27/04/2024
SPRINGTIME & DOGS: AN EVOLUTIONARY BIOLOGY PERSPECTIVE
Spring is often a long awaited event for many of us after a wet and cold winter. A mere glimpse of daffodil bulbs, and the promise of longer and warmer days can see us cleaning our homes and doing chores we had been putting off for months. For dogs however, a change in seasons can signal multifaceted physiological and behaviour patterns that have been determined from evolutionary biology.
Animal neuro-endocrine systems undergo seasonal shifts. In winter, melatonin activity for example (which is directly related to duration of sunlight exposure) decreases firing of the retinal nerves which trigger hormones for breeding in some species Seasonal breeding is commonly seen due to this, with some groups being assigned as 'short-day breeders’ (eg: sheep , deer and fox ) and long-day breeders ( eg: wolves, horses)
This is also referred to as a 'photoperiod' (an organism’s daily exposure to light) The ancestral control pathway of photoperiodism is thought to have originated before the divergence of mammalian and avian vertebrate lineages in the evolutionary timeline.
However, dogs and other species such as cattle and pigs, are polyestrous, which means they can cycle all year round. Fascinatingly, some exceptions are seen in Basenji and sled dogs who breed photoperiodically.
Dogs are shown to not require a photoperiod to regulate the reproductive cycle ,but their shedding cycles and immune systems are affected by photoperiodic mechanisms.
Most certainly breeding and feeding patterns of other species of both plants and animals affect our dogs’ behaviour seasonally.
Spring brings new and exciting smells from plant and animal activity. Dogs senses typically heighten during this time, and this can mean they get easily immersed or distracted, often manifesting in hunting, amplified olfactory or foraging behaviours depending on the breed and location of the dog. In multi-dog homes this can become challenging if one dog is more prey or scent driven than others, or if all are.
While these fall within perimeters of normal behaviour, dog professionals might get increased enquiries during this time about dogs not recalling , hunting excessively, grass and plant ingesting , not coming inside from the garden, or suddenly becoming fixated by some prey animals. Puppies exposed to the wider world for the first time after their vaccinations can experience sensory overload as well as adolescent dogs who's pre-frontal cortexes are still under development.
Another seasonal affect potentially in pet dogs, who mostly follow human like diurnal sleep patterns, might see an increase in crepuscular activity, like waking at 5.30am or becoming restless around dusk.
Diurnal sleep patterns in pet dogs are hypothesized to be an adaptation to living alongside humans, because variations of nocturnal and crepuscular patterns are observed in most other canids whereas diurnal activity is rarely seen. There are some data to suggest that dogs can benefit from a dark room to achieve sleep efficiency. This might be relevant in the modern environment where open plan light filled rooms are commonly seen.
Spring can therefore quickly become a frustrating time for both dogs and their humans, but recognising the effects of evolutionary biology and making some adjustments can help.
Depending on what is reinforcing for the dog, some ideas for springtime could include providing targeted exploratory enrichment, long line walks to avoid predation or avoiding prey species photoperiodic activity , safe opportunities to dig, scent work or simply some good naps on the sofa together.
Boo Blackhurst CDBC
References:
L. Senger, Phillip 2005, Pathways to Pregnancy and Parturition
Robert Bodiz et al 2019, Sleep in the dog: comparative, behavioral and translational relevance
Brian J. Prendergast 2005, Internalization of seasonal time
Lofts B 1978, Animal Photoperiodism
