NOTE: The following list contains 84 scientific studies published between 2005 & 2020.
—Have we missed any recent research on the human-comparable intelligence of other species? Submit here.

  1. JUST LIKE HUMANS, Whales Grieve For Their Dead|Nature World '16
  2. Bees JUST LIKE HUMANS Form False Memories|Queen Mary, U of L '15
  3. Bird Song JUST LIKE HUMAN Syntax|Pacific Standard '16
  4. Canines Dream JUST LIKE HUMANS, New Research Finds|CitizenNews '16
  5. Pigeons Can Gamble JUST LIKE HUMANS|Proc. of Royal Society '10
  6. Horses Smile and Pout JUST LIKE HUMANS, Study Says|Time '16
  7. Horse Facial Expressions JUST LIKE HUMANS|Nat Geo '17
  8. Human, Seahorse Pregnancy INCREDIBLY ALIKE|Nat Geo '15
  9. Whales & Dolphins Have Rich HUMAN-LIKE Cultures|Sci Daily '17
  10. Scientists Claim Animals Have HUMAN-LIKE Consciousness|Artsmia '13
  11. Further Proof Dolphins Have HUMAN-LIKE Intelligence|Awaken '15
  12. Study Says Chimpanzees Use HUMAN-LIKE Gestures|BBC '12
  13. Test Shows Pigeons Learn LIKE HUMAN Children|Redorbit '15
  14. Ravens Can Possess HUMAN-LIKE features of intelligence|Sust Times '19
  15. Frogs Found SURPRISINGLY LIKE HUMANS, Genetically|Live Sci '10
  16. Ape Speech SURPRISINGLY LIKE OURS|Christ Sci Monitor '16
  17. Crows Have SURPRISING COGNITIVE ABILITIES|ScienceBlogs '10
  18. Rodents Have SURPRISING EMPATHETIC ABILITIES|Science Direct '11
  19. Honeybee shows SURPRISING NUMERIC SKILLS|ScienceAGo '09
  20. Sea Urchin DNA's SURPRISING RELATIONSHIP to Human's|Nat. Sci '06
  21. Whale Brains Are SURPRISINGLY SIMILAR to Human Brain|Softpedia '06
  22. Brain Scan Shows STRIKING SIMILARITIES B/t Dogs, Humans|WIRED '14
  23. Chimps Can Walk  SURPRISINGLY SIMILAR To Humans|Smithson '15
  24. A Slime Mold Shows SURPRISING DEGREE OF INTELLIGENCE|Disc Mag '08
  25. Speech of Japanese Bird SURPRISINGLY LIKE HUMANS|Pulse '16
  26. Scientists Find Our Brain SURPRISINGLY SIMILAR to Ugly Fish|Inverse '16
  27. Research Says Prairie Dogs SURPRISINGLY APT At Chatting|Futurism '13
  28. Spider Gene Mapped, Reveals SURPRISING SIMILARITIES to Us|Sci Daily '14
  29. Shark & Human Proteins are SURPRISINGLY SIMILAR|Cornell Chron '13
  30. Human, Fly, & Worm Genome SURPRISINGLY SIMILAR|ANN News '14
  31. Dogs, Humans Process Speech in REMARKABLY SIMILAR Ways|Gizmo '14
  32. When Place Learning Mice Brains FUNCTION SIMILARLY To Ours|KU-L '19
  33. Why are Insect & Human Brains SO SIMILAR|Futurity '13
  34. Human and Ape Baby Gestures MORE SIMILAR Than Expected|Smithson '13
  35. Why Dogs & Human Brains MORE SIMILAR Than Thought|Giz Neuro '14
  36. Cats Possess Personalities SIMILAR TO HUMANS, Study Finds|Par Hrld '16
  37. Birds & Humans Have SIMILAR BRAIN WIRING|ScienceDaily '13
  38. Animal Talk Shows SIMILARITIES TO HUMAN LANGUAGE|Sci Mag '14
  39. Humans, Cats Have IDENTICAL BRAIN REGIONS for Emotion|Psych2go '1
  40. Pigs Actually Are ALMOST IDENTICAL to Us, Say Scientists|DailyMail '12
  41. Shark Simply Are MORE LIKE US Than You Think|Futurity '13 
  42. Gorillas Found MORE RELATED TO US Than Thought|Nat. Geo. '12
  43. Chimps Found ALMOST HUMAN, and Sometimes Smarter|NYT '07
