Wildlife Ecology in a Changing World
Humans as an Embedded Part of Nature
A central theme of modern wildlife ecology is the human dimension of environmental impact and the shaping of wildlife populations.
Humans are absolutely embedded within nature; we are a part of nature, we affect nature, and nature affects us in return.
Conservation efforts must account for how human activities shape ecological processes and interactions.
Wildlife ecology is often driven by a personal connection to wildlife and the desire to conserve it for future generations.
Global Impact and the "Land of Extremes"
Australia is frequently characterized as a "land of extremes" due to the rapid succession of intense environmental events.
Examples of recent extreme events (occurring in close succession circa -) include:
The "Black Summer" bushfires: These horrific fires impacted large portions of Eastern Australia, Western Australia, and South Australia.
Dust storms and floods occurred shortly after the fires.
Extreme hail events: Hailstones the size of tennis balls fell on Parliament, smashing windows and causing significant damage.
While these events have historical precedents, their frequency is increasing as a direct result of climate change.
Human impacts on the globe are profound and confronting, necessitating scientific intervention to minimize damage and begin recovery processes.
Trends in Global Biodiversity Loss
Cumulative data on species extinctions from the year to the present show significant declines in amphibians, mammals, birds, reptiles, and fishes.
Documentation Bias: The data likely reflects a bias toward well-studied species. Many invertebrates, plants, and fungi have likely gone extinct in certain regions but remain poorly documented.
Conservation Risk Proportions:
Data Deficient: Indicates a complete lack of information regarding a species' status.
Least Concern: Species currently at low risk.
Critically Endangered/Extinct: The highest risk categories.
Specific groups, such as cycads and amphibians, have fared particularly poorly compared to others.
Ecosystem Collapse: The Australian and Antarctic Assessment
A research collaboration led by Dana Bergstrom (including the lecturer) assessed the state of ecosystems spanning from Northern Australia to the Antarctic region.
Study Methodology:
Data Type: Utilized both quantitative data (population data, remotely sensed data) and qualitative data (expert information).
Duration: Required data spanning at least years, highlighting the importance of long-term ecology.
Study Area: A massive region covering nearly .
Criteria for Ecosystem Collapse:
Substantial reduction in population size or geographical distribution.
Loss of keystone species (species vital for ecosystem stability).
Large changes in biomass.
Loss of ecosystem engineers (species that shape the physical environment).
Loss of characteristic species.
Decline in ecosystem functions and services (e.g., water flows, predation, pollination).
Mechanisms of Threat: Presses vs. Pulses
Global Pressures: Large-scale factors like climate change (changes in precipitation and temperature) affect the majority of ecosystems.
Regional Pressures: Factors like invasive species, habitat loss/land clearing, overgrazing, and water extraction.
Definitions of Threat Dynamics:
Press (constant): A threat that continues constantly through time and often worsens. Example: Increasing global temperatures.
Pulse (irregular): A strong, immediate impact that comes and goes rather than being constant. Examples: Fires, floods, storms, and heatwaves.
Visual Evidence and Manifestations of Ecosystem Collapse
Graphical Models of Collapse:
An ecosystem may be stable relative to a baseline threshold until it reaches a point of rapid change.
Once a threshold is crossed, the system no longer represents its original state.
Collapse types: Can be gradual with a final crash, a smooth transition over time, a series of steps, or fluctuations between states until a new equilibrium is reached.
The Great Barrier Reef Example: A diverse system of coral, fish, and invertebrates can transform into an algae-dominated system following coral bleaching events. Such systems may not be able to revert if conditions are no longer favorable.
Savannah Ecosystems (Northern Australia): Healthy savannahs are being invaded by non-native Gamba grass (introduced for cattle grazing). Gamba grass grows tall and promotes high-intensity fires that reach the tree canopy, killing trees and creating a grass monoculture.
Marine Kelp Forests (Great Southern Reef): Kelp forests provide a three-dimensional architecture for marine life. Increasing temperatures and overgrazing by sea urchins lead to the loss of this structure, removing food and cover for dependent species.
Desert Ecosystems: Transitions are driven by the combined effects of overgrazing, fire, and drought.
Proactive Conservation: The "Three A's" Approach and Management Case Studies
The Three A's Framework:
Aware: Recognizing the values within an ecosystem (e.g., high-value, ancient, or restricted species).
Anticipate: Identifying upcoming pressures (e.g., climate change impacts).
