Author: James T. Stroud Page 4 of 6

While doing some local herping for fun this weekend with a couple of friends visiting from out of town (Janson Jones of previous AA fame; 1,2,3,4,5), we happened upon this Cuban knight anole (Anolis equestris) with a fairly conspicuous hole in its dewlap. Despite this, the lizard appeared in prime condition. Other reports of strange dewlaps have been documented on AA before, such as these grey-dewlapped Puerto Rican crested anoles (A. cristatellus) and American green anoles (A. carolinensis), but has anyone ever seen any individuals with tissue missing from the core region of the dewlap (as opposed to injuries sustained on the peripheries, such as this Cuban brown anole (A. sagrei), which aren’t generally that uncommon)?

Here’s one example, from an AA post from four years ago.

On a fleeting one-night stopover in Miami last week, Anthony Geneva had the chance to pop in and say hello at Fairchild Tropical Botanical Gardens and take a morning stroll to view some of the resident anoles (see others posts about Fairchild anoles here: 1,2,3,4). While waiting to be joined by fellow local anolologist and distichus aficionado Winter Beckles (University of Miami), Anthony and I noticed some commotion by the edge of a nearby pond. Upon closer inspection, we realized that a tricolored heron (Egretta tricolor) appeared to be juggling a large anole in it’s mouth! In my morning rush, I had managed to forget not just my anole-catching noose pole, but alas, also my camera. Fortunately, Anthony was on hand to fill the David Bailey role.

After re-positioning the lizard a few times, the heron appeared to do something peculiar – it repeatedly dunked the lizard in and out of the water. This happened perhaps 5-6 times. Was this an attempt to expedite a fatality prior to consumption, or perhaps a neat trick to help lubricate such a large prey item?

In all, the process of ingestion took less than 10 seconds, following a couple of minutes of dunking and repositioning.

This observation follows a recent hot post reporting the predation of anoles by reintroduced whooping cranes (Grus americana) in Louisiana, which itself was preceded by various observations of avian-fuelled anolivory in South Florida (1, 2, 3, 4). Even more recently, while showing Thom Sanger and Bonnie Kircher around Fairchild Gardens a few weeks back, we observed a Cooper’s hawk (Accipiter cooperii), a widely-regarded bird specialist, snatch an American green anole (A. carolinensis) from the frond of a towering Royal Palm (Roystonea regia) – an event Rob Heathcote and I had observed the previous year with an adult male A. cristatellus in nearby Matheson Hammock. Unfortunately none of us were privileged with Anthony’s camera reflexes to capture any of those events.

So, why’s this interesting? (Excluding the obvious natural history enlightenment of revealing, at least personally, a previously unclear predator-prey interaction). Well, tricolored herons are a widespread breeding resident throughout much of the US Gulf states and as far south through the Caribbean to central Brazil and Peru. Therefore, the consumption of crested anoles (A. cristatellus) isn’t necessarily a novel interspecific interaction – it’s possible that this occurs in the native range of A. cristatellus, Puerto Rico, where both exist. However, although tricolored herons are natural residents of South Florida, it would be a tough sell to argue that crested anoles would be naturally on the menu. Crested anoles were first introduced to South Miami in the 1970s – the original site of introduction being a mere stone’s throw from this observation (for a review of the subsequent dispersal patterns of A. cristatellus in Miami see Kolbe et al. 2016; pdf here). So although crested anoles are being exposed to many novel biotic interactions in Miami, it seems they can’t escape some.

Have any Puerto Rico anolophiles observed this interaction before?

A smug bird.

As I mentioned in a previous post (1), community ecology is a confusing field, confounded by the interchangeable use of many fundamental terms.

A group of graduate students and I discussed this paradigm and thought we would see what people’s own interpretations were, as an update and extension of a previous exercise conducted by Fauth et al. (1996). We created an online poll asking contributors to describe which factors are most important in defining the following key terms in community ecology: ‘community,’ ‘assemblage,’ ‘guild’ and ‘ensemble.’

There was certainly a lot of variation! We decided it was interesting enough to draft the results up into a manuscript, and it has eventually found some light in Ecology and Evolution. Specifically, we discussed the interpretation of each term from the perspective of undergraduate, graduate, non-academic, and professor perspectives, and conducted a thorough review of many ecology and evolution textbooks to investigate similarities in use. The abstract is detailed below, and you can find a link to the original paper here. Many thanks to all of you who contributed to the survey, your input it very much appreciated!

Abstract:

Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; “community,” “assemblage,” “guild,” and “ensemble”. We revisit Fauth et al.’s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre-1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups.

Figure 1. Relative interest in community ecology terms from 1977 to 2013, as reflected by respective citation histories (trends are overlayed, not stacked). The publication date of Fauth et al. is indicated by a vertical dashed line. Terms were searched for in the“ecology” category of ISI Web of Science (accessed 20 February 14).

Stroud, J.T., Bush, M.R., Ladd, M.C., Nowicki, R.J., Shantz, A.A., and Sweatman, J. (2015) – Is a community still a community? Reviewing definitions of key terms in community ecology. Ecology and Evolution, 5(21): 4757-4765

Although one tragedy did occur – we were a month too late to get into the issue sporting a beautiful green anole as the cover photo! Credit goes to Simon Lailvaux and colleagues for getting yet another anole front page.