Mind the gap: treefalls as drivers of parental trade‐offs

Abstract

Tree‐fall gaps are small‐scale disturbances whose formation, colonization, and role in forest dynamics are well documented, but whose effects on animal ecology are still greatly overlooked, except for studies comparing species richness of gaps 6+ months old to that in the closed canopy. Other factors associated with the invasion of fresh tree‐fall gaps such as animal breeding adaptations have been largely neglected. I studied the immediate (within hours and days) arrival of the poison frog Dendrobates tinctorius in new tree‐fall gaps to examine the dynamics of their invasion in relation to tadpole rearing. I found that rearing sites are occupied sooner and tadpoles deposited at higher rates in fresh gaps than in the closed forest, but that the rate of cannibalism is also much greater in the former. This suggests that invading new tree‐fall gaps can be the best parental decision when parents arrive early because they get access to fresh, high‐quality resources, but it could be to the detriment of the offspring if parents arrive late, because of overcrowding and cannibalism. These results highlight the importance of studying the earliest stages of invasions in order to have a better understanding of the composition of communities in disturbed ecosystems at later successional stages.

Relying on known or exploring for new? Movement patterns and reproductive resource use in a tadpole-transporting frog

“…Finally, other indirect cues, such as pool-associated microhabitat (e.g., as in salamanders ( Jenkins, McGarigal & Timm, 2006 )) or calls of heterospecifics (e.g., as in newts ( Diego-Rasilla & Luengo, 2007 )), might be used by tadpole-transporting frogs to discover breeding sites. For example, transporting males of the poison frog Dendrobates tinctorius were found to gather at sites of fresh treefalls, which often provide new deposition sites ( Rojas, 2015 ).…”

From Habitat Use to Social Behavior: Natural History of a Voiceless Poison Frog, Dendrobates tinctorius

“…), even conspecifics ( Fig. 7A; Rojas , 2015. Tadpole 256 mouthparts are well suited for their carnivorous diet, with hardened serrated jaw sheath (Silverstone 1975; 257 Some males carrying more than one tadpole were seen depositing one of them in a pool and leaving with 266 the second tadpole still attached to their back, whereas other males were seen depositing their two 267 tadpoles in the same pool, at the same time.…”

“…These structures are 307 used as oviposition sites (this study), and are also the types of structures that accumulate rainwater, Males' association with structured habitats may also be the key reason why they are more likely to be 317 found in tree-fall gaps long after their formation. A recent study reported higher tadpole deposition rates 318 in pools at recent tree-fall gaps in comparison to pools in the closed forest (Rojas 2015), suggesting that 319 the availability of new places for tadpole deposition is one of the drivers of tree-fall gap invasion in this 320 species. However, the immediate arrival in tree-fall gaps is not exclusive of males.…”

Peer Review #1 of "Relying on known or exploring for new? Movement patterns and reproductive resource use in a tadpole-transporting frog (v0.1)"

“…Finally, other indirect cues, such as pool-associated microhabitat (e.g., as in salamanders (Jenkins, McGarigal & Timm, 2006)) or calls of heterospecifics (e.g., as in newts (Diego-Rasilla & Luengo, 2007)), might be used by tadpoletransporting frogs to discover breeding sites. For example, transporting males of the poison frog Dendrobates tinctorius were found to gather at sites of fresh treefalls, which often provide new deposition sites (Rojas, 2015).…”