Propagule size and sex ratio influence colonisation dynamics after introduction of a non-native lizard Number of Authors: 92022 (English)In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 91, no 4, p. 845-857Article in journal (Refereed) Published

Abstract [en]

1. The composition of founding populations plays an important role in colonisation dynamics and can influence population growth during early stages of biological invasion. Specifically, founding populations with small propagules (i.e. low number of founders) are vulnerable to the Allee effect and have reduced likelihood of establishment compared to those with large propagules. The founding sex ratio can also impact establishment via its influence on mating success and offspring production.
2. Our goal was to test the effects of propagule size and sex ratio on offspring production and annual population growth following introductions of a non-native lizard species (Anolis sagrei). We manipulated propagule composition on nine small islands, then examined offspring production, population growth and survival rate of founders and their descendants encompassing three generations.
3. By the third reproductive season, per capita offspring production was higher on islands seeded with a relatively large propagule size, but population growth was not associated with propagule size. Propagule sex ratio did not affect offspring production, but populations with a female-biased propagule had positive growth, whereas those with a male-biased propagule had negative growth in the first year. Populations were not affected by propagule sex ratio in subsequent years, possibly due to rapid shifts towards balanced (or slightly female biased) population sex ratios.
4. Overall, we show that different components of population fitness have different responses to propagule size and sex ratio in ways that could affect early stages of biological invasion. Despite these effects, the short life span and high fecundity of A. sagrei likely helped small populations to overcome Allee effects and enabled all populations to successfully establish.
5. Our rare experimental manipulation of propagule size and sex ratio can inform predictions of colonisation dynamics in response to different compositions of founding populations, which is critical in the context of population ecology and invasion dynamics.

Place, publisher, year, edition, pages

2022. Vol. 91, no 4, p. 845-857

Keywords [en]

Allee effect, Anolis sagrei, biological invasion, invasive species, population establishment, population estimation, population growth

National Category

Biological Sciences

Identifiers

URN: urn:nbn:se:su:diva-203160DOI: 10.1111/1365-2656.13671ISI: 000761800400001PubMedID: 35114034Scopus ID: 2-s2.0-85124759506OAI: oai:DiVA.org:su-203160DiVA, id: diva2:1646947

Available from: 2022-03-24 Created: 2022-03-24 Last updated: 2022-06-08Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMedScopus

Authority records

Kahrl, Ariel F.

Search in DiVA

By author/editor

Kahrl, Ariel F.

By organisation

Department of Zoology

In the same journal

Journal of Animal Ecology

On the subject

Biological Sciences

Search outside of DiVA

GoogleGoogle ScholarTotal: 36 hits