supplementation from captive-stock is still required as recruitment of wild-born juveniles is, as yet, very low.

Key words: Chlamydotis undulata, Saudi Arabia, reintroduction, captive breeding

Modlinger, P., Chobot, J. & Péczely, P. 1998. Successful artificial insemination method for the captive breeding of the Great Bustard. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 239.

In the last five years we have developed a new breeding technology for captive birds for the protection of the Great Bustard: the collection of semen from free moving, displaying males and, after validation, the artificial insemination of females. In 1997, four out of five inseminated females laid eggs (7.2 eggs per female). The lowest egg production was three per female, and the highest egg production was 19 per female. The significant increase of egg production was attained by the immediate collection of the laid eggs. The first egg was laid at 10 May, the last one on 11 July. The hens were inseminated four times, between 2 and 25 May. The average fertility rate was 36.1%, (16.7 –75.0%). The last fertile egg was found 34 days later after the last insemination. The hatchability of fertile eggs was 23.1%, three chicks per 13 eggs (technical problem at the level of the hatching-machines). The period of incubation was 25.6 days. The newly hatched chickens were fed with insects (in the first two weeks), and later with granulated bustard-food. After improvements have been made to the hatching technique, an effective breeding method will be available for increasing the Great Bustard population.

Key words: Great Bustard, semen collection, artificial insemination

Sarrazin, F., Legendre, S. & Clobert, J. 1998. Modelling bird reintroduction: A way to compare reintroduction strategies. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 239 - 240.

Reintroductions are often used for bird conservation. However, the determinants of their success are poorly known. Population Viability Analyses may help understanding the conditions of a successful reintroduction. We therefore need to develop modelling tools to compare a priori reintroduction strategies. Such models have to consider both life history traits (life cycle, breeding systems) and release parameters (number and duration of releases, origin and age class of individuals, habitat quality). Using the software ULM (a computer program for population dynamics modelling designed in our laboratory), we developed two-sex models including demographic stochasticity to compare the consequence of breeding systems and life cycle on reintroduced population viability for different number and duration of releases as well as different levels of environmental stochasticity. Taking into account breeding systems was crucial in these analyses. Furthermore, we compared the relative efficiency of releasing juveniles or adults for a given life cycle. This family of models accounted for possible reduction of survival and fertility of released adults. Such a model was applied to the case of the reintroduction of Griffon Vultures Gypsfulvus in southern France for which accurate monitoring allowed us to estimate demographic rates and consequences of releases. Overall, for Griffon vultures, it appeared that it was more efficient to release adults than juveniles, despite the observed costs of captive rearing.

Key words: reintroduction, Population Viability Analysis, stochastic models, ULM, Griffon Vulture

Moorcroft, D., Bradbury, R.B. & Wilson, J.D. 1998. The diet of nestling Linnets Carduelis cannabina before and after agricultural intensification in the UK. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 240.

Linnet nestling diet was examined in 1996 to 1997 on mixed lowland farmland near Oxford, UK for comparison with the results of a study carried out in the same area in 1962 to 1964. The number of food taxa fed to nestlings has changed little, but diet composition is markedly different. Some foods have become more prominent than in the 1960s (e.g. seeds of dandelions Taraxacum for early broods), whilst formerly preferred seeds are now rare in the diet due to chemical weed control (e.g. charlock Sinapis arvensis). Charlock seed has now been replaced by cultivated oilseed rape Brassica napus oleifera, and many broods are fed almost exclusively on it from June until the end of the breeding season in August. Despite agricultural intensification over the last 30 years, overall seed availability is unlikely to be an important factor limiting Linnet populations in mixed farming systems where oilseed rape and grassland sources of dandelion, chickweed Stellaria media, docks Rumex, and thistles Cirsium are available. In intensively managed, pure tillage systems, breeding season food availability may be severely limited if oilseed rape is not available.

Key words: Linnet, nestling, diet, granivore, breeding