Beavers: Ecology, Behaviour, Conservation, and Management

Cover
Beavers: Ecology, Behaviour, Conservation, and Management
Copyright
Preface
Contents
Chapter 1: Introducing the beaver
1.1 A buck-toothed wonder
1.2 All in the name
1.3 A robust rodent
1.4 The two beavers
1.5 Fossil beavers
1.6 Modern beavers
1.7 Mistaken identity
References
Chapter 2: Utilization and distribution of beavers
2.1 An ancient relationship
2.1.1 Early human interactions
2.1.2 Beaver place names
2.2 Myths, folklore, and religious beliefs
2.3 Beaver territories as resources
2.4 Cultural value of beaver teeth and bones
2.5 Castoreum and its creative uses
2.6 Beavers as food
2.7 The fur trade: ‘brown or soft gold’
2.7.1 Beaver hats
2.8 Historic and current distribution range
2.8.1 Eurasian beaver distribution
2.8.2 North American beaver native distribution
2.8.3 North American beaver introductions
References
Chapter 3: Beaver morphology and physiology
3.1 Body form and keeping water out
3.1.1 Fur
3.1.2 Skeleton and skull
3.1.3 Teeth
3.1.4 Legs and feet
3.1.5 The tail
3.1.6 The cloaca
3.2 Internal organs
3.2.1 Brain
3.2.2 Digestive organs
3.2.2.1 Digestion of food in the mouth and stomach
3.2.2.2 Digestion in the stomach–intestinal canal
3.2.3 Liver
3.2.4 Spleen and thymus
3.2.5 Heart, blood vessels, and blood chemistry
3.2.6 Lungs
3.2.7 Kidneys
3.2.8 Reproductive organs
3.2.9 Castor sacs
3.2.10 Anal glands
3.3 Sense organs
3.3.1 Eyes and vision underwater
3.3.2 Ears and hearing
3.3.3 Nose and smell
3.4 Significant physiological processes
3.4.1 Nutrient uptake
3.4.2 Swimming and the diving reflex
3.4.3 Thermoregulation
3.4.4 Seasonal changes and surviving winter
3.4.5 Living underground
References
Chapter 4: Habitat use and constructions
4.1 Habitat selection: where can we find beavers?
4.1.1 Important habitat factors
4.1.2 Preferred and potential habitats
4.1.3 Hydrology
4.1.4 Vegetation, dam, and intrinsic modelling approaches
4.1.5 Urbanized landscapes
4.1.6 Local to ecoregional scale
4.1.7 Individual variation
4.1.8 Differences in habitat use between the two beaver species
4.2 Beaver-made constructions
4.2.1 Shelters: burrows, lodges, and lairs
4.2.1.1 Burrows
4.2.1.2 Lodges
Lodge construction
Lodge structure: exterior
Lodge structure: from the entrance to the interior
4.2.1.3 Lairs (day nests) and other shelters
4.3 The food cache
4.3.1 Food cache construction
4.3.2 Plant species in the food cache
4.3.3 Factors affecting the food cache size
4.3.4 Invisible food caches
4.4 The dam
4.4.1 Dam selection: where do beavers build dams?
4.4.2 Why do beavers build dams?
4.4.3 Dam construction
4.4.4 Dam dimensions
4.4.5 Dam maintenance and failure
4.5 Trails and canals
References
Chapter 5: The seasonal vegetarian
5.1 The opportunistic generalist
5.1.1 Seasonal variation
5.2 Foraging behaviours
5.2.1 Central-place foraging
5.2.2 Woody species processing and felling
5.2.3 Sex and age differences in foraging times and forage selection
5.3 The importance of different woody species and genera
5.4 Important herbs and forbs
5.5 Important crop plants
5.6 Aquatic vegetation
5.6.1 Important aquatic and wetland plants
5.7 Variation in the diet
5.8 Plant defences and responses to beaver feeding
5.8.1 Plant responses to beaver foraging
5.8.2 Physiological defence of plants
References
Chapter 6: Activity patterns and life history
6.1 Daily activity patterns
6.1.1 Time budgets and associated roles according to sex and age class
6.2 Winter: the secret time of year
6.3 The family group
6.4 Mate choice and pair bonding
6.5 Sexual maturity and mating
6.5.1 Extra-pair copulations and paternity
6.5.2 Inbreeding
6.6 Time of birth and litter size
6.7 Other factors affecting reproduction
6.7.1 Hunting
6.7.2 Latitude
6.7.3 Altitude
6.7.4 Weight and age of mother
6.7.5 Physical condition of mother
6.7.6 Density of beavers
6.7.7 Habitat quality
6.7.8 Climatic factors
6.7.9 Duration of territory occupation
6.8 Kit development and the life inside beaver lodges
6.9 Dispersal of offspring
6.9.1 Age at dispersal
6.9.2 Extra-territorial movements
6.9.3 Time of year
6.9.4 Obstacles, distance, and direction
6.9.5 Floaters
6.10 Mate change, length of pair bonds, and loss of family members
6.11 Longevity
