Breeding season for coyote isn't something that comes and goes in a totally predictable time frame . We can pin it down to kind of a time period from January to March though . I took a den of coyote pups as early as the 8th of April , that had 6 new born pups maybe a day old , and one with new born pups as late as the 15th of June , that had , four , one day old pups in it . The den in April had an old female she was probably 6 or 7 years old , she had thick ears and showed quite a lot of wear on her teeth . The den in June had a younger female she was only a yearling . She still had thin ears and sharp points on her teeth . Over the years of keeping notes I found that it appears that the older females pup earlier then the younger females . I also noted that the size of the litter depends on the available food . More food healthier females carrying and having more pups . Less food available and smaller litters of pups . More then once I have taken dens with 10 to 13 pups in the litter when they had plenty of prey to feed on . When the prey base was low often I would take dens with an average of 5 pups , some with only 3 to 4 pups and some with up to 6 pups . Even in good years with plenty of prey my notes show that the younger females didn't have as many pups as the older females . When you check out the females it showed that the older females had a better layer of fat on them then the younger females so I concluded the litter size was due to the abilities of the females to hunt and feed themselves thus the health of the females . I believe that also has a big part in the timing of the females cycle and receptiveness to being bred . Last year one of the guys that I worked closely with took a female that didn't have a uterus . In more then 40 years this was the first time I had ever heard of that being the case . It would be interesting to know what the cause of that was , but he didn't send her in for study just took pictures , And new things just keep showing up don't they .