New peer-reviewed study: Tiger colour morphs in Thai zoos raise welfare and conservation concerns

We are pleased to share that our latest peer-reviewed paper, “Tiger colour morphs in zoos raise conservation and welfare concerns,” has been published in Discover Animals.

This study represents the first multi-year analysis of tiger colour morphs in Thailand’s captive zoo population. Between 2017 and 2025, we collected data from 44 zoos housing tigers across the country, recording the presence of white, golden and snow colour morphs, assessing exhibit signage, and documenting the use of these animals in visitor interactions.

Why study tiger colour morphs?

Tigers (Panthera tigris) are globally endangered in the wild, yet thousands are held in captivity. In zoos, most tigers have the familiar orange coat. However, some are bred for unusual colour patterns, commonly referred to as white, golden, or snow morphs.

While such colour morphs attract public attention, they are the result of recessive genetic traits that are amplified through selective breeding. This raises important questions about animal welfare, genetic management and the educational role of zoos.

white tiger

snow tiger

golden tiger

What we found

Across the eight years of data collection:

• Colour morphs consistently made up between 12% and 20% of tigers observed each year.

• There was no statistically significant overall increase in morph prevalence over time.

• However, after the COVID-19 period, we detected significant increases in golden and snow morphs specifically.

• Private zoos accounted for the majority of colour morph tigers throughout the study period.

• Accredited and government institutions contributed comparatively few, with one recent increase due to a change in accreditation status rather than new breeding.

In 2025, we also assessed signage at exhibits displaying colour morphs. Most signs did not clearly explain that these morphs result from genetic mutations linked to selective breeding. None mentioned inbreeding risks or associated health concerns, and several presented morphs as rare or exceptional without conservation context.

Additionally, nearly half of zoos offering tiger–visitor interactions in 2025 used colour morph tigers in at least one type of interaction.

What does this mean?

Modern zoos generally describe their core roles as conservation, education, research, recreation and the provision of good welfare. Selective breeding for colour morphs does not contribute to conservation breeding programmes aimed at maintaining genetic diversity. In fact, prioritising specific visual traits can reduce genetic health in captive populations.

Our findings suggest that the continued display and, in some cases, increase of certain morphs may reflect commercial priorities rather than conservation goals. This is particularly relevant in countries with large captive tiger populations and strong wildlife tourism sectors.

Our recommendations

Based on our findings, we recommend:

• Ending the intentional breeding of tiger colour morphs.

• Strengthening policy and accreditation standards around genetic management.

• Improving exhibit signage to accurately explain the origins and limitations of colour morphs.

• Aligning captive tiger management practices more closely with conservation and welfare principles.

This research is part of our broader commitment to evidence-based advocacy. By documenting long-term trends and presenting transparent data, we hope to support informed discussion within the zoo and conservation community.