References
Chapter 7: Territoriality, communication, and populations
7.1 Territory establishment and size, and factors affecting territory size
7.1.1 Establishment
7.1.2 Territory size
7.1.3 Factors affecting territory size
7.1.3.2 Habitat quality and quantity
7.1.3.3 Habitat type (stream, river, or pond)
7.1.3.4 Density of beaver populations
7.1.3.5 Social factors (sex and age)
7.1.3.6 Time of year (season)
7.2 Territorial defence
7.2.1 Patrolling and travelling
7.2.2 Using scent communication
7.2.2.1 Castoreum
7.2.2.2 The anal glands
7.2.2.3 Scent marking behaviour
7.2.3 Fighting, aggression, and tail scars
7.2.4 Stick display
7.3 Duration of territory occupation
7.4 Communication
7.4.1 Vocalization
7.4.2 The tail slap
7.4.3 Body posture and movements
7.5 Populations
7.5.1 Pattern of population development
7.5.2 Densities
7.5.3 Abandonment of sites
References
Chapter 8: Mortality and morbidity
8.1 Mortality
8.2 Pre- and postnatal mortality
8.3 Natural mortality factors
8.3.1 Predation
8.3.2 Common predators
8.3.3 Infrequent predators
8.3.4 Drowning, water regulations, and floods
8.3.5 Dental issues
8.3.6 Harsh winters
8.3.7 Drought
8.3.8 More unusual endings
8.4 Human factors
8.4.1 Pollutants
8.4.2 Hunting and trapping
8.4.3 Road traffic and motorboat accidents
8.5 Diseases, pathogens, and parasites
8.5.1 Viruses
8.5.2 Bacteria
8.5.3 Parasites
8.5.3.1 Endoparasites
8.5.3.2 Ectoparasites
References
Chapter 9: The ecological engineer
9.1 Shapers of landscapes
9.1.1 A keystone species
9.2 Wetland creation and floodplain reconnection
9.2.1 Water storage
9.2.2 Erosion and sedimentation
9.2.3 Water quality and nutrient cycling
9.2.4 Water temperature
9.3 Positive and negative effects on plants and animals
9.3.1 Riparian and aquatic plants
9.3.2 Invertebrates
9.3.3 Fish
9.3.4 Amphibians
9.3.5 Reptiles
9.3.6 Birds
9.3.7 Mammals
References
Chapter 10: Animal management and population monitoring
10.1 Not a typical zoo animal
10.2 Captive husbandry requirements
10.2.1 Key enclosure requirements
10.2.1.1 Animal grouping
10.2.1.2 Shelter
10.2.1.3 Substrate
10.2.1.4 Water
10.2.1.5 Retention
10.2.2 Dietary requirements
10.3 Captive issues
10.3.1 Behavioural concerns
10.3.2 Health and hygiene
10.3.2.1 Dental issues
10.4 Animal husbandry and field monitoring techniques
10.4.1 Capturing and handling
10.4.1.1 Welfare during trapping and handling
10.4.1.2 Live capture methods
10.4.1.3 Trap placement and bait
10.4.1.4 Chemical immobilization
10.4.1.5 Handling without anaesthetic
10.4.1.6 Sample collection
10.4.1.7 Transportation
10.4.2 Remote monitoring and tagging
10.4.2.1 PIT/microchip tagging
10.4.2.2 Ear tagging
10.4.2.3 External tagging
10.4.2.4 Intraperitoneal tagging
10.4.2.5 Remote cameras
10.4.2.6 Aerial surveys and drones
10.4.2.7 Hair trapping
10.4.2.8 Questionnaires
10.4.3 Breeding and sex determination
10.4.4 Age determination
10.5 Monitoring population dynamics
10.5.1 Identifying potential habitat and key signs of activity
10.5.2 Determining number of active families
10.5.3 Determining family group size
References
Chapter 11: Living with beavers: an ‘adorable nuisance’?
11.1 Why should we live with the beaver?
11.2 Beaver restoration and human–wildlife conflict management
11.2.1 Conflicts with humans
11.3 Beaver introductions, coexistence of the two species, and eradication programs
11.4 Techniques for effective management
11.4.1 Scaring devices, unpalatable and scent deterrents
11.4.2 Tree protection and deterrent fencing
11.4.3 Buffer zones and provision of alternative resources
11.4.4 Dam prevention, manipulation, and removal
11.4.5 Flow devices
11.4.6 Culvert protection
11.4.7 Bank protection and restoration
11.4.8 Fertility control
11.4.9 Hunting, trapping, lethal control, and euthanasia
11.4.10 Exclusion zones
11.4.11 Preventative management
11.4.12 Public education and outreach programmes
11.4.13 Management of captive collections
11.5 Role as a charismatic flagship species for conservation projects
11.5.1 Wildlife tourism
11.6 Beaver restoration
11.6.1 Release site suitability assessment and release techniques
11.6.2 Release site fidelity and dispersal
11.7 Long-term management strategies and future planning
References
Index