The spatial and temporal characteristics of the environment have exerted pressure on organisms, resulting in the different forms of life that we know today. It is easy to understand that a living being occupies a physical ecological niche, for example, in the marshes we can see how many species of herons, spoonbills and waders feed, that is their ecological niche where they obtain food and most likely shelter. This will also be the feeding niche for eagles, harriers or falcons.
On the other hand, otters also have the same ecological niche as the aforementioned animals, but we will never see them together, because they live in different time bandsor put another way, when these birds go to sleep the otter goes out to hunt fish and crustaceans, they feed on the same resource but do not compete for it because the temporary ecological niche is different.
This is one of the advantages obtained by the crepuscular animals and, therefore, in this article on our site we will explain what they are and we will give some examples.
What are twilight animals?
Twilight animals are those that become active at dusk and/or dawn. This type of behavior, like being diurnal or nocturnal, is regulated by the biological cycles inherent to each species.
Twilight animals gain certain advantages from their lifestyle. In desert climates they protect themselves from the high temperatures of the day and the low temperatures at night, since they come out just at the moment when the ambient temperature begins to oscillate.
They are more protected from being hunted by diurnal predators if we assume that the predator has already obtained food during the day. When a twilight animal leaves its refuge, the nocturnal animals will not have done so yet.
During the time these animals begin their activity, the sun's rays hit the earth's surface in such a way that it is more complicated for both a diurnal predator and a nocturnal predator to detect their prey.
Cardiac rhtyms
To better understand the biological cycles of crepuscular animals, we will talk about circadian rhythms. chronobiology is the discipline that studies biological rhythms, describing both their temporal characteristics and their implications for life. A biological rhythm is an oscillation of a biological parameter that depends on the endogenous clock (physiology and genetics) and environmental synchronizers (variations in the environment).
So, there are different types of biological rhythms:
- Circadian rhythm: biological activity that occurs with a periodicity of approximately 24 hours. Depending on how this cycle is regulated, daytime, nighttime and crepuscular animals will appear.
- Ultradian rhythm: biological activity that occurs in cycles of less than 20 hours (for example, feeding).
- Infradian rhythm: biological activity whose frequency is greater than 24 hours, that is, they occur less than once a day (for example lunar cycles).
Examples of crepuscular animals
Many animal species lead this twilight lifestyle either by living in arid climates, avoiding predators, or not having to compete for certain resources with other species. Below we show some animal species with twilight habits:
- The Gila monster (Heloderma suspectum): This reptile is the largest venomous lizard in the United States. It only comes out of its den when the sun goes down, sometimes it can go days and weeks without coming out and it will only do so if the weather turns rainy.
- The Striped Skunk (Mephitis mephitis) is another crepuscular species. During the day it spends time in its burrow, but at dusk and dawn it goes out in search of food. It is a very calm animal that tends to ignore other animals, but if it feels threatened it will spray a foul-smelling liquid on its attacker.
- The European otter (Lutra lutra), difficult to see and very elusive, has its peak of activity during twilight.
- The field rabbit (Oryctolagus cuniculus), although they can be seen during the day when the temperature is hot, are crepuscular animals. This allows them to avoid some aerial predators, such as the eagle.
- The wildcat (Felis silvestris), very similar to the common cat, like this one, has crepuscular habits. In the Iberian Peninsula there are several subspecies of wildcat, all of them with the same habits.
