Oral01: Behaviour
Oral01.1. Female choice for good genes: Paradigm shifts and publication biases? Alatalo, R.V.
Oral01.2. Ultraviolet ornamentation and sexual selection in Bluethroats. Johnsen, A., Andersson, S., Örnborg, J. & Lifjeld, J.T.
Oral01.4. Sexual conflicts in the polyandrous sex-role reversed Bronze-winged Jacana Metopidius indicus. Butchart, S.H.M.
Oral01.5. Two-stage development of defence behaviour in altricial Ficedula hypoleuca nestlings: Learning the ‘inborn’ behaviour. Alexandrov, L.I., Korneeva, E.V. & Golubeva, T.B.
Oral01.6. A field test of intra- and interspecific brood parasitism in the Red-backed Shrike Lanius collurio. Moskat, C. & Fuisz, T.I.
Oral01.7. Winter social behaviour of Chinese Grouse at Lianhuashan, Gansu, China. Fang, Y. & Sun, Y.
Oral01.8. Quality of food eaten by parent sunbirds directly affects their brood-care effort. Markman, S., Pinshow, B., & Wright, J.
Oral01.1: Female choice for good genes: Paradigm shifts and publication biases?
Rauno V. Alatalo
Department of Biology and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40351 Jyvaskyla, Finland, e-mail Alatalo@Jylk.Jyu.Fi
Alatalo, R.V. 1998. Female choice for good genes: Paradigm shifts and publication biases? In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 193.
The possibility of female choice for indirect benefits appearing only in the offspring performance has raised conflicting opinions. While field ornithologists have always appreciated that females might gain good genes, the theoretical paradigm strongly denied this in favour of the Fisherian process based on arbitrary male sexiness alone. By now, there has been a paradigm shift in favour of the good gene benefits. I will review our empirical knowledge recalling the risk of publication biases during any paradigm shifts. Many bird studies favouring large indirect benefits have appeared recently. Heritabilities of male ornaments have been relatively large, and the effects on offspring performance have been surprisingly clear. However, the studies may reflect publication bias at the time when the novel paradigm favoured such results. Powers of statistical tests have not been large, even if large sample sizes would be needed to detect any small effects. Thus, we should be cautious in our conclusions. This example calls for cautiousness in using the criteria of statistically significant effects as the basis of accepting papers in scientific journals.
Key words: female choice, sexual selection, good genes, paradigm
Oral01.2: Ultraviolet ornamentation and sexual selection in Bluethroats
Arild Johnsen, Staffan Andersson, Jonas Örnborg & Jan T. Lifjeld
Department of Zoology, University of Göteborg, Medicinaregatan 18, 413 90 Göteborg, Sweden, e-mail Jonas.Ornborg@zool.gu.se
Johnsen, A., Andersson, S., Örnborg, J. & Lifjeld, J.T. 1998. Ultraviolet ornamentation and sexual selection in Bluethroats. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 193.
The plumage ornament of male Bluethroats Luscinia svecica show strong reflectance in the ultraviolet (UV) waveband (320-400 nm). The throat is actively displayed during courtship, hence suggesting sexual selection on a UV signal. A recent aviary experiment also found that females discriminated against males with artificially reduced UV reflectance (Andersson, S. & Amundsen, T. 1997. Proc. R. Soc. Lond. B 264, 1587-1591). Here we report the results of a similar experimental manipulation applied on free-ranging males. UV reduced (UVR) males had a lower success in attracting mates, as judged from a significantly later start of egg laying, compared to control (C) males. UVR males also spent significantly less time advertising for additional males when their own mate was fertile. Using microsatellite markers, UVR males were found to be less successful in achieving extra-pair fertilisations. In spite of an increased mate guarding effort, UVR males also lost more paternity in their own broods than did C males. We conclude that the treatment affected both social and extra-pair mate choice. This is the first experimental evidence that UV signalling influences male mating success in free-ranging birds.
