Conditional female strategies influence hatching success in a communally nesting iguana
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
Journal titleEcology and Evolution
MetadataShow full item record
AbstractThe decision of females to nest communally has important consequences for reproductive success. While often associated with reduced energetic expenditure, conspecific aggregations also expose females and offspring to conspecific aggression, exploitation, and infanticide. Intrasexual competition pressures are expected to favor the evolution of conditional strategies, which could be based on simple decision rules (i.e., availability of nesting sites and synchronicity with conspecifics) or on a focal individual's condition or status (i.e., body size). Oviparous reptiles that reproduce seasonally and provide limited to no postnatal care provide ideal systems for disentangling social factors that influence different female reproductive tactics from those present in offspring‐rearing environments. In this study, we investigated whether nesting strategies in a West Indian rock iguana, Cyclura nubila caymanensis, vary conditionally with reproductive timing or body size, and evaluated consequences for nesting success. Nesting surveys were conducted on Little Cayman, Cayman Islands, British West Indies for four consecutive years. Use of high‐density nesting sites was increasingly favored up to seasonal nesting activity peaks, after which nesting was generally restricted to low‐density nesting areas. Although larger females were not more likely than smaller females to nest in high‐density areas, larger females nested earlier and gained access to priority oviposition sites. Smaller females constructed nests later in the season, apparently foregoing investment in extended nest defense. Late‐season nests were also constructed at shallower depths and exhibited shorter incubation periods. While nest depth and incubation length had significant effects on reproductive outcomes, so did local nest densities. Higher densities were associated with significant declines in hatching success, with up to 20% of egg‐filled nests experiencing later intrusion by a conspecific. Despite these risks, nests in high‐density areas were significantly more successful than elsewhere due to the benefits of greater chamber depths and longer incubation times. These results imply that communal nest sites convey honest signals of habitat quality, but that gaining and defending priority oviposition sites requires competitive ability.
DescriptionSister Isles rock iguanas lay a single clutch of eggs annually, often communally in areas varying in nest density. In this study, we investigated whether female nesting strategies differ with body size or timing, and evaluated consequences for reproductive success. Use of high‐density communal areas increased up to nesting activity peaks, after which nesting was generally restricted to low‐density areas. Larger females nested earlier, constructed deeper nests associated with longer incubation times, and gained access to priority sites within communal areas. Higher nest densities were associated with decreased hatching success, with up to 20% of nests experiencing intrusion by another female. Despite this, nests in high‐density areas were more successful than elsewhere due to the benefits of greater chamber depths and longer incubation times. These results imply that communal nest sites convey honest signals of habitat quality, but that gaining access to and defending priority nest sites requires competitive ability.
Except where otherwise noted, this item's license is described as https://creativecommons.org/licenses/by/4.0/