Act: Managing pressures to avoid impact, or aiding recovery through restoration.
Wollamay Pine Case Study:
The Wollamay Pine is an ancient "living fossil" millions of years old, restricted to small microclimate pockets west of Sydney.
During the "Black Summer" fires, firefighters used helicopters to abseil into these pockets and set up sprinkler systems.
This proactive intervention saved the pines, which are highly vulnerable to fire.
Mountain Pygmy Possum Case Study:
Wildfires depleted natural food resources (like Bogong moths).
Zoos Victoria developed "Bogong Bickies"—high-protein biscuits distributed to help the possums survive the food shortage.
The Emergence of Novel Ecosystems
Novel Ecosystems: Heavily modified systems containing a mixture of native and non-native species interacting in new ways.
The Conservation Conundrum of the Southern Brown Bandicoot:
This endangered species lives in highly modified landscapes in Southeast Melbourne (e.g., Cranbourne).
The understory is often composed of invasive, non-native plants.
However, these invasive plants provide the bandicoots with essential protection from feral cats and foxes.
Managing invasive plants in these areas requires caution, as removing the cover could lead to the local extinction of the native bandicoot.
The COVID-19 Pandemic: Lessons from the "Anthropause"
The pandemic provided a unique opportunity to observe wildlife in the absence of human activity.
Wildlife Behavior: Many animals fear humans as predators and avoid active human areas. During lockdowns, animals occupied previously restricted spaces:
Goats walked the main streets of towns in Wales.
Coyotes entered highly populated areas of San Francisco.
A kangaroo was seen hopping down the main street of Adelaide.
Pollution Reduction: Water in Venice became temporarily clearer due to reduced boat traffic.
Seismic Activity: Scientists monitoring the oceans found a drop in vibrations caused by human infrastructure and transportation. This is significant because seismic noise interferes with whale communication, movement, and location abilities.
Socio-Economic Impacts of Human Interaction with Nature
Conservation must account for social and economic factors, as the most vulnerable human populations often suffer most during environmental changes.
During the pandemic, some regions saw negative environmental outcomes:
In areas where tourism or fishing economies failed, people migrated from coastal to agricultural areas.
This led to "slash and burn" agriculture, destroying habitats.
Poaching and harvesting of wild animals increased due to lack of food security.
Human-Wildlife Conflict and Coexistence: The Romanian Case Study
Romania contains the largest intact forest in Europe (Carpathian Mountains) and high populations of large carnivores: brown bears, wolves, and lynx.
Traditional Coexistence: Shepherds use domestic guardian dogs to protect livestock. Research using camera traps showed that these dogs have a positive impact on the ecosystem by deterring large predators, which indirectly benefits smaller predators like red foxes.
Impact of Humans: There is a strong negative effect of humans on deer species, both directly and indirectly through their dogs.
Institutional Failures: Conflict arises when agencies fail to manage interactions properly:
Bears entering homes and bathrooms, causing property damage and "mayhem."
Failed bear-proof infrastructure: Metal rubbish bins were easily ripped open by powerful bears.
Learned Behavior: Mother bears were observed bringing cubs to restaurants at night to forage for leftovers. This taught the young to associate humans with food, leading to persistent conflict.
Health Risks: Bear scat was found to contain large amounts of plastic, which can lead to the death of the animal.
Leverage Points for Managing Human-Wildlife Conflict
The Law of the Lever: To achieve significant change (lift a heavy weight), one needs a deep, powerful lever.
In conservation, leverage points for reducing conflict in human-dominated landscapes (HDL) include:
Understanding the biology and landscape use of carnivores.
Integrating social sciences to understand the behaviors, values, and norms of human communities.
Guardian Animals: Used for centuries by Greeks, Romans, and cultures in Asia and Africa. In Australia, Maremma dogs (featured in the movie Oddball) and donkeys are effective at deterring predators like dingoes and foxes.
Ecosystem Restoration and the Role of Digging Mammals
Restoration Realism: It may not always be possible to return an ecosystem to its pristine original state, but functional improvements can be made.
Digging Mammals: Many (Bilbies, Bettongs, Bandicoots) have been driven to local or complete extinction by red foxes and feral cats.
Eastern Barred Bandicoot (Work by Lauren Halstead):
Quantified the impact of digging on Philip Island, French Island, and Churchill Island.