Key words: UV vision, UV colouration, mate guarding, sexual selection, Luscinia svecica
Oral01.4: Sexual conflicts in the polyandrous sex-role reversed Bronze-winged Jacana Metopidius indicus
Stuart H.M. Butchart
Department of Zoology, Cambridge, UK
Butchart, S.H.M. 1998. Sexual conflicts in the polyandrous sex-role reversed Bronze-winged Jacana Metopidius indicus. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 194.
Sexual conflicts underlie classical polyandry, in which males carry out the parental care and females compete for multiple mates. In female Bronze-winged Jacanas reproductive success is likely to increase with harem size, but for males it is likely to decrease through competition with co-mates for clutches and paternity. Removal experiments and observations show that males attempt to maximise territory size. This tends to minimise harem size because females are able to monopolise more males where males have smaller territories. Females copulate with all available mates prior to laying each clutch, but give most copulations to the male which receives the clutch and provides the care. Males are unable to protect their paternity through forced copulations or mate guarding because females are much larger. Instead, males compete for female sexual access by giving ‘yell’ calls which attract the female to their territory from a co-mate's territory. Females respond to natural yells and to experimental playbacks by flying to the yeller's territory, and often copulating with him. Yells also attract female intruders, so resident females may be forced to respond to their mates' yells in order to maintain their harem.
Key words: classical polyandry, territory dynamics, removal experiments, sexual access, communication
Oral01.5: Two-stage development of defence behaviour in altricial Ficedula hypoleuca nestlings: Learning the ‘inborn’ behaviour
L.I. Alexandrov, E.V. Korneeva & T.B. Golubeva
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Butlerov Street, 5a, Moscow, Russia, e-mail neuroont@neuroont.msk.ru
Alexandrov, L.I., Korneeva, E.V. & Golubeva, T.B. 1998. Two-stage development of defence behaviour in altricial Ficedula hypoleuca nestlings: Learning the ‘inborn’ behaviour. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 194.
Defence reaction (freezing) in Pied Flycatcher nestlings, one of the first two early behavioural patterns, is observed starting with post-hatching day 5-6 only in response to adults' alarm call (AC). When calling, adults do not warm the young, causing hypothermia in still non-homeothermic nestlings. Between days 6 and 9 AC caused insignificant decrease in frequency and duration of begging in flycatcher broods. Starting with day 9, AC dramatically decreased the frequency and duration of beggings even in very hungry nestlings. On days 13-15 the young practically never beg when AC is heard. After day 9, the young begin to freeze also in response to artificial auditory and visual stimuli previously effective for begging. The significant change of heart rate during the exposition to AC is observed after day 9. Effective thermocontrol is established in the young by day 9, parallel to the rapid increase in the capability of fine discrimination of auditory and visual signals and significant increase in vocalisation intensity. It is suggested that the true defence reaction is learned on the basis of provisory freezing and enhanced sensory abilities. This study was supported by RFBR grant # 96-04-50260.
Key words: alarm call, ontogeny, altricial nestlings, sensory development, chick
Oral01.6: A field test of intra- and interspecific brood parasitism in the Red-backed Shrike Lanius collurio
C. Moskat & T.I. Fuisz
Animal Ecology Research Group of HAS, c/o Hungarian Natural History Museum, Budapest, Baross u. 13, H-1088, Hungary, e-mail moskat@zoo.zoo.nhmus.hu
Moskat, C. & Fuisz, T.I. 1998. A field test of intra- and interspecific brood parasitism in the Red-backed Shrike Lanius collurio. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 195.
The Red-backed Shrike Lanius collurio is known to be an occasional host of the Common Cuckoo Cuculus canorus. However, there are some Red-backed Shrike populations in Germany and in the Czech Republic, where they are intensely parasitised locally by the Cuckoo, but in Hungary it cannot be regarded as a host species. Using two types of artificial Cuckoo eggs (mimetic spotted eggs, and unlike blue eggs) we tested the relationship of the Cuckoo and the Red-backed Shrike in Hungary, in the light of the evolutionary arms race hypothesis. High proportion of rejection of both type of eggs by the host species shows that the Red-backed Shrike has a well-developed egg-recognition ability, which suggests that the Red-backed Shrike could have been a host of the Cuckoo in the past, and the Cuckoo was forced to change host. Nowadays the Robin Erithacus rubecula is the main Cuckoo host in Hungarian woodland habitats, which is still a naive species, accepting all Cuckoo eggs including unlike eggs. Exchange of eggs among Red-backed Shrike nests were carried out to test reactions against simulated intraspecific brood parasitism in the species. Shrikes showed the same types of answer to real conspecific eggs as against the artificial Cuckoo eggs: ejection, desertion and acceptance. When complete clutches in nests of rejectors were exchanged, birds accepted the foreign clutch in all cases. We think that shrikes compare egg to each other within the clutch, and their well-developed egg-recognition ability arose from their arms race with the Cuckoo.
