When Love Is in the Air: Understanding Why Dogs Tend to Mate when It Rains - PubMed (original) (raw)
When Love Is in the Air: Understanding Why Dogs Tend to Mate when It Rains
Sreejani Sen Majumder et al. PLoS One. 2015.
Abstract
Seasonality of reproduction is observed in many species of organisms, across taxa, and is influenced by both biotic and abiotic factors. While such seasonality is easy to understand in temperate species exposed to extreme climates, it is more difficult to explain in the tropics. In many tropical species offspring are born during the season of high precipitation, which also coincides with high resource availability. Interestingly, in India, free-ranging dogs seem to mate, and not whelp, when it rains--an observation that cannot be explained by the resource abundance hypothesis. We carried out an extensive study to identify the mating seasons of free-ranging dogs, and observed a strong correlation between both the incidence and frequency of mating related behaviours of dogs, and precipitation levels. There are two clear mating seasons, of which the primary mating season coincides with the monsoon (rainy season) and the secondary mating season coincides with the nor'westerlies in this part of India. We speculate that this strong correlation is an effect of chemistry, rather than biology. While male dogs can mate round the year, females come into estrous seasonally. In the urban environment, dogs are exposed to a lot of olfactory noise, which can dilute the signal present in sex pheromones of the females in heat. A shower leads to increased humidity and reduced temperature of the air, leading to intensification of pheromone signals that trigger a sexual response in the dogs.
Conflict of interest statement
Competing Interests: The authors have declared that no competing interests exist.
Figures
Fig 1. The occurrence of mating related behaviours (MRB) was highly correlated with precipitation levels (mm).
The precipitation levels reported here are actual readings of precipitation on the day of observations, as given by IMD. The linear fit is given by the black line, represented by the equation y = 0.4888x + 18.893, R2 = 0.6117.
Fig 2. The frequency of MRB varied with precipitation levels.
The bar chart shows the mean and standard deviation of the frequency of all MRB occurring at different levels of precipitation (as noted during the time of observations), over four years, 2010 to 2013, during the primary mating season. Variation in the frequency of MRB was not significant across the four years within a precipitation category (alphabets), but varied significantly different levels of precipitation within a year (*).
Fig 3. All MRB showed variation across precipitation categories.
Mean and standard deviation of the frequency of different mating related behaviours observed at the three precipitation levels noted during the time of observations—the different alphabets represent significant differences within a behaviour category, between precipitation levels.
Fig 4. The year-long census showed that highest MRB occur in the monsoon.
A bar chart showing the mean and standard deviation of the frequency of MRB per location in the four seasons. Different alphabets represent significant differences in the frequency of MRB between seasons. 40 locations were used in the study.
Fig 5. The frequency of MRB per location increased with increased precipitation.
A scatterplot showing the significant interaction between the numbers of MRB observed per location at different levels of precipitation (as recorded from IMD). The dotted line shows the linear fit, and is represented by the equation y = 0.1243x + 0.581, R2 = 0.4704.
Fig 6. MRB and precipitation patterns show convergent double binomial trends.
The plot shows the relationship between the occurrence of mating related behaviours (MRB) and precipitation levels over a year, on a fortnightly basis. The red dots represent the number of MRB averaged over the number of locations sampled in a fortnight and blue dots represent the average precipitation level (from IMD) considering only the days of the census. Both the datasets fit double normal distributions, as represented by the lines of the respective colours. A1 and A2 represent the two amplitudes of the respective curves at x0 time as read from the x-axis.
Similar articles
- Why do most tropical animals reproduce seasonally? Testing hypotheses on an Australian snake.
Brown GP, Shine R. Brown GP, et al. Ecology. 2006 Jan;87(1):133-43. doi: 10.1890/04-1882. Ecology. 2006. PMID: 16634304 - Male mating strategies and reproductive constraints in a group of wild tufted capuchin monkeys (Cebus apella nigritus).
Alfaro JW. Alfaro JW. Am J Primatol. 2005 Nov;67(3):313-28. doi: 10.1002/ajp.20188. Am J Primatol. 2005. PMID: 16287110 - An integrative view of sexual selection in Tribolium flour beetles.
