Ecology of Lappet-faced Vulture Torgos tracheliotus in Saudi Arabia

178 Pages·2004·0.69 MB·English

by  Catherine Tsagarakis

Ecology of Lappet-faced Vulture Torgos
tracheliotus in Saudi Arabia

Mohammed Shobrak

Presented for candidature for Doctor of Philosophy to the Faculty of Science, University of Glasgow,
January 1996.
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Candidates declaration

I declare that the work recorded in this thesis is entirely my own, unless otherwise stated, and that it is my
own composition. No part of this work has been submitted for any other degree.

Mohammed Shobrak

January 1996

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Contents

Dedication
Acknowledgements
Abstract
Chapter 1. Introduction
1.1 Vulture in Saudi Arabia
1.2 The lappet-faced vulture in Saudi Arabia
1.3 Feeding ecology of the lappet-faced vulture
1.4 Social behaviour of vultures
1.5 Movements
1.6 Introduction to the study
1.7 Aims and lay-out of the thesis
Chapter 2. Study area
2.1 Mahazat as-Sayd reserve
2.2 Vulture study area
2.3 Topography
2.4 Climate
2.5 Funa and flora
2.5.1 Fauna
2.5.2 Flora
2.6 Social economy
Chapter 3. Food availability
3.1 Introduction
3.2 Material and methods
3.2.1 Size of the wild and domestic ungulates herds
1- Aerial surveys
2- Questionnaires
3- Ground counts
3.2.2 Husbandry practices of pastoral agriculture
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3.2.3 Rate of mortality and the cause of death
3.2.4 Crop size of lappet-faced vulture in the reserve
3.3 Results
3.3.1 Numbers and mortality rates of wild ungulates in the reserve
3.3.2 Size of the livestock population in the study area
1- Aerial surveys
2- ground counts
3- Questionnires
4- Ministry of Agriculture reports
3.3.3 The husbandry practices of pastoral agriculture
1- Aerial survey
2- Questionnires
3- Ground survey
3.3.4 Mortality rates and causes of death in the domestic ungulates
1- Questioners
2- Ground survey
3- Ministry of Agriculture
3.4 Discussion
3.4.1 Livestock population
3.4.2 Livestock mortality
3.4.3 The availability of food and the vultures requirements
3.4.4 Conclusion
Chapter 4. Food selection
4.1 Introduction
4.2 Material and methods
4.3 Results
4.4 Discussion
4.4.1 Predation and seasonal variation in the lappet-faced vultures
4.4.2 The relations between the prey items selected by lappet-faced
and the range of prey species within the foraging area.
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Chapter 5. Locating and exploiting the carcasses
5.1 Introduction
5.2 Material and Methods
5.2.1 At what time of day do lappet-faced vultures commence foraging?
5.2.2 The factors affecting the presence and abundance of scavengers at carcasses
5.3 Results
5.3.1 At what time of day do lappet-faced vultures commence foraging?
5.3.2 Factors affecting the presence of scavengers at carcasses
(I) lappet-faced vulture
(II) brown-necked raven
(III) eagle
(IV) Egyptian vulture
(V) mammalian scavengers
5.3.3 The feeding behaviour
(I) smaller scavenging birds
(II) large scavenging species
5.4 Discussion
5.4.1 Lappet-faced vulture departures from roosts
5.4.2 Locating the carcasses
5.4.3 Feeding behaviour
Chapter 6. Competitive interactions between scavenging species
6.1 Introduction
6.2 Methods
6.2.1 The amount of food utilised from the carcasses by different types of scavenging animal.
6.2.2 The dominance hierarchy between the scavenging species and among the
scavenging birds.
6.2.3 The important of lappet-faced vultures as carrion feeders in the desert ecosystem.
6.3 Results
6.3.1 the amount of food removed from the carcasses by deferent group of scavenging
animals.
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6.3.2 the dominance hierarchy between scavenging species and among scavenging birds.
6.3.3 the importance of the lappet-faced vulture as a scavenger in this desert ecosystem.
(I) morphology
(II) status
6.4 Discussion
Chapter 7. Parental investment in breeding
7.1 Introduction
7.2 Methods
7.2.1 the timing of breeding season, copulation, and time spent incubating by the two sexes.
7.2.2 guarding the nestling and the post-fledging dependence period
7.2.3 chick feeding and energy requirements
7.2.4 the importance of shading the chick from direct sunlight
7.2.5 the activity pattern of the nestling
7.3 Results
7.3.1 the nesting time and sites, copulation, and the time spent incubating by the two sexes
7.3.2 guarding the nestling and the post fledging dependence period.
7.3.3 chick feeding and energy requirements
7.3.4 the importance of shading the chick from direct sunlight
7.3.5 the activity pattern of the chick in the nest
7.4 Discussion
7.4.1 breeding season, copulation behaviour and time spent incubating by the two sexes
7.4.2 guarding the chick and the post-fledging dependence period
7.4.3 chick feeding
7.4.4 the important of shading from direct sunlight to the chick
Chapter 8. Movements
8.1 Introduction
8.2 Methods
8.2.1 seasonal abundance of the lappet-faced vultures in the reserve
8.2.2 resightings of marked birds
8.2.3 movements of radio-tagged juveniles
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8.2.4 movements of birds fitted with satellite transmitters
(I) capture
(II) tracking equipment
8.2.5 home range
8.2.6 mortality
8.3 Results
8.3.1 seasonal abundance of lappet-faced vultures in the reserve
8.3.2 resighting of marked birds
8.3.3 movements of radio-tagged juveniles
8.3.4 movements of the birds fitted with satellite transmitters
8.3.5 home range
(I) the radio-tagged fledging chicks
(II) the immature birds fitted with satellite transmitter
8.3.6 mortality
8.4 Discussion
8.4.1 seasonal abundance of the lappet-faced vultures in the reserve
8.4.2 resightings of marked birds
8.4.3 movement of radio-tagged juvenile
8.4.4 movement of the birds fitted with stellite transmitters
8.4.5 home range
8.4.6 mortality
Chapter 9. General discussion and conservation
9.1 General discussion
9.1.1 food supply
9.1.2 competition over the food supply
(I) with mammals
(II) with other birds
9.1.3 breeding and chick rearing
9.1.4 bird movements
9.2 Factors affecting the lappet-faced vulture population
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9.3 Conservation implication
9.3.1 nest management
9.3.2 public awareness
9.3.3 monitoring and future research

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Dedication

This thesis is dedicated to my wife, my parents, and HRH prince Saud Al-Faisal for their
support and encouragement throughout my academic career.

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