Key words: egg recognition, egg discrimination, arms race, Lanius collurio, Cuculus canorus
Oral01.7: Winter social behaviour of Chinese Grouse at Lianhuashan, Gansu, China
Yun Fang & Yue-Hua Sun
Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China, e-mail sunyh@sun.midwest.com.cn
Fang, Y. & Sun, Y. 1998. Winter social behaviour of Chinese Grouse at Lianhuashan, Gansu, China. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 195.
Winter social behaviour of Chinese Grouse Bonasa sewerzowi was studied in winter 1994-1996 at Lianhuashan Natural Reserve in Gansu Province, China. Our data were obtained from 30 radio-marked birds, observations and habitat analysis. Flocks were first observed in mid-October, when broods were disintegrating. Flock size increased, with largest flocks of 13-14 birds in December. Flock size varied in different habitats. Most females (93.8%, based on radio tagged birds) were in flocks in winter. However, males showed various behaviour. Males held territories in spring and autumn. Non-territorial young males were in flock in winter (n = 3). Seventy three point three percent of radio tagged (n = 15) abandoned their territories, while 26.7% remained solitary in their territories during the whole winter. Territory location and quality may be the main factors underlying this difference. Flock areas were located at the junction of south and north slopes, where bushes of willow were abundant. In good weather, several flocking adult males returned to their territories for short time. Flock birds favoured feeding on the Sea Buckthorn Hippophae rhamnoides, which was distributed in clusters on south slopes, where no coniferous trees served as cover. We suggest that the main reasons for flocking were food concentration and mutual vigilance against avian predators. Radio-tracking data also showed that most flock members were stable, and loose pair bonds were found in late winter. Female groups were observed in flocks.
Key words: Bonasa sewerzowi, winter, social behaviour, radio-tracking, flocking
Oral01.8: Quality of food eaten by parent sunbirds directly affects their brood-care effort
S. Markman1, B. Pinshow1 & J. Wright2
1Department of Life Sciences and Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 84990 Israel, e-mail smarkman@bgumail.bgu.ac.il; 2School of Biological Sciences, University of Wales, Bangor, Gwynedd LL57 2UW, UK
Markman, S., Pinshow, B. & Wright, J. 1998. Quality of food eaten by parent sunbirds directly affects their brood-care effort. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban. Ostrich 69: 196.
While studying how adult Orange-tufted Sunbirds Nectarinia osea adjust parental investment according to the quality of their own food, we found that only adults eat nectar, while nestlings are fed arthropods only. This provided a unique opportunity to experimentally manipulate food eaten by parent sunbirds independent of that fed their offspring. Feeders containing low, medium or high concentration sugar solutions were randomly assigned to breeding pairs with two or three chicks (n = 6 nests at each concentration for each brood size). Adult pairs consumed similar volumes of sugar solution regardless of concentration. Thus, the concentration groups had different supplementary energy intakes. We found that (1) parental visits to their nests increased with increased sugar concentration, (2) increased provisioning rate was more pronounced in females than males; males increased their nest-guarding time with increasing sugar concentration, (3) visit rates per chick decreased with decreasing sugar concentration and increasing brood size which was reflected in lower growth rates and survival of young, and (4) inter-brood intervals were reduced in pairs fed high sugar concentrations. We concluded that increased food quality available for self-feeding allows parent sunbirds to invest more time and/or energy in their young, with consequent positive effects on their fitness.
Key words: Orange-tufted Sunbird, parental investment, feeding rate, food quality, Nectarinia osea