Timing is everything, especially when it comes to reproduction. Well-timed reproduction improves reproductive success. For example, offspring that hatch when food is abundant or predators are scarce are more likely to survive. However, changing environmental conditions may cause organisms to miss the best time to reproduce. Since environmental variability is ubiquitous on a wide range of spatial and temporal scales, the ability to adjust to changing conditions can improve an organism’s chances of reproducing “on time”.
|Ovigerous Uca deichmanni female. Photo by Arthur Anker|
Most, though not all, of the ways that organisms can maintain reproductive timing in response to temperature changes are behavioural. For example, as changing climate is causing earlier springs, some bird species are laying eggs earlier in the year so that their offspring still hatch when their food is most abundant. Another possible response is to select the location where the eggs will be laid and incubated based on temperature, such as a relatively warmer location if temperature decreases before the eggs are laid, or a cooler location if temperature increases. Some lizards and spiders use this method of adjustment. For species that carry their eggs throughout incubation or that can control the temperature of the incubation site throughout development, there is the option of actively regulating the temperature that the embryos experience. Some bird species actively maintain the temperature of their nests. This is also probably a more common response in egg-carrying invertebrates than has been documented thus far.
|Uca terpsichores courting male. Photo by Kecia Kerr|
Surprisingly, behavioural adjustments to environmental variability, and the diversity of responses that species employ, remain underappreciated. However, over the last few years there have been calls for increased attention to the potential importance of plastic behavioural responses in mitigation of detrimental effects of environmental variation (Kearney et al. 2009, Sih et al. 2010). While many species are already being negatively affected by climate change, many others are likely able to diminish the impacts, at least to some extent, via behavioural responses. Much more research is needed to better understand how organisms respond to variable environmental conditions and what impacts these responses may have on their ecology.
Kearney M, Shine R, Porter WP (2009) The Potential for Behavioral Thermoregulation to Buffer “cold-Blooded” Animals Against Climate Warming. PNAS 106:3835–3840
Sih A, Stamps J, Yang LH, McElreath R, Ramenofsky M (2010) Behavior as a key component of integrative biology in a human-altered world. Integrative and Comparative Biology 50:934–944