How Menagerie measures captive exotic animal welfare
This document defines the methodology for the Menagerie Welfare Index (MWI), the care score system used throughout the Menagerie app to assess the welfare state of captive exotic animals.
It is written to serve three audiences simultaneously:
So they understand what the score means and trust it as a genuine reflection of their animal's welfare, not a gamification element.
So they can evaluate the methodology, identify its limitations honestly, and determine whether the dataset is suitable for scientific use.
So the implementation is consistent, documented, and maintainable as the platform grows.
The MWI is built on the Five Domains Model of Animal Welfare developed by David Mellor and colleagues, widely adopted in veterinary science, zoo management, and animal welfare research. The Five Domains are:
The MWI maps directly to this framework. Each domain is scored independently using available keeper log data, then combined into an overall welfare index score. The Mental State domain is treated as an emergent property of the other four rather than a directly measurable input, consistent with the original Five Domains framework.
This grounding in established peer-reviewed science means the MWI is not an invented metric. It is an implementation of a recognized framework using novel data collection methods.
The MWI is designed to function at two levels simultaneously.
Individual level: A keeper understands how their specific animal is doing and what aspects of care need attention.
Population level: Aggregated across all animals of a species in Menagerie, the MWI produces the first continuous longitudinal welfare dataset for captive exotic species ever assembled at scale.
Population-level MWI data can answer questions that have existed in herpetology for decades but have lacked sufficient data to address:
Nutrition
What it measures: Whether the animal is receiving appropriate food and water in appropriate quantities and frequencies for its species and life stage.
Data inputsEnvironment
What it measures: Whether the animal's physical living conditions (temperature, humidity, lighting, enclosure size, substrate) are appropriate for the species.
Data inputsThe gradient completeness principle: For heliothermic species (tegus, monitor lizards, bearded dragons), a complete thermal gradient is a welfare requirement, not a preference. The Environment domain penalizes incomplete gradient data more heavily for these species than for thermoconforming species.
Health
What it measures: The absence of disease, injury, and physiological dysfunction, and the presence of positive health indicators.
Data inputsBehavior
What it measures: Whether the animal is able to express species-appropriate natural behaviors and whether its behavioral patterns are consistent with positive welfare state.
Data inputsMental State
What it measures: The subjective experiential state of the animal and whether it is experiencing positive or negative affect.
Implementation approach: Mental state is not directly measurable through keeper logs. It is treated as an emergent integration of the other four domains, consistent with Mellor's original framework.
In the MWI, Mental State is represented by the overall score integration and is not calculated as a separate domain. Future development may incorporate proxies such as:
This is an area where the MWI explicitly acknowledges its limitations and invites future methodological development.
Domain weights are not equal across species. The following profiles reflect the relative importance of each domain for major species categories in Menagerie. All profiles sum to 100%. These weights are initial estimates based on husbandry literature and expert keeper knowledge, designed to be updated as population-level data accumulates and empirical validation becomes possible.
Heliothermic Lizards
Tegus, Monitor Lizards, Bearded Dragons, UromastyxEnvironment weighted highest because thermal gradient is physiologically critical for digestion, immune function, and all metabolic processes.
Colubrid and Boid Snakes
Boas, Ball Pythons, Kingsnakes, Corn SnakesBehavior weighted low as cryptic species with limited behavioral expression in captivity. Feeding response is the primary behavioral signal.
Arboreal Chameleons
Veiled, Panther, Jackson'sEnvironment weighted highest of any profile. Chameleons are the most environmentally sensitive species in common captive keeping.
Tarantulas and Theraphosidae
Nutrition weighted lowest as tarantulas naturally fast for extended periods. Molt quality is the primary welfare indicator.
Amblypygi (Whip Spiders)
Humidity is the primary welfare variable. Behavioral assessment is limited by nocturnal, cryptic habits.
Myriapods
Giant African Millipedes, CentipedesHumidity and substrate depth are primary welfare variables for millipedes.
Amphibians
Tree Frogs, Axolotls, Dart FrogsWater quality, humidity, and temperature are critical for amphibian welfare. Skin health serves as a proxy health indicator.
Domestic Mammals
Cats, Dogs in Multi-Species CollectionsBehavior weighted highest of any profile. Behavioral indicators are the primary welfare signal for cognitively complex mammals.
Exotic Mammals
Sugar Gliders, African Pygmy HedgehogsEnvironment more important than domestic mammals due to specific temperature and humidity requirements. Behavior more important than reptiles.
Each domain score decays over time as care events age. Decay is not linear — recent events carry more weight than older ones. Decay rates are species-appropriate and state-aware.
Recency weighting: A feeding log from yesterday is weighted more heavily than one from two weeks ago, even if both represent appropriate care. This reflects that current welfare state is more relevant than historical welfare state.
