Early life differences in behavioral predispositions in two Alligatoridae species

Abstract

Behavioral predispositions are innate tendencies of animals to behave in a given way without the input of learning. They increase survival chances and, due to environmental and ecological challenges, may vary substantially even between closely related taxa. These differences are likely to be especially pronounced in long-lived species like crocodilians. This order is particularly relevant for comparative cognition due to its phylogenetic proximity to birds. Here we compared early life behavioral predispositions in two Alligatoridae species. We exposed American alligator and spectacled caiman hatchlings to three different novel situations: a novel object, a novel environment that was open and a novel environment with a shelter. This was then repeated a week later. During exposure to the novel environments, alligators moved around more and explored a larger range of the arena than the caimans. When exposed to the novel object, the alligators reduced the mean distance to the novel object in the second phase, while the caimans further increased it, indicating diametrically opposite ontogenetic development in behavioral predispositions. Although all crocodilian hatchlings face comparable challenges, e.g., high predation pressure, the effectiveness of parental protection might explain the observed pattern. American alligators are apex predators capable of protecting their offspring against most dangers, whereas adult spectacled caimans are frequently predated themselves. Their distancing behavior might be related to increased predator avoidance and also explain the success of invasive spectacled caimans in the natural habitats of other crocodilians.

Naive poison frog tadpoles use bi-modal cues to avoid insect predators but not heterospecific predatory tadpoles

“…For example, while reduced mobility and activity or hiding can considerably reduce predation risk ( Lawler, 1989 ), it also reduces the time available for mating and foraging ( Sih, 1987 ). Such physiological or reproductive trade-offs are found across a wide range of taxa ( Tollrian and Harvell, 1999 ) and have probably led to the evolution of flexible anti-predator responses in animals ( Reber et al, 2021 ).…”

ManyBirds: A multi-site collaborative Open Science approach to avian cognition and behavior research

“…We will actively utilise Open Science practices, including pre-registration and/or Registered Reports, open data and code on repositories alongside relevant publications, pre-prints, as well as the use of open-access publishing to ensure wide accessibility, as transparency and pre-registration is necessary for effective collaborations (Allen & Mehler, 2019). Aspects that we believe are novel for the ManyX projects include our aim to incorporate automated video analysis (e.g., Reber et al, 2021) to reduce the time investment of manual coding & control for reliability, and include captive (lab, zoo, private residence) plus field studies to improve generalisability and increase within-species comparisons.…”

“…We are in the process of expanding on this pilot work to form our first ManyBirds study by opening up new collaborations with bird species outside the corvid family, in order to test neophobia in birds with a focus on a) species differences, b) influence of socio-ecological factors, and c) individual temporal and contextual consistency. This work involves modifying the corvid protocol to be suitable for testing other bird species (e.g., in social settings or at non-academic sites), and introducing the use of automatic video analysis software (Reber et al, 2021). Additionally, to the existing corvid data set, Mettke-Hofmann et al (2002) tested object neophobia in 61 parrot species with comparable methods.…”

ManyBirds: A multi-site collaborative Open Science approach to avian cognition and behaviour research

“…We are in the process of expanding on this pilot work to form our first ManyBirds study by opening up new collaborations with bird species outside the corvid family, in order to test neophobia in birds with a focus on a) species differences b) influence of socio-ecological factors c) individual temporal and contextual consistency. This work involves modifying the corvid protocol to be suitable for testing other bird species (e.g., in social settings or at non-academic sites), and introducing the use of automatic video analysis software [61]. Additionally, to the existing corvid data set, Mettke-Hofmann et al [64] tested object neophobia in 61 parrot species with comparable methods.…”