  44. Common Fish SMARTER THAN YOU THINK|IFL Science '15
  45. Your Dog is SMARTER THAN WE THINK|Philly Inquirer '09
  46. Crows Are SMARTER THAN YOU THINK|Univ of Iowa '14
  47. Horses are SMARTER THAN WE REALIZE|Mother Nature Net '15 
  48. Ducklings: SMARTER THAN YOU THINK|Wash. Post '16
  49. Insects Are SMARTER THAN WE THOUGHT|Sydney Morn Hrld '16
  50. Goats: Way SMARTER THAN YOU THOUGHT|USA Today '14
  51. Chickens Are SMARTER THAN WE THINK|AAHA '17
  52. Sheep Are Far SMARTER THAN PREVIOUSLY THOUGHT|Telegraph '11
  53. Bees Are Much SMARTER THAN WE THOUGHT|PanSwiss '12
  54. Study Shows Kea SMARTER THAN PREVIOUSLY THOUGHT|News Hub '20
  55. Elephants Are Even SMARTER THAN WE IMAGINED|Sci Amer '14
  56. The Dodo Maybe SMARTER THAN WE THOUGHT|Time.com '16
  57. Chicken Have STARTLING INTELLIGENCE|Sci Amer '14
  58. Cows Are WAY MORE INTELLIGENT Than Likely Thought|Huff Post '15
  59. Pigs Are INTELLIGENT, EMOTIONAL, & Cognitively Complex|Psych Today '15
  60. Octopi SO SMART: DNA Sequencing Suggests Why|ExtremeTech '15
  61. Orca Are SO SMART They Can Learn to Speak "Dolphin"|ZME Science '14
  62. Crows Can Be SO CLEVER; Here's Why|Financial Times '16
  63. Animals Can Use ABSTRACT THOUGHT|Newser '14
  64. Tiny Insect Brains CAN SOLVE BIG PROBLEMS|NBCnews '09
  65. Human Intelligence ISN'T SUPERIOR To Other Animals|Huff Post '13
  66. Animals' Howls & Chirps JUST AS COMPLEX As Human Speech|DailyMail '14
  67. Chimp's Working Memory FAR SUPERIOR To Our Own|Med Daily '13
  68. New Study Confirms Horses CAN READ HUMAN EMOTIONS|Inverse '16
  69. Finding Suggests That Whales CAN LOVE|UPI '06
  70. Dolphins So Intelligent They've INDIVIDUAL NAMES|DailyMail '13
  71. Language, Birdsong May Use SAME BRAIN STRUCTURES|BBC '15
  72. Scientists Say Dolphins Do DESERVE SAME RIGHTS AS HUMANS|BBC News '12
  73. Wild Birds & Humans CONVERSE, Study Shows|The Guardian '16
  74. Nonhuman Animals ARE CONSCIOUS BEINGS, Say Scientists|Psyc Today '12
  75. Dolphins, Humans LEARNING COMMON LANGUAGE|CBS News '11
  76. Brain Cells that MAKE US HUMAN Found in Whales|New Scientist '06
  77. Humans, Birds SHARE THE SAME Singing Genes|New Scientist '14
  78. In animals 6 UNIQUELY HUMAN Traits Now Found|New Scientist '18
  79. Considered UNIQUELY HUMAN, Regret Observed in Rats|UMN Health '14
  80. Animals THINK & FEEL Here's How We Know|Nat Geo News '15
  81. Insects ARE CONSCIOUS|Science Alert '16
  82. Birds MORE NEURONS than Mammals|Sci-News '16
  83. Bee NEURONS MIMIC HUMAN'S Whilst Deciding|Science Daily '11
  84. INSTINCT is SCIENCE FICTION: Non-Humans Think Like Us|The MM '20

Postscript: The peculiar arrangement of source headlines above hearkens to a quote from Carl Sagan & Ann Druyan:

Quote by Carl Sagan: "Humans—who enslave, castrate, experiment on, ..."
Carl Sagan: "Humans—who enslave, castrate, experiment on, and fillet other animals—have had an understandable penchant for pretending animals do not…

The counter is also true. if other species are actually just like us, their continued enslavement is both logically untenable & morally malfeasant.