Species-appropriate decay rates: The decay rate reflects how quickly the absence of a care event becomes a welfare signal for that species.
| Species Category | Feeding Decay Half-Life | Environment Decay Half-Life |
|---|---|---|
| Active heliothermic lizards | 4 days | 2 days |
| Boid snakes | 14 days | 3 days |
| Colubrids | 10 days | 3 days |
| Tarantulas | 21 days | 5 days |
| Amblypygi | 14 days | 3 days |
| Millipedes | 10 days | 4 days |
| Amphibians | 7 days | 2 days |
| Domestic cats/dogs | 2 days | 7 days |
Every MWI score is accompanied by a confidence value representing how much data underlies the score. A score of 84 based on 847 data points over 18 months means something fundamentally different from a score of 84 based on 6 data points over 2 weeks. Both display as 84. The confidence indicator communicates the difference.
In Advanced mode, confidence is displayed as a percentage alongside the score. In Standard mode, confidence is shown as a subtle indicator. In Simple mode, confidence is not displayed — new animals show "Getting to know [name]" instead of a low-confidence score.
Not all data is equal. The MWI tracks data quality through source flags on every log entry.
| Source Flag | Meaning | Score Impact |
|---|---|---|
manual | Keeper-entered observation | Full weight |
govee | Sensor auto-log, validated | Full weight, higher precision for Environment domain |
govee_calibration | Sensor data during calibration period | Excluded from score calculation |
imported | Historical data imported from external source | Reduced weight (70% of manual) |
demo | Demo account data | Excluded from all aggregate calculations |
Research queries automatically filter to source IN ('manual', 'govee') and exclude is_demo = true accounts.
The Collective Score is the population-level aggregate of individual MWI scores for a species.
What it represents: The mean MWI score for all animals of a species in Menagerie, weighted by confidence level. Low-confidence individual scores contribute less to the aggregate than high-confidence scores.
What it answers: "How well are captive [species] being kept, on average, by Menagerie keepers?"
How it surfaces to keepers: In Advanced mode, a keeper can see their animal's score compared to the species population distribution. For example: "This animal scores 84. The Argentine Tegu population mean is 71. You are in the top 23% of tegu keepers by welfare score."
This is not gamification. It is genuine population context that makes the individual score meaningful.
Minimum population threshold: Collective Scores are only displayed when a species has at least 50 animals with high-confidence scores in the database. Below this threshold, the score is not shown as there is insufficient data for a meaningful population baseline.
Research use: Collective Scores and the underlying distribution data are the primary research output of the Menagerie dataset. They represent the first continuous longitudinal welfare assessment for captive exotic species at population scale.
The MWI is presented differently depending on the keeper's selected experience level within the app.
The MWI is a tool, not a verdict. Several important limitations apply:
Keepers who use Menagerie more consistently produce higher-quality data and may show higher scores partly because of logging completeness rather than superior husbandry. The confidence indicator partially addresses this but does not eliminate it.
Keepers who use a care tracking app are likely more engaged than the general keeper population. MWI scores may not be representative of captive exotic animal welfare broadly. They represent the welfare of animals kept by engaged keepers who chose to track their care.
The domain weightings are initial estimates based on husbandry literature and expert knowledge. They have not been empirically validated against health outcomes. Validation is a future research priority.
The Five Domains model acknowledges that mental state in non-human animals is difficult to assess. The MWI's treatment of mental state as emergent rather than directly measured is a principled choice but also a limitation.
Behavioral observations are the least consistently logged data type. The Behavior domain score is therefore the least reliable component of the MWI in most cases.
These limitations are published alongside the methodology, not hidden. Scientific credibility requires honest accounting of what a dataset can and cannot tell you.
As the dataset matures, domain weights can be tested against health outcomes. Do animals with consistently high Environment domain scores show fewer health events? Do animals with high Nutrition domain scores show better weight trajectories? This validation is the path from informed estimate to empirically grounded methodology.
With partner veterinary practices, MWI scores can be correlated with clinical health outcomes. This is the most rigorous validation pathway and the one most likely to result in peer-reviewed publication.
A first-year keeper and a ten-year keeper keeping the same species under the same conditions may produce different log completeness. The MWI could eventually adjust for keeper experience level to isolate animal welfare signal from keeper behavior variation.
The dataset will eventually support seasonal and longitudinal pattern analysis: how do species-level welfare scores vary by season, by geographic region, by keeper tenure? These patterns are research outputs, not app features.
The HERP Laboratory at Eckerd College (herp.eckerd.edu) focuses on how captive environments affect reptile behavior and cognition. Their research questions and Menagerie's dataset are naturally complementary. A formal data sharing agreement would benefit both.
Menagerie data is collected with keeper consent for research contribution. Keepers who opt in explicitly agree to their anonymized data being used for welfare research.
If you are a researcher, veterinarian, or institution interested in accessing Menagerie welfare data or discussing a formal partnership, please reach out directly.
Contact the Research Team hello@mymenagerie.pet · Subject: Research Inquiry© 2026 Madcow Venture Company. All rights reserved.
Menagerie Welfare Index and MWI are trademarks of Madcow Venture Company.