Effects of incubation temperature on behavior of hatchling pine snakes: implications for reptilian distribution

Abstract

Incubation temperatures in vertebrates affectincubation periods, and in some reptiles incubation temperature determines sex ratios and some limited behavior. Here I present evidence that incubation temperature in pine snakes (Pituophis melanoleucus) affects not only incubation periods and posthatching behavior in the laboratory, but also the behavior of hatchlings required for successful emergence and survival. These behavioral differences have evolutionary implications for selection of hatchlings from particular temperature nests. With increasing temperature, incubation periods decreased in the laboratory. In addition, incubation temperature affected hatching and emergence times as well as movement speed and foraging ability. Hatchlings from medium temperature conditions emerged from nests in the field in less time than hatchlings incubated at high or low temperatures, and hatchlings from low temperatures moved slower and were less able to capture and eat mice in the laboratory than hatchlings incubated at medium or high temperatures. Taken together, these laboratory and field experiments suggest that hatchlings from low temperature nests, compared to those from higher temperature nests, would be less able to emerge, find food, and locate hibernation sites prior to the onset of cold temperatures in the New Jersey Pine Barrens. These results suggest that incubation temperature affects a whole range of behavior and that distributional ranges of reptiles and other poikilotherms could be affected by summer temperatures (via incubation period and subsequent behavior) as well as ambient winter temperatures.

Successful lizard eggs in a human-disturbed habitat

“…1 and 4). A number of laboratory and field studies have shown that warmer soil temperature results in a shorter incubation time of ectothermic, squamate eggs (e.g., Muth 1980;Burger 1991;Van Damme et al 1992;Castilla and Swallow 1996;Shine et al 1997;Elphick and Shine1998;Andrews et al 2000;Angilletta et al 2000). In these studies, a 1C warmer nest environment translated into a 4-10 day (7-12%) shorter incubation period.…”

“…Temperature has the most pronounced effect on incubation time at the cooler end of a species' developmental range (Muth 1980;Burger 1991;Castilla and Swallow 1996;Andrews et al 2000;Angilletta et al 2000). Forest soils at this elevation (1,300 m) might frequently experience temperatures for which the rate of embryonic growth is arrested or severely reduced.…”

Reproductive strategies in snakes

“…(iii) Incubation environment. In egg-laying squamates, thermal and hydric conditions during incubation can substantially modify developmental rates (and thus, the timing of hatching) and also phenotypic traits of the offspring (Burger 1989(Burger , 1990(Burger , 1991(Burger , 1998Burger et al 1987;Burger & Zappalorti 1988). Thus, reproducing females directly influence the phenotypes of their offspring by selecting nest-sites with specific incubation conditions .…”

Effect of tidal overwash on the embryonic development of leatherback turtles in French Guiana

“…Hatching success for organisms that lay eggs in a nest, such as sea turtles, is believed to be influenced by numerous biotic and abiotic factors such as predation, type of substrate, porosity, temperature, moisture content, salinity, slope of the beach, nest elevation, rainfall and tidal inundation (Mortimer, 1990;Horrocks and Scott, 1991;Ackerman, 1997;Wood and Bjorndal, 2000;Allen et al, 2001;Bilinski et al, 2001;Donlan et al, 2004;Foley et al, 2006). In many oviparous reptiles, however, environmental factors not only influence embryo survivorship (Horrocks and Scott, 1991;Resetarits, 1996), but also hatchling size (Packard and Packard, 1988), performance (Janzen, 1993), growth (Bobyn and Brooks, 1994), behaviour (Burger, 1991), and sex determination (Spotila et al, 1994). After the emergence of hatchling turtles, their survival may be strongly related to the distance at which the nest is laid from the sea and from supra-littoral vegetation behind the beach (Mrosovsky, 1983).…”