Zygomycete Mucorales grow on decaying organic matter such as spoiled food or excrement. These fascinating organisms have a range of interesting sensory responses - negatively geotropic, negatively phototropic, and touch-avoidance which allows them to grow away from neighbouring objects. Phycomyces species have colourful sporangia up to 10cm tall and have been called "the most intelligent of fungi". This grey fuzzy mass was growing on the spilled seed/guano under a bird feeder. Sporangiophores ~5 cm long, hyaline near sporangia, unbranched, sporangia yellow then black. Spores elliptical/oblong ~25µm long. Based on the key to species (Benjamin & Hesseltine (1959) Studies on the genus Phycomyces. Mycologia, 51(6), 751-771):

1 Sporangiospores oval to elliptical -> 2 - Sporangiospores globose -> P. microsporus 2 Sporangiospores averaging 15-30 µm in length -> P. nitens *