Fedina TY, Lewis SM. Fedina TY, et al. Biol Rev Camb Philos Soc. 2008 May;83(2):151-71. doi: 10.1111/j.1469-185X.2008.00037.x. Biol Rev Camb Philos Soc. 2008. PMID: 18429767 Review. - Can the limited marsupium space be a limiting factor for Syngnathus abaster females? Insights from a population with size-assortative mating.
Silva K, Vieira MN, Almada VC, Monteiro NM. Silva K, et al. J Anim Ecol. 2008 Mar;77(2):390-4. doi: 10.1111/j.1365-2656.2007.01346.x. Epub 2008 Jan 8. J Anim Ecol. 2008. PMID: 18194263 - Reproductive strategies in snakes.
Shine R. Shine R. Proc Biol Sci. 2003 May 22;270(1519):995-1004. doi: 10.1098/rspb.2002.2307. Proc Biol Sci. 2003. PMID: 12803888 Free PMC article. Review.
Cited by
- Photoperiod and Melatonin Supplementation: Variable Effects on the Quality of Chilled Dog Semen.
Mitjana O, Ausejo R, Mendoza N, Miguel J, Tejedor MT, Garrido AM, Falceto MV. Mitjana O, et al. Front Vet Sci. 2022 Jul 12;9:956630. doi: 10.3389/fvets.2022.956630. eCollection 2022. Front Vet Sci. 2022. PMID: 35903132 Free PMC article. - Seasonal Patterns of Oestrus and Reproduction in Street Dogs of Indian Cities.
Brill G, Kartal T, Yadav DP, Bhyan M, Patel C, Sheoran SK, Patel P, Painuly B, Chaudhari A. Brill G, et al. Front Vet Sci. 2022 Jun 17;9:821424. doi: 10.3389/fvets.2022.821424. eCollection 2022. Front Vet Sci. 2022. PMID: 35782534 Free PMC article. - Magnitudes of diseases in dogs vary among different levels of age, gender, breed, and season: A hospital-based, retrospective cross-sectional study.
Uddin MM, Talukder H, Islam O, Asaduzzaman M, Das M, Ahsan MI, Islam S. Uddin MM, et al. Heliyon. 2021 Oct 29;7(11):e08287. doi: 10.1016/j.heliyon.2021.e08287. eCollection 2021 Nov. Heliyon. 2021. PMID: 34778579 Free PMC article. - Canine Olfaction: Physiology, Behavior, and Possibilities for Practical Applications.
Kokocińska-Kusiak A, Woszczyło M, Zybala M, Maciocha J, Barłowska K, Dzięcioł M. Kokocińska-Kusiak A, et al. Animals (Basel). 2021 Aug 21;11(8):2463. doi: 10.3390/ani11082463. Animals (Basel). 2021. PMID: 34438920 Free PMC article. Review. - Canine olfactory detection and its relevance to medical detection.
Jendrny P, Twele F, Meller S, Osterhaus ADME, Schalke E, Volk HA. Jendrny P, et al. BMC Infect Dis. 2021 Aug 19;21(1):838. doi: 10.1186/s12879-021-06523-8. BMC Infect Dis. 2021. PMID: 34412582 Free PMC article. Review.
References
- Bronson FH. Mammalian reproductive biology, pp. 51–52 Chicago, IL: The University of Chicago Press; 1989.
- Bronson FH, Heideman PD. Seasonal regulation of reproduction in mammals In The physiology of reproduction (eds Knobil E., Neill J. D.), 2nd edn New York, NY: Raven Press; 1994.
- Prendergast B. Internalization of seasonal time. Horm Behav. 2005; 48: 503–511. - PubMed
- Bronson FH. Seasonal variation in human reproduction: environmental factors. Quart. Rev. Biol. 1995; 70: 141–164. - PubMed
- Brockman DK, van Schaik CP. Seasonality in primates: Studies of living and extinct human and non-human primates. Cambridge University Press; 2005.
Publication types
MeSH terms
Grants and funding
The work was funded by the Women's Excellence Award No. SB/WEA-005/2013 by the Science and Engineering Board, Department of Science and Technology, India to AB; Indian Institute of Science Education and Research Kolkata, India provided infrastructural support.
LinkOut - more resources
Full Text Sources
Other Literature Sources