One bandicoot can turn over a volume of soil equivalent to the weight of an elephant each year.
Digging creates conical foraging holes that increase water infiltration and soil moisture (making soil more friable).
These pits trap seeds and nutrients, promoting plant germination.
The Mutualistic Association: Bandicoots and Fungi
Bandicoots forage for hypogeal fungi (fungi that grow underground).
Research by Sarah McLagan on Southern Brown Bandicoots:
Studied fungal "morphotypes" (since many Australian fungi species are not yet taxonomically described).
Novel sites (highly modified urban areas in Cranbourne) were found to have a high proportion of unique fungi species.
The Symbiotic Loop:
Fungi have a mutualistic association with plant roots (mycorrhizae).
Fungi provide plants with micronutrients (vital in nutrient-poor Australian soil) in exchange for sugars from photosynthesis.
Bandicoots eat the fungi and spread the spores across the landscape, maintaining ecosystem function even in modified environments.
Functional Predator Roles: Spotted-Tailed Quolls and Invasive Rabbits
Research at Mount Rothwell Sanctuary examined the diet of the Spotted-tailed Quoll (including individuals with a "piebald" color pattern).
Despite an abundance of native prey (brushtail possums, bettongs, bandicoots), quolls predominantly hunt European rabbits.
Historical Context: Early attempts to introduce rabbits in Southern Australia initially failed due to quoll predation. Rabbits only exploded in number after quolls declined due to foxes, cats, and disease.
Reintroducing quolls could be a tool for managing rabbits, which currently impact over of Australia's threatened plant species.
Urban Ecology and Green Infrastructure
Many threatened species live exclusively in or around cities.
Research by Kylie Soanes and Pia Lentini quantified the presence of these species in urban environments.
Green Infrastructure (Research by Sarah Beckersy):
Reimagining cities like Melbourne with plants on roofs and green walls.
Benefits: Increases local biodiversity, improves cooling/reduces the need for air conditioning (saving energy), and improves water management on hard surfaces.
Examination Preparation and Assessment Details
Structure: The exam covers four main themes:
Population Ecology.
Wildlife Survey Techniques.
Conservation Theory and Practice.
Wildlife Management (including guest lectures).
Exam Format:
Duration: hours within a -hour window (starts at AM).
Components: Multiple Choice Questions (randomly selected from ) and Short Answer Questions (randomly selected from ).
Weighting: All Multiple Choice Questions are worth mark. Short answer questions have varying point values (e.g., to marks), which indicate the required level of detail.
Rules and Logistics:
Open Book: Notes and handouts are permitted; third-party assistance or AI tools (e.g., ChatGPT) are strictly prohibited and detectable.
Deakin Access Plan: Extra time is added automatically by the resource office.
Internet/IT: Ensure a reliable connection. If issues occur, a ticket must be lodged with Deakin IT immediately.
Success Strategies:
The exam tests only what was covered in lectures. Readings are supplementary.
Read questions carefully (e.g., "explain and use an example").
Dot points are acceptable for short answers as long as the concept is clear.
Manage time: Do not stick to low-weight questions if high-weight questions remain.
Sample Question (Multiple Choice):
Q: Boom and bust population patterns in a single population where there are "all winners or all losers."
A: Exploitation competition. (Note: Interference competition would typically result in a leveling off/carrying capacity effect).
Sample Question (Short Answer):
Q: Distinguish between the fundamental and realized niche using examples.
Requirements: Verbatim definitions and specific animal/species names to illustrate the concept.
Questions & Discussion
Interviewer/Student: Can you confirm the exam date?
Speaker: The exam is approximately on June . (Correction: The lecturer later notes the submission window expiry is June at AM).
Student (Taylor): Where is the exam located on the site?
Speaker: It is accessed through the "Assignment" or "Assessment" section in the unit site under a "Quiz" section. An email will be sent with specific details.
Student (Nathan): Is there material for revision for the final assessment?
Speaker: There are no extensive revision question sets. Everything in the lectures and handouts is assessable. The lecturer has explicitly stated in specific lectures what not to worry about. The readings are to build knowledge but are not directly tested.
Speaker's Closing: The lecturer expresses gratitude to the students for their patience during a difficult personal trimester (due to the passing of his mother) and encourages students to reach out regarding honors research or career advice.
In-Chat Interaction: Students (Chichesh, Taylor, Nathan) provided feedback and confirmed technical details throughout the session.