Lately, usually after reading the news, I find myself looking at my dog and saying, ‘Now here is an honest mammal’. Like all dogs, Mister Garçon lacks the ability to understand how lying may get him ahead in life. He may put on a show when treats are on offer, sure; but he doesn't lie. ‘I commend you on your honesty, Mister Garçon’, I say, and then I rough him up a little bit to remind him who's boss.

The thing is, it's not true. Dogs do lie. And small male dogs like Mister Garçon are the worst of the bunch. Perhaps out of academic interest or perhaps from being burned by a dog one too many times, Betty McGuire and her team at Cornell University endeavoured to get to the bottom of this dishonesty once and for all.

The dishonesty in question has to do with scent marking. Scent can convey all sorts of information, including sex, age, health, kinship, individual identity, and social and reproductive status. As such, scent marking is a common way for animals to transmit information about themselves into the future for other individuals to receive. We've all seen this before, usually in the form of dogs peeing on (i.e. transmitting) or sniffing (i.e. receiving) neighbourhood infrastructure. Interestingly, when dogs do this, the information they transmit or receive is conveyed not only in the scent signal itself, but also in the space it occupies: a scent located high up the lamppost signifies that a large dog walks these streets. For male dogs, this potentially wards off rival males while simultaneously attracting curious females.

Knowing this, the Cornell team hypothesized that adult male dogs embellish their height when urine marking, predicting that small male dogs aimed higher up the lamppost than large male dogs. To test this, the team first investigated whether raised-leg angle is indeed a proxy for urine mark height. Turns out it is. The researchers found that the angle between a dog's raised leg and the axis perpendicular to the ground was positively correlated with the height of the urine mark in similarly sized dogs. In fact, raised-leg angle was the best predictor of any proxy they investigated.

With this confirmed, McGuire and her team got to the meat of it: do small dogs raise their legs higher than large dogs? Yes! The findings revealed that the smaller the dog, the higher the raised-leg angle. This implies not only that urine marking can be dishonest, but also that small male dogs do what they can to appear more intimidating and/or alluring than they actually are. In other words, they lie.

My relationship with Mister Garçon has been affected by these findings. A goal of any guardian is to foster honesty in those they care for, and how this has manifested for the two of us is through my awkward attempts to physically push Mister Garçon’s leg down while simultaneously trying to avoid looking weird in front of the neighbours. ‘He's being dishonest’, I say in response to their baffled looks from the porch; ‘I'll send you the paper’. Fostering honesty while keeping up appearances has been a delicate dance, and it's not been an easy one. Perhaps I'll just relent and heed that age-old advice to let a peeing dog lie.

McGuire
,
B.
,
Olsen
,
B.
,
Bemis
,
K. E.
and
Orantes
,
D.
(
2018
).
Urine marking in male domestic dogs: honest or dishonest?
